2026-10-27T14:24:03.902Z START SHA c740ee52fabfabea61f16a43a1591c5777d54eca COMMAND node apps/server/src/bin.ts start --base-dir <fresh isolated home> --port 46621 --dev-url <local origin> --no-browser; runtime-driver.mjs /home/ubuntu/wt/pr-17885 head codex
2026-10-27T14:24:04.253Z ENV {"host":"fs-33","os":"linux 6.1.102","node":"v26.12.1","claude":"2.1.303 (Claude Code)","codex":"codex-cli 0.163.0","provider":"codex","model":"gpt-5.6-sol","root":"/home/ubuntu/wt/pr-17885","home":"/tmp/lead-17885-r1/evidence-capture/head-codex-2026-10-27T14-24-03.807Z/home","client":"RPC/WebSocket plus isolated t3 thread send CLI/MCP; no browser","seed":"fresh database; T3CODE_DEV_SEED=0; synthetic git project","clock":"real UTC; no visual rendering"}
2026-10-27T14:24:04.367Z SPAWN {"pid":2861777}
2026-10-27T14:24:21.321Z PROJECTION {"runs":[{"id":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:1","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","ordinal":1,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1","userMessageId":"message:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:1:d0cf3e58-eadb-4bf0-9156-434ce4cf2248","rootNodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1:root","activeAttemptId":"run-attempt:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1:attempt:1","status":"starting","queuePosition":null,"requestedAt":"2026-10-27T14:24:20.885Z","startedAt":null,"completedAt":null,"checkpointId":null,"contextHandoffId":null,"workspacePreparation":{"type":"root"}}],"messages":[{"createdBy":"user","creationSource":"web","id":"message:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:1:d0cf3e58-eadb-4bf0-9156-434ce4cf2248","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:1","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1:root","role":"user","text":"Synthetic scheduler evidence. Do not change files. Make 60 separate foreground Bash calls strictly sequentially, exactly one echo per call: echo initial-step-1 through echo initial-step-60. No loops, no background commands. After all calls reply INITIAL_DONE.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:20.885Z","updatedAt":"2026-10-27T14:24:20.885Z"}],"subagents":[],"providerThreads":[{"id":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1","driver":"codex","providerInstanceId":"codex","providerSessionId":"provider-session:provider-instance:codex:shared","appThreadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","ownerNodeId":null,"nativeThreadRef":null,"nativeConversationHeadRef":null,"status":"not_loaded","firstRunOrdinal":1,"lastRunOrdinal":1,"handoffIds":[],"forkedFrom":null,"pendingBackgroundTasks":[],"contextUsage":null,"nativeMetadata":null,"goal":null,"createdAt":"2026-10-27T14:24:20.885Z","updatedAt":"2026-10-27T14:24:20.885Z"}]}
2026-10-27T14:24:24.121Z PROJECTION {"runs":[{"id":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:1","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","ordinal":1,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1","userMessageId":"message:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:1:d0cf3e58-eadb-4bf0-9156-434ce4cf2248","rootNodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1:root","activeAttemptId":"run-attempt:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1:attempt:1","status":"running","queuePosition":null,"requestedAt":"2026-10-27T14:24:20.885Z","startedAt":"2026-10-27T14:24:23.359Z","completedAt":null,"checkpointId":null,"contextHandoffId":null,"workspacePreparation":{"type":"root"}}],"messages":[{"createdBy":"user","creationSource":"web","id":"message:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:1:d0cf3e58-eadb-4bf0-9156-434ce4cf2248","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:1","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1:root","role":"user","text":"Synthetic scheduler evidence. Do not change files. Make 60 separate foreground Bash calls strictly sequentially, exactly one echo per call: echo initial-step-1 through echo initial-step-60. No loops, no background commands. After all calls reply INITIAL_DONE.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:20.885Z","updatedAt":"2026-10-27T14:24:20.885Z"}],"subagents":[],"providerThreads":[{"id":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1","driver":"codex","providerInstanceId":"codex","providerSessionId":"provider-session:provider-instance:codex:shared","appThreadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","ownerNodeId":null,"nativeThreadRef":{"driver":"codex","nativeId":"01a17dbf-79ef-7c90-b227-4614d5023bd6","strength":"strong"},"nativeConversationHeadRef":null,"status":"active","firstRunOrdinal":1,"lastRunOrdinal":1,"handoffIds":[],"forkedFrom":null,"pendingBackgroundTasks":[],"contextUsage":null,"nativeMetadata":null,"goal":null,"createdAt":"2026-10-27T14:24:20.885Z","updatedAt":"2026-10-27T14:24:23.359Z"}]}
2026-10-27T14:24:24.123Z STEP {"action":"user RPC dispatch","command":{"type":"message.dispatch","messageId":"8761646d-95e5-41f4-8794-73e2013e532a","text":"HELD_Q_17885: When explicitly released, reply exactly HELD_Q_DONE. No tools.","attachments":[],"createdBy":"user","creationSource":"web","dispatchMode":{"type":"queue_after_active"}}}
2026-10-27T14:24:24.275Z PROJECTION {"runs":[{"id":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:1","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","ordinal":1,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1","userMessageId":"message:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:1:d0cf3e58-eadb-4bf0-9156-434ce4cf2248","rootNodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1:root","activeAttemptId":"run-attempt:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1:attempt:1","status":"running","queuePosition":null,"requestedAt":"2026-10-27T14:24:20.885Z","startedAt":"2026-10-27T14:24:23.359Z","completedAt":null,"checkpointId":null,"contextHandoffId":null,"workspacePreparation":{"type":"root"}},{"id":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:2","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","ordinal":2,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1","userMessageId":"8761646d-95e5-41f4-8794-73e2013e532a","rootNodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A2:root","activeAttemptId":"run-attempt:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A2:attempt:1","status":"queued","queuePosition":1,"requestedAt":"2026-10-27T14:24:24.188Z","startedAt":null,"completedAt":null,"checkpointId":null,"contextHandoffId":null}],"messages":[{"createdBy":"user","creationSource":"web","id":"message:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:1:d0cf3e58-eadb-4bf0-9156-434ce4cf2248","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:1","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1:root","role":"user","text":"Synthetic scheduler evidence. Do not change files. Make 60 separate foreground Bash calls strictly sequentially, exactly one echo per call: echo initial-step-1 through echo initial-step-60. No loops, no background commands. After all calls reply INITIAL_DONE.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:20.885Z","updatedAt":"2026-10-27T14:24:20.885Z"},{"createdBy":"user","creationSource":"web","id":"8761646d-95e5-41f4-8794-73e2013e532a","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:2","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A2:root","role":"user","text":"HELD_Q_17885: When explicitly released, reply exactly HELD_Q_DONE. No tools.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:24.188Z","updatedAt":"2026-10-27T14:24:24.188Z"}],"subagents":[],"providerThreads":[{"id":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1","driver":"codex","providerInstanceId":"codex","providerSessionId":"provider-session:provider-instance:codex:shared","appThreadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","ownerNodeId":null,"nativeThreadRef":{"driver":"codex","nativeId":"01a17dbf-79ef-7c90-b227-4614d5023bd6","strength":"strong"},"nativeConversationHeadRef":null,"status":"active","firstRunOrdinal":1,"lastRunOrdinal":1,"handoffIds":[],"forkedFrom":null,"pendingBackgroundTasks":[],"contextUsage":null,"nativeMetadata":null,"goal":null,"createdAt":"2026-10-27T14:24:20.885Z","updatedAt":"2026-10-27T14:24:23.359Z"}]}
2026-10-27T14:24:24.276Z STEP {"action":"user RPC dispatch","command":{"type":"thread.stop","reason":"Hold queued synthetic Q"}}
2026-10-27T14:24:24.443Z PROJECTION {"runs":[{"id":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:1","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","ordinal":1,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1","userMessageId":"message:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:1:d0cf3e58-eadb-4bf0-9156-434ce4cf2248","rootNodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1:root","activeAttemptId":"run-attempt:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1:attempt:1","status":"interrupted","queuePosition":null,"requestedAt":"2026-10-27T14:24:20.885Z","startedAt":"2026-10-27T14:24:23.359Z","completedAt":"2026-10-27T14:24:24.307Z","checkpointId":null,"contextHandoffId":null,"workspacePreparation":{"type":"root"}},{"id":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:2","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","ordinal":2,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1","userMessageId":"8761646d-95e5-41f4-8794-73e2013e532a","rootNodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A2:root","activeAttemptId":"run-attempt:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A2:attempt:1","status":"queued","queuePosition":1,"queueHeld":true,"requestedAt":"2026-10-27T14:24:24.188Z","startedAt":null,"completedAt":null,"checkpointId":null,"contextHandoffId":null}],"messages":[{"createdBy":"user","creationSource":"web","id":"message:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:1:d0cf3e58-eadb-4bf0-9156-434ce4cf2248","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:1","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1:root","role":"user","text":"Synthetic scheduler evidence. Do not change files. Make 60 separate foreground Bash calls strictly sequentially, exactly one echo per call: echo initial-step-1 through echo initial-step-60. No loops, no background commands. After all calls reply INITIAL_DONE.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:20.885Z","updatedAt":"2026-10-27T14:24:20.885Z"},{"createdBy":"user","creationSource":"web","id":"8761646d-95e5-41f4-8794-73e2013e532a","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:2","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A2:root","role":"user","text":"HELD_Q_17885: When explicitly released, reply exactly HELD_Q_DONE. No tools.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:24.188Z","updatedAt":"2026-10-27T14:24:24.188Z"}],"subagents":[],"providerThreads":[{"id":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1","driver":"codex","providerInstanceId":"codex","providerSessionId":"provider-session:provider-instance:codex:shared","appThreadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","ownerNodeId":null,"nativeThreadRef":{"driver":"codex","nativeId":"01a17dbf-79ef-7c90-b227-4614d5023bd6","strength":"strong"},"nativeConversationHeadRef":null,"status":"active","firstRunOrdinal":1,"lastRunOrdinal":1,"handoffIds":[],"forkedFrom":null,"pendingBackgroundTasks":[],"contextUsage":null,"nativeMetadata":null,"goal":null,"createdAt":"2026-10-27T14:24:20.885Z","updatedAt":"2026-10-27T14:24:23.359Z"}]}
2026-10-27T14:24:24.444Z HELD_Q_BEFORE {"id":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:2","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","ordinal":2,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1","userMessageId":"8761646d-95e5-41f4-8794-73e2013e532a","rootNodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A2:root","activeAttemptId":"run-attempt:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A2:attempt:1","status":"queued","queuePosition":1,"queueHeld":true,"requestedAt":"2026-10-27T14:24:24.188Z","startedAt":null,"completedAt":null,"checkpointId":null,"contextHandoffId":null}
2026-10-27T14:24:24.445Z STEP {"action":"CLI/MCP send; preserves held queue","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","text":"Synthetic scheduler probe, no file edits. Use exec_command to run node -e 'setTimeout(()=>console.log(\"CODEX_BACKGROUND_17885_DONE\"),45000)' with yield_time_ms=1000. It must remain a running command session. Do not use a shell & or redirect. Do not poll or wait for it. Immediately end this turn with CODEX_ROOT_SETTLED. When a real later command-completion notification is delivered, reply exactly CODEX_DETAIL_ACK_17885 followed by the command result. Do not fabricate notifications."}
2026-10-27T14:24:38.370Z PROJECTION {"runs":[{"id":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:1","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","ordinal":1,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1","userMessageId":"message:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:1:d0cf3e58-eadb-4bf0-9156-434ce4cf2248","rootNodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1:root","activeAttemptId":"run-attempt:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1:attempt:1","status":"interrupted","queuePosition":null,"requestedAt":"2026-10-27T14:24:20.885Z","startedAt":"2026-10-27T14:24:23.359Z","completedAt":"2026-10-27T14:24:24.307Z","checkpointId":null,"contextHandoffId":null,"workspacePreparation":{"type":"root"}},{"id":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:2","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","ordinal":2,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1","userMessageId":"8761646d-95e5-41f4-8794-73e2013e532a","rootNodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A2:root","activeAttemptId":"run-attempt:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A2:attempt:1","status":"queued","queuePosition":1,"queueHeld":true,"requestedAt":"2026-10-27T14:24:24.188Z","startedAt":null,"completedAt":null,"checkpointId":null,"contextHandoffId":null},{"id":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:3","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","ordinal":3,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1","userMessageId":"message:mcp:client%3A403306bf-8b12-4c21-8b83-a4274a2d202e:thread-send:e68ed982-aad7-4822-a5f9-4d4166e8cf71","rootNodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A3:root","activeAttemptId":"run-attempt:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A3:attempt:1","status":"running","queuePosition":null,"requestedAt":"2026-10-27T14:24:38.099Z","startedAt":"2026-10-27T14:24:38.313Z","completedAt":null,"checkpointId":null,"contextHandoffId":null}],"messages":[{"createdBy":"user","creationSource":"web","id":"message:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:1:d0cf3e58-eadb-4bf0-9156-434ce4cf2248","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:1","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1:root","role":"user","text":"Synthetic scheduler evidence. Do not change files. Make 60 separate foreground Bash calls strictly sequentially, exactly one echo per call: echo initial-step-1 through echo initial-step-60. No loops, no background commands. After all calls reply INITIAL_DONE.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:20.885Z","updatedAt":"2026-10-27T14:24:20.885Z"},{"createdBy":"agent","creationSource":"mcp","id":"message:mcp:client%3A403306bf-8b12-4c21-8b83-a4274a2d202e:thread-send:e68ed982-aad7-4822-a5f9-4d4166e8cf71","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:3","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A3:root","role":"user","text":"Synthetic scheduler probe, no file edits. Use exec_command to run node -e 'setTimeout(()=>console.log(\"CODEX_BACKGROUND_17885_DONE\"),45000)' with yield_time_ms=1000. It must remain a running command session. Do not use a shell & or redirect. Do not poll or wait for it. Immediately end this turn with CODEX_ROOT_SETTLED. When a real later command-completion notification is delivered, reply exactly CODEX_DETAIL_ACK_17885 followed by the command result. Do not fabricate notifications.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:38.099Z","updatedAt":"2026-10-27T14:24:38.099Z"},{"createdBy":"user","creationSource":"web","id":"8761646d-95e5-41f4-8794-73e2013e532a","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:2","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A2:root","role":"user","text":"HELD_Q_17885: When explicitly released, reply exactly HELD_Q_DONE. No tools.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:24.188Z","updatedAt":"2026-10-27T14:24:24.188Z"}],"subagents":[],"providerThreads":[{"id":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1","driver":"codex","providerInstanceId":"codex","providerSessionId":"provider-session:provider-instance:codex:shared","appThreadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","ownerNodeId":null,"nativeThreadRef":{"driver":"codex","nativeId":"01a17dbf-79ef-7c90-b227-4614d5023bd6","strength":"strong"},"nativeConversationHeadRef":null,"status":"active","firstRunOrdinal":1,"lastRunOrdinal":3,"handoffIds":[],"forkedFrom":null,"pendingBackgroundTasks":[],"contextUsage":null,"nativeMetadata":null,"goal":null,"createdAt":"2026-10-27T14:24:20.885Z","updatedAt":"2026-10-27T14:24:38.313Z"}]}
2026-10-27T14:24:38.672Z CLI_RESULT {"code":0,"out":"{\"threadId\":\"b0b36ab1-aa99-4e65-9f48-86022b42ccb1\",\"link\":\"[Held queue codex evidence](t3-thread://v1/b0b36ab1-aa99-4e65-9f48-86022b42ccb1)\",\"messageId\":\"message:mcp:client%3A403306bf-8b12-4c21-8b83-a4274a2d202e:thread-send:e68ed982-aad7-4822-a5f9-4d4166e8cf71\",\"runId\":\"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:3\",\"status\":\"starting\",\"delivery\":\"started\"}\n"}
2026-10-27T14:24:38.673Z IDLE_TO_A {"qHeld":{"id":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:2","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","ordinal":2,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1","userMessageId":"8761646d-95e5-41f4-8794-73e2013e532a","rootNodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A2:root","activeAttemptId":"run-attempt:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A2:attempt:1","status":"queued","queuePosition":1,"queueHeld":true,"requestedAt":"2026-10-27T14:24:24.188Z","startedAt":null,"completedAt":null,"checkpointId":null,"contextHandoffId":null},"active":{"id":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:3","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","ordinal":3,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1","userMessageId":"message:mcp:client%3A403306bf-8b12-4c21-8b83-a4274a2d202e:thread-send:e68ed982-aad7-4822-a5f9-4d4166e8cf71","rootNodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A3:root","activeAttemptId":"run-attempt:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A3:attempt:1","status":"running","queuePosition":null,"requestedAt":"2026-10-27T14:24:38.099Z","startedAt":"2026-10-27T14:24:38.313Z","completedAt":null,"checkpointId":null,"contextHandoffId":null}}
2026-10-27T14:24:42.178Z PROJECTION {"runs":[{"id":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:1","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","ordinal":1,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1","userMessageId":"message:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:1:d0cf3e58-eadb-4bf0-9156-434ce4cf2248","rootNodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1:root","activeAttemptId":"run-attempt:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1:attempt:1","status":"interrupted","queuePosition":null,"requestedAt":"2026-10-27T14:24:20.885Z","startedAt":"2026-10-27T14:24:23.359Z","completedAt":"2026-10-27T14:24:24.307Z","checkpointId":null,"contextHandoffId":null,"workspacePreparation":{"type":"root"}},{"id":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:2","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","ordinal":2,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1","userMessageId":"8761646d-95e5-41f4-8794-73e2013e532a","rootNodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A2:root","activeAttemptId":"run-attempt:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A2:attempt:1","status":"queued","queuePosition":1,"queueHeld":true,"requestedAt":"2026-10-27T14:24:24.188Z","startedAt":null,"completedAt":null,"checkpointId":null,"contextHandoffId":null},{"id":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:3","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","ordinal":3,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1","userMessageId":"message:mcp:client%3A403306bf-8b12-4c21-8b83-a4274a2d202e:thread-send:e68ed982-aad7-4822-a5f9-4d4166e8cf71","rootNodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A3:root","activeAttemptId":"run-attempt:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A3:attempt:1","status":"running","queuePosition":null,"requestedAt":"2026-10-27T14:24:38.099Z","startedAt":"2026-10-27T14:24:38.313Z","completedAt":null,"checkpointId":null,"contextHandoffId":null}],"messages":[{"createdBy":"user","creationSource":"web","id":"message:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:1:d0cf3e58-eadb-4bf0-9156-434ce4cf2248","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:1","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1:root","role":"user","text":"Synthetic scheduler evidence. Do not change files. Make 60 separate foreground Bash calls strictly sequentially, exactly one echo per call: echo initial-step-1 through echo initial-step-60. No loops, no background commands. After all calls reply INITIAL_DONE.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:20.885Z","updatedAt":"2026-10-27T14:24:20.885Z"},{"createdBy":"agent","creationSource":"mcp","id":"message:mcp:client%3A403306bf-8b12-4c21-8b83-a4274a2d202e:thread-send:e68ed982-aad7-4822-a5f9-4d4166e8cf71","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:3","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A3:root","role":"user","text":"Synthetic scheduler probe, no file edits. Use exec_command to run node -e 'setTimeout(()=>console.log(\"CODEX_BACKGROUND_17885_DONE\"),45000)' with yield_time_ms=1000. It must remain a running command session. Do not use a shell & or redirect. Do not poll or wait for it. Immediately end this turn with CODEX_ROOT_SETTLED. When a real later command-completion notification is delivered, reply exactly CODEX_DETAIL_ACK_17885 followed by the command result. Do not fabricate notifications.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:38.099Z","updatedAt":"2026-10-27T14:24:38.099Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b4299c10819aa33e4779dfefd048","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:3","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b4299c10819aa33e4779dfefd048","role":"assistant","text":"I’ll start the foreground Node timer as a persistent command session, then return immediately without polling it.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:41.681Z","updatedAt":"2026-10-27T14:24:42.113Z"},{"createdBy":"user","creationSource":"web","id":"8761646d-95e5-41f4-8794-73e2013e532a","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:2","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A2:root","role":"user","text":"HELD_Q_17885: When explicitly released, reply exactly HELD_Q_DONE. No tools.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:24.188Z","updatedAt":"2026-10-27T14:24:24.188Z"}],"subagents":[],"providerThreads":[{"id":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1","driver":"codex","providerInstanceId":"codex","providerSessionId":"provider-session:provider-instance:codex:shared","appThreadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","ownerNodeId":null,"nativeThreadRef":{"driver":"codex","nativeId":"01a17dbf-79ef-7c90-b227-4614d5023bd6","strength":"strong"},"nativeConversationHeadRef":null,"status":"active","firstRunOrdinal":1,"lastRunOrdinal":3,"handoffIds":[],"forkedFrom":null,"pendingBackgroundTasks":[],"contextUsage":null,"nativeMetadata":null,"goal":null,"createdAt":"2026-10-27T14:24:20.885Z","updatedAt":"2026-10-27T14:24:38.313Z"}]}
2026-10-27T14:24:45.349Z PROJECTION {"runs":[{"id":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:1","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","ordinal":1,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1","userMessageId":"message:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:1:d0cf3e58-eadb-4bf0-9156-434ce4cf2248","rootNodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1:root","activeAttemptId":"run-attempt:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1:attempt:1","status":"interrupted","queuePosition":null,"requestedAt":"2026-10-27T14:24:20.885Z","startedAt":"2026-10-27T14:24:23.359Z","completedAt":"2026-10-27T14:24:24.307Z","checkpointId":null,"contextHandoffId":null,"workspacePreparation":{"type":"root"}},{"id":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:2","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","ordinal":2,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1","userMessageId":"8761646d-95e5-41f4-8794-73e2013e532a","rootNodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A2:root","activeAttemptId":"run-attempt:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A2:attempt:1","status":"queued","queuePosition":1,"queueHeld":true,"requestedAt":"2026-10-27T14:24:24.188Z","startedAt":null,"completedAt":null,"checkpointId":null,"contextHandoffId":null},{"id":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:3","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","ordinal":3,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1","userMessageId":"message:mcp:client%3A403306bf-8b12-4c21-8b83-a4274a2d202e:thread-send:e68ed982-aad7-4822-a5f9-4d4166e8cf71","rootNodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A3:root","activeAttemptId":"run-attempt:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A3:attempt:1","status":"waiting","queuePosition":null,"requestedAt":"2026-10-27T14:24:38.099Z","startedAt":"2026-10-27T14:24:38.313Z","completedAt":null,"checkpointId":null,"contextHandoffId":null}],"messages":[{"createdBy":"user","creationSource":"web","id":"message:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:1:d0cf3e58-eadb-4bf0-9156-434ce4cf2248","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:1","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1:root","role":"user","text":"Synthetic scheduler evidence. Do not change files. Make 60 separate foreground Bash calls strictly sequentially, exactly one echo per call: echo initial-step-1 through echo initial-step-60. No loops, no background commands. After all calls reply INITIAL_DONE.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:20.885Z","updatedAt":"2026-10-27T14:24:20.885Z"},{"createdBy":"agent","creationSource":"mcp","id":"message:mcp:client%3A403306bf-8b12-4c21-8b83-a4274a2d202e:thread-send:e68ed982-aad7-4822-a5f9-4d4166e8cf71","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:3","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A3:root","role":"user","text":"Synthetic scheduler probe, no file edits. Use exec_command to run node -e 'setTimeout(()=>console.log(\"CODEX_BACKGROUND_17885_DONE\"),45000)' with yield_time_ms=1000. It must remain a running command session. Do not use a shell & or redirect. Do not poll or wait for it. Immediately end this turn with CODEX_ROOT_SETTLED. When a real later command-completion notification is delivered, reply exactly CODEX_DETAIL_ACK_17885 followed by the command result. Do not fabricate notifications.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:38.099Z","updatedAt":"2026-10-27T14:24:38.099Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b4299c10819aa33e4779dfefd048","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:3","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b4299c10819aa33e4779dfefd048","role":"assistant","text":"I’ll start the foreground Node timer as a persistent command session, then return immediately without polling it.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:41.681Z","updatedAt":"2026-10-27T14:24:42.113Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b42d1b30819a9fdea2a5e6fccfb3","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:3","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b42d1b30819a9fdea2a5e6fccfb3","role":"assistant","text":"CODEX_ROOT_SETTLED","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:45.195Z","updatedAt":"2026-10-27T14:24:45.218Z"},{"createdBy":"user","creationSource":"web","id":"8761646d-95e5-41f4-8794-73e2013e532a","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:2","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A2:root","role":"user","text":"HELD_Q_17885: When explicitly released, reply exactly HELD_Q_DONE. No tools.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:24.188Z","updatedAt":"2026-10-27T14:24:24.188Z"}],"subagents":[],"providerThreads":[{"id":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1","driver":"codex","providerInstanceId":"codex","providerSessionId":"provider-session:provider-instance:codex:shared","appThreadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","ownerNodeId":null,"nativeThreadRef":{"driver":"codex","nativeId":"01a17dbf-79ef-7c90-b227-4614d5023bd6","strength":"strong"},"nativeConversationHeadRef":null,"status":"idle","firstRunOrdinal":1,"lastRunOrdinal":3,"handoffIds":[],"forkedFrom":null,"pendingBackgroundTasks":[],"contextUsage":null,"nativeMetadata":null,"goal":null,"createdAt":"2026-10-27T14:24:20.885Z","updatedAt":"2026-10-27T14:24:45.288Z"}]}
2026-10-27T14:24:46.159Z PROJECTION {"runs":[{"id":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:1","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","ordinal":1,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1","userMessageId":"message:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:1:d0cf3e58-eadb-4bf0-9156-434ce4cf2248","rootNodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1:root","activeAttemptId":"run-attempt:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1:attempt:1","status":"interrupted","queuePosition":null,"requestedAt":"2026-10-27T14:24:20.885Z","startedAt":"2026-10-27T14:24:23.359Z","completedAt":"2026-10-27T14:24:24.307Z","checkpointId":null,"contextHandoffId":null,"workspacePreparation":{"type":"root"}},{"id":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:2","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","ordinal":2,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1","userMessageId":"8761646d-95e5-41f4-8794-73e2013e532a","rootNodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A2:root","activeAttemptId":"run-attempt:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A2:attempt:1","status":"queued","queuePosition":1,"queueHeld":true,"requestedAt":"2026-10-27T14:24:24.188Z","startedAt":null,"completedAt":null,"checkpointId":null,"contextHandoffId":null},{"id":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:3","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","ordinal":3,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1","userMessageId":"message:mcp:client%3A403306bf-8b12-4c21-8b83-a4274a2d202e:thread-send:e68ed982-aad7-4822-a5f9-4d4166e8cf71","rootNodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A3:root","activeAttemptId":"run-attempt:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A3:attempt:1","status":"completed","queuePosition":null,"requestedAt":"2026-10-27T14:24:38.099Z","startedAt":"2026-10-27T14:24:38.313Z","completedAt":"2026-10-27T14:24:45.326Z","checkpointId":"checkpoint:scope:checkpoint-scope%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aname%3Aroot:name:3","contextHandoffId":null}],"messages":[{"createdBy":"user","creationSource":"web","id":"message:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:1:d0cf3e58-eadb-4bf0-9156-434ce4cf2248","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:1","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1:root","role":"user","text":"Synthetic scheduler evidence. Do not change files. Make 60 separate foreground Bash calls strictly sequentially, exactly one echo per call: echo initial-step-1 through echo initial-step-60. No loops, no background commands. After all calls reply INITIAL_DONE.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:20.885Z","updatedAt":"2026-10-27T14:24:20.885Z"},{"createdBy":"agent","creationSource":"mcp","id":"message:mcp:client%3A403306bf-8b12-4c21-8b83-a4274a2d202e:thread-send:e68ed982-aad7-4822-a5f9-4d4166e8cf71","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:3","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A3:root","role":"user","text":"Synthetic scheduler probe, no file edits. Use exec_command to run node -e 'setTimeout(()=>console.log(\"CODEX_BACKGROUND_17885_DONE\"),45000)' with yield_time_ms=1000. It must remain a running command session. Do not use a shell & or redirect. Do not poll or wait for it. Immediately end this turn with CODEX_ROOT_SETTLED. When a real later command-completion notification is delivered, reply exactly CODEX_DETAIL_ACK_17885 followed by the command result. Do not fabricate notifications.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:38.099Z","updatedAt":"2026-10-27T14:24:38.099Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b4299c10819aa33e4779dfefd048","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:3","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b4299c10819aa33e4779dfefd048","role":"assistant","text":"I’ll start the foreground Node timer as a persistent command session, then return immediately without polling it.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:41.681Z","updatedAt":"2026-10-27T14:24:42.113Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b42d1b30819a9fdea2a5e6fccfb3","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:3","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b42d1b30819a9fdea2a5e6fccfb3","role":"assistant","text":"CODEX_ROOT_SETTLED","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:45.195Z","updatedAt":"2026-10-27T14:24:45.218Z"},{"createdBy":"user","creationSource":"web","id":"8761646d-95e5-41f4-8794-73e2013e532a","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:2","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A2:root","role":"user","text":"HELD_Q_17885: When explicitly released, reply exactly HELD_Q_DONE. No tools.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:24.188Z","updatedAt":"2026-10-27T14:24:24.188Z"}],"subagents":[],"providerThreads":[{"id":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1","driver":"codex","providerInstanceId":"codex","providerSessionId":"provider-session:provider-instance:codex:shared","appThreadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","ownerNodeId":null,"nativeThreadRef":{"driver":"codex","nativeId":"01a17dbf-79ef-7c90-b227-4614d5023bd6","strength":"strong"},"nativeConversationHeadRef":null,"status":"idle","firstRunOrdinal":1,"lastRunOrdinal":3,"handoffIds":[],"forkedFrom":null,"pendingBackgroundTasks":[],"contextUsage":null,"nativeMetadata":null,"goal":null,"createdAt":"2026-10-27T14:24:20.885Z","updatedAt":"2026-10-27T14:24:45.288Z"}]}
2026-10-27T14:24:46.170Z STEP {"action":"CLI/MCP send; preserves held queue","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","text":"Synthetic evidence active companion. Run node -e 'setTimeout(()=>console.log(\"CODEX_ACTIVE_17885_DONE\"),40000)' in exec_command with yield_time_ms=1000. Then write a 1500 word plain essay about serial queues. Do not poll the command session or wait. Do not change files. If a background command detail is already delivered acknowledge it once."}
2026-10-27T14:24:55.529Z PROJECTION {"runs":[{"id":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:1","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","ordinal":1,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1","userMessageId":"message:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:1:d0cf3e58-eadb-4bf0-9156-434ce4cf2248","rootNodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1:root","activeAttemptId":"run-attempt:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1:attempt:1","status":"interrupted","queuePosition":null,"requestedAt":"2026-10-27T14:24:20.885Z","startedAt":"2026-10-27T14:24:23.359Z","completedAt":"2026-10-27T14:24:24.307Z","checkpointId":null,"contextHandoffId":null,"workspacePreparation":{"type":"root"}},{"id":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:2","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","ordinal":2,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1","userMessageId":"8761646d-95e5-41f4-8794-73e2013e532a","rootNodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A2:root","activeAttemptId":"run-attempt:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A2:attempt:1","status":"queued","queuePosition":1,"queueHeld":true,"requestedAt":"2026-10-27T14:24:24.188Z","startedAt":null,"completedAt":null,"checkpointId":null,"contextHandoffId":null},{"id":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:3","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","ordinal":3,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1","userMessageId":"message:mcp:client%3A403306bf-8b12-4c21-8b83-a4274a2d202e:thread-send:e68ed982-aad7-4822-a5f9-4d4166e8cf71","rootNodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A3:root","activeAttemptId":"run-attempt:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A3:attempt:1","status":"completed","queuePosition":null,"requestedAt":"2026-10-27T14:24:38.099Z","startedAt":"2026-10-27T14:24:38.313Z","completedAt":"2026-10-27T14:24:45.326Z","checkpointId":"checkpoint:scope:checkpoint-scope%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aname%3Aroot:name:3","contextHandoffId":null},{"id":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:4","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","ordinal":4,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1","userMessageId":"message:mcp:client%3A23308f20-1e1f-46cd-8b3a-788b4a7900cc:thread-send:0fd04def-0197-42bc-80c0-bd615180c894","rootNodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A4:root","activeAttemptId":"run-attempt:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A4:attempt:1","status":"running","queuePosition":null,"requestedAt":"2026-10-27T14:24:55.341Z","startedAt":"2026-10-27T14:24:55.446Z","completedAt":null,"checkpointId":null,"contextHandoffId":null}],"messages":[{"createdBy":"user","creationSource":"web","id":"message:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:1:d0cf3e58-eadb-4bf0-9156-434ce4cf2248","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:1","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1:root","role":"user","text":"Synthetic scheduler evidence. Do not change files. Make 60 separate foreground Bash calls strictly sequentially, exactly one echo per call: echo initial-step-1 through echo initial-step-60. No loops, no background commands. After all calls reply INITIAL_DONE.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:20.885Z","updatedAt":"2026-10-27T14:24:20.885Z"},{"createdBy":"agent","creationSource":"mcp","id":"message:mcp:client%3A403306bf-8b12-4c21-8b83-a4274a2d202e:thread-send:e68ed982-aad7-4822-a5f9-4d4166e8cf71","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:3","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A3:root","role":"user","text":"Synthetic scheduler probe, no file edits. Use exec_command to run node -e 'setTimeout(()=>console.log(\"CODEX_BACKGROUND_17885_DONE\"),45000)' with yield_time_ms=1000. It must remain a running command session. Do not use a shell & or redirect. Do not poll or wait for it. Immediately end this turn with CODEX_ROOT_SETTLED. When a real later command-completion notification is delivered, reply exactly CODEX_DETAIL_ACK_17885 followed by the command result. Do not fabricate notifications.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:38.099Z","updatedAt":"2026-10-27T14:24:38.099Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b4299c10819aa33e4779dfefd048","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:3","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b4299c10819aa33e4779dfefd048","role":"assistant","text":"I’ll start the foreground Node timer as a persistent command session, then return immediately without polling it.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:41.681Z","updatedAt":"2026-10-27T14:24:42.113Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b42d1b30819a9fdea2a5e6fccfb3","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:3","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b42d1b30819a9fdea2a5e6fccfb3","role":"assistant","text":"CODEX_ROOT_SETTLED","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:45.195Z","updatedAt":"2026-10-27T14:24:45.218Z"},{"createdBy":"agent","creationSource":"mcp","id":"message:mcp:client%3A23308f20-1e1f-46cd-8b3a-788b4a7900cc:thread-send:0fd04def-0197-42bc-80c0-bd615180c894","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:4","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A4:root","role":"user","text":"Synthetic evidence active companion. Run node -e 'setTimeout(()=>console.log(\"CODEX_ACTIVE_17885_DONE\"),40000)' in exec_command with yield_time_ms=1000. Then write a 1500 word plain essay about serial queues. Do not poll the command session or wait. Do not change files. If a background command detail is already delivered acknowledge it once.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:55.341Z","updatedAt":"2026-10-27T14:24:55.341Z"},{"createdBy":"user","creationSource":"web","id":"8761646d-95e5-41f4-8794-73e2013e532a","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:2","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A2:root","role":"user","text":"HELD_Q_17885: When explicitly released, reply exactly HELD_Q_DONE. No tools.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:24.188Z","updatedAt":"2026-10-27T14:24:24.188Z"}],"subagents":[],"providerThreads":[{"id":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1","driver":"codex","providerInstanceId":"codex","providerSessionId":"provider-session:provider-instance:codex:shared","appThreadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","ownerNodeId":null,"nativeThreadRef":{"driver":"codex","nativeId":"01a17dbf-79ef-7c90-b227-4614d5023bd6","strength":"strong"},"nativeConversationHeadRef":null,"status":"active","firstRunOrdinal":1,"lastRunOrdinal":4,"handoffIds":[],"forkedFrom":null,"pendingBackgroundTasks":[],"contextUsage":{"usedTokens":20126,"maxTokens":258400},"nativeMetadata":null,"goal":null,"createdAt":"2026-10-27T14:24:20.885Z","updatedAt":"2026-10-27T14:24:55.446Z"}]}
2026-10-27T14:24:55.856Z CLI_RESULT {"code":0,"out":"{\"threadId\":\"b0b36ab1-aa99-4e65-9f48-86022b42ccb1\",\"link\":\"[Held queue codex evidence](t3-thread://v1/b0b36ab1-aa99-4e65-9f48-86022b42ccb1)\",\"messageId\":\"message:mcp:client%3A23308f20-1e1f-46cd-8b3a-788b4a7900cc:thread-send:0fd04def-0197-42bc-80c0-bd615180c894\",\"runId\":\"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:4\",\"status\":\"starting\",\"delivery\":\"started\"}\n"}
2026-10-27T14:24:55.856Z OBSERVATION_WINDOW {"milliseconds":65000,"narration":"Observe real command completions while held Q exists; no release"}
2026-10-27T14:24:57.876Z PROJECTION {"runs":[{"id":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:1","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","ordinal":1,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1","userMessageId":"message:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:1:d0cf3e58-eadb-4bf0-9156-434ce4cf2248","rootNodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1:root","activeAttemptId":"run-attempt:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1:attempt:1","status":"interrupted","queuePosition":null,"requestedAt":"2026-10-27T14:24:20.885Z","startedAt":"2026-10-27T14:24:23.359Z","completedAt":"2026-10-27T14:24:24.307Z","checkpointId":null,"contextHandoffId":null,"workspacePreparation":{"type":"root"}},{"id":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:2","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","ordinal":2,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1","userMessageId":"8761646d-95e5-41f4-8794-73e2013e532a","rootNodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A2:root","activeAttemptId":"run-attempt:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A2:attempt:1","status":"queued","queuePosition":1,"queueHeld":true,"requestedAt":"2026-10-27T14:24:24.188Z","startedAt":null,"completedAt":null,"checkpointId":null,"contextHandoffId":null},{"id":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:3","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","ordinal":3,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1","userMessageId":"message:mcp:client%3A403306bf-8b12-4c21-8b83-a4274a2d202e:thread-send:e68ed982-aad7-4822-a5f9-4d4166e8cf71","rootNodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A3:root","activeAttemptId":"run-attempt:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A3:attempt:1","status":"completed","queuePosition":null,"requestedAt":"2026-10-27T14:24:38.099Z","startedAt":"2026-10-27T14:24:38.313Z","completedAt":"2026-10-27T14:24:45.326Z","checkpointId":"checkpoint:scope:checkpoint-scope%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aname%3Aroot:name:3","contextHandoffId":null},{"id":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:4","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","ordinal":4,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1","userMessageId":"message:mcp:client%3A23308f20-1e1f-46cd-8b3a-788b4a7900cc:thread-send:0fd04def-0197-42bc-80c0-bd615180c894","rootNodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A4:root","activeAttemptId":"run-attempt:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A4:attempt:1","status":"running","queuePosition":null,"requestedAt":"2026-10-27T14:24:55.341Z","startedAt":"2026-10-27T14:24:55.446Z","completedAt":null,"checkpointId":null,"contextHandoffId":null}],"messages":[{"createdBy":"user","creationSource":"web","id":"message:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:1:d0cf3e58-eadb-4bf0-9156-434ce4cf2248","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:1","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1:root","role":"user","text":"Synthetic scheduler evidence. Do not change files. Make 60 separate foreground Bash calls strictly sequentially, exactly one echo per call: echo initial-step-1 through echo initial-step-60. No loops, no background commands. After all calls reply INITIAL_DONE.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:20.885Z","updatedAt":"2026-10-27T14:24:20.885Z"},{"createdBy":"agent","creationSource":"mcp","id":"message:mcp:client%3A403306bf-8b12-4c21-8b83-a4274a2d202e:thread-send:e68ed982-aad7-4822-a5f9-4d4166e8cf71","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:3","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A3:root","role":"user","text":"Synthetic scheduler probe, no file edits. Use exec_command to run node -e 'setTimeout(()=>console.log(\"CODEX_BACKGROUND_17885_DONE\"),45000)' with yield_time_ms=1000. It must remain a running command session. Do not use a shell & or redirect. Do not poll or wait for it. Immediately end this turn with CODEX_ROOT_SETTLED. When a real later command-completion notification is delivered, reply exactly CODEX_DETAIL_ACK_17885 followed by the command result. Do not fabricate notifications.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:38.099Z","updatedAt":"2026-10-27T14:24:38.099Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b4299c10819aa33e4779dfefd048","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:3","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b4299c10819aa33e4779dfefd048","role":"assistant","text":"I’ll start the foreground Node timer as a persistent command session, then return immediately without polling it.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:41.681Z","updatedAt":"2026-10-27T14:24:42.113Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b42d1b30819a9fdea2a5e6fccfb3","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:3","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b42d1b30819a9fdea2a5e6fccfb3","role":"assistant","text":"CODEX_ROOT_SETTLED","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:45.195Z","updatedAt":"2026-10-27T14:24:45.218Z"},{"createdBy":"agent","creationSource":"mcp","id":"message:mcp:client%3A23308f20-1e1f-46cd-8b3a-788b4a7900cc:thread-send:0fd04def-0197-42bc-80c0-bd615180c894","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:4","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A4:root","role":"user","text":"Synthetic evidence active companion. Run node -e 'setTimeout(()=>console.log(\"CODEX_ACTIVE_17885_DONE\"),40000)' in exec_command with yield_time_ms=1000. Then write a 1500 word plain essay about serial queues. Do not poll the command session or wait. Do not change files. If a background command detail is already delivered acknowledge it once.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:55.341Z","updatedAt":"2026-10-27T14:24:55.341Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b439932c819ab7bb9fba46894634","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:4","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b439932c819ab7bb9fba46894634","role":"assistant","text":"I’ll launch the second timer as another persistent foreground session, won’t poll either session, and will use the remaining turn for the requested essay.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:57.606Z","updatedAt":"2026-10-27T14:24:57.835Z"},{"createdBy":"user","creationSource":"web","id":"8761646d-95e5-41f4-8794-73e2013e532a","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:2","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A2:root","role":"user","text":"HELD_Q_17885: When explicitly released, reply exactly HELD_Q_DONE. No tools.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:24.188Z","updatedAt":"2026-10-27T14:24:24.188Z"}],"subagents":[],"providerThreads":[{"id":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1","driver":"codex","providerInstanceId":"codex","providerSessionId":"provider-session:provider-instance:codex:shared","appThreadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","ownerNodeId":null,"nativeThreadRef":{"driver":"codex","nativeId":"01a17dbf-79ef-7c90-b227-4614d5023bd6","strength":"strong"},"nativeConversationHeadRef":null,"status":"active","firstRunOrdinal":1,"lastRunOrdinal":4,"handoffIds":[],"forkedFrom":null,"pendingBackgroundTasks":[],"contextUsage":{"usedTokens":20126,"maxTokens":258400},"nativeMetadata":null,"goal":null,"createdAt":"2026-10-27T14:24:20.885Z","updatedAt":"2026-10-27T14:24:55.446Z"}]}
2026-10-27T14:25:27.805Z PROJECTION {"runs":[{"id":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:1","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","ordinal":1,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1","userMessageId":"message:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:1:d0cf3e58-eadb-4bf0-9156-434ce4cf2248","rootNodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1:root","activeAttemptId":"run-attempt:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1:attempt:1","status":"interrupted","queuePosition":null,"requestedAt":"2026-10-27T14:24:20.885Z","startedAt":"2026-10-27T14:24:23.359Z","completedAt":"2026-10-27T14:24:24.307Z","checkpointId":null,"contextHandoffId":null,"workspacePreparation":{"type":"root"}},{"id":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:2","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","ordinal":2,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1","userMessageId":"8761646d-95e5-41f4-8794-73e2013e532a","rootNodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A2:root","activeAttemptId":"run-attempt:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A2:attempt:1","status":"queued","queuePosition":1,"queueHeld":true,"requestedAt":"2026-10-27T14:24:24.188Z","startedAt":null,"completedAt":null,"checkpointId":null,"contextHandoffId":null},{"id":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:3","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","ordinal":3,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1","userMessageId":"message:mcp:client%3A403306bf-8b12-4c21-8b83-a4274a2d202e:thread-send:e68ed982-aad7-4822-a5f9-4d4166e8cf71","rootNodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A3:root","activeAttemptId":"run-attempt:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A3:attempt:1","status":"completed","queuePosition":null,"requestedAt":"2026-10-27T14:24:38.099Z","startedAt":"2026-10-27T14:24:38.313Z","completedAt":"2026-10-27T14:24:45.326Z","checkpointId":"checkpoint:scope:checkpoint-scope%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aname%3Aroot:name:3","contextHandoffId":null},{"id":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:4","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","ordinal":4,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1","userMessageId":"message:mcp:client%3A23308f20-1e1f-46cd-8b3a-788b4a7900cc:thread-send:0fd04def-0197-42bc-80c0-bd615180c894","rootNodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A4:root","activeAttemptId":"run-attempt:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A4:attempt:1","status":"running","queuePosition":null,"requestedAt":"2026-10-27T14:24:55.341Z","startedAt":"2026-10-27T14:24:55.446Z","completedAt":null,"checkpointId":null,"contextHandoffId":null},{"id":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:5","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","ordinal":5,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1","userMessageId":"message:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:1:16e3c6c1-8927-4e29-8dd9-979f6ff5c8b1","rootNodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A5:root","activeAttemptId":"run-attempt:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A5:attempt:1","status":"queued","queuePosition":2,"queueHeld":true,"requestedAt":"2026-10-27T14:25:27.753Z","startedAt":null,"completedAt":null,"checkpointId":null,"contextHandoffId":null}],"messages":[{"createdBy":"user","creationSource":"web","id":"message:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:1:d0cf3e58-eadb-4bf0-9156-434ce4cf2248","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:1","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1:root","role":"user","text":"Synthetic scheduler evidence. Do not change files. Make 60 separate foreground Bash calls strictly sequentially, exactly one echo per call: echo initial-step-1 through echo initial-step-60. No loops, no background commands. After all calls reply INITIAL_DONE.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:20.885Z","updatedAt":"2026-10-27T14:24:20.885Z"},{"createdBy":"agent","creationSource":"mcp","id":"message:mcp:client%3A403306bf-8b12-4c21-8b83-a4274a2d202e:thread-send:e68ed982-aad7-4822-a5f9-4d4166e8cf71","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:3","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A3:root","role":"user","text":"Synthetic scheduler probe, no file edits. Use exec_command to run node -e 'setTimeout(()=>console.log(\"CODEX_BACKGROUND_17885_DONE\"),45000)' with yield_time_ms=1000. It must remain a running command session. Do not use a shell & or redirect. Do not poll or wait for it. Immediately end this turn with CODEX_ROOT_SETTLED. When a real later command-completion notification is delivered, reply exactly CODEX_DETAIL_ACK_17885 followed by the command result. Do not fabricate notifications.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:38.099Z","updatedAt":"2026-10-27T14:24:38.099Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b4299c10819aa33e4779dfefd048","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:3","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b4299c10819aa33e4779dfefd048","role":"assistant","text":"I’ll start the foreground Node timer as a persistent command session, then return immediately without polling it.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:41.681Z","updatedAt":"2026-10-27T14:24:42.113Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b42d1b30819a9fdea2a5e6fccfb3","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:3","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b42d1b30819a9fdea2a5e6fccfb3","role":"assistant","text":"CODEX_ROOT_SETTLED","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:45.195Z","updatedAt":"2026-10-27T14:24:45.218Z"},{"createdBy":"agent","creationSource":"mcp","id":"message:mcp:client%3A23308f20-1e1f-46cd-8b3a-788b4a7900cc:thread-send:0fd04def-0197-42bc-80c0-bd615180c894","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:4","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A4:root","role":"user","text":"Synthetic evidence active companion. Run node -e 'setTimeout(()=>console.log(\"CODEX_ACTIVE_17885_DONE\"),40000)' in exec_command with yield_time_ms=1000. Then write a 1500 word plain essay about serial queues. Do not poll the command session or wait. Do not change files. If a background command detail is already delivered acknowledge it once.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:55.341Z","updatedAt":"2026-10-27T14:24:55.341Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b439932c819ab7bb9fba46894634","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:4","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b439932c819ab7bb9fba46894634","role":"assistant","text":"I’ll launch the second timer as another persistent foreground session, won’t poll either session, and will use the remaining turn for the requested essay.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:57.606Z","updatedAt":"2026-10-27T14:24:57.835Z"},{"createdBy":"user","creationSource":"web","id":"8761646d-95e5-41f4-8794-73e2013e532a","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:2","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A2:root","role":"user","text":"HELD_Q_17885: When explicitly released, reply exactly HELD_Q_DONE. No tools.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:24.188Z","updatedAt":"2026-10-27T14:24:24.188Z"},{"notification":{"source":{"kind":"command"},"outcome":"completed","summary":"Command \"/bin/bash -lc \"node -e 'setTimeout(()=>console.log(\\\"CODEX_BACKGROUND_17885_DON…\" finished (exit 0)","detail":"/bin/bash -lc \"node -e 'setTimeout(()=>console.log(\\\"CODEX_BACKGROUND_17885_DONE\\\"),45000)'\""},"createdBy":"agent","creationSource":"server","id":"message:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:1:16e3c6c1-8927-4e29-8dd9-979f6ff5c8b1","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:5","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A5:root","role":"user","text":"Background command completed (exit 0): /bin/bash -lc \"node -e 'setTimeout(()=>console.log(\\\"CODEX_BACKGROUND_17885_DONE\\\"),45000)'\"\n\nOutput tail:\nCODEX_BACKGROUND_17885_DONE","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:27.753Z","updatedAt":"2026-10-27T14:25:27.753Z"}],"subagents":[],"providerThreads":[{"id":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1","driver":"codex","providerInstanceId":"codex","providerSessionId":"provider-session:provider-instance:codex:shared","appThreadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","ownerNodeId":null,"nativeThreadRef":{"driver":"codex","nativeId":"01a17dbf-79ef-7c90-b227-4614d5023bd6","strength":"strong"},"nativeConversationHeadRef":null,"status":"active","firstRunOrdinal":1,"lastRunOrdinal":4,"handoffIds":[],"forkedFrom":null,"pendingBackgroundTasks":[],"contextUsage":{"usedTokens":20126,"maxTokens":258400},"nativeMetadata":null,"goal":null,"createdAt":"2026-10-27T14:24:20.885Z","updatedAt":"2026-10-27T14:24:55.446Z"}]}
2026-10-27T14:25:35.308Z PROJECTION {"runs":[{"id":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:1","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","ordinal":1,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1","userMessageId":"message:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:1:d0cf3e58-eadb-4bf0-9156-434ce4cf2248","rootNodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1:root","activeAttemptId":"run-attempt:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1:attempt:1","status":"interrupted","queuePosition":null,"requestedAt":"2026-10-27T14:24:20.885Z","startedAt":"2026-10-27T14:24:23.359Z","completedAt":"2026-10-27T14:24:24.307Z","checkpointId":null,"contextHandoffId":null,"workspacePreparation":{"type":"root"}},{"id":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:2","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","ordinal":2,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1","userMessageId":"8761646d-95e5-41f4-8794-73e2013e532a","rootNodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A2:root","activeAttemptId":"run-attempt:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A2:attempt:1","status":"queued","queuePosition":1,"queueHeld":true,"requestedAt":"2026-10-27T14:24:24.188Z","startedAt":null,"completedAt":null,"checkpointId":null,"contextHandoffId":null},{"id":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:3","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","ordinal":3,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1","userMessageId":"message:mcp:client%3A403306bf-8b12-4c21-8b83-a4274a2d202e:thread-send:e68ed982-aad7-4822-a5f9-4d4166e8cf71","rootNodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A3:root","activeAttemptId":"run-attempt:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A3:attempt:1","status":"completed","queuePosition":null,"requestedAt":"2026-10-27T14:24:38.099Z","startedAt":"2026-10-27T14:24:38.313Z","completedAt":"2026-10-27T14:24:45.326Z","checkpointId":"checkpoint:scope:checkpoint-scope%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aname%3Aroot:name:3","contextHandoffId":null},{"id":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:4","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","ordinal":4,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1","userMessageId":"message:mcp:client%3A23308f20-1e1f-46cd-8b3a-788b4a7900cc:thread-send:0fd04def-0197-42bc-80c0-bd615180c894","rootNodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A4:root","activeAttemptId":"run-attempt:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A4:attempt:1","status":"running","queuePosition":null,"requestedAt":"2026-10-27T14:24:55.341Z","startedAt":"2026-10-27T14:24:55.446Z","completedAt":null,"checkpointId":null,"contextHandoffId":null},{"id":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:5","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","ordinal":5,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1","userMessageId":"message:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:1:16e3c6c1-8927-4e29-8dd9-979f6ff5c8b1","rootNodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A5:root","activeAttemptId":"run-attempt:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A5:attempt:1","status":"queued","queuePosition":2,"queueHeld":true,"requestedAt":"2026-10-27T14:25:27.753Z","startedAt":null,"completedAt":null,"checkpointId":null,"contextHandoffId":null}],"messages":[{"createdBy":"user","creationSource":"web","id":"message:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:1:d0cf3e58-eadb-4bf0-9156-434ce4cf2248","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:1","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1:root","role":"user","text":"Synthetic scheduler evidence. Do not change files. Make 60 separate foreground Bash calls strictly sequentially, exactly one echo per call: echo initial-step-1 through echo initial-step-60. No loops, no background commands. After all calls reply INITIAL_DONE.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:20.885Z","updatedAt":"2026-10-27T14:24:20.885Z"},{"createdBy":"agent","creationSource":"mcp","id":"message:mcp:client%3A403306bf-8b12-4c21-8b83-a4274a2d202e:thread-send:e68ed982-aad7-4822-a5f9-4d4166e8cf71","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:3","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A3:root","role":"user","text":"Synthetic scheduler probe, no file edits. Use exec_command to run node -e 'setTimeout(()=>console.log(\"CODEX_BACKGROUND_17885_DONE\"),45000)' with yield_time_ms=1000. It must remain a running command session. Do not use a shell & or redirect. Do not poll or wait for it. Immediately end this turn with CODEX_ROOT_SETTLED. When a real later command-completion notification is delivered, reply exactly CODEX_DETAIL_ACK_17885 followed by the command result. Do not fabricate notifications.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:38.099Z","updatedAt":"2026-10-27T14:24:38.099Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b4299c10819aa33e4779dfefd048","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:3","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b4299c10819aa33e4779dfefd048","role":"assistant","text":"I’ll start the foreground Node timer as a persistent command session, then return immediately without polling it.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:41.681Z","updatedAt":"2026-10-27T14:24:42.113Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b42d1b30819a9fdea2a5e6fccfb3","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:3","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b42d1b30819a9fdea2a5e6fccfb3","role":"assistant","text":"CODEX_ROOT_SETTLED","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:45.195Z","updatedAt":"2026-10-27T14:24:45.218Z"},{"createdBy":"agent","creationSource":"mcp","id":"message:mcp:client%3A23308f20-1e1f-46cd-8b3a-788b4a7900cc:thread-send:0fd04def-0197-42bc-80c0-bd615180c894","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:4","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A4:root","role":"user","text":"Synthetic evidence active companion. Run node -e 'setTimeout(()=>console.log(\"CODEX_ACTIVE_17885_DONE\"),40000)' in exec_command with yield_time_ms=1000. Then write a 1500 word plain essay about serial queues. Do not poll the command session or wait. Do not change files. If a background command detail is already delivered acknowledge it once.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:55.341Z","updatedAt":"2026-10-27T14:24:55.341Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b439932c819ab7bb9fba46894634","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:4","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b439932c819ab7bb9fba46894634","role":"assistant","text":"I’ll launch the second timer as another persistent foreground session, won’t poll either session, and will use the remaining turn for the requested essay.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:57.606Z","updatedAt":"2026-10-27T14:24:57.835Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b43ecccc819ab970f50660380727","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:4","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b43ecccc819ab970f50660380727","role":"assistant","text":"A serial queue is one of the simplest ways to organize work in a computer system. Tasks enter the queue in some order, and a single worker processes them one at a time. The next task does not begin until the current task has finished, failed, or otherwise released control. This model can look unsophisticated beside thread pools, distributed schedulers, and highly concurrent pipelines, yet its simplicity gives it unusual power. A serial queue turns many difficult coordination problems into ordinary sequencing problems. When the order of operations matters, shared state must remain consistent, or predictability is more valuable than maximum throughput, serial execution is often the clearest design available.\n\nThe defining property of a serial queue is exclusivity. At most one queued task is executing through that queue at any moment. This does not necessarily mean the entire program uses only one thread, nor does it mean every operation is synchronous. A task might begin an asynchronous network request, register a callback, and yield the underlying thread. What matters is the queue’s completion rule. If the queue considers the task complete immediately after the request begins, later tasks may overlap with it. If completion is deferred until the callback arrives, the queue preserves strict logical serialization. Designers must therefore distinguish serial dispatch from serial completion. The former controls when code starts; the latter controls when effects are considered finished.\n\nOrdering is the most obvious benefit. Suppose an application receives commands to create an account, change its email address, and then delete it. If those commands execute concurrently, timing can produce strange outcomes: deletion may finish first, creation may overwrite it, or the email update may fail because the account temporarily does not exist. A serial queue processes the commands in their accepted order and makes the result easier to understand. The same principle applies to writing files, updating a local cache, advancing a workflow, applying database events, or controlling a physical device. The queue becomes a narrow channel through which state transitions occur in a deliberate sequence.\n\nSerial queues also provide a useful form of mutual exclusion. Traditional locking asks every piece of code that touches shared state to acquire and release the correct lock. This is efficient when done carefully, but careful locking is difficult. A forgotten lock creates a race, inconsistent lock ordering creates deadlock, and holding a lock across slow work can stall unrelated operations. Queue confinement offers another approach: shared mutable state belongs to one serial queue, and all access to that state is submitted as work. Since only one task runs at a time, state transitions cannot interleave unexpectedly. The queue acts as both scheduler and ownership boundary.\n\nThis ownership model improves reasoning. A developer can inspect a task and assume that no other task on the same queue is simultaneously changing the protected state. Invariants need to hold at task boundaries rather than at every individual instruction. Tests become more deterministic because fewer outcomes depend on thread timing. Logs naturally reflect a meaningful order. Failures can be tied to particular queue entries, and replay becomes possible when inputs are durable. Serial queues do not eliminate every bug, but they reduce the number of possible histories that a developer must consider.\n\nThe cost is limited throughput. A queue with one active worker cannot execute two independent tasks simultaneously, even when the machine has many available processors. One slow task delays everything behind it, a phenomenon often called head-of-line blocking. If a task waits thirty seconds for an external service, every later task waits as well when strict completion is required. The queue may grow faster than it drains, increasing latency and memory use. This tradeoff is fundamental: serialization buys order and isolation by giving up overlap. A successful design uses that bargain only where ordering or exclusivity is genuinely needed.\n\nQueue scope therefore matters. A single global serial queue is easy to construct but frequently too broad. If one customer’s slow operation blocks every other customer, unrelated work has been coupled unnecessarily. A better design may use one serial queue per account, document, device, or other natural ownership key. Tasks concerning the same key remain ordered, while tasks for different keys run concurrently. This pattern is sometimes called keyed serialization or partitioned queues. It preserves local consistency without sacrificing all system-wide parallelism. Choosing the partition key is an architectural decision because it defines which operations may safely overlap.\n\nFairness is another concern. A basic first-in, first-out queue treats arrival order as priority, which is often reasonable but not universally desirable. A stream of large background jobs can delay an urgent interactive action. Conversely, continually admitting urgent tasks can starve routine maintenance. Some systems use multiple serial queues with a higher-level scheduler that rotates among them. Others assign priorities, deadlines, or quotas. These policies complicate the clean FIFO model, but the core execution guarantee can remain intact: within the relevant domain, only one task runs at a time.\n\nError handling must be explicit. If a task throws an exception or returns a rejected promise, the queue should record the failure and decide whether subsequent work may continue. Automatically stopping the queue protects dependent operations from running after a broken prerequisite, but it can leave the system permanently wedged. Automatically continuing improves availability, but later tasks may encounter corrupted or incomplete state. A robust queue often classifies failures. Transient errors may trigger bounded retries with backoff. Permanent errors may move the task to a dead-letter store. Invariant violations may pause the queue and alert an operator. Whatever policy is chosen should be observable rather than implicit.\n\nCancellation presents similar questions. Removing a task that has not started is usually straightforward, provided no later task depends on it. Cancelling a running task is harder because arbitrary interruption can leave partial effects. Cooperative cancellation is safer: the task checks a signal at known points and performs cleanup before completing. For externally visible operations, cancellation may be impossible once a request has been accepted. In that case, the system may need a compensating task rather than pretending the original operation never happened. A queue preserves order, but it cannot make irreversible side effects reversible.\n\nBackpressure is essential when producers can outpace the consumer. An unbounded queue hides overload temporarily by accumulating work, then fails through excessive latency or memory exhaustion. A bounded queue makes capacity visible. Producers may block, receive a rejection, shed low-value work, or store tasks durably for later processing. Monitoring should include queue depth, oldest-task age, arrival rate, completion rate, execution duration, and failure count. Depth alone can mislead: ten millisecond-long tasks are harmless, while ten hour-long tasks may indicate a serious incident. Age and service time reveal the user-visible consequences more clearly.\n\nDurability separates in-memory serial queues from persistent job systems. An in-memory queue is fast and appropriate for coordinating state inside a process, but queued tasks disappear if that process crashes. A durable queue stores work before acknowledging acceptance and recovers unfinished tasks after restart. Durability introduces questions about delivery semantics. Most practical systems provide at-least-once execution, meaning a task may run again after ambiguous failure. Tasks must then be idempotent or carry deduplication keys. Exactly-once effects are difficult because the queue and the affected resource may fail independently. Serialization controls order; it does not by itself guarantee unique execution.\n\nReentrancy can cause subtle deadlocks. Imagine a task running on a serial queue that synchronously submits another task to the same queue and waits for its result. The inner task cannot start until the outer task finishes, while the outer task refuses to finish until the inner one runs. Queue APIs should discourage or detect this pattern. Code already executing within the queue can call an internal function directly, submit asynchronously without waiting, or use a reentrant execution rule where appropriate. The safest choice depends on whether immediate nested execution would violate the expected ordering.\n\nSerial queues are especially valuable at boundaries. A user interface often funnels state mutations through one event loop. An actor processes messages sequentially to protect its private state. A database uses ordered logs to establish a history of transactions. A device controller serializes commands because the hardware cannot perform conflicting motions at once. Even systems celebrated for concurrency frequently contain small islands of serialization. Concurrency happens between independent owners, while each owner processes its own stream in order. This combination is more scalable than either total serialization or unrestricted parallelism.\n\nTesting a serial queue should cover more than successful FIFO execution. Tests should confirm behavior after failure, cancellation, timeout, shutdown, and restart. They should verify that a task cannot overlap another task in the same partition and that different partitions can progress independently. Tests should exercise tasks that complete synchronously and asynchronously, because inconsistent completion handling is a common source of accidental concurrency. Shutdown deserves particular attention: the system must decide whether to drain queued work, reject new submissions, persist unfinished tasks, or terminate immediately. Clear lifecycle states prevent tasks from being silently lost.\n\nA serial queue is ultimately a tool for controlling histories. Concurrent systems permit many possible interleavings, and every additional interleaving increases the burden of reasoning, testing, and recovery. Serialization deliberately removes possibilities. That restraint can reduce raw speed, but it often improves correctness, operability, and human understanding. The best designs do not serialize everything. They identify the smallest domains in which order and exclusive ownership matter, place a queue around each domain, and allow concurrency between them. Used this way, the serial queue is not an outdated substitute for parallelism. It is one of the basic structures that makes safe parallelism possible.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:02.856Z","updatedAt":"2026-10-27T14:25:35.210Z"},{"createdBy":"user","creationSource":"web","id":"8761646d-95e5-41f4-8794-73e2013e532a","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:2","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A2:root","role":"user","text":"HELD_Q_17885: When explicitly released, reply exactly HELD_Q_DONE. No tools.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:24.188Z","updatedAt":"2026-10-27T14:24:24.188Z"},{"notification":{"source":{"kind":"command"},"outcome":"completed","summary":"Command \"/bin/bash -lc \"node -e 'setTimeout(()=>console.log(\\\"CODEX_BACKGROUND_17885_DON…\" finished (exit 0)","detail":"/bin/bash -lc \"node -e 'setTimeout(()=>console.log(\\\"CODEX_BACKGROUND_17885_DONE\\\"),45000)'\""},"createdBy":"agent","creationSource":"server","id":"message:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:1:16e3c6c1-8927-4e29-8dd9-979f6ff5c8b1","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:5","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A5:root","role":"user","text":"Background command completed (exit 0): /bin/bash -lc \"node -e 'setTimeout(()=>console.log(\\\"CODEX_BACKGROUND_17885_DONE\\\"),45000)'\"\n\nOutput tail:\nCODEX_BACKGROUND_17885_DONE","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:27.753Z","updatedAt":"2026-10-27T14:25:27.753Z"}],"subagents":[],"providerThreads":[{"id":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1","driver":"codex","providerInstanceId":"codex","providerSessionId":"provider-session:provider-instance:codex:shared","appThreadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","ownerNodeId":null,"nativeThreadRef":{"driver":"codex","nativeId":"01a17dbf-79ef-7c90-b227-4614d5023bd6","strength":"strong"},"nativeConversationHeadRef":null,"status":"active","firstRunOrdinal":1,"lastRunOrdinal":4,"handoffIds":[],"forkedFrom":null,"pendingBackgroundTasks":[],"contextUsage":{"usedTokens":20126,"maxTokens":258400},"nativeMetadata":null,"goal":null,"createdAt":"2026-10-27T14:24:20.885Z","updatedAt":"2026-10-27T14:24:55.446Z"}]}
2026-10-27T14:25:35.354Z PROJECTION {"runs":[{"id":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:1","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","ordinal":1,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1","userMessageId":"message:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:1:d0cf3e58-eadb-4bf0-9156-434ce4cf2248","rootNodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1:root","activeAttemptId":"run-attempt:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1:attempt:1","status":"interrupted","queuePosition":null,"requestedAt":"2026-10-27T14:24:20.885Z","startedAt":"2026-10-27T14:24:23.359Z","completedAt":"2026-10-27T14:24:24.307Z","checkpointId":null,"contextHandoffId":null,"workspacePreparation":{"type":"root"}},{"id":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:2","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","ordinal":2,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1","userMessageId":"8761646d-95e5-41f4-8794-73e2013e532a","rootNodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A2:root","activeAttemptId":"run-attempt:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A2:attempt:1","status":"queued","queuePosition":1,"queueHeld":true,"requestedAt":"2026-10-27T14:24:24.188Z","startedAt":null,"completedAt":null,"checkpointId":null,"contextHandoffId":null},{"id":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:3","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","ordinal":3,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1","userMessageId":"message:mcp:client%3A403306bf-8b12-4c21-8b83-a4274a2d202e:thread-send:e68ed982-aad7-4822-a5f9-4d4166e8cf71","rootNodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A3:root","activeAttemptId":"run-attempt:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A3:attempt:1","status":"completed","queuePosition":null,"requestedAt":"2026-10-27T14:24:38.099Z","startedAt":"2026-10-27T14:24:38.313Z","completedAt":"2026-10-27T14:24:45.326Z","checkpointId":"checkpoint:scope:checkpoint-scope%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aname%3Aroot:name:3","contextHandoffId":null},{"id":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:4","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","ordinal":4,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1","userMessageId":"message:mcp:client%3A23308f20-1e1f-46cd-8b3a-788b4a7900cc:thread-send:0fd04def-0197-42bc-80c0-bd615180c894","rootNodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A4:root","activeAttemptId":"run-attempt:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A4:attempt:1","status":"waiting","queuePosition":null,"requestedAt":"2026-10-27T14:24:55.341Z","startedAt":"2026-10-27T14:24:55.446Z","completedAt":null,"checkpointId":null,"contextHandoffId":null},{"id":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:5","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","ordinal":5,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1","userMessageId":"message:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:1:16e3c6c1-8927-4e29-8dd9-979f6ff5c8b1","rootNodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A5:root","activeAttemptId":"run-attempt:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A5:attempt:1","status":"queued","queuePosition":2,"queueHeld":true,"requestedAt":"2026-10-27T14:25:27.753Z","startedAt":null,"completedAt":null,"checkpointId":null,"contextHandoffId":null}],"messages":[{"createdBy":"user","creationSource":"web","id":"message:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:1:d0cf3e58-eadb-4bf0-9156-434ce4cf2248","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:1","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1:root","role":"user","text":"Synthetic scheduler evidence. Do not change files. Make 60 separate foreground Bash calls strictly sequentially, exactly one echo per call: echo initial-step-1 through echo initial-step-60. No loops, no background commands. After all calls reply INITIAL_DONE.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:20.885Z","updatedAt":"2026-10-27T14:24:20.885Z"},{"createdBy":"agent","creationSource":"mcp","id":"message:mcp:client%3A403306bf-8b12-4c21-8b83-a4274a2d202e:thread-send:e68ed982-aad7-4822-a5f9-4d4166e8cf71","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:3","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A3:root","role":"user","text":"Synthetic scheduler probe, no file edits. Use exec_command to run node -e 'setTimeout(()=>console.log(\"CODEX_BACKGROUND_17885_DONE\"),45000)' with yield_time_ms=1000. It must remain a running command session. Do not use a shell & or redirect. Do not poll or wait for it. Immediately end this turn with CODEX_ROOT_SETTLED. When a real later command-completion notification is delivered, reply exactly CODEX_DETAIL_ACK_17885 followed by the command result. Do not fabricate notifications.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:38.099Z","updatedAt":"2026-10-27T14:24:38.099Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b4299c10819aa33e4779dfefd048","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:3","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b4299c10819aa33e4779dfefd048","role":"assistant","text":"I’ll start the foreground Node timer as a persistent command session, then return immediately without polling it.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:41.681Z","updatedAt":"2026-10-27T14:24:42.113Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b42d1b30819a9fdea2a5e6fccfb3","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:3","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b42d1b30819a9fdea2a5e6fccfb3","role":"assistant","text":"CODEX_ROOT_SETTLED","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:45.195Z","updatedAt":"2026-10-27T14:24:45.218Z"},{"createdBy":"agent","creationSource":"mcp","id":"message:mcp:client%3A23308f20-1e1f-46cd-8b3a-788b4a7900cc:thread-send:0fd04def-0197-42bc-80c0-bd615180c894","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:4","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A4:root","role":"user","text":"Synthetic evidence active companion. Run node -e 'setTimeout(()=>console.log(\"CODEX_ACTIVE_17885_DONE\"),40000)' in exec_command with yield_time_ms=1000. Then write a 1500 word plain essay about serial queues. Do not poll the command session or wait. Do not change files. If a background command detail is already delivered acknowledge it once.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:55.341Z","updatedAt":"2026-10-27T14:24:55.341Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b439932c819ab7bb9fba46894634","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:4","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b439932c819ab7bb9fba46894634","role":"assistant","text":"I’ll launch the second timer as another persistent foreground session, won’t poll either session, and will use the remaining turn for the requested essay.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:57.606Z","updatedAt":"2026-10-27T14:24:57.835Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b43ecccc819ab970f50660380727","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:4","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b43ecccc819ab970f50660380727","role":"assistant","text":"A serial queue is one of the simplest ways to organize work in a computer system. Tasks enter the queue in some order, and a single worker processes them one at a time. The next task does not begin until the current task has finished, failed, or otherwise released control. This model can look unsophisticated beside thread pools, distributed schedulers, and highly concurrent pipelines, yet its simplicity gives it unusual power. A serial queue turns many difficult coordination problems into ordinary sequencing problems. When the order of operations matters, shared state must remain consistent, or predictability is more valuable than maximum throughput, serial execution is often the clearest design available.\n\nThe defining property of a serial queue is exclusivity. At most one queued task is executing through that queue at any moment. This does not necessarily mean the entire program uses only one thread, nor does it mean every operation is synchronous. A task might begin an asynchronous network request, register a callback, and yield the underlying thread. What matters is the queue’s completion rule. If the queue considers the task complete immediately after the request begins, later tasks may overlap with it. If completion is deferred until the callback arrives, the queue preserves strict logical serialization. Designers must therefore distinguish serial dispatch from serial completion. The former controls when code starts; the latter controls when effects are considered finished.\n\nOrdering is the most obvious benefit. Suppose an application receives commands to create an account, change its email address, and then delete it. If those commands execute concurrently, timing can produce strange outcomes: deletion may finish first, creation may overwrite it, or the email update may fail because the account temporarily does not exist. A serial queue processes the commands in their accepted order and makes the result easier to understand. The same principle applies to writing files, updating a local cache, advancing a workflow, applying database events, or controlling a physical device. The queue becomes a narrow channel through which state transitions occur in a deliberate sequence.\n\nSerial queues also provide a useful form of mutual exclusion. Traditional locking asks every piece of code that touches shared state to acquire and release the correct lock. This is efficient when done carefully, but careful locking is difficult. A forgotten lock creates a race, inconsistent lock ordering creates deadlock, and holding a lock across slow work can stall unrelated operations. Queue confinement offers another approach: shared mutable state belongs to one serial queue, and all access to that state is submitted as work. Since only one task runs at a time, state transitions cannot interleave unexpectedly. The queue acts as both scheduler and ownership boundary.\n\nThis ownership model improves reasoning. A developer can inspect a task and assume that no other task on the same queue is simultaneously changing the protected state. Invariants need to hold at task boundaries rather than at every individual instruction. Tests become more deterministic because fewer outcomes depend on thread timing. Logs naturally reflect a meaningful order. Failures can be tied to particular queue entries, and replay becomes possible when inputs are durable. Serial queues do not eliminate every bug, but they reduce the number of possible histories that a developer must consider.\n\nThe cost is limited throughput. A queue with one active worker cannot execute two independent tasks simultaneously, even when the machine has many available processors. One slow task delays everything behind it, a phenomenon often called head-of-line blocking. If a task waits thirty seconds for an external service, every later task waits as well when strict completion is required. The queue may grow faster than it drains, increasing latency and memory use. This tradeoff is fundamental: serialization buys order and isolation by giving up overlap. A successful design uses that bargain only where ordering or exclusivity is genuinely needed.\n\nQueue scope therefore matters. A single global serial queue is easy to construct but frequently too broad. If one customer’s slow operation blocks every other customer, unrelated work has been coupled unnecessarily. A better design may use one serial queue per account, document, device, or other natural ownership key. Tasks concerning the same key remain ordered, while tasks for different keys run concurrently. This pattern is sometimes called keyed serialization or partitioned queues. It preserves local consistency without sacrificing all system-wide parallelism. Choosing the partition key is an architectural decision because it defines which operations may safely overlap.\n\nFairness is another concern. A basic first-in, first-out queue treats arrival order as priority, which is often reasonable but not universally desirable. A stream of large background jobs can delay an urgent interactive action. Conversely, continually admitting urgent tasks can starve routine maintenance. Some systems use multiple serial queues with a higher-level scheduler that rotates among them. Others assign priorities, deadlines, or quotas. These policies complicate the clean FIFO model, but the core execution guarantee can remain intact: within the relevant domain, only one task runs at a time.\n\nError handling must be explicit. If a task throws an exception or returns a rejected promise, the queue should record the failure and decide whether subsequent work may continue. Automatically stopping the queue protects dependent operations from running after a broken prerequisite, but it can leave the system permanently wedged. Automatically continuing improves availability, but later tasks may encounter corrupted or incomplete state. A robust queue often classifies failures. Transient errors may trigger bounded retries with backoff. Permanent errors may move the task to a dead-letter store. Invariant violations may pause the queue and alert an operator. Whatever policy is chosen should be observable rather than implicit.\n\nCancellation presents similar questions. Removing a task that has not started is usually straightforward, provided no later task depends on it. Cancelling a running task is harder because arbitrary interruption can leave partial effects. Cooperative cancellation is safer: the task checks a signal at known points and performs cleanup before completing. For externally visible operations, cancellation may be impossible once a request has been accepted. In that case, the system may need a compensating task rather than pretending the original operation never happened. A queue preserves order, but it cannot make irreversible side effects reversible.\n\nBackpressure is essential when producers can outpace the consumer. An unbounded queue hides overload temporarily by accumulating work, then fails through excessive latency or memory exhaustion. A bounded queue makes capacity visible. Producers may block, receive a rejection, shed low-value work, or store tasks durably for later processing. Monitoring should include queue depth, oldest-task age, arrival rate, completion rate, execution duration, and failure count. Depth alone can mislead: ten millisecond-long tasks are harmless, while ten hour-long tasks may indicate a serious incident. Age and service time reveal the user-visible consequences more clearly.\n\nDurability separates in-memory serial queues from persistent job systems. An in-memory queue is fast and appropriate for coordinating state inside a process, but queued tasks disappear if that process crashes. A durable queue stores work before acknowledging acceptance and recovers unfinished tasks after restart. Durability introduces questions about delivery semantics. Most practical systems provide at-least-once execution, meaning a task may run again after ambiguous failure. Tasks must then be idempotent or carry deduplication keys. Exactly-once effects are difficult because the queue and the affected resource may fail independently. Serialization controls order; it does not by itself guarantee unique execution.\n\nReentrancy can cause subtle deadlocks. Imagine a task running on a serial queue that synchronously submits another task to the same queue and waits for its result. The inner task cannot start until the outer task finishes, while the outer task refuses to finish until the inner one runs. Queue APIs should discourage or detect this pattern. Code already executing within the queue can call an internal function directly, submit asynchronously without waiting, or use a reentrant execution rule where appropriate. The safest choice depends on whether immediate nested execution would violate the expected ordering.\n\nSerial queues are especially valuable at boundaries. A user interface often funnels state mutations through one event loop. An actor processes messages sequentially to protect its private state. A database uses ordered logs to establish a history of transactions. A device controller serializes commands because the hardware cannot perform conflicting motions at once. Even systems celebrated for concurrency frequently contain small islands of serialization. Concurrency happens between independent owners, while each owner processes its own stream in order. This combination is more scalable than either total serialization or unrestricted parallelism.\n\nTesting a serial queue should cover more than successful FIFO execution. Tests should confirm behavior after failure, cancellation, timeout, shutdown, and restart. They should verify that a task cannot overlap another task in the same partition and that different partitions can progress independently. Tests should exercise tasks that complete synchronously and asynchronously, because inconsistent completion handling is a common source of accidental concurrency. Shutdown deserves particular attention: the system must decide whether to drain queued work, reject new submissions, persist unfinished tasks, or terminate immediately. Clear lifecycle states prevent tasks from being silently lost.\n\nA serial queue is ultimately a tool for controlling histories. Concurrent systems permit many possible interleavings, and every additional interleaving increases the burden of reasoning, testing, and recovery. Serialization deliberately removes possibilities. That restraint can reduce raw speed, but it often improves correctness, operability, and human understanding. The best designs do not serialize everything. They identify the smallest domains in which order and exclusive ownership matter, place a queue around each domain, and allow concurrency between them. Used this way, the serial queue is not an outdated substitute for parallelism. It is one of the basic structures that makes safe parallelism possible.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:02.856Z","updatedAt":"2026-10-27T14:25:35.210Z"},{"createdBy":"user","creationSource":"web","id":"8761646d-95e5-41f4-8794-73e2013e532a","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:2","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A2:root","role":"user","text":"HELD_Q_17885: When explicitly released, reply exactly HELD_Q_DONE. No tools.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:24.188Z","updatedAt":"2026-10-27T14:24:24.188Z"},{"notification":{"source":{"kind":"command"},"outcome":"completed","summary":"Command \"/bin/bash -lc \"node -e 'setTimeout(()=>console.log(\\\"CODEX_BACKGROUND_17885_DON…\" finished (exit 0)","detail":"/bin/bash -lc \"node -e 'setTimeout(()=>console.log(\\\"CODEX_BACKGROUND_17885_DONE\\\"),45000)'\""},"createdBy":"agent","creationSource":"server","id":"message:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:1:16e3c6c1-8927-4e29-8dd9-979f6ff5c8b1","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:5","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A5:root","role":"user","text":"Background command completed (exit 0): /bin/bash -lc \"node -e 'setTimeout(()=>console.log(\\\"CODEX_BACKGROUND_17885_DONE\\\"),45000)'\"\n\nOutput tail:\nCODEX_BACKGROUND_17885_DONE","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:27.753Z","updatedAt":"2026-10-27T14:25:27.753Z"}],"subagents":[],"providerThreads":[{"id":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1","driver":"codex","providerInstanceId":"codex","providerSessionId":"provider-session:provider-instance:codex:shared","appThreadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","ownerNodeId":null,"nativeThreadRef":{"driver":"codex","nativeId":"01a17dbf-79ef-7c90-b227-4614d5023bd6","strength":"strong"},"nativeConversationHeadRef":null,"status":"idle","firstRunOrdinal":1,"lastRunOrdinal":4,"handoffIds":[],"forkedFrom":null,"pendingBackgroundTasks":[],"contextUsage":{"usedTokens":20126,"maxTokens":258400},"nativeMetadata":null,"goal":null,"createdAt":"2026-10-27T14:24:20.885Z","updatedAt":"2026-10-27T14:25:35.280Z"}]}
2026-10-27T14:25:36.502Z PROJECTION 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hetic scheduler evidence. Do not change files. Make 60 separate foreground Bash calls strictly sequentially, exactly one echo per call: echo initial-step-1 through echo initial-step-60. No loops, no background commands. After all calls reply INITIAL_DONE.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:20.885Z","updatedAt":"2026-10-27T14:24:20.885Z"},{"createdBy":"agent","creationSource":"mcp","id":"message:mcp:client%3A403306bf-8b12-4c21-8b83-a4274a2d202e:thread-send:e68ed982-aad7-4822-a5f9-4d4166e8cf71","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:3","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A3:root","role":"user","text":"Synthetic scheduler probe, no file edits. Use exec_command to run node -e 'setTimeout(()=>console.log(\"CODEX_BACKGROUND_17885_DONE\"),45000)' with yield_time_ms=1000. It must remain a running command session. Do not use a shell & or redirect. Do not poll or wait for it. Immediately end this turn with CODEX_ROOT_SETTLED. When a real later command-completion notification is delivered, reply exactly CODEX_DETAIL_ACK_17885 followed by the command result. Do not fabricate notifications.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:38.099Z","updatedAt":"2026-10-27T14:24:38.099Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b4299c10819aa33e4779dfefd048","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:3","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b4299c10819aa33e4779dfefd048","role":"assistant","text":"I’ll start the foreground Node timer as a persistent command session, then return immediately without polling it.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:41.681Z","updatedAt":"2026-10-27T14:24:42.113Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b42d1b30819a9fdea2a5e6fccfb3","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:3","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b42d1b30819a9fdea2a5e6fccfb3","role":"assistant","text":"CODEX_ROOT_SETTLED","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:45.195Z","updatedAt":"2026-10-27T14:24:45.218Z"},{"createdBy":"agent","creationSource":"mcp","id":"message:mcp:client%3A23308f20-1e1f-46cd-8b3a-788b4a7900cc:thread-send:0fd04def-0197-42bc-80c0-bd615180c894","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:4","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A4:root","role":"user","text":"Synthetic evidence active companion. Run node -e 'setTimeout(()=>console.log(\"CODEX_ACTIVE_17885_DONE\"),40000)' in exec_command with yield_time_ms=1000. Then write a 1500 word plain essay about serial queues. Do not poll the command session or wait. Do not change files. If a background command detail is already delivered acknowledge it once.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:55.341Z","updatedAt":"2026-10-27T14:24:55.341Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b439932c819ab7bb9fba46894634","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:4","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b439932c819ab7bb9fba46894634","role":"assistant","text":"I’ll launch the second timer as another persistent foreground session, won’t poll either session, and will use the remaining turn for the requested essay.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:57.606Z","updatedAt":"2026-10-27T14:24:57.835Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b43ecccc819ab970f50660380727","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:4","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b43ecccc819ab970f50660380727","role":"assistant","text":"A serial queue is one of the simplest ways to organize work in a computer system. Tasks enter the queue in some order, and a single worker processes them one at a time. The next task does not begin until the current task has finished, failed, or otherwise released control. This model can look unsophisticated beside thread pools, distributed schedulers, and highly concurrent pipelines, yet its simplicity gives it unusual power. A serial queue turns many difficult coordination problems into ordinary sequencing problems. When the order of operations matters, shared state must remain consistent, or predictability is more valuable than maximum throughput, serial execution is often the clearest design available.\n\nThe defining property of a serial queue is exclusivity. At most one queued task is executing through that queue at any moment. This does not necessarily mean the entire program uses only one thread, nor does it mean every operation is synchronous. A task might begin an asynchronous network request, register a callback, and yield the underlying thread. What matters is the queue’s completion rule. If the queue considers the task complete immediately after the request begins, later tasks may overlap with it. If completion is deferred until the callback arrives, the queue preserves strict logical serialization. Designers must therefore distinguish serial dispatch from serial completion. The former controls when code starts; the latter controls when effects are considered finished.\n\nOrdering is the most obvious benefit. Suppose an application receives commands to create an account, change its email address, and then delete it. If those commands execute concurrently, timing can produce strange outcomes: deletion may finish first, creation may overwrite it, or the email update may fail because the account temporarily does not exist. A serial queue processes the commands in their accepted order and makes the result easier to understand. The same principle applies to writing files, updating a local cache, advancing a workflow, applying database events, or controlling a physical device. The queue becomes a narrow channel through which state transitions occur in a deliberate sequence.\n\nSerial queues also provide a useful form of mutual exclusion. Traditional locking asks every piece of code that touches shared state to acquire and release the correct lock. This is efficient when done carefully, but careful locking is difficult. A forgotten lock creates a race, inconsistent lock ordering creates deadlock, and holding a lock across slow work can stall unrelated operations. Queue confinement offers another approach: shared mutable state belongs to one serial queue, and all access to that state is submitted as work. Since only one task runs at a time, state transitions cannot interleave unexpectedly. The queue acts as both scheduler and ownership boundary.\n\nThis ownership model improves reasoning. A developer can inspect a task and assume that no other task on the same queue is simultaneously changing the protected state. Invariants need to hold at task boundaries rather than at every individual instruction. Tests become more deterministic because fewer outcomes depend on thread timing. Logs naturally reflect a meaningful order. Failures can be tied to particular queue entries, and replay becomes possible when inputs are durable. Serial queues do not eliminate every bug, but they reduce the number of possible histories that a developer must consider.\n\nThe cost is limited throughput. A queue with one active worker cannot execute two independent tasks simultaneously, even when the machine has many available processors. One slow task delays everything behind it, a phenomenon often called head-of-line blocking. If a task waits thirty seconds for an external service, every later task waits as well when strict completion is required. The queue may grow faster than it drains, increasing latency and memory use. This tradeoff is fundamental: serialization buys order and isolation by giving up overlap. A successful design uses that bargain only where ordering or exclusivity is genuinely needed.\n\nQueue scope therefore matters. A single global serial queue is easy to construct but frequently too broad. If one customer’s slow operation blocks every other customer, unrelated work has been coupled unnecessarily. A better design may use one serial queue per account, document, device, or other natural ownership key. Tasks concerning the same key remain ordered, while tasks for different keys run concurrently. This pattern is sometimes called keyed serialization or partitioned queues. It preserves local consistency without sacrificing all system-wide parallelism. Choosing the partition key is an architectural decision because it defines which operations may safely overlap.\n\nFairness is another concern. A basic first-in, first-out queue treats arrival order as priority, which is often reasonable but not universally desirable. A stream of large background jobs can delay an urgent interactive action. Conversely, continually admitting urgent tasks can starve routine maintenance. Some systems use multiple serial queues with a higher-level scheduler that rotates among them. Others assign priorities, deadlines, or quotas. These policies complicate the clean FIFO model, but the core execution guarantee can remain intact: within the relevant domain, only one task runs at a time.\n\nError handling must be explicit. If a task throws an exception or returns a rejected promise, the queue should record the failure and decide whether subsequent work may continue. Automatically stopping the queue protects dependent operations from running after a broken prerequisite, but it can leave the system permanently wedged. Automatically continuing improves availability, but later tasks may encounter corrupted or incomplete state. A robust queue often classifies failures. Transient errors may trigger bounded retries with backoff. Permanent errors may move the task to a dead-letter store. Invariant violations may pause the queue and alert an operator. Whatever policy is chosen should be observable rather than implicit.\n\nCancellation presents similar questions. Removing a task that has not started is usually straightforward, provided no later task depends on it. Cancelling a running task is harder because arbitrary interruption can leave partial effects. Cooperative cancellation is safer: the task checks a signal at known points and performs cleanup before completing. For externally visible operations, cancellation may be impossible once a request has been accepted. In that case, the system may need a compensating task rather than pretending the original operation never happened. A queue preserves order, but it cannot make irreversible side effects reversible.\n\nBackpressure is essential when producers can outpace the consumer. An unbounded queue hides overload temporarily by accumulating work, then fails through excessive latency or memory exhaustion. A bounded queue makes capacity visible. Producers may block, receive a rejection, shed low-value work, or store tasks durably for later processing. Monitoring should include queue depth, oldest-task age, arrival rate, completion rate, execution duration, and failure count. Depth alone can mislead: ten millisecond-long tasks are harmless, while ten hour-long tasks may indicate a serious incident. Age and service time reveal the user-visible consequences more clearly.\n\nDurability separates in-memory serial queues from persistent job systems. An in-memory queue is fast and appropriate for coordinating state inside a process, but queued tasks disappear if that process crashes. A durable queue stores work before acknowledging acceptance and recovers unfinished tasks after restart. Durability introduces questions about delivery semantics. Most practical systems provide at-least-once execution, meaning a task may run again after ambiguous failure. Tasks must then be idempotent or carry deduplication keys. Exactly-once effects are difficult because the queue and the affected resource may fail independently. Serialization controls order; it does not by itself guarantee unique execution.\n\nReentrancy can cause subtle deadlocks. Imagine a task running on a serial queue that synchronously submits another task to the same queue and waits for its result. The inner task cannot start until the outer task finishes, while the outer task refuses to finish until the inner one runs. Queue APIs should discourage or detect this pattern. Code already executing within the queue can call an internal function directly, submit asynchronously without waiting, or use a reentrant execution rule where appropriate. The safest choice depends on whether immediate nested execution would violate the expected ordering.\n\nSerial queues are especially valuable at boundaries. A user interface often funnels state mutations through one event loop. An actor processes messages sequentially to protect its private state. A database uses ordered logs to establish a history of transactions. A device controller serializes commands because the hardware cannot perform conflicting motions at once. Even systems celebrated for concurrency frequently contain small islands of serialization. Concurrency happens between independent owners, while each owner processes its own stream in order. This combination is more scalable than either total serialization or unrestricted parallelism.\n\nTesting a serial queue should cover more than successful FIFO execution. Tests should confirm behavior after failure, cancellation, timeout, shutdown, and restart. They should verify that a task cannot overlap another task in the same partition and that different partitions can progress independently. Tests should exercise tasks that complete synchronously and asynchronously, because inconsistent completion handling is a common source of accidental concurrency. Shutdown deserves particular attention: the system must decide whether to drain queued work, reject new submissions, persist unfinished tasks, or terminate immediately. Clear lifecycle states prevent tasks from being silently lost.\n\nA serial queue is ultimately a tool for controlling histories. Concurrent systems permit many possible interleavings, and every additional interleaving increases the burden of reasoning, testing, and recovery. Serialization deliberately removes possibilities. That restraint can reduce raw speed, but it often improves correctness, operability, and human understanding. The best designs do not serialize everything. They identify the smallest domains in which order and exclusive ownership matter, place a queue around each domain, and allow concurrency between them. Used this way, the serial queue is not an outdated substitute for parallelism. It is one of the basic structures that makes safe parallelism possible.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:02.856Z","updatedAt":"2026-10-27T14:25:35.210Z"},{"createdBy":"user","creationSource":"web","id":"8761646d-95e5-41f4-8794-73e2013e532a","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:2","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A2:root","role":"user","text":"HELD_Q_17885: When explicitly released, reply exactly HELD_Q_DONE. No tools.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:24.188Z","updatedAt":"2026-10-27T14:24:24.188Z"},{"notification":{"source":{"kind":"command"},"outcome":"completed","summary":"Command \"/bin/bash -lc \"node -e 'setTimeout(()=>console.log(\\\"CODEX_BACKGROUND_17885_DON…\" finished (exit 0)","detail":"/bin/bash -lc \"node -e 'setTimeout(()=>console.log(\\\"CODEX_BACKGROUND_17885_DONE\\\"),45000)'\""},"createdBy":"agent","creationSource":"server","id":"message:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:1:16e3c6c1-8927-4e29-8dd9-979f6ff5c8b1","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:5","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A5:root","role":"user","text":"Background command completed (exit 0): /bin/bash -lc \"node -e 'setTimeout(()=>console.log(\\\"CODEX_BACKGROUND_17885_DONE\\\"),45000)'\"\n\nOutput tail:\nCODEX_BACKGROUND_17885_DONE","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:27.753Z","updatedAt":"2026-10-27T14:25:27.753Z"}],"subagents":[],"providerThreads":[{"id":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1","driver":"codex","providerInstanceId":"codex","providerSessionId":"provider-session:provider-instance:codex:shared","appThreadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","ownerNodeId":null,"nativeThreadRef":{"driver":"codex","nativeId":"01a17dbf-79ef-7c90-b227-4614d5023bd6","strength":"strong"},"nativeConversationHeadRef":null,"status":"idle","firstRunOrdinal":1,"lastRunOrdinal":4,"handoffIds":[],"forkedFrom":null,"pendingBackgroundTasks":[],"contextUsage":{"usedTokens":20126,"maxTokens":258400},"nativeMetadata":null,"goal":null,"createdAt":"2026-10-27T14:24:20.885Z","updatedAt":"2026-10-27T14:25:35.280Z"}]}
2026-10-27T14:25:40.346Z PROJECTION 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scheduler evidence. Do not change files. Make 60 separate foreground Bash calls strictly sequentially, exactly one echo per call: echo initial-step-1 through echo initial-step-60. No loops, no background commands. After all calls reply INITIAL_DONE.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:20.885Z","updatedAt":"2026-10-27T14:24:20.885Z"},{"createdBy":"agent","creationSource":"mcp","id":"message:mcp:client%3A403306bf-8b12-4c21-8b83-a4274a2d202e:thread-send:e68ed982-aad7-4822-a5f9-4d4166e8cf71","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:3","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A3:root","role":"user","text":"Synthetic scheduler probe, no file edits. Use exec_command to run node -e 'setTimeout(()=>console.log(\"CODEX_BACKGROUND_17885_DONE\"),45000)' with yield_time_ms=1000. It must remain a running command session. Do not use a shell & or redirect. Do not poll or wait for it. Immediately end this turn with CODEX_ROOT_SETTLED. When a real later command-completion notification is delivered, reply exactly CODEX_DETAIL_ACK_17885 followed by the command result. Do not fabricate notifications.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:38.099Z","updatedAt":"2026-10-27T14:24:38.099Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b4299c10819aa33e4779dfefd048","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:3","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b4299c10819aa33e4779dfefd048","role":"assistant","text":"I’ll start the foreground Node timer as a persistent command session, then return immediately without polling it.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:41.681Z","updatedAt":"2026-10-27T14:24:42.113Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b42d1b30819a9fdea2a5e6fccfb3","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:3","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b42d1b30819a9fdea2a5e6fccfb3","role":"assistant","text":"CODEX_ROOT_SETTLED","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:45.195Z","updatedAt":"2026-10-27T14:24:45.218Z"},{"createdBy":"agent","creationSource":"mcp","id":"message:mcp:client%3A23308f20-1e1f-46cd-8b3a-788b4a7900cc:thread-send:0fd04def-0197-42bc-80c0-bd615180c894","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:4","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A4:root","role":"user","text":"Synthetic evidence active companion. Run node -e 'setTimeout(()=>console.log(\"CODEX_ACTIVE_17885_DONE\"),40000)' in exec_command with yield_time_ms=1000. Then write a 1500 word plain essay about serial queues. Do not poll the command session or wait. Do not change files. If a background command detail is already delivered acknowledge it once.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:55.341Z","updatedAt":"2026-10-27T14:24:55.341Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b439932c819ab7bb9fba46894634","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:4","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b439932c819ab7bb9fba46894634","role":"assistant","text":"I’ll launch the second timer as another persistent foreground session, won’t poll either session, and will use the remaining turn for the requested essay.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:57.606Z","updatedAt":"2026-10-27T14:24:57.835Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b43ecccc819ab970f50660380727","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:4","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b43ecccc819ab970f50660380727","role":"assistant","text":"A serial queue is one of the simplest ways to organize work in a computer system. Tasks enter the queue in some order, and a single worker processes them one at a time. The next task does not begin until the current task has finished, failed, or otherwise released control. This model can look unsophisticated beside thread pools, distributed schedulers, and highly concurrent pipelines, yet its simplicity gives it unusual power. A serial queue turns many difficult coordination problems into ordinary sequencing problems. When the order of operations matters, shared state must remain consistent, or predictability is more valuable than maximum throughput, serial execution is often the clearest design available.\n\nThe defining property of a serial queue is exclusivity. At most one queued task is executing through that queue at any moment. This does not necessarily mean the entire program uses only one thread, nor does it mean every operation is synchronous. A task might begin an asynchronous network request, register a callback, and yield the underlying thread. What matters is the queue’s completion rule. If the queue considers the task complete immediately after the request begins, later tasks may overlap with it. If completion is deferred until the callback arrives, the queue preserves strict logical serialization. Designers must therefore distinguish serial dispatch from serial completion. The former controls when code starts; the latter controls when effects are considered finished.\n\nOrdering is the most obvious benefit. Suppose an application receives commands to create an account, change its email address, and then delete it. If those commands execute concurrently, timing can produce strange outcomes: deletion may finish first, creation may overwrite it, or the email update may fail because the account temporarily does not exist. A serial queue processes the commands in their accepted order and makes the result easier to understand. The same principle applies to writing files, updating a local cache, advancing a workflow, applying database events, or controlling a physical device. The queue becomes a narrow channel through which state transitions occur in a deliberate sequence.\n\nSerial queues also provide a useful form of mutual exclusion. Traditional locking asks every piece of code that touches shared state to acquire and release the correct lock. This is efficient when done carefully, but careful locking is difficult. A forgotten lock creates a race, inconsistent lock ordering creates deadlock, and holding a lock across slow work can stall unrelated operations. Queue confinement offers another approach: shared mutable state belongs to one serial queue, and all access to that state is submitted as work. Since only one task runs at a time, state transitions cannot interleave unexpectedly. The queue acts as both scheduler and ownership boundary.\n\nThis ownership model improves reasoning. A developer can inspect a task and assume that no other task on the same queue is simultaneously changing the protected state. Invariants need to hold at task boundaries rather than at every individual instruction. Tests become more deterministic because fewer outcomes depend on thread timing. Logs naturally reflect a meaningful order. Failures can be tied to particular queue entries, and replay becomes possible when inputs are durable. Serial queues do not eliminate every bug, but they reduce the number of possible histories that a developer must consider.\n\nThe cost is limited throughput. A queue with one active worker cannot execute two independent tasks simultaneously, even when the machine has many available processors. One slow task delays everything behind it, a phenomenon often called head-of-line blocking. If a task waits thirty seconds for an external service, every later task waits as well when strict completion is required. The queue may grow faster than it drains, increasing latency and memory use. This tradeoff is fundamental: serialization buys order and isolation by giving up overlap. A successful design uses that bargain only where ordering or exclusivity is genuinely needed.\n\nQueue scope therefore matters. A single global serial queue is easy to construct but frequently too broad. If one customer’s slow operation blocks every other customer, unrelated work has been coupled unnecessarily. A better design may use one serial queue per account, document, device, or other natural ownership key. Tasks concerning the same key remain ordered, while tasks for different keys run concurrently. This pattern is sometimes called keyed serialization or partitioned queues. It preserves local consistency without sacrificing all system-wide parallelism. Choosing the partition key is an architectural decision because it defines which operations may safely overlap.\n\nFairness is another concern. A basic first-in, first-out queue treats arrival order as priority, which is often reasonable but not universally desirable. A stream of large background jobs can delay an urgent interactive action. Conversely, continually admitting urgent tasks can starve routine maintenance. Some systems use multiple serial queues with a higher-level scheduler that rotates among them. Others assign priorities, deadlines, or quotas. These policies complicate the clean FIFO model, but the core execution guarantee can remain intact: within the relevant domain, only one task runs at a time.\n\nError handling must be explicit. If a task throws an exception or returns a rejected promise, the queue should record the failure and decide whether subsequent work may continue. Automatically stopping the queue protects dependent operations from running after a broken prerequisite, but it can leave the system permanently wedged. Automatically continuing improves availability, but later tasks may encounter corrupted or incomplete state. A robust queue often classifies failures. Transient errors may trigger bounded retries with backoff. Permanent errors may move the task to a dead-letter store. Invariant violations may pause the queue and alert an operator. Whatever policy is chosen should be observable rather than implicit.\n\nCancellation presents similar questions. Removing a task that has not started is usually straightforward, provided no later task depends on it. Cancelling a running task is harder because arbitrary interruption can leave partial effects. Cooperative cancellation is safer: the task checks a signal at known points and performs cleanup before completing. For externally visible operations, cancellation may be impossible once a request has been accepted. In that case, the system may need a compensating task rather than pretending the original operation never happened. A queue preserves order, but it cannot make irreversible side effects reversible.\n\nBackpressure is essential when producers can outpace the consumer. An unbounded queue hides overload temporarily by accumulating work, then fails through excessive latency or memory exhaustion. A bounded queue makes capacity visible. Producers may block, receive a rejection, shed low-value work, or store tasks durably for later processing. Monitoring should include queue depth, oldest-task age, arrival rate, completion rate, execution duration, and failure count. Depth alone can mislead: ten millisecond-long tasks are harmless, while ten hour-long tasks may indicate a serious incident. Age and service time reveal the user-visible consequences more clearly.\n\nDurability separates in-memory serial queues from persistent job systems. An in-memory queue is fast and appropriate for coordinating state inside a process, but queued tasks disappear if that process crashes. A durable queue stores work before acknowledging acceptance and recovers unfinished tasks after restart. Durability introduces questions about delivery semantics. Most practical systems provide at-least-once execution, meaning a task may run again after ambiguous failure. Tasks must then be idempotent or carry deduplication keys. Exactly-once effects are difficult because the queue and the affected resource may fail independently. Serialization controls order; it does not by itself guarantee unique execution.\n\nReentrancy can cause subtle deadlocks. Imagine a task running on a serial queue that synchronously submits another task to the same queue and waits for its result. The inner task cannot start until the outer task finishes, while the outer task refuses to finish until the inner one runs. Queue APIs should discourage or detect this pattern. Code already executing within the queue can call an internal function directly, submit asynchronously without waiting, or use a reentrant execution rule where appropriate. The safest choice depends on whether immediate nested execution would violate the expected ordering.\n\nSerial queues are especially valuable at boundaries. A user interface often funnels state mutations through one event loop. An actor processes messages sequentially to protect its private state. A database uses ordered logs to establish a history of transactions. A device controller serializes commands because the hardware cannot perform conflicting motions at once. Even systems celebrated for concurrency frequently contain small islands of serialization. Concurrency happens between independent owners, while each owner processes its own stream in order. This combination is more scalable than either total serialization or unrestricted parallelism.\n\nTesting a serial queue should cover more than successful FIFO execution. Tests should confirm behavior after failure, cancellation, timeout, shutdown, and restart. They should verify that a task cannot overlap another task in the same partition and that different partitions can progress independently. Tests should exercise tasks that complete synchronously and asynchronously, because inconsistent completion handling is a common source of accidental concurrency. Shutdown deserves particular attention: the system must decide whether to drain queued work, reject new submissions, persist unfinished tasks, or terminate immediately. Clear lifecycle states prevent tasks from being silently lost.\n\nA serial queue is ultimately a tool for controlling histories. Concurrent systems permit many possible interleavings, and every additional interleaving increases the burden of reasoning, testing, and recovery. Serialization deliberately removes possibilities. That restraint can reduce raw speed, but it often improves correctness, operability, and human understanding. The best designs do not serialize everything. They identify the smallest domains in which order and exclusive ownership matter, place a queue around each domain, and allow concurrency between them. Used this way, the serial queue is not an outdated substitute for parallelism. It is one of the basic structures that makes safe parallelism possible.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:02.856Z","updatedAt":"2026-10-27T14:25:35.210Z"},{"createdBy":"user","creationSource":"web","id":"8761646d-95e5-41f4-8794-73e2013e532a","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:2","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A2:root","role":"user","text":"HELD_Q_17885: When explicitly released, reply exactly HELD_Q_DONE. No tools.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:24.188Z","updatedAt":"2026-10-27T14:24:24.188Z"},{"notification":{"source":{"kind":"command"},"outcome":"completed","summary":"Command \"/bin/bash -lc \"node -e 'setTimeout(()=>console.log(\\\"CODEX_BACKGROUND_17885_DON…\" finished (exit 0)","detail":"/bin/bash -lc \"node -e 'setTimeout(()=>console.log(\\\"CODEX_BACKGROUND_17885_DONE\\\"),45000)'\""},"createdBy":"agent","creationSource":"server","id":"message:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:1:16e3c6c1-8927-4e29-8dd9-979f6ff5c8b1","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:5","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A5:root","role":"user","text":"Background command completed (exit 0): /bin/bash -lc \"node -e 'setTimeout(()=>console.log(\\\"CODEX_BACKGROUND_17885_DONE\\\"),45000)'\"\n\nOutput tail:\nCODEX_BACKGROUND_17885_DONE","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:27.753Z","updatedAt":"2026-10-27T14:25:27.753Z"},{"notification":{"source":{"kind":"command"},"outcome":"completed","summary":"Command \"/bin/bash -lc \"node -e 'setTimeout(()=>console.log(\\\"CODEX_ACTIVE_17885_DONE\\\")…\" finished (exit 0)","detail":"/bin/bash -lc \"node -e 'setTimeout(()=>console.log(\\\"CODEX_ACTIVE_17885_DONE\\\"),40000)'\""},"createdBy":"agent","creationSource":"server","id":"message:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:1:478f0547-4f14-4203-94d2-159690821463","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:6","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A6:root","role":"user","text":"Background command completed (exit 0): /bin/bash -lc \"node -e 'setTimeout(()=>console.log(\\\"CODEX_ACTIVE_17885_DONE\\\"),40000)'\"\n\nOutput tail:\nCODEX_ACTIVE_17885_DONE","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:40.146Z","updatedAt":"2026-10-27T14:25:40.146Z"}],"subagents":[],"providerThreads":[{"id":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1","driver":"codex","providerInstanceId":"codex","providerSessionId":"provider-session:provider-instance:codex:shared","appThreadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","ownerNodeId":null,"nativeThreadRef":{"driver":"codex","nativeId":"01a17dbf-79ef-7c90-b227-4614d5023bd6","strength":"strong"},"nativeConversationHeadRef":null,"status":"idle","firstRunOrdinal":1,"lastRunOrdinal":6,"handoffIds":[],"forkedFrom":null,"pendingBackgroundTasks":[],"contextUsage":{"usedTokens":20126,"maxTokens":258400},"nativeMetadata":null,"goal":null,"createdAt":"2026-10-27T14:24:20.885Z","updatedAt":"2026-10-27T14:25:40.146Z"}]}
2026-10-27T14:25:40.407Z PROJECTION 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6ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:1:478f0547-4f14-4203-94d2-159690821463","rootNodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A6:root","activeAttemptId":"run-attempt:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A6:attempt:1","status":"running","queuePosition":null,"requestedAt":"2026-10-27T14:25:40.146Z","startedAt":"2026-10-27T14:25:40.312Z","completedAt":null,"checkpointId":null,"contextHandoffId":null,"workStartedAt":"2026-10-27T14:24:55.446Z"}],"messages":[{"createdBy":"user","creationSource":"web","id":"message:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:1:d0cf3e58-eadb-4bf0-9156-434ce4cf2248","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:1","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1:root","role":"user","text":"Synthetic scheduler evidence. Do not change files. Make 60 separate foreground Bash calls strictly sequentially, exactly one echo per call: echo initial-step-1 through echo initial-step-60. No loops, no background commands. After all calls reply INITIAL_DONE.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:20.885Z","updatedAt":"2026-10-27T14:24:20.885Z"},{"createdBy":"agent","creationSource":"mcp","id":"message:mcp:client%3A403306bf-8b12-4c21-8b83-a4274a2d202e:thread-send:e68ed982-aad7-4822-a5f9-4d4166e8cf71","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:3","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A3:root","role":"user","text":"Synthetic scheduler probe, no file edits. Use exec_command to run node -e 'setTimeout(()=>console.log(\"CODEX_BACKGROUND_17885_DONE\"),45000)' with yield_time_ms=1000. It must remain a running command session. Do not use a shell & or redirect. Do not poll or wait for it. Immediately end this turn with CODEX_ROOT_SETTLED. When a real later command-completion notification is delivered, reply exactly CODEX_DETAIL_ACK_17885 followed by the command result. Do not fabricate notifications.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:38.099Z","updatedAt":"2026-10-27T14:24:38.099Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b4299c10819aa33e4779dfefd048","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:3","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b4299c10819aa33e4779dfefd048","role":"assistant","text":"I’ll start the foreground Node timer as a persistent command session, then return immediately without polling it.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:41.681Z","updatedAt":"2026-10-27T14:24:42.113Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b42d1b30819a9fdea2a5e6fccfb3","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:3","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b42d1b30819a9fdea2a5e6fccfb3","role":"assistant","text":"CODEX_ROOT_SETTLED","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:45.195Z","updatedAt":"2026-10-27T14:24:45.218Z"},{"createdBy":"agent","creationSource":"mcp","id":"message:mcp:client%3A23308f20-1e1f-46cd-8b3a-788b4a7900cc:thread-send:0fd04def-0197-42bc-80c0-bd615180c894","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:4","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A4:root","role":"user","text":"Synthetic evidence active companion. Run node -e 'setTimeout(()=>console.log(\"CODEX_ACTIVE_17885_DONE\"),40000)' in exec_command with yield_time_ms=1000. Then write a 1500 word plain essay about serial queues. Do not poll the command session or wait. Do not change files. If a background command detail is already delivered acknowledge it once.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:55.341Z","updatedAt":"2026-10-27T14:24:55.341Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b439932c819ab7bb9fba46894634","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:4","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b439932c819ab7bb9fba46894634","role":"assistant","text":"I’ll launch the second timer as another persistent foreground session, won’t poll either session, and will use the remaining turn for the requested essay.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:57.606Z","updatedAt":"2026-10-27T14:24:57.835Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b43ecccc819ab970f50660380727","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:4","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b43ecccc819ab970f50660380727","role":"assistant","text":"A serial queue is one of the simplest ways to organize work in a computer system. Tasks enter the queue in some order, and a single worker processes them one at a time. The next task does not begin until the current task has finished, failed, or otherwise released control. This model can look unsophisticated beside thread pools, distributed schedulers, and highly concurrent pipelines, yet its simplicity gives it unusual power. A serial queue turns many difficult coordination problems into ordinary sequencing problems. When the order of operations matters, shared state must remain consistent, or predictability is more valuable than maximum throughput, serial execution is often the clearest design available.\n\nThe defining property of a serial queue is exclusivity. At most one queued task is executing through that queue at any moment. This does not necessarily mean the entire program uses only one thread, nor does it mean every operation is synchronous. A task might begin an asynchronous network request, register a callback, and yield the underlying thread. What matters is the queue’s completion rule. If the queue considers the task complete immediately after the request begins, later tasks may overlap with it. If completion is deferred until the callback arrives, the queue preserves strict logical serialization. Designers must therefore distinguish serial dispatch from serial completion. The former controls when code starts; the latter controls when effects are considered finished.\n\nOrdering is the most obvious benefit. Suppose an application receives commands to create an account, change its email address, and then delete it. If those commands execute concurrently, timing can produce strange outcomes: deletion may finish first, creation may overwrite it, or the email update may fail because the account temporarily does not exist. A serial queue processes the commands in their accepted order and makes the result easier to understand. The same principle applies to writing files, updating a local cache, advancing a workflow, applying database events, or controlling a physical device. The queue becomes a narrow channel through which state transitions occur in a deliberate sequence.\n\nSerial queues also provide a useful form of mutual exclusion. Traditional locking asks every piece of code that touches shared state to acquire and release the correct lock. This is efficient when done carefully, but careful locking is difficult. A forgotten lock creates a race, inconsistent lock ordering creates deadlock, and holding a lock across slow work can stall unrelated operations. Queue confinement offers another approach: shared mutable state belongs to one serial queue, and all access to that state is submitted as work. Since only one task runs at a time, state transitions cannot interleave unexpectedly. The queue acts as both scheduler and ownership boundary.\n\nThis ownership model improves reasoning. A developer can inspect a task and assume that no other task on the same queue is simultaneously changing the protected state. Invariants need to hold at task boundaries rather than at every individual instruction. Tests become more deterministic because fewer outcomes depend on thread timing. Logs naturally reflect a meaningful order. Failures can be tied to particular queue entries, and replay becomes possible when inputs are durable. Serial queues do not eliminate every bug, but they reduce the number of possible histories that a developer must consider.\n\nThe cost is limited throughput. A queue with one active worker cannot execute two independent tasks simultaneously, even when the machine has many available processors. One slow task delays everything behind it, a phenomenon often called head-of-line blocking. If a task waits thirty seconds for an external service, every later task waits as well when strict completion is required. The queue may grow faster than it drains, increasing latency and memory use. This tradeoff is fundamental: serialization buys order and isolation by giving up overlap. A successful design uses that bargain only where ordering or exclusivity is genuinely needed.\n\nQueue scope therefore matters. A single global serial queue is easy to construct but frequently too broad. If one customer’s slow operation blocks every other customer, unrelated work has been coupled unnecessarily. A better design may use one serial queue per account, document, device, or other natural ownership key. Tasks concerning the same key remain ordered, while tasks for different keys run concurrently. This pattern is sometimes called keyed serialization or partitioned queues. It preserves local consistency without sacrificing all system-wide parallelism. Choosing the partition key is an architectural decision because it defines which operations may safely overlap.\n\nFairness is another concern. A basic first-in, first-out queue treats arrival order as priority, which is often reasonable but not universally desirable. A stream of large background jobs can delay an urgent interactive action. Conversely, continually admitting urgent tasks can starve routine maintenance. Some systems use multiple serial queues with a higher-level scheduler that rotates among them. Others assign priorities, deadlines, or quotas. These policies complicate the clean FIFO model, but the core execution guarantee can remain intact: within the relevant domain, only one task runs at a time.\n\nError handling must be explicit. If a task throws an exception or returns a rejected promise, the queue should record the failure and decide whether subsequent work may continue. Automatically stopping the queue protects dependent operations from running after a broken prerequisite, but it can leave the system permanently wedged. Automatically continuing improves availability, but later tasks may encounter corrupted or incomplete state. A robust queue often classifies failures. Transient errors may trigger bounded retries with backoff. Permanent errors may move the task to a dead-letter store. Invariant violations may pause the queue and alert an operator. Whatever policy is chosen should be observable rather than implicit.\n\nCancellation presents similar questions. Removing a task that has not started is usually straightforward, provided no later task depends on it. Cancelling a running task is harder because arbitrary interruption can leave partial effects. Cooperative cancellation is safer: the task checks a signal at known points and performs cleanup before completing. For externally visible operations, cancellation may be impossible once a request has been accepted. In that case, the system may need a compensating task rather than pretending the original operation never happened. A queue preserves order, but it cannot make irreversible side effects reversible.\n\nBackpressure is essential when producers can outpace the consumer. An unbounded queue hides overload temporarily by accumulating work, then fails through excessive latency or memory exhaustion. A bounded queue makes capacity visible. Producers may block, receive a rejection, shed low-value work, or store tasks durably for later processing. Monitoring should include queue depth, oldest-task age, arrival rate, completion rate, execution duration, and failure count. Depth alone can mislead: ten millisecond-long tasks are harmless, while ten hour-long tasks may indicate a serious incident. Age and service time reveal the user-visible consequences more clearly.\n\nDurability separates in-memory serial queues from persistent job systems. An in-memory queue is fast and appropriate for coordinating state inside a process, but queued tasks disappear if that process crashes. A durable queue stores work before acknowledging acceptance and recovers unfinished tasks after restart. Durability introduces questions about delivery semantics. Most practical systems provide at-least-once execution, meaning a task may run again after ambiguous failure. Tasks must then be idempotent or carry deduplication keys. Exactly-once effects are difficult because the queue and the affected resource may fail independently. Serialization controls order; it does not by itself guarantee unique execution.\n\nReentrancy can cause subtle deadlocks. Imagine a task running on a serial queue that synchronously submits another task to the same queue and waits for its result. The inner task cannot start until the outer task finishes, while the outer task refuses to finish until the inner one runs. Queue APIs should discourage or detect this pattern. Code already executing within the queue can call an internal function directly, submit asynchronously without waiting, or use a reentrant execution rule where appropriate. The safest choice depends on whether immediate nested execution would violate the expected ordering.\n\nSerial queues are especially valuable at boundaries. A user interface often funnels state mutations through one event loop. An actor processes messages sequentially to protect its private state. A database uses ordered logs to establish a history of transactions. A device controller serializes commands because the hardware cannot perform conflicting motions at once. Even systems celebrated for concurrency frequently contain small islands of serialization. Concurrency happens between independent owners, while each owner processes its own stream in order. This combination is more scalable than either total serialization or unrestricted parallelism.\n\nTesting a serial queue should cover more than successful FIFO execution. Tests should confirm behavior after failure, cancellation, timeout, shutdown, and restart. They should verify that a task cannot overlap another task in the same partition and that different partitions can progress independently. Tests should exercise tasks that complete synchronously and asynchronously, because inconsistent completion handling is a common source of accidental concurrency. Shutdown deserves particular attention: the system must decide whether to drain queued work, reject new submissions, persist unfinished tasks, or terminate immediately. Clear lifecycle states prevent tasks from being silently lost.\n\nA serial queue is ultimately a tool for controlling histories. Concurrent systems permit many possible interleavings, and every additional interleaving increases the burden of reasoning, testing, and recovery. Serialization deliberately removes possibilities. That restraint can reduce raw speed, but it often improves correctness, operability, and human understanding. The best designs do not serialize everything. They identify the smallest domains in which order and exclusive ownership matter, place a queue around each domain, and allow concurrency between them. Used this way, the serial queue is not an outdated substitute for parallelism. It is one of the basic structures that makes safe parallelism possible.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:02.856Z","updatedAt":"2026-10-27T14:25:35.210Z"},{"createdBy":"user","creationSource":"web","id":"8761646d-95e5-41f4-8794-73e2013e532a","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:2","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A2:root","role":"user","text":"HELD_Q_17885: When explicitly released, reply exactly HELD_Q_DONE. No tools.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:24.188Z","updatedAt":"2026-10-27T14:24:24.188Z"},{"notification":{"source":{"kind":"command"},"outcome":"completed","summary":"Command \"/bin/bash -lc \"node -e 'setTimeout(()=>console.log(\\\"CODEX_BACKGROUND_17885_DON…\" finished (exit 0)","detail":"/bin/bash -lc \"node -e 'setTimeout(()=>console.log(\\\"CODEX_BACKGROUND_17885_DONE\\\"),45000)'\""},"createdBy":"agent","creationSource":"server","id":"message:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:1:16e3c6c1-8927-4e29-8dd9-979f6ff5c8b1","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:5","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A5:root","role":"user","text":"Background command completed (exit 0): /bin/bash -lc \"node -e 'setTimeout(()=>console.log(\\\"CODEX_BACKGROUND_17885_DONE\\\"),45000)'\"\n\nOutput tail:\nCODEX_BACKGROUND_17885_DONE","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:27.753Z","updatedAt":"2026-10-27T14:25:27.753Z"},{"notification":{"source":{"kind":"command"},"outcome":"completed","summary":"Command \"/bin/bash -lc \"node -e 'setTimeout(()=>console.log(\\\"CODEX_ACTIVE_17885_DONE\\\")…\" finished (exit 0)","detail":"/bin/bash -lc \"node -e 'setTimeout(()=>console.log(\\\"CODEX_ACTIVE_17885_DONE\\\"),40000)'\""},"createdBy":"agent","creationSource":"server","id":"message:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:1:478f0547-4f14-4203-94d2-159690821463","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:6","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A6:root","role":"user","text":"Background command completed (exit 0): /bin/bash -lc \"node -e 'setTimeout(()=>console.log(\\\"CODEX_ACTIVE_17885_DONE\\\"),40000)'\"\n\nOutput tail:\nCODEX_ACTIVE_17885_DONE","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:40.146Z","updatedAt":"2026-10-27T14:25:40.146Z"}],"subagents":[],"providerThreads":[{"id":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1","driver":"codex","providerInstanceId":"codex","providerSessionId":"provider-session:provider-instance:codex:shared","appThreadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","ownerNodeId":null,"nativeThreadRef":{"driver":"codex","nativeId":"01a17dbf-79ef-7c90-b227-4614d5023bd6","strength":"strong"},"nativeConversationHeadRef":null,"status":"active","firstRunOrdinal":1,"lastRunOrdinal":6,"handoffIds":[],"forkedFrom":null,"pendingBackgroundTasks":[],"contextUsage":{"usedTokens":22308,"maxTokens":258400},"nativeMetadata":null,"goal":null,"createdAt":"2026-10-27T14:24:20.885Z","updatedAt":"2026-10-27T14:25:40.312Z"}]}
2026-10-27T14:25:43.538Z PROJECTION {"runs":[{"id":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:1","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","ordinal":1,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1","userMessageId":"message:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:1:d0cf3e58-eadb-4bf0-9156-434ce4cf2248","rootNodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1:root","activeAttemptId":"run-attempt:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1:attempt:1","status":"interrupted","queuePosition":null,"requestedAt":"2026-10-27T14:24:20.885Z","startedAt":"2026-10-27T14:24:23.359Z","completedAt":"2026-10-27T14:24:24.307Z","checkpointId":null,"contextHandoffId":null,"workspacePreparation":{"type":"root"}},{"id":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:2","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","ordinal":2,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1","userMessageId":"8761646d-95e5-41f4-8794-73e2013e532a","rootNodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A2:root","activeAttemptId":"run-attempt:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A2:attempt:1","status":"queued","queuePosition":1,"queueHeld":true,"requestedAt":"2026-10-27T14:24:24.188Z","startedAt":null,"completedAt":null,"checkpointId":null,"contextHandoffId":null},{"id":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:3","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","ordinal":3,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1","userMessageId":"message:mcp:client%3A403306bf-8b12-4c21-8b83-a4274a2d202e:thread-send:e68ed982-aad7-4822-a5f9-4d4166e8cf71","rootNodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A3:root","activeAttemptId":"run-attempt:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A3:attempt:1","status":"completed","queuePosition":null,"requestedAt":"2026-10-27T14:24:38.099Z","startedAt":"2026-10-27T14:24:38.313Z","completedAt":"2026-10-27T14:24:45.326Z","checkpointId":"checkpoint:scope:checkpoint-scope%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aname%3Aroot:name:3","contextHandoffId":null},{"id":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:4","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","ordinal":4,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1","userMessageId":"message:mcp:client%3A23308f20-1e1f-46cd-8b3a-788b4a7900cc:thread-send:0fd04def-0197-42bc-80c0-bd615180c894","rootNodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A4:root","activeAttemptId":"run-attempt:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A4:attempt:1","status":"completed","queuePosition":null,"requestedAt":"2026-10-27T14:24:55.341Z","startedAt":"2026-10-27T14:24:55.446Z","completedAt":"2026-10-27T14:25:35.320Z","checkpointId":"checkpoint:scope:checkpoint-scope%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aname%3Aroot:name:4","contextHandoffId":null},{"id":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:5","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","ordinal":5,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1","userMessageId":"message:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:1:16e3c6c1-8927-4e29-8dd9-979f6ff5c8b1","rootNodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A5:root","activeAttemptId":"run-attempt:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A5:attempt:1","status":"queued","queuePosition":2,"queueHeld":true,"requestedAt":"2026-10-27T14:25:27.753Z","startedAt":null,"completedAt":null,"checkpointId":null,"contextHandoffId":null},{"id":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:6","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","ordinal":6,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1","userMessageId":"message:thread:b0b3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scheduler evidence. Do not change files. Make 60 separate foreground Bash calls strictly sequentially, exactly one echo per call: echo initial-step-1 through echo initial-step-60. No loops, no background commands. After all calls reply INITIAL_DONE.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:20.885Z","updatedAt":"2026-10-27T14:24:20.885Z"},{"createdBy":"agent","creationSource":"mcp","id":"message:mcp:client%3A403306bf-8b12-4c21-8b83-a4274a2d202e:thread-send:e68ed982-aad7-4822-a5f9-4d4166e8cf71","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:3","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A3:root","role":"user","text":"Synthetic scheduler probe, no file edits. Use exec_command to run node -e 'setTimeout(()=>console.log(\"CODEX_BACKGROUND_17885_DONE\"),45000)' with yield_time_ms=1000. It must remain a running command session. Do not use a shell & or redirect. Do not poll or wait for it. Immediately end this turn with CODEX_ROOT_SETTLED. When a real later command-completion notification is delivered, reply exactly CODEX_DETAIL_ACK_17885 followed by the command result. Do not fabricate notifications.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:38.099Z","updatedAt":"2026-10-27T14:24:38.099Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b4299c10819aa33e4779dfefd048","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:3","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b4299c10819aa33e4779dfefd048","role":"assistant","text":"I’ll start the foreground Node timer as a persistent command session, then return immediately without polling it.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:41.681Z","updatedAt":"2026-10-27T14:24:42.113Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b42d1b30819a9fdea2a5e6fccfb3","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:3","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b42d1b30819a9fdea2a5e6fccfb3","role":"assistant","text":"CODEX_ROOT_SETTLED","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:45.195Z","updatedAt":"2026-10-27T14:24:45.218Z"},{"createdBy":"agent","creationSource":"mcp","id":"message:mcp:client%3A23308f20-1e1f-46cd-8b3a-788b4a7900cc:thread-send:0fd04def-0197-42bc-80c0-bd615180c894","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:4","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A4:root","role":"user","text":"Synthetic evidence active companion. Run node -e 'setTimeout(()=>console.log(\"CODEX_ACTIVE_17885_DONE\"),40000)' in exec_command with yield_time_ms=1000. Then write a 1500 word plain essay about serial queues. Do not poll the command session or wait. Do not change files. If a background command detail is already delivered acknowledge it once.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:55.341Z","updatedAt":"2026-10-27T14:24:55.341Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b439932c819ab7bb9fba46894634","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:4","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b439932c819ab7bb9fba46894634","role":"assistant","text":"I’ll launch the second timer as another persistent foreground session, won’t poll either session, and will use the remaining turn for the requested essay.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:57.606Z","updatedAt":"2026-10-27T14:24:57.835Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b43ecccc819ab970f50660380727","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:4","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b43ecccc819ab970f50660380727","role":"assistant","text":"A serial queue is one of the simplest ways to organize work in a computer system. Tasks enter the queue in some order, and a single worker processes them one at a time. The next task does not begin until the current task has finished, failed, or otherwise released control. This model can look unsophisticated beside thread pools, distributed schedulers, and highly concurrent pipelines, yet its simplicity gives it unusual power. A serial queue turns many difficult coordination problems into ordinary sequencing problems. When the order of operations matters, shared state must remain consistent, or predictability is more valuable than maximum throughput, serial execution is often the clearest design available.\n\nThe defining property of a serial queue is exclusivity. At most one queued task is executing through that queue at any moment. This does not necessarily mean the entire program uses only one thread, nor does it mean every operation is synchronous. A task might begin an asynchronous network request, register a callback, and yield the underlying thread. What matters is the queue’s completion rule. If the queue considers the task complete immediately after the request begins, later tasks may overlap with it. If completion is deferred until the callback arrives, the queue preserves strict logical serialization. Designers must therefore distinguish serial dispatch from serial completion. The former controls when code starts; the latter controls when effects are considered finished.\n\nOrdering is the most obvious benefit. Suppose an application receives commands to create an account, change its email address, and then delete it. If those commands execute concurrently, timing can produce strange outcomes: deletion may finish first, creation may overwrite it, or the email update may fail because the account temporarily does not exist. A serial queue processes the commands in their accepted order and makes the result easier to understand. The same principle applies to writing files, updating a local cache, advancing a workflow, applying database events, or controlling a physical device. The queue becomes a narrow channel through which state transitions occur in a deliberate sequence.\n\nSerial queues also provide a useful form of mutual exclusion. Traditional locking asks every piece of code that touches shared state to acquire and release the correct lock. This is efficient when done carefully, but careful locking is difficult. A forgotten lock creates a race, inconsistent lock ordering creates deadlock, and holding a lock across slow work can stall unrelated operations. Queue confinement offers another approach: shared mutable state belongs to one serial queue, and all access to that state is submitted as work. Since only one task runs at a time, state transitions cannot interleave unexpectedly. The queue acts as both scheduler and ownership boundary.\n\nThis ownership model improves reasoning. A developer can inspect a task and assume that no other task on the same queue is simultaneously changing the protected state. Invariants need to hold at task boundaries rather than at every individual instruction. Tests become more deterministic because fewer outcomes depend on thread timing. Logs naturally reflect a meaningful order. Failures can be tied to particular queue entries, and replay becomes possible when inputs are durable. Serial queues do not eliminate every bug, but they reduce the number of possible histories that a developer must consider.\n\nThe cost is limited throughput. A queue with one active worker cannot execute two independent tasks simultaneously, even when the machine has many available processors. One slow task delays everything behind it, a phenomenon often called head-of-line blocking. If a task waits thirty seconds for an external service, every later task waits as well when strict completion is required. The queue may grow faster than it drains, increasing latency and memory use. This tradeoff is fundamental: serialization buys order and isolation by giving up overlap. A successful design uses that bargain only where ordering or exclusivity is genuinely needed.\n\nQueue scope therefore matters. A single global serial queue is easy to construct but frequently too broad. If one customer’s slow operation blocks every other customer, unrelated work has been coupled unnecessarily. A better design may use one serial queue per account, document, device, or other natural ownership key. Tasks concerning the same key remain ordered, while tasks for different keys run concurrently. This pattern is sometimes called keyed serialization or partitioned queues. It preserves local consistency without sacrificing all system-wide parallelism. Choosing the partition key is an architectural decision because it defines which operations may safely overlap.\n\nFairness is another concern. A basic first-in, first-out queue treats arrival order as priority, which is often reasonable but not universally desirable. A stream of large background jobs can delay an urgent interactive action. Conversely, continually admitting urgent tasks can starve routine maintenance. Some systems use multiple serial queues with a higher-level scheduler that rotates among them. Others assign priorities, deadlines, or quotas. These policies complicate the clean FIFO model, but the core execution guarantee can remain intact: within the relevant domain, only one task runs at a time.\n\nError handling must be explicit. If a task throws an exception or returns a rejected promise, the queue should record the failure and decide whether subsequent work may continue. Automatically stopping the queue protects dependent operations from running after a broken prerequisite, but it can leave the system permanently wedged. Automatically continuing improves availability, but later tasks may encounter corrupted or incomplete state. A robust queue often classifies failures. Transient errors may trigger bounded retries with backoff. Permanent errors may move the task to a dead-letter store. Invariant violations may pause the queue and alert an operator. Whatever policy is chosen should be observable rather than implicit.\n\nCancellation presents similar questions. Removing a task that has not started is usually straightforward, provided no later task depends on it. Cancelling a running task is harder because arbitrary interruption can leave partial effects. Cooperative cancellation is safer: the task checks a signal at known points and performs cleanup before completing. For externally visible operations, cancellation may be impossible once a request has been accepted. In that case, the system may need a compensating task rather than pretending the original operation never happened. A queue preserves order, but it cannot make irreversible side effects reversible.\n\nBackpressure is essential when producers can outpace the consumer. An unbounded queue hides overload temporarily by accumulating work, then fails through excessive latency or memory exhaustion. A bounded queue makes capacity visible. Producers may block, receive a rejection, shed low-value work, or store tasks durably for later processing. Monitoring should include queue depth, oldest-task age, arrival rate, completion rate, execution duration, and failure count. Depth alone can mislead: ten millisecond-long tasks are harmless, while ten hour-long tasks may indicate a serious incident. Age and service time reveal the user-visible consequences more clearly.\n\nDurability separates in-memory serial queues from persistent job systems. An in-memory queue is fast and appropriate for coordinating state inside a process, but queued tasks disappear if that process crashes. A durable queue stores work before acknowledging acceptance and recovers unfinished tasks after restart. Durability introduces questions about delivery semantics. Most practical systems provide at-least-once execution, meaning a task may run again after ambiguous failure. Tasks must then be idempotent or carry deduplication keys. Exactly-once effects are difficult because the queue and the affected resource may fail independently. Serialization controls order; it does not by itself guarantee unique execution.\n\nReentrancy can cause subtle deadlocks. Imagine a task running on a serial queue that synchronously submits another task to the same queue and waits for its result. The inner task cannot start until the outer task finishes, while the outer task refuses to finish until the inner one runs. Queue APIs should discourage or detect this pattern. Code already executing within the queue can call an internal function directly, submit asynchronously without waiting, or use a reentrant execution rule where appropriate. The safest choice depends on whether immediate nested execution would violate the expected ordering.\n\nSerial queues are especially valuable at boundaries. A user interface often funnels state mutations through one event loop. An actor processes messages sequentially to protect its private state. A database uses ordered logs to establish a history of transactions. A device controller serializes commands because the hardware cannot perform conflicting motions at once. Even systems celebrated for concurrency frequently contain small islands of serialization. Concurrency happens between independent owners, while each owner processes its own stream in order. This combination is more scalable than either total serialization or unrestricted parallelism.\n\nTesting a serial queue should cover more than successful FIFO execution. Tests should confirm behavior after failure, cancellation, timeout, shutdown, and restart. They should verify that a task cannot overlap another task in the same partition and that different partitions can progress independently. Tests should exercise tasks that complete synchronously and asynchronously, because inconsistent completion handling is a common source of accidental concurrency. Shutdown deserves particular attention: the system must decide whether to drain queued work, reject new submissions, persist unfinished tasks, or terminate immediately. Clear lifecycle states prevent tasks from being silently lost.\n\nA serial queue is ultimately a tool for controlling histories. Concurrent systems permit many possible interleavings, and every additional interleaving increases the burden of reasoning, testing, and recovery. Serialization deliberately removes possibilities. That restraint can reduce raw speed, but it often improves correctness, operability, and human understanding. The best designs do not serialize everything. They identify the smallest domains in which order and exclusive ownership matter, place a queue around each domain, and allow concurrency between them. Used this way, the serial queue is not an outdated substitute for parallelism. It is one of the basic structures that makes safe parallelism possible.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:02.856Z","updatedAt":"2026-10-27T14:25:35.210Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b46744e0819ab5f92a182984bcc9","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:6","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b46744e0819ab5f92a182984bcc9","role":"assistant","text":"CODEX_DETAIL_ACK_17885\nCODEX_ACTIVE_17885_DONE","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:43.297Z","updatedAt":"2026-10-27T14:25:43.395Z"},{"createdBy":"user","creationSource":"web","id":"8761646d-95e5-41f4-8794-73e2013e532a","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:2","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A2:root","role":"user","text":"HELD_Q_17885: When explicitly released, reply exactly HELD_Q_DONE. No tools.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:24.188Z","updatedAt":"2026-10-27T14:24:24.188Z"},{"notification":{"source":{"kind":"command"},"outcome":"completed","summary":"Command \"/bin/bash -lc \"node -e 'setTimeout(()=>console.log(\\\"CODEX_BACKGROUND_17885_DON…\" finished (exit 0)","detail":"/bin/bash -lc \"node -e 'setTimeout(()=>console.log(\\\"CODEX_BACKGROUND_17885_DONE\\\"),45000)'\""},"createdBy":"agent","creationSource":"server","id":"message:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:1:16e3c6c1-8927-4e29-8dd9-979f6ff5c8b1","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:5","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A5:root","role":"user","text":"Background command completed (exit 0): /bin/bash -lc \"node -e 'setTimeout(()=>console.log(\\\"CODEX_BACKGROUND_17885_DONE\\\"),45000)'\"\n\nOutput tail:\nCODEX_BACKGROUND_17885_DONE","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:27.753Z","updatedAt":"2026-10-27T14:25:27.753Z"},{"notification":{"source":{"kind":"command"},"outcome":"completed","summary":"Command \"/bin/bash -lc \"node -e 'setTimeout(()=>console.log(\\\"CODEX_ACTIVE_17885_DONE\\\")…\" finished (exit 0)","detail":"/bin/bash -lc \"node -e 'setTimeout(()=>console.log(\\\"CODEX_ACTIVE_17885_DONE\\\"),40000)'\""},"createdBy":"agent","creationSource":"server","id":"message:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:1:478f0547-4f14-4203-94d2-159690821463","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:6","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A6:root","role":"user","text":"Background command completed (exit 0): /bin/bash -lc \"node -e 'setTimeout(()=>console.log(\\\"CODEX_ACTIVE_17885_DONE\\\"),40000)'\"\n\nOutput tail:\nCODEX_ACTIVE_17885_DONE","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:40.146Z","updatedAt":"2026-10-27T14:25:40.146Z"}],"subagents":[],"providerThreads":[{"id":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1","driver":"codex","providerInstanceId":"codex","providerSessionId":"provider-session:provider-instance:codex:shared","appThreadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","ownerNodeId":null,"nativeThreadRef":{"driver":"codex","nativeId":"01a17dbf-79ef-7c90-b227-4614d5023bd6","strength":"strong"},"nativeConversationHeadRef":null,"status":"idle","firstRunOrdinal":1,"lastRunOrdinal":6,"handoffIds":[],"forkedFrom":null,"pendingBackgroundTasks":[],"contextUsage":{"usedTokens":22308,"maxTokens":258400},"nativeMetadata":null,"goal":null,"createdAt":"2026-10-27T14:24:20.885Z","updatedAt":"2026-10-27T14:25:43.450Z"}]}
2026-10-27T14:25:44.380Z PROJECTION 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scheduler evidence. Do not change files. Make 60 separate foreground Bash calls strictly sequentially, exactly one echo per call: echo initial-step-1 through echo initial-step-60. No loops, no background commands. After all calls reply INITIAL_DONE.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:20.885Z","updatedAt":"2026-10-27T14:24:20.885Z"},{"createdBy":"agent","creationSource":"mcp","id":"message:mcp:client%3A403306bf-8b12-4c21-8b83-a4274a2d202e:thread-send:e68ed982-aad7-4822-a5f9-4d4166e8cf71","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:3","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A3:root","role":"user","text":"Synthetic scheduler probe, no file edits. Use exec_command to run node -e 'setTimeout(()=>console.log(\"CODEX_BACKGROUND_17885_DONE\"),45000)' with yield_time_ms=1000. It must remain a running command session. Do not use a shell & or redirect. Do not poll or wait for it. Immediately end this turn with CODEX_ROOT_SETTLED. When a real later command-completion notification is delivered, reply exactly CODEX_DETAIL_ACK_17885 followed by the command result. Do not fabricate notifications.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:38.099Z","updatedAt":"2026-10-27T14:24:38.099Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b4299c10819aa33e4779dfefd048","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:3","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b4299c10819aa33e4779dfefd048","role":"assistant","text":"I’ll start the foreground Node timer as a persistent command session, then return immediately without polling it.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:41.681Z","updatedAt":"2026-10-27T14:24:42.113Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b42d1b30819a9fdea2a5e6fccfb3","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:3","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b42d1b30819a9fdea2a5e6fccfb3","role":"assistant","text":"CODEX_ROOT_SETTLED","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:45.195Z","updatedAt":"2026-10-27T14:24:45.218Z"},{"createdBy":"agent","creationSource":"mcp","id":"message:mcp:client%3A23308f20-1e1f-46cd-8b3a-788b4a7900cc:thread-send:0fd04def-0197-42bc-80c0-bd615180c894","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:4","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A4:root","role":"user","text":"Synthetic evidence active companion. Run node -e 'setTimeout(()=>console.log(\"CODEX_ACTIVE_17885_DONE\"),40000)' in exec_command with yield_time_ms=1000. Then write a 1500 word plain essay about serial queues. Do not poll the command session or wait. Do not change files. If a background command detail is already delivered acknowledge it once.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:55.341Z","updatedAt":"2026-10-27T14:24:55.341Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b439932c819ab7bb9fba46894634","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:4","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b439932c819ab7bb9fba46894634","role":"assistant","text":"I’ll launch the second timer as another persistent foreground session, won’t poll either session, and will use the remaining turn for the requested essay.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:57.606Z","updatedAt":"2026-10-27T14:24:57.835Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b43ecccc819ab970f50660380727","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:4","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b43ecccc819ab970f50660380727","role":"assistant","text":"A serial queue is one of the simplest ways to organize work in a computer system. Tasks enter the queue in some order, and a single worker processes them one at a time. The next task does not begin until the current task has finished, failed, or otherwise released control. This model can look unsophisticated beside thread pools, distributed schedulers, and highly concurrent pipelines, yet its simplicity gives it unusual power. A serial queue turns many difficult coordination problems into ordinary sequencing problems. When the order of operations matters, shared state must remain consistent, or predictability is more valuable than maximum throughput, serial execution is often the clearest design available.\n\nThe defining property of a serial queue is exclusivity. At most one queued task is executing through that queue at any moment. This does not necessarily mean the entire program uses only one thread, nor does it mean every operation is synchronous. A task might begin an asynchronous network request, register a callback, and yield the underlying thread. What matters is the queue’s completion rule. If the queue considers the task complete immediately after the request begins, later tasks may overlap with it. If completion is deferred until the callback arrives, the queue preserves strict logical serialization. Designers must therefore distinguish serial dispatch from serial completion. The former controls when code starts; the latter controls when effects are considered finished.\n\nOrdering is the most obvious benefit. Suppose an application receives commands to create an account, change its email address, and then delete it. If those commands execute concurrently, timing can produce strange outcomes: deletion may finish first, creation may overwrite it, or the email update may fail because the account temporarily does not exist. A serial queue processes the commands in their accepted order and makes the result easier to understand. The same principle applies to writing files, updating a local cache, advancing a workflow, applying database events, or controlling a physical device. The queue becomes a narrow channel through which state transitions occur in a deliberate sequence.\n\nSerial queues also provide a useful form of mutual exclusion. Traditional locking asks every piece of code that touches shared state to acquire and release the correct lock. This is efficient when done carefully, but careful locking is difficult. A forgotten lock creates a race, inconsistent lock ordering creates deadlock, and holding a lock across slow work can stall unrelated operations. Queue confinement offers another approach: shared mutable state belongs to one serial queue, and all access to that state is submitted as work. Since only one task runs at a time, state transitions cannot interleave unexpectedly. The queue acts as both scheduler and ownership boundary.\n\nThis ownership model improves reasoning. A developer can inspect a task and assume that no other task on the same queue is simultaneously changing the protected state. Invariants need to hold at task boundaries rather than at every individual instruction. Tests become more deterministic because fewer outcomes depend on thread timing. Logs naturally reflect a meaningful order. Failures can be tied to particular queue entries, and replay becomes possible when inputs are durable. Serial queues do not eliminate every bug, but they reduce the number of possible histories that a developer must consider.\n\nThe cost is limited throughput. A queue with one active worker cannot execute two independent tasks simultaneously, even when the machine has many available processors. One slow task delays everything behind it, a phenomenon often called head-of-line blocking. If a task waits thirty seconds for an external service, every later task waits as well when strict completion is required. The queue may grow faster than it drains, increasing latency and memory use. This tradeoff is fundamental: serialization buys order and isolation by giving up overlap. A successful design uses that bargain only where ordering or exclusivity is genuinely needed.\n\nQueue scope therefore matters. A single global serial queue is easy to construct but frequently too broad. If one customer’s slow operation blocks every other customer, unrelated work has been coupled unnecessarily. A better design may use one serial queue per account, document, device, or other natural ownership key. Tasks concerning the same key remain ordered, while tasks for different keys run concurrently. This pattern is sometimes called keyed serialization or partitioned queues. It preserves local consistency without sacrificing all system-wide parallelism. Choosing the partition key is an architectural decision because it defines which operations may safely overlap.\n\nFairness is another concern. A basic first-in, first-out queue treats arrival order as priority, which is often reasonable but not universally desirable. A stream of large background jobs can delay an urgent interactive action. Conversely, continually admitting urgent tasks can starve routine maintenance. Some systems use multiple serial queues with a higher-level scheduler that rotates among them. Others assign priorities, deadlines, or quotas. These policies complicate the clean FIFO model, but the core execution guarantee can remain intact: within the relevant domain, only one task runs at a time.\n\nError handling must be explicit. If a task throws an exception or returns a rejected promise, the queue should record the failure and decide whether subsequent work may continue. Automatically stopping the queue protects dependent operations from running after a broken prerequisite, but it can leave the system permanently wedged. Automatically continuing improves availability, but later tasks may encounter corrupted or incomplete state. A robust queue often classifies failures. Transient errors may trigger bounded retries with backoff. Permanent errors may move the task to a dead-letter store. Invariant violations may pause the queue and alert an operator. Whatever policy is chosen should be observable rather than implicit.\n\nCancellation presents similar questions. Removing a task that has not started is usually straightforward, provided no later task depends on it. Cancelling a running task is harder because arbitrary interruption can leave partial effects. Cooperative cancellation is safer: the task checks a signal at known points and performs cleanup before completing. For externally visible operations, cancellation may be impossible once a request has been accepted. In that case, the system may need a compensating task rather than pretending the original operation never happened. A queue preserves order, but it cannot make irreversible side effects reversible.\n\nBackpressure is essential when producers can outpace the consumer. An unbounded queue hides overload temporarily by accumulating work, then fails through excessive latency or memory exhaustion. A bounded queue makes capacity visible. Producers may block, receive a rejection, shed low-value work, or store tasks durably for later processing. Monitoring should include queue depth, oldest-task age, arrival rate, completion rate, execution duration, and failure count. Depth alone can mislead: ten millisecond-long tasks are harmless, while ten hour-long tasks may indicate a serious incident. Age and service time reveal the user-visible consequences more clearly.\n\nDurability separates in-memory serial queues from persistent job systems. An in-memory queue is fast and appropriate for coordinating state inside a process, but queued tasks disappear if that process crashes. A durable queue stores work before acknowledging acceptance and recovers unfinished tasks after restart. Durability introduces questions about delivery semantics. Most practical systems provide at-least-once execution, meaning a task may run again after ambiguous failure. Tasks must then be idempotent or carry deduplication keys. Exactly-once effects are difficult because the queue and the affected resource may fail independently. Serialization controls order; it does not by itself guarantee unique execution.\n\nReentrancy can cause subtle deadlocks. Imagine a task running on a serial queue that synchronously submits another task to the same queue and waits for its result. The inner task cannot start until the outer task finishes, while the outer task refuses to finish until the inner one runs. Queue APIs should discourage or detect this pattern. Code already executing within the queue can call an internal function directly, submit asynchronously without waiting, or use a reentrant execution rule where appropriate. The safest choice depends on whether immediate nested execution would violate the expected ordering.\n\nSerial queues are especially valuable at boundaries. A user interface often funnels state mutations through one event loop. An actor processes messages sequentially to protect its private state. A database uses ordered logs to establish a history of transactions. A device controller serializes commands because the hardware cannot perform conflicting motions at once. Even systems celebrated for concurrency frequently contain small islands of serialization. Concurrency happens between independent owners, while each owner processes its own stream in order. This combination is more scalable than either total serialization or unrestricted parallelism.\n\nTesting a serial queue should cover more than successful FIFO execution. Tests should confirm behavior after failure, cancellation, timeout, shutdown, and restart. They should verify that a task cannot overlap another task in the same partition and that different partitions can progress independently. Tests should exercise tasks that complete synchronously and asynchronously, because inconsistent completion handling is a common source of accidental concurrency. Shutdown deserves particular attention: the system must decide whether to drain queued work, reject new submissions, persist unfinished tasks, or terminate immediately. Clear lifecycle states prevent tasks from being silently lost.\n\nA serial queue is ultimately a tool for controlling histories. Concurrent systems permit many possible interleavings, and every additional interleaving increases the burden of reasoning, testing, and recovery. Serialization deliberately removes possibilities. That restraint can reduce raw speed, but it often improves correctness, operability, and human understanding. The best designs do not serialize everything. They identify the smallest domains in which order and exclusive ownership matter, place a queue around each domain, and allow concurrency between them. Used this way, the serial queue is not an outdated substitute for parallelism. It is one of the basic structures that makes safe parallelism possible.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:02.856Z","updatedAt":"2026-10-27T14:25:35.210Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b46744e0819ab5f92a182984bcc9","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:6","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b46744e0819ab5f92a182984bcc9","role":"assistant","text":"CODEX_DETAIL_ACK_17885\nCODEX_ACTIVE_17885_DONE","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:43.297Z","updatedAt":"2026-10-27T14:25:43.395Z"},{"createdBy":"user","creationSource":"web","id":"8761646d-95e5-41f4-8794-73e2013e532a","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:2","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A2:root","role":"user","text":"HELD_Q_17885: When explicitly released, reply exactly HELD_Q_DONE. No tools.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:24.188Z","updatedAt":"2026-10-27T14:24:24.188Z"},{"notification":{"source":{"kind":"command"},"outcome":"completed","summary":"Command \"/bin/bash -lc \"node -e 'setTimeout(()=>console.log(\\\"CODEX_BACKGROUND_17885_DON…\" finished (exit 0)","detail":"/bin/bash -lc \"node -e 'setTimeout(()=>console.log(\\\"CODEX_BACKGROUND_17885_DONE\\\"),45000)'\""},"createdBy":"agent","creationSource":"server","id":"message:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:1:16e3c6c1-8927-4e29-8dd9-979f6ff5c8b1","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:5","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A5:root","role":"user","text":"Background command completed (exit 0): /bin/bash -lc \"node -e 'setTimeout(()=>console.log(\\\"CODEX_BACKGROUND_17885_DONE\\\"),45000)'\"\n\nOutput tail:\nCODEX_BACKGROUND_17885_DONE","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:27.753Z","updatedAt":"2026-10-27T14:25:27.753Z"}],"subagents":[],"providerThreads":[{"id":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1","driver":"codex","providerInstanceId":"codex","providerSessionId":"provider-session:provider-instance:codex:shared","appThreadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","ownerNodeId":null,"nativeThreadRef":{"driver":"codex","nativeId":"01a17dbf-79ef-7c90-b227-4614d5023bd6","strength":"strong"},"nativeConversationHeadRef":null,"status":"idle","firstRunOrdinal":1,"lastRunOrdinal":6,"handoffIds":[],"forkedFrom":null,"pendingBackgroundTasks":[],"contextUsage":{"usedTokens":22308,"maxTokens":258400},"nativeMetadata":null,"goal":null,"createdAt":"2026-10-27T14:24:20.885Z","updatedAt":"2026-10-27T14:25:43.450Z"}]}
2026-10-27T14:26:00.858Z BEFORE_RELEASE 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scheduler evidence. Do not change files. Make 60 separate foreground Bash calls strictly sequentially, exactly one echo per call: echo initial-step-1 through echo initial-step-60. No loops, no background commands. After all calls reply INITIAL_DONE.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:20.885Z","updatedAt":"2026-10-27T14:24:20.885Z"},{"createdBy":"agent","creationSource":"mcp","id":"message:mcp:client%3A403306bf-8b12-4c21-8b83-a4274a2d202e:thread-send:e68ed982-aad7-4822-a5f9-4d4166e8cf71","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:3","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A3:root","role":"user","text":"Synthetic scheduler probe, no file edits. Use exec_command to run node -e 'setTimeout(()=>console.log(\"CODEX_BACKGROUND_17885_DONE\"),45000)' with yield_time_ms=1000. It must remain a running command session. Do not use a shell & or redirect. Do not poll or wait for it. Immediately end this turn with CODEX_ROOT_SETTLED. When a real later command-completion notification is delivered, reply exactly CODEX_DETAIL_ACK_17885 followed by the command result. Do not fabricate notifications.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:38.099Z","updatedAt":"2026-10-27T14:24:38.099Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b4299c10819aa33e4779dfefd048","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:3","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b4299c10819aa33e4779dfefd048","role":"assistant","text":"I’ll start the foreground Node timer as a persistent command session, then return immediately without polling it.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:41.681Z","updatedAt":"2026-10-27T14:24:42.113Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b42d1b30819a9fdea2a5e6fccfb3","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:3","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b42d1b30819a9fdea2a5e6fccfb3","role":"assistant","text":"CODEX_ROOT_SETTLED","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:45.195Z","updatedAt":"2026-10-27T14:24:45.218Z"},{"createdBy":"agent","creationSource":"mcp","id":"message:mcp:client%3A23308f20-1e1f-46cd-8b3a-788b4a7900cc:thread-send:0fd04def-0197-42bc-80c0-bd615180c894","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:4","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A4:root","role":"user","text":"Synthetic evidence active companion. Run node -e 'setTimeout(()=>console.log(\"CODEX_ACTIVE_17885_DONE\"),40000)' in exec_command with yield_time_ms=1000. Then write a 1500 word plain essay about serial queues. Do not poll the command session or wait. Do not change files. If a background command detail is already delivered acknowledge it once.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:55.341Z","updatedAt":"2026-10-27T14:24:55.341Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b439932c819ab7bb9fba46894634","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:4","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b439932c819ab7bb9fba46894634","role":"assistant","text":"I’ll launch the second timer as another persistent foreground session, won’t poll either session, and will use the remaining turn for the requested essay.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:57.606Z","updatedAt":"2026-10-27T14:24:57.835Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b43ecccc819ab970f50660380727","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:4","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b43ecccc819ab970f50660380727","role":"assistant","text":"A serial queue is one of the simplest ways to organize work in a computer system. Tasks enter the queue in some order, and a single worker processes them one at a time. The next task does not begin until the current task has finished, failed, or otherwise released control. This model can look unsophisticated beside thread pools, distributed schedulers, and highly concurrent pipelines, yet its simplicity gives it unusual power. A serial queue turns many difficult coordination problems into ordinary sequencing problems. When the order of operations matters, shared state must remain consistent, or predictability is more valuable than maximum throughput, serial execution is often the clearest design available.\n\nThe defining property of a serial queue is exclusivity. At most one queued task is executing through that queue at any moment. This does not necessarily mean the entire program uses only one thread, nor does it mean every operation is synchronous. A task might begin an asynchronous network request, register a callback, and yield the underlying thread. What matters is the queue’s completion rule. If the queue considers the task complete immediately after the request begins, later tasks may overlap with it. If completion is deferred until the callback arrives, the queue preserves strict logical serialization. Designers must therefore distinguish serial dispatch from serial completion. The former controls when code starts; the latter controls when effects are considered finished.\n\nOrdering is the most obvious benefit. Suppose an application receives commands to create an account, change its email address, and then delete it. If those commands execute concurrently, timing can produce strange outcomes: deletion may finish first, creation may overwrite it, or the email update may fail because the account temporarily does not exist. A serial queue processes the commands in their accepted order and makes the result easier to understand. The same principle applies to writing files, updating a local cache, advancing a workflow, applying database events, or controlling a physical device. The queue becomes a narrow channel through which state transitions occur in a deliberate sequence.\n\nSerial queues also provide a useful form of mutual exclusion. Traditional locking asks every piece of code that touches shared state to acquire and release the correct lock. This is efficient when done carefully, but careful locking is difficult. A forgotten lock creates a race, inconsistent lock ordering creates deadlock, and holding a lock across slow work can stall unrelated operations. Queue confinement offers another approach: shared mutable state belongs to one serial queue, and all access to that state is submitted as work. Since only one task runs at a time, state transitions cannot interleave unexpectedly. The queue acts as both scheduler and ownership boundary.\n\nThis ownership model improves reasoning. A developer can inspect a task and assume that no other task on the same queue is simultaneously changing the protected state. Invariants need to hold at task boundaries rather than at every individual instruction. Tests become more deterministic because fewer outcomes depend on thread timing. Logs naturally reflect a meaningful order. Failures can be tied to particular queue entries, and replay becomes possible when inputs are durable. Serial queues do not eliminate every bug, but they reduce the number of possible histories that a developer must consider.\n\nThe cost is limited throughput. A queue with one active worker cannot execute two independent tasks simultaneously, even when the machine has many available processors. One slow task delays everything behind it, a phenomenon often called head-of-line blocking. If a task waits thirty seconds for an external service, every later task waits as well when strict completion is required. The queue may grow faster than it drains, increasing latency and memory use. This tradeoff is fundamental: serialization buys order and isolation by giving up overlap. A successful design uses that bargain only where ordering or exclusivity is genuinely needed.\n\nQueue scope therefore matters. A single global serial queue is easy to construct but frequently too broad. If one customer’s slow operation blocks every other customer, unrelated work has been coupled unnecessarily. A better design may use one serial queue per account, document, device, or other natural ownership key. Tasks concerning the same key remain ordered, while tasks for different keys run concurrently. This pattern is sometimes called keyed serialization or partitioned queues. It preserves local consistency without sacrificing all system-wide parallelism. Choosing the partition key is an architectural decision because it defines which operations may safely overlap.\n\nFairness is another concern. A basic first-in, first-out queue treats arrival order as priority, which is often reasonable but not universally desirable. A stream of large background jobs can delay an urgent interactive action. Conversely, continually admitting urgent tasks can starve routine maintenance. Some systems use multiple serial queues with a higher-level scheduler that rotates among them. Others assign priorities, deadlines, or quotas. These policies complicate the clean FIFO model, but the core execution guarantee can remain intact: within the relevant domain, only one task runs at a time.\n\nError handling must be explicit. If a task throws an exception or returns a rejected promise, the queue should record the failure and decide whether subsequent work may continue. Automatically stopping the queue protects dependent operations from running after a broken prerequisite, but it can leave the system permanently wedged. Automatically continuing improves availability, but later tasks may encounter corrupted or incomplete state. A robust queue often classifies failures. Transient errors may trigger bounded retries with backoff. Permanent errors may move the task to a dead-letter store. Invariant violations may pause the queue and alert an operator. Whatever policy is chosen should be observable rather than implicit.\n\nCancellation presents similar questions. Removing a task that has not started is usually straightforward, provided no later task depends on it. Cancelling a running task is harder because arbitrary interruption can leave partial effects. Cooperative cancellation is safer: the task checks a signal at known points and performs cleanup before completing. For externally visible operations, cancellation may be impossible once a request has been accepted. In that case, the system may need a compensating task rather than pretending the original operation never happened. A queue preserves order, but it cannot make irreversible side effects reversible.\n\nBackpressure is essential when producers can outpace the consumer. An unbounded queue hides overload temporarily by accumulating work, then fails through excessive latency or memory exhaustion. A bounded queue makes capacity visible. Producers may block, receive a rejection, shed low-value work, or store tasks durably for later processing. Monitoring should include queue depth, oldest-task age, arrival rate, completion rate, execution duration, and failure count. Depth alone can mislead: ten millisecond-long tasks are harmless, while ten hour-long tasks may indicate a serious incident. Age and service time reveal the user-visible consequences more clearly.\n\nDurability separates in-memory serial queues from persistent job systems. An in-memory queue is fast and appropriate for coordinating state inside a process, but queued tasks disappear if that process crashes. A durable queue stores work before acknowledging acceptance and recovers unfinished tasks after restart. Durability introduces questions about delivery semantics. Most practical systems provide at-least-once execution, meaning a task may run again after ambiguous failure. Tasks must then be idempotent or carry deduplication keys. Exactly-once effects are difficult because the queue and the affected resource may fail independently. Serialization controls order; it does not by itself guarantee unique execution.\n\nReentrancy can cause subtle deadlocks. Imagine a task running on a serial queue that synchronously submits another task to the same queue and waits for its result. The inner task cannot start until the outer task finishes, while the outer task refuses to finish until the inner one runs. Queue APIs should discourage or detect this pattern. Code already executing within the queue can call an internal function directly, submit asynchronously without waiting, or use a reentrant execution rule where appropriate. The safest choice depends on whether immediate nested execution would violate the expected ordering.\n\nSerial queues are especially valuable at boundaries. A user interface often funnels state mutations through one event loop. An actor processes messages sequentially to protect its private state. A database uses ordered logs to establish a history of transactions. A device controller serializes commands because the hardware cannot perform conflicting motions at once. Even systems celebrated for concurrency frequently contain small islands of serialization. Concurrency happens between independent owners, while each owner processes its own stream in order. This combination is more scalable than either total serialization or unrestricted parallelism.\n\nTesting a serial queue should cover more than successful FIFO execution. Tests should confirm behavior after failure, cancellation, timeout, shutdown, and restart. They should verify that a task cannot overlap another task in the same partition and that different partitions can progress independently. Tests should exercise tasks that complete synchronously and asynchronously, because inconsistent completion handling is a common source of accidental concurrency. Shutdown deserves particular attention: the system must decide whether to drain queued work, reject new submissions, persist unfinished tasks, or terminate immediately. Clear lifecycle states prevent tasks from being silently lost.\n\nA serial queue is ultimately a tool for controlling histories. Concurrent systems permit many possible interleavings, and every additional interleaving increases the burden of reasoning, testing, and recovery. Serialization deliberately removes possibilities. That restraint can reduce raw speed, but it often improves correctness, operability, and human understanding. The best designs do not serialize everything. They identify the smallest domains in which order and exclusive ownership matter, place a queue around each domain, and allow concurrency between them. Used this way, the serial queue is not an outdated substitute for parallelism. It is one of the basic structures that makes safe parallelism possible.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:02.856Z","updatedAt":"2026-10-27T14:25:35.210Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b46744e0819ab5f92a182984bcc9","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:6","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b46744e0819ab5f92a182984bcc9","role":"assistant","text":"CODEX_DETAIL_ACK_17885\nCODEX_ACTIVE_17885_DONE","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:43.297Z","updatedAt":"2026-10-27T14:25:43.395Z"},{"createdBy":"user","creationSource":"web","id":"8761646d-95e5-41f4-8794-73e2013e532a","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:2","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A2:root","role":"user","text":"HELD_Q_17885: When explicitly released, reply exactly HELD_Q_DONE. No tools.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:24.188Z","updatedAt":"2026-10-27T14:24:24.188Z"},{"notification":{"source":{"kind":"command"},"outcome":"completed","summary":"Command \"/bin/bash -lc \"node -e 'setTimeout(()=>console.log(\\\"CODEX_BACKGROUND_17885_DON…\" finished (exit 0)","detail":"/bin/bash -lc \"node -e 'setTimeout(()=>console.log(\\\"CODEX_BACKGROUND_17885_DONE\\\"),45000)'\""},"createdBy":"agent","creationSource":"server","id":"message:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:1:16e3c6c1-8927-4e29-8dd9-979f6ff5c8b1","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:5","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A5:root","role":"user","text":"Background command completed (exit 0): /bin/bash -lc \"node -e 'setTimeout(()=>console.log(\\\"CODEX_BACKGROUND_17885_DONE\\\"),45000)'\"\n\nOutput tail:\nCODEX_BACKGROUND_17885_DONE","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:27.753Z","updatedAt":"2026-10-27T14:25:27.753Z"}]}
2026-10-27T14:26:00.858Z STEP {"action":"user RPC dispatch","command":{"type":"queue.resume"}}
2026-10-27T14:26:00.948Z OBSERVATION_WINDOW {"milliseconds":45000,"narration":"Observe one fresh prompt for each released notification and queued Q"}
2026-10-27T14:26:01.331Z PROJECTION 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modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1","userMessageId":"8761646d-95e5-41f4-8794-73e2013e532a","rootNodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A2:root","activeAttemptId":"run-attempt:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A2:attempt:1","status":"starting","queuePosition":null,"queueHeld":false,"requestedAt":"2026-10-27T14:24:24.188Z","startedAt":null,"completedAt":null,"checkpointId":null,"contextHandoffId":null}],"messages":[{"createdBy":"user","creationSource":"web","id":"message:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:1:d0cf3e58-eadb-4bf0-9156-434ce4cf2248","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:1","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1:root","role":"user","text":"Synthetic scheduler evidence. Do not change files. Make 60 separate foreground Bash calls strictly sequentially, exactly one echo per call: echo initial-step-1 through echo initial-step-60. No loops, no background commands. After all calls reply INITIAL_DONE.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:20.885Z","updatedAt":"2026-10-27T14:24:20.885Z"},{"createdBy":"agent","creationSource":"mcp","id":"message:mcp:client%3A403306bf-8b12-4c21-8b83-a4274a2d202e:thread-send:e68ed982-aad7-4822-a5f9-4d4166e8cf71","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:3","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A3:root","role":"user","text":"Synthetic scheduler probe, no file edits. Use exec_command to run node -e 'setTimeout(()=>console.log(\"CODEX_BACKGROUND_17885_DONE\"),45000)' with yield_time_ms=1000. It must remain a running command session. Do not use a shell & or redirect. Do not poll or wait for it. Immediately end this turn with CODEX_ROOT_SETTLED. When a real later command-completion notification is delivered, reply exactly CODEX_DETAIL_ACK_17885 followed by the command result. Do not fabricate notifications.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:38.099Z","updatedAt":"2026-10-27T14:24:38.099Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b4299c10819aa33e4779dfefd048","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:3","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b4299c10819aa33e4779dfefd048","role":"assistant","text":"I’ll start the foreground Node timer as a persistent command session, then return immediately without polling it.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:41.681Z","updatedAt":"2026-10-27T14:24:42.113Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b42d1b30819a9fdea2a5e6fccfb3","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:3","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b42d1b30819a9fdea2a5e6fccfb3","role":"assistant","text":"CODEX_ROOT_SETTLED","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:45.195Z","updatedAt":"2026-10-27T14:24:45.218Z"},{"createdBy":"agent","creationSource":"mcp","id":"message:mcp:client%3A23308f20-1e1f-46cd-8b3a-788b4a7900cc:thread-send:0fd04def-0197-42bc-80c0-bd615180c894","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:4","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A4:root","role":"user","text":"Synthetic evidence active companion. Run node -e 'setTimeout(()=>console.log(\"CODEX_ACTIVE_17885_DONE\"),40000)' in exec_command with yield_time_ms=1000. Then write a 1500 word plain essay about serial queues. Do not poll the command session or wait. Do not change files. If a background command detail is already delivered acknowledge it once.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:55.341Z","updatedAt":"2026-10-27T14:24:55.341Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b439932c819ab7bb9fba46894634","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:4","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b439932c819ab7bb9fba46894634","role":"assistant","text":"I’ll launch the second timer as another persistent foreground session, won’t poll either session, and will use the remaining turn for the requested essay.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:57.606Z","updatedAt":"2026-10-27T14:24:57.835Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b43ecccc819ab970f50660380727","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:4","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b43ecccc819ab970f50660380727","role":"assistant","text":"A serial queue is one of the simplest ways to organize work in a computer system. Tasks enter the queue in some order, and a single worker processes them one at a time. The next task does not begin until the current task has finished, failed, or otherwise released control. This model can look unsophisticated beside thread pools, distributed schedulers, and highly concurrent pipelines, yet its simplicity gives it unusual power. A serial queue turns many difficult coordination problems into ordinary sequencing problems. When the order of operations matters, shared state must remain consistent, or predictability is more valuable than maximum throughput, serial execution is often the clearest design available.\n\nThe defining property of a serial queue is exclusivity. At most one queued task is executing through that queue at any moment. This does not necessarily mean the entire program uses only one thread, nor does it mean every operation is synchronous. A task might begin an asynchronous network request, register a callback, and yield the underlying thread. What matters is the queue’s completion rule. If the queue considers the task complete immediately after the request begins, later tasks may overlap with it. If completion is deferred until the callback arrives, the queue preserves strict logical serialization. Designers must therefore distinguish serial dispatch from serial completion. The former controls when code starts; the latter controls when effects are considered finished.\n\nOrdering is the most obvious benefit. Suppose an application receives commands to create an account, change its email address, and then delete it. If those commands execute concurrently, timing can produce strange outcomes: deletion may finish first, creation may overwrite it, or the email update may fail because the account temporarily does not exist. A serial queue processes the commands in their accepted order and makes the result easier to understand. The same principle applies to writing files, updating a local cache, advancing a workflow, applying database events, or controlling a physical device. The queue becomes a narrow channel through which state transitions occur in a deliberate sequence.\n\nSerial queues also provide a useful form of mutual exclusion. Traditional locking asks every piece of code that touches shared state to acquire and release the correct lock. This is efficient when done carefully, but careful locking is difficult. A forgotten lock creates a race, inconsistent lock ordering creates deadlock, and holding a lock across slow work can stall unrelated operations. Queue confinement offers another approach: shared mutable state belongs to one serial queue, and all access to that state is submitted as work. Since only one task runs at a time, state transitions cannot interleave unexpectedly. The queue acts as both scheduler and ownership boundary.\n\nThis ownership model improves reasoning. A developer can inspect a task and assume that no other task on the same queue is simultaneously changing the protected state. Invariants need to hold at task boundaries rather than at every individual instruction. Tests become more deterministic because fewer outcomes depend on thread timing. Logs naturally reflect a meaningful order. Failures can be tied to particular queue entries, and replay becomes possible when inputs are durable. Serial queues do not eliminate every bug, but they reduce the number of possible histories that a developer must consider.\n\nThe cost is limited throughput. A queue with one active worker cannot execute two independent tasks simultaneously, even when the machine has many available processors. One slow task delays everything behind it, a phenomenon often called head-of-line blocking. If a task waits thirty seconds for an external service, every later task waits as well when strict completion is required. The queue may grow faster than it drains, increasing latency and memory use. This tradeoff is fundamental: serialization buys order and isolation by giving up overlap. A successful design uses that bargain only where ordering or exclusivity is genuinely needed.\n\nQueue scope therefore matters. A single global serial queue is easy to construct but frequently too broad. If one customer’s slow operation blocks every other customer, unrelated work has been coupled unnecessarily. A better design may use one serial queue per account, document, device, or other natural ownership key. Tasks concerning the same key remain ordered, while tasks for different keys run concurrently. This pattern is sometimes called keyed serialization or partitioned queues. It preserves local consistency without sacrificing all system-wide parallelism. Choosing the partition key is an architectural decision because it defines which operations may safely overlap.\n\nFairness is another concern. A basic first-in, first-out queue treats arrival order as priority, which is often reasonable but not universally desirable. A stream of large background jobs can delay an urgent interactive action. Conversely, continually admitting urgent tasks can starve routine maintenance. Some systems use multiple serial queues with a higher-level scheduler that rotates among them. Others assign priorities, deadlines, or quotas. These policies complicate the clean FIFO model, but the core execution guarantee can remain intact: within the relevant domain, only one task runs at a time.\n\nError handling must be explicit. If a task throws an exception or returns a rejected promise, the queue should record the failure and decide whether subsequent work may continue. Automatically stopping the queue protects dependent operations from running after a broken prerequisite, but it can leave the system permanently wedged. Automatically continuing improves availability, but later tasks may encounter corrupted or incomplete state. A robust queue often classifies failures. Transient errors may trigger bounded retries with backoff. Permanent errors may move the task to a dead-letter store. Invariant violations may pause the queue and alert an operator. Whatever policy is chosen should be observable rather than implicit.\n\nCancellation presents similar questions. Removing a task that has not started is usually straightforward, provided no later task depends on it. Cancelling a running task is harder because arbitrary interruption can leave partial effects. Cooperative cancellation is safer: the task checks a signal at known points and performs cleanup before completing. For externally visible operations, cancellation may be impossible once a request has been accepted. In that case, the system may need a compensating task rather than pretending the original operation never happened. A queue preserves order, but it cannot make irreversible side effects reversible.\n\nBackpressure is essential when producers can outpace the consumer. An unbounded queue hides overload temporarily by accumulating work, then fails through excessive latency or memory exhaustion. A bounded queue makes capacity visible. Producers may block, receive a rejection, shed low-value work, or store tasks durably for later processing. Monitoring should include queue depth, oldest-task age, arrival rate, completion rate, execution duration, and failure count. Depth alone can mislead: ten millisecond-long tasks are harmless, while ten hour-long tasks may indicate a serious incident. Age and service time reveal the user-visible consequences more clearly.\n\nDurability separates in-memory serial queues from persistent job systems. An in-memory queue is fast and appropriate for coordinating state inside a process, but queued tasks disappear if that process crashes. A durable queue stores work before acknowledging acceptance and recovers unfinished tasks after restart. Durability introduces questions about delivery semantics. Most practical systems provide at-least-once execution, meaning a task may run again after ambiguous failure. Tasks must then be idempotent or carry deduplication keys. Exactly-once effects are difficult because the queue and the affected resource may fail independently. Serialization controls order; it does not by itself guarantee unique execution.\n\nReentrancy can cause subtle deadlocks. Imagine a task running on a serial queue that synchronously submits another task to the same queue and waits for its result. The inner task cannot start until the outer task finishes, while the outer task refuses to finish until the inner one runs. Queue APIs should discourage or detect this pattern. Code already executing within the queue can call an internal function directly, submit asynchronously without waiting, or use a reentrant execution rule where appropriate. The safest choice depends on whether immediate nested execution would violate the expected ordering.\n\nSerial queues are especially valuable at boundaries. A user interface often funnels state mutations through one event loop. An actor processes messages sequentially to protect its private state. A database uses ordered logs to establish a history of transactions. A device controller serializes commands because the hardware cannot perform conflicting motions at once. Even systems celebrated for concurrency frequently contain small islands of serialization. Concurrency happens between independent owners, while each owner processes its own stream in order. This combination is more scalable than either total serialization or unrestricted parallelism.\n\nTesting a serial queue should cover more than successful FIFO execution. Tests should confirm behavior after failure, cancellation, timeout, shutdown, and restart. They should verify that a task cannot overlap another task in the same partition and that different partitions can progress independently. Tests should exercise tasks that complete synchronously and asynchronously, because inconsistent completion handling is a common source of accidental concurrency. Shutdown deserves particular attention: the system must decide whether to drain queued work, reject new submissions, persist unfinished tasks, or terminate immediately. Clear lifecycle states prevent tasks from being silently lost.\n\nA serial queue is ultimately a tool for controlling histories. Concurrent systems permit many possible interleavings, and every additional interleaving increases the burden of reasoning, testing, and recovery. Serialization deliberately removes possibilities. That restraint can reduce raw speed, but it often improves correctness, operability, and human understanding. The best designs do not serialize everything. They identify the smallest domains in which order and exclusive ownership matter, place a queue around each domain, and allow concurrency between them. Used this way, the serial queue is not an outdated substitute for parallelism. It is one of the basic structures that makes safe parallelism possible.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:02.856Z","updatedAt":"2026-10-27T14:25:35.210Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b46744e0819ab5f92a182984bcc9","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:6","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b46744e0819ab5f92a182984bcc9","role":"assistant","text":"CODEX_DETAIL_ACK_17885\nCODEX_ACTIVE_17885_DONE","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:43.297Z","updatedAt":"2026-10-27T14:25:43.395Z"},{"createdBy":"user","creationSource":"web","id":"8761646d-95e5-41f4-8794-73e2013e532a","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:2","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A2:root","role":"user","text":"HELD_Q_17885: When explicitly released, reply exactly HELD_Q_DONE. No tools.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:24.188Z","updatedAt":"2026-10-27T14:24:24.188Z"},{"notification":{"source":{"kind":"command"},"outcome":"completed","summary":"Command \"/bin/bash -lc \"node -e 'setTimeout(()=>console.log(\\\"CODEX_BACKGROUND_17885_DON…\" finished (exit 0)","detail":"/bin/bash -lc \"node -e 'setTimeout(()=>console.log(\\\"CODEX_BACKGROUND_17885_DONE\\\"),45000)'\""},"createdBy":"agent","creationSource":"server","id":"message:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:1:16e3c6c1-8927-4e29-8dd9-979f6ff5c8b1","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:5","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A5:root","role":"user","text":"Background command completed (exit 0): /bin/bash -lc \"node -e 'setTimeout(()=>console.log(\\\"CODEX_BACKGROUND_17885_DONE\\\"),45000)'\"\n\nOutput tail:\nCODEX_BACKGROUND_17885_DONE","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:27.753Z","updatedAt":"2026-10-27T14:25:27.753Z"}],"subagents":[],"providerThreads":[{"id":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1","driver":"codex","providerInstanceId":"codex","providerSessionId":"provider-session:provider-instance:codex:shared","appThreadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","ownerNodeId":null,"nativeThreadRef":{"driver":"codex","nativeId":"01a17dbf-79ef-7c90-b227-4614d5023bd6","strength":"strong"},"nativeConversationHeadRef":null,"status":"not_loaded","firstRunOrdinal":1,"lastRunOrdinal":7,"handoffIds":[],"forkedFrom":null,"pendingBackgroundTasks":[],"contextUsage":{"usedTokens":22308,"maxTokens":258400},"nativeMetadata":null,"goal":null,"createdAt":"2026-10-27T14:24:20.885Z","updatedAt":"2026-10-27T14:26:00.878Z"}]}
2026-10-27T14:26:01.486Z PROJECTION 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scheduler evidence. Do not change files. Make 60 separate foreground Bash calls strictly sequentially, exactly one echo per call: echo initial-step-1 through echo initial-step-60. No loops, no background commands. After all calls reply INITIAL_DONE.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:20.885Z","updatedAt":"2026-10-27T14:24:20.885Z"},{"createdBy":"agent","creationSource":"mcp","id":"message:mcp:client%3A403306bf-8b12-4c21-8b83-a4274a2d202e:thread-send:e68ed982-aad7-4822-a5f9-4d4166e8cf71","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:3","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A3:root","role":"user","text":"Synthetic scheduler probe, no file edits. Use exec_command to run node -e 'setTimeout(()=>console.log(\"CODEX_BACKGROUND_17885_DONE\"),45000)' with yield_time_ms=1000. It must remain a running command session. Do not use a shell & or redirect. Do not poll or wait for it. Immediately end this turn with CODEX_ROOT_SETTLED. When a real later command-completion notification is delivered, reply exactly CODEX_DETAIL_ACK_17885 followed by the command result. Do not fabricate notifications.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:38.099Z","updatedAt":"2026-10-27T14:24:38.099Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b4299c10819aa33e4779dfefd048","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:3","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b4299c10819aa33e4779dfefd048","role":"assistant","text":"I’ll start the foreground Node timer as a persistent command session, then return immediately without polling it.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:41.681Z","updatedAt":"2026-10-27T14:24:42.113Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b42d1b30819a9fdea2a5e6fccfb3","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:3","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b42d1b30819a9fdea2a5e6fccfb3","role":"assistant","text":"CODEX_ROOT_SETTLED","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:45.195Z","updatedAt":"2026-10-27T14:24:45.218Z"},{"createdBy":"agent","creationSource":"mcp","id":"message:mcp:client%3A23308f20-1e1f-46cd-8b3a-788b4a7900cc:thread-send:0fd04def-0197-42bc-80c0-bd615180c894","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:4","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A4:root","role":"user","text":"Synthetic evidence active companion. Run node -e 'setTimeout(()=>console.log(\"CODEX_ACTIVE_17885_DONE\"),40000)' in exec_command with yield_time_ms=1000. Then write a 1500 word plain essay about serial queues. Do not poll the command session or wait. Do not change files. If a background command detail is already delivered acknowledge it once.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:55.341Z","updatedAt":"2026-10-27T14:24:55.341Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b439932c819ab7bb9fba46894634","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:4","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b439932c819ab7bb9fba46894634","role":"assistant","text":"I’ll launch the second timer as another persistent foreground session, won’t poll either session, and will use the remaining turn for the requested essay.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:57.606Z","updatedAt":"2026-10-27T14:24:57.835Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b43ecccc819ab970f50660380727","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:4","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b43ecccc819ab970f50660380727","role":"assistant","text":"A serial queue is one of the simplest ways to organize work in a computer system. Tasks enter the queue in some order, and a single worker processes them one at a time. The next task does not begin until the current task has finished, failed, or otherwise released control. This model can look unsophisticated beside thread pools, distributed schedulers, and highly concurrent pipelines, yet its simplicity gives it unusual power. A serial queue turns many difficult coordination problems into ordinary sequencing problems. When the order of operations matters, shared state must remain consistent, or predictability is more valuable than maximum throughput, serial execution is often the clearest design available.\n\nThe defining property of a serial queue is exclusivity. At most one queued task is executing through that queue at any moment. This does not necessarily mean the entire program uses only one thread, nor does it mean every operation is synchronous. A task might begin an asynchronous network request, register a callback, and yield the underlying thread. What matters is the queue’s completion rule. If the queue considers the task complete immediately after the request begins, later tasks may overlap with it. If completion is deferred until the callback arrives, the queue preserves strict logical serialization. Designers must therefore distinguish serial dispatch from serial completion. The former controls when code starts; the latter controls when effects are considered finished.\n\nOrdering is the most obvious benefit. Suppose an application receives commands to create an account, change its email address, and then delete it. If those commands execute concurrently, timing can produce strange outcomes: deletion may finish first, creation may overwrite it, or the email update may fail because the account temporarily does not exist. A serial queue processes the commands in their accepted order and makes the result easier to understand. The same principle applies to writing files, updating a local cache, advancing a workflow, applying database events, or controlling a physical device. The queue becomes a narrow channel through which state transitions occur in a deliberate sequence.\n\nSerial queues also provide a useful form of mutual exclusion. Traditional locking asks every piece of code that touches shared state to acquire and release the correct lock. This is efficient when done carefully, but careful locking is difficult. A forgotten lock creates a race, inconsistent lock ordering creates deadlock, and holding a lock across slow work can stall unrelated operations. Queue confinement offers another approach: shared mutable state belongs to one serial queue, and all access to that state is submitted as work. Since only one task runs at a time, state transitions cannot interleave unexpectedly. The queue acts as both scheduler and ownership boundary.\n\nThis ownership model improves reasoning. A developer can inspect a task and assume that no other task on the same queue is simultaneously changing the protected state. Invariants need to hold at task boundaries rather than at every individual instruction. Tests become more deterministic because fewer outcomes depend on thread timing. Logs naturally reflect a meaningful order. Failures can be tied to particular queue entries, and replay becomes possible when inputs are durable. Serial queues do not eliminate every bug, but they reduce the number of possible histories that a developer must consider.\n\nThe cost is limited throughput. A queue with one active worker cannot execute two independent tasks simultaneously, even when the machine has many available processors. One slow task delays everything behind it, a phenomenon often called head-of-line blocking. If a task waits thirty seconds for an external service, every later task waits as well when strict completion is required. The queue may grow faster than it drains, increasing latency and memory use. This tradeoff is fundamental: serialization buys order and isolation by giving up overlap. A successful design uses that bargain only where ordering or exclusivity is genuinely needed.\n\nQueue scope therefore matters. A single global serial queue is easy to construct but frequently too broad. If one customer’s slow operation blocks every other customer, unrelated work has been coupled unnecessarily. A better design may use one serial queue per account, document, device, or other natural ownership key. Tasks concerning the same key remain ordered, while tasks for different keys run concurrently. This pattern is sometimes called keyed serialization or partitioned queues. It preserves local consistency without sacrificing all system-wide parallelism. Choosing the partition key is an architectural decision because it defines which operations may safely overlap.\n\nFairness is another concern. A basic first-in, first-out queue treats arrival order as priority, which is often reasonable but not universally desirable. A stream of large background jobs can delay an urgent interactive action. Conversely, continually admitting urgent tasks can starve routine maintenance. Some systems use multiple serial queues with a higher-level scheduler that rotates among them. Others assign priorities, deadlines, or quotas. These policies complicate the clean FIFO model, but the core execution guarantee can remain intact: within the relevant domain, only one task runs at a time.\n\nError handling must be explicit. If a task throws an exception or returns a rejected promise, the queue should record the failure and decide whether subsequent work may continue. Automatically stopping the queue protects dependent operations from running after a broken prerequisite, but it can leave the system permanently wedged. Automatically continuing improves availability, but later tasks may encounter corrupted or incomplete state. A robust queue often classifies failures. Transient errors may trigger bounded retries with backoff. Permanent errors may move the task to a dead-letter store. Invariant violations may pause the queue and alert an operator. Whatever policy is chosen should be observable rather than implicit.\n\nCancellation presents similar questions. Removing a task that has not started is usually straightforward, provided no later task depends on it. Cancelling a running task is harder because arbitrary interruption can leave partial effects. Cooperative cancellation is safer: the task checks a signal at known points and performs cleanup before completing. For externally visible operations, cancellation may be impossible once a request has been accepted. In that case, the system may need a compensating task rather than pretending the original operation never happened. A queue preserves order, but it cannot make irreversible side effects reversible.\n\nBackpressure is essential when producers can outpace the consumer. An unbounded queue hides overload temporarily by accumulating work, then fails through excessive latency or memory exhaustion. A bounded queue makes capacity visible. Producers may block, receive a rejection, shed low-value work, or store tasks durably for later processing. Monitoring should include queue depth, oldest-task age, arrival rate, completion rate, execution duration, and failure count. Depth alone can mislead: ten millisecond-long tasks are harmless, while ten hour-long tasks may indicate a serious incident. Age and service time reveal the user-visible consequences more clearly.\n\nDurability separates in-memory serial queues from persistent job systems. An in-memory queue is fast and appropriate for coordinating state inside a process, but queued tasks disappear if that process crashes. A durable queue stores work before acknowledging acceptance and recovers unfinished tasks after restart. Durability introduces questions about delivery semantics. Most practical systems provide at-least-once execution, meaning a task may run again after ambiguous failure. Tasks must then be idempotent or carry deduplication keys. Exactly-once effects are difficult because the queue and the affected resource may fail independently. Serialization controls order; it does not by itself guarantee unique execution.\n\nReentrancy can cause subtle deadlocks. Imagine a task running on a serial queue that synchronously submits another task to the same queue and waits for its result. The inner task cannot start until the outer task finishes, while the outer task refuses to finish until the inner one runs. Queue APIs should discourage or detect this pattern. Code already executing within the queue can call an internal function directly, submit asynchronously without waiting, or use a reentrant execution rule where appropriate. The safest choice depends on whether immediate nested execution would violate the expected ordering.\n\nSerial queues are especially valuable at boundaries. A user interface often funnels state mutations through one event loop. An actor processes messages sequentially to protect its private state. A database uses ordered logs to establish a history of transactions. A device controller serializes commands because the hardware cannot perform conflicting motions at once. Even systems celebrated for concurrency frequently contain small islands of serialization. Concurrency happens between independent owners, while each owner processes its own stream in order. This combination is more scalable than either total serialization or unrestricted parallelism.\n\nTesting a serial queue should cover more than successful FIFO execution. Tests should confirm behavior after failure, cancellation, timeout, shutdown, and restart. They should verify that a task cannot overlap another task in the same partition and that different partitions can progress independently. Tests should exercise tasks that complete synchronously and asynchronously, because inconsistent completion handling is a common source of accidental concurrency. Shutdown deserves particular attention: the system must decide whether to drain queued work, reject new submissions, persist unfinished tasks, or terminate immediately. Clear lifecycle states prevent tasks from being silently lost.\n\nA serial queue is ultimately a tool for controlling histories. Concurrent systems permit many possible interleavings, and every additional interleaving increases the burden of reasoning, testing, and recovery. Serialization deliberately removes possibilities. That restraint can reduce raw speed, but it often improves correctness, operability, and human understanding. The best designs do not serialize everything. They identify the smallest domains in which order and exclusive ownership matter, place a queue around each domain, and allow concurrency between them. Used this way, the serial queue is not an outdated substitute for parallelism. It is one of the basic structures that makes safe parallelism possible.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:02.856Z","updatedAt":"2026-10-27T14:25:35.210Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b46744e0819ab5f92a182984bcc9","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:6","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b46744e0819ab5f92a182984bcc9","role":"assistant","text":"CODEX_DETAIL_ACK_17885\nCODEX_ACTIVE_17885_DONE","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:43.297Z","updatedAt":"2026-10-27T14:25:43.395Z"},{"createdBy":"user","creationSource":"web","id":"8761646d-95e5-41f4-8794-73e2013e532a","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:2","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A2:root","role":"user","text":"HELD_Q_17885: When explicitly released, reply exactly HELD_Q_DONE. No tools.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:24.188Z","updatedAt":"2026-10-27T14:24:24.188Z"},{"notification":{"source":{"kind":"command"},"outcome":"completed","summary":"Command \"/bin/bash -lc \"node -e 'setTimeout(()=>console.log(\\\"CODEX_BACKGROUND_17885_DON…\" finished (exit 0)","detail":"/bin/bash -lc \"node -e 'setTimeout(()=>console.log(\\\"CODEX_BACKGROUND_17885_DONE\\\"),45000)'\""},"createdBy":"agent","creationSource":"server","id":"message:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:1:16e3c6c1-8927-4e29-8dd9-979f6ff5c8b1","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:5","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A5:root","role":"user","text":"Background command completed (exit 0): /bin/bash -lc \"node -e 'setTimeout(()=>console.log(\\\"CODEX_BACKGROUND_17885_DONE\\\"),45000)'\"\n\nOutput tail:\nCODEX_BACKGROUND_17885_DONE","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:27.753Z","updatedAt":"2026-10-27T14:25:27.753Z"}],"subagents":[],"providerThreads":[{"id":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1","driver":"codex","providerInstanceId":"codex","providerSessionId":"provider-session:provider-instance:codex:shared","appThreadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","ownerNodeId":null,"nativeThreadRef":{"driver":"codex","nativeId":"01a17dbf-79ef-7c90-b227-4614d5023bd6","strength":"strong"},"nativeConversationHeadRef":null,"status":"active","firstRunOrdinal":1,"lastRunOrdinal":7,"handoffIds":[],"forkedFrom":null,"pendingBackgroundTasks":[],"contextUsage":{"usedTokens":22415,"maxTokens":258400},"nativeMetadata":null,"goal":null,"createdAt":"2026-10-27T14:24:20.885Z","updatedAt":"2026-10-27T14:26:01.231Z"}]}
2026-10-27T14:26:04.763Z PROJECTION 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scheduler evidence. Do not change files. Make 60 separate foreground Bash calls strictly sequentially, exactly one echo per call: echo initial-step-1 through echo initial-step-60. No loops, no background commands. After all calls reply INITIAL_DONE.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:20.885Z","updatedAt":"2026-10-27T14:24:20.885Z"},{"createdBy":"agent","creationSource":"mcp","id":"message:mcp:client%3A403306bf-8b12-4c21-8b83-a4274a2d202e:thread-send:e68ed982-aad7-4822-a5f9-4d4166e8cf71","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:3","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A3:root","role":"user","text":"Synthetic scheduler probe, no file edits. Use exec_command to run node -e 'setTimeout(()=>console.log(\"CODEX_BACKGROUND_17885_DONE\"),45000)' with yield_time_ms=1000. It must remain a running command session. Do not use a shell & or redirect. Do not poll or wait for it. Immediately end this turn with CODEX_ROOT_SETTLED. When a real later command-completion notification is delivered, reply exactly CODEX_DETAIL_ACK_17885 followed by the command result. Do not fabricate notifications.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:38.099Z","updatedAt":"2026-10-27T14:24:38.099Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b4299c10819aa33e4779dfefd048","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:3","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b4299c10819aa33e4779dfefd048","role":"assistant","text":"I’ll start the foreground Node timer as a persistent command session, then return immediately without polling it.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:41.681Z","updatedAt":"2026-10-27T14:24:42.113Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b42d1b30819a9fdea2a5e6fccfb3","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:3","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b42d1b30819a9fdea2a5e6fccfb3","role":"assistant","text":"CODEX_ROOT_SETTLED","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:45.195Z","updatedAt":"2026-10-27T14:24:45.218Z"},{"createdBy":"agent","creationSource":"mcp","id":"message:mcp:client%3A23308f20-1e1f-46cd-8b3a-788b4a7900cc:thread-send:0fd04def-0197-42bc-80c0-bd615180c894","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:4","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A4:root","role":"user","text":"Synthetic evidence active companion. Run node -e 'setTimeout(()=>console.log(\"CODEX_ACTIVE_17885_DONE\"),40000)' in exec_command with yield_time_ms=1000. Then write a 1500 word plain essay about serial queues. Do not poll the command session or wait. Do not change files. If a background command detail is already delivered acknowledge it once.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:55.341Z","updatedAt":"2026-10-27T14:24:55.341Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b439932c819ab7bb9fba46894634","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:4","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b439932c819ab7bb9fba46894634","role":"assistant","text":"I’ll launch the second timer as another persistent foreground session, won’t poll either session, and will use the remaining turn for the requested essay.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:57.606Z","updatedAt":"2026-10-27T14:24:57.835Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b43ecccc819ab970f50660380727","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:4","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b43ecccc819ab970f50660380727","role":"assistant","text":"A serial queue is one of the simplest ways to organize work in a computer system. Tasks enter the queue in some order, and a single worker processes them one at a time. The next task does not begin until the current task has finished, failed, or otherwise released control. This model can look unsophisticated beside thread pools, distributed schedulers, and highly concurrent pipelines, yet its simplicity gives it unusual power. A serial queue turns many difficult coordination problems into ordinary sequencing problems. When the order of operations matters, shared state must remain consistent, or predictability is more valuable than maximum throughput, serial execution is often the clearest design available.\n\nThe defining property of a serial queue is exclusivity. At most one queued task is executing through that queue at any moment. This does not necessarily mean the entire program uses only one thread, nor does it mean every operation is synchronous. A task might begin an asynchronous network request, register a callback, and yield the underlying thread. What matters is the queue’s completion rule. If the queue considers the task complete immediately after the request begins, later tasks may overlap with it. If completion is deferred until the callback arrives, the queue preserves strict logical serialization. Designers must therefore distinguish serial dispatch from serial completion. The former controls when code starts; the latter controls when effects are considered finished.\n\nOrdering is the most obvious benefit. Suppose an application receives commands to create an account, change its email address, and then delete it. If those commands execute concurrently, timing can produce strange outcomes: deletion may finish first, creation may overwrite it, or the email update may fail because the account temporarily does not exist. A serial queue processes the commands in their accepted order and makes the result easier to understand. The same principle applies to writing files, updating a local cache, advancing a workflow, applying database events, or controlling a physical device. The queue becomes a narrow channel through which state transitions occur in a deliberate sequence.\n\nSerial queues also provide a useful form of mutual exclusion. Traditional locking asks every piece of code that touches shared state to acquire and release the correct lock. This is efficient when done carefully, but careful locking is difficult. A forgotten lock creates a race, inconsistent lock ordering creates deadlock, and holding a lock across slow work can stall unrelated operations. Queue confinement offers another approach: shared mutable state belongs to one serial queue, and all access to that state is submitted as work. Since only one task runs at a time, state transitions cannot interleave unexpectedly. The queue acts as both scheduler and ownership boundary.\n\nThis ownership model improves reasoning. A developer can inspect a task and assume that no other task on the same queue is simultaneously changing the protected state. Invariants need to hold at task boundaries rather than at every individual instruction. Tests become more deterministic because fewer outcomes depend on thread timing. Logs naturally reflect a meaningful order. Failures can be tied to particular queue entries, and replay becomes possible when inputs are durable. Serial queues do not eliminate every bug, but they reduce the number of possible histories that a developer must consider.\n\nThe cost is limited throughput. A queue with one active worker cannot execute two independent tasks simultaneously, even when the machine has many available processors. One slow task delays everything behind it, a phenomenon often called head-of-line blocking. If a task waits thirty seconds for an external service, every later task waits as well when strict completion is required. The queue may grow faster than it drains, increasing latency and memory use. This tradeoff is fundamental: serialization buys order and isolation by giving up overlap. A successful design uses that bargain only where ordering or exclusivity is genuinely needed.\n\nQueue scope therefore matters. A single global serial queue is easy to construct but frequently too broad. If one customer’s slow operation blocks every other customer, unrelated work has been coupled unnecessarily. A better design may use one serial queue per account, document, device, or other natural ownership key. Tasks concerning the same key remain ordered, while tasks for different keys run concurrently. This pattern is sometimes called keyed serialization or partitioned queues. It preserves local consistency without sacrificing all system-wide parallelism. Choosing the partition key is an architectural decision because it defines which operations may safely overlap.\n\nFairness is another concern. A basic first-in, first-out queue treats arrival order as priority, which is often reasonable but not universally desirable. A stream of large background jobs can delay an urgent interactive action. Conversely, continually admitting urgent tasks can starve routine maintenance. Some systems use multiple serial queues with a higher-level scheduler that rotates among them. Others assign priorities, deadlines, or quotas. These policies complicate the clean FIFO model, but the core execution guarantee can remain intact: within the relevant domain, only one task runs at a time.\n\nError handling must be explicit. If a task throws an exception or returns a rejected promise, the queue should record the failure and decide whether subsequent work may continue. Automatically stopping the queue protects dependent operations from running after a broken prerequisite, but it can leave the system permanently wedged. Automatically continuing improves availability, but later tasks may encounter corrupted or incomplete state. A robust queue often classifies failures. Transient errors may trigger bounded retries with backoff. Permanent errors may move the task to a dead-letter store. Invariant violations may pause the queue and alert an operator. Whatever policy is chosen should be observable rather than implicit.\n\nCancellation presents similar questions. Removing a task that has not started is usually straightforward, provided no later task depends on it. Cancelling a running task is harder because arbitrary interruption can leave partial effects. Cooperative cancellation is safer: the task checks a signal at known points and performs cleanup before completing. For externally visible operations, cancellation may be impossible once a request has been accepted. In that case, the system may need a compensating task rather than pretending the original operation never happened. A queue preserves order, but it cannot make irreversible side effects reversible.\n\nBackpressure is essential when producers can outpace the consumer. An unbounded queue hides overload temporarily by accumulating work, then fails through excessive latency or memory exhaustion. A bounded queue makes capacity visible. Producers may block, receive a rejection, shed low-value work, or store tasks durably for later processing. Monitoring should include queue depth, oldest-task age, arrival rate, completion rate, execution duration, and failure count. Depth alone can mislead: ten millisecond-long tasks are harmless, while ten hour-long tasks may indicate a serious incident. Age and service time reveal the user-visible consequences more clearly.\n\nDurability separates in-memory serial queues from persistent job systems. An in-memory queue is fast and appropriate for coordinating state inside a process, but queued tasks disappear if that process crashes. A durable queue stores work before acknowledging acceptance and recovers unfinished tasks after restart. Durability introduces questions about delivery semantics. Most practical systems provide at-least-once execution, meaning a task may run again after ambiguous failure. Tasks must then be idempotent or carry deduplication keys. Exactly-once effects are difficult because the queue and the affected resource may fail independently. Serialization controls order; it does not by itself guarantee unique execution.\n\nReentrancy can cause subtle deadlocks. Imagine a task running on a serial queue that synchronously submits another task to the same queue and waits for its result. The inner task cannot start until the outer task finishes, while the outer task refuses to finish until the inner one runs. Queue APIs should discourage or detect this pattern. Code already executing within the queue can call an internal function directly, submit asynchronously without waiting, or use a reentrant execution rule where appropriate. The safest choice depends on whether immediate nested execution would violate the expected ordering.\n\nSerial queues are especially valuable at boundaries. A user interface often funnels state mutations through one event loop. An actor processes messages sequentially to protect its private state. A database uses ordered logs to establish a history of transactions. A device controller serializes commands because the hardware cannot perform conflicting motions at once. Even systems celebrated for concurrency frequently contain small islands of serialization. Concurrency happens between independent owners, while each owner processes its own stream in order. This combination is more scalable than either total serialization or unrestricted parallelism.\n\nTesting a serial queue should cover more than successful FIFO execution. Tests should confirm behavior after failure, cancellation, timeout, shutdown, and restart. They should verify that a task cannot overlap another task in the same partition and that different partitions can progress independently. Tests should exercise tasks that complete synchronously and asynchronously, because inconsistent completion handling is a common source of accidental concurrency. Shutdown deserves particular attention: the system must decide whether to drain queued work, reject new submissions, persist unfinished tasks, or terminate immediately. Clear lifecycle states prevent tasks from being silently lost.\n\nA serial queue is ultimately a tool for controlling histories. Concurrent systems permit many possible interleavings, and every additional interleaving increases the burden of reasoning, testing, and recovery. Serialization deliberately removes possibilities. That restraint can reduce raw speed, but it often improves correctness, operability, and human understanding. The best designs do not serialize everything. They identify the smallest domains in which order and exclusive ownership matter, place a queue around each domain, and allow concurrency between them. Used this way, the serial queue is not an outdated substitute for parallelism. It is one of the basic structures that makes safe parallelism possible.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:02.856Z","updatedAt":"2026-10-27T14:25:35.210Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b46744e0819ab5f92a182984bcc9","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:6","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b46744e0819ab5f92a182984bcc9","role":"assistant","text":"CODEX_DETAIL_ACK_17885\nCODEX_ACTIVE_17885_DONE","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:43.297Z","updatedAt":"2026-10-27T14:25:43.395Z"},{"createdBy":"user","creationSource":"web","id":"8761646d-95e5-41f4-8794-73e2013e532a","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:2","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A2:root","role":"user","text":"HELD_Q_17885: When explicitly released, reply exactly HELD_Q_DONE. No tools.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:24.188Z","updatedAt":"2026-10-27T14:24:24.188Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b47c71b8819aa241fd13084debfe","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:2","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b47c71b8819aa241fd13084debfe","role":"assistant","text":"HELD_Q_DONE","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:26:04.498Z","updatedAt":"2026-10-27T14:26:04.627Z"},{"notification":{"source":{"kind":"command"},"outcome":"completed","summary":"Command \"/bin/bash -lc \"node -e 'setTimeout(()=>console.log(\\\"CODEX_BACKGROUND_17885_DON…\" finished (exit 0)","detail":"/bin/bash -lc \"node -e 'setTimeout(()=>console.log(\\\"CODEX_BACKGROUND_17885_DONE\\\"),45000)'\""},"createdBy":"agent","creationSource":"server","id":"message:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:1:16e3c6c1-8927-4e29-8dd9-979f6ff5c8b1","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:5","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A5:root","role":"user","text":"Background command completed (exit 0): /bin/bash -lc \"node -e 'setTimeout(()=>console.log(\\\"CODEX_BACKGROUND_17885_DONE\\\"),45000)'\"\n\nOutput tail:\nCODEX_BACKGROUND_17885_DONE","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:27.753Z","updatedAt":"2026-10-27T14:25:27.753Z"}],"subagents":[],"providerThreads":[{"id":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1","driver":"codex","providerInstanceId":"codex","providerSessionId":"provider-session:provider-instance:codex:shared","appThreadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","ownerNodeId":null,"nativeThreadRef":{"driver":"codex","nativeId":"01a17dbf-79ef-7c90-b227-4614d5023bd6","strength":"strong"},"nativeConversationHeadRef":null,"status":"active","firstRunOrdinal":1,"lastRunOrdinal":7,"handoffIds":[],"forkedFrom":null,"pendingBackgroundTasks":[],"contextUsage":{"usedTokens":22415,"maxTokens":258400},"nativeMetadata":null,"goal":null,"createdAt":"2026-10-27T14:24:20.885Z","updatedAt":"2026-10-27T14:26:01.231Z"}]}
2026-10-27T14:26:05.095Z PROJECTION 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scheduler evidence. Do not change files. Make 60 separate foreground Bash calls strictly sequentially, exactly one echo per call: echo initial-step-1 through echo initial-step-60. No loops, no background commands. After all calls reply INITIAL_DONE.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:20.885Z","updatedAt":"2026-10-27T14:24:20.885Z"},{"createdBy":"agent","creationSource":"mcp","id":"message:mcp:client%3A403306bf-8b12-4c21-8b83-a4274a2d202e:thread-send:e68ed982-aad7-4822-a5f9-4d4166e8cf71","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:3","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A3:root","role":"user","text":"Synthetic scheduler probe, no file edits. Use exec_command to run node -e 'setTimeout(()=>console.log(\"CODEX_BACKGROUND_17885_DONE\"),45000)' with yield_time_ms=1000. It must remain a running command session. Do not use a shell & or redirect. Do not poll or wait for it. Immediately end this turn with CODEX_ROOT_SETTLED. When a real later command-completion notification is delivered, reply exactly CODEX_DETAIL_ACK_17885 followed by the command result. Do not fabricate notifications.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:38.099Z","updatedAt":"2026-10-27T14:24:38.099Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b4299c10819aa33e4779dfefd048","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:3","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b4299c10819aa33e4779dfefd048","role":"assistant","text":"I’ll start the foreground Node timer as a persistent command session, then return immediately without polling it.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:41.681Z","updatedAt":"2026-10-27T14:24:42.113Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b42d1b30819a9fdea2a5e6fccfb3","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:3","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b42d1b30819a9fdea2a5e6fccfb3","role":"assistant","text":"CODEX_ROOT_SETTLED","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:45.195Z","updatedAt":"2026-10-27T14:24:45.218Z"},{"createdBy":"agent","creationSource":"mcp","id":"message:mcp:client%3A23308f20-1e1f-46cd-8b3a-788b4a7900cc:thread-send:0fd04def-0197-42bc-80c0-bd615180c894","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:4","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A4:root","role":"user","text":"Synthetic evidence active companion. Run node -e 'setTimeout(()=>console.log(\"CODEX_ACTIVE_17885_DONE\"),40000)' in exec_command with yield_time_ms=1000. Then write a 1500 word plain essay about serial queues. Do not poll the command session or wait. Do not change files. If a background command detail is already delivered acknowledge it once.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:55.341Z","updatedAt":"2026-10-27T14:24:55.341Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b439932c819ab7bb9fba46894634","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:4","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b439932c819ab7bb9fba46894634","role":"assistant","text":"I’ll launch the second timer as another persistent foreground session, won’t poll either session, and will use the remaining turn for the requested essay.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:57.606Z","updatedAt":"2026-10-27T14:24:57.835Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b43ecccc819ab970f50660380727","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:4","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b43ecccc819ab970f50660380727","role":"assistant","text":"A serial queue is one of the simplest ways to organize work in a computer system. Tasks enter the queue in some order, and a single worker processes them one at a time. The next task does not begin until the current task has finished, failed, or otherwise released control. This model can look unsophisticated beside thread pools, distributed schedulers, and highly concurrent pipelines, yet its simplicity gives it unusual power. A serial queue turns many difficult coordination problems into ordinary sequencing problems. When the order of operations matters, shared state must remain consistent, or predictability is more valuable than maximum throughput, serial execution is often the clearest design available.\n\nThe defining property of a serial queue is exclusivity. At most one queued task is executing through that queue at any moment. This does not necessarily mean the entire program uses only one thread, nor does it mean every operation is synchronous. A task might begin an asynchronous network request, register a callback, and yield the underlying thread. What matters is the queue’s completion rule. If the queue considers the task complete immediately after the request begins, later tasks may overlap with it. If completion is deferred until the callback arrives, the queue preserves strict logical serialization. Designers must therefore distinguish serial dispatch from serial completion. The former controls when code starts; the latter controls when effects are considered finished.\n\nOrdering is the most obvious benefit. Suppose an application receives commands to create an account, change its email address, and then delete it. If those commands execute concurrently, timing can produce strange outcomes: deletion may finish first, creation may overwrite it, or the email update may fail because the account temporarily does not exist. A serial queue processes the commands in their accepted order and makes the result easier to understand. The same principle applies to writing files, updating a local cache, advancing a workflow, applying database events, or controlling a physical device. The queue becomes a narrow channel through which state transitions occur in a deliberate sequence.\n\nSerial queues also provide a useful form of mutual exclusion. Traditional locking asks every piece of code that touches shared state to acquire and release the correct lock. This is efficient when done carefully, but careful locking is difficult. A forgotten lock creates a race, inconsistent lock ordering creates deadlock, and holding a lock across slow work can stall unrelated operations. Queue confinement offers another approach: shared mutable state belongs to one serial queue, and all access to that state is submitted as work. Since only one task runs at a time, state transitions cannot interleave unexpectedly. The queue acts as both scheduler and ownership boundary.\n\nThis ownership model improves reasoning. A developer can inspect a task and assume that no other task on the same queue is simultaneously changing the protected state. Invariants need to hold at task boundaries rather than at every individual instruction. Tests become more deterministic because fewer outcomes depend on thread timing. Logs naturally reflect a meaningful order. Failures can be tied to particular queue entries, and replay becomes possible when inputs are durable. Serial queues do not eliminate every bug, but they reduce the number of possible histories that a developer must consider.\n\nThe cost is limited throughput. A queue with one active worker cannot execute two independent tasks simultaneously, even when the machine has many available processors. One slow task delays everything behind it, a phenomenon often called head-of-line blocking. If a task waits thirty seconds for an external service, every later task waits as well when strict completion is required. The queue may grow faster than it drains, increasing latency and memory use. This tradeoff is fundamental: serialization buys order and isolation by giving up overlap. A successful design uses that bargain only where ordering or exclusivity is genuinely needed.\n\nQueue scope therefore matters. A single global serial queue is easy to construct but frequently too broad. If one customer’s slow operation blocks every other customer, unrelated work has been coupled unnecessarily. A better design may use one serial queue per account, document, device, or other natural ownership key. Tasks concerning the same key remain ordered, while tasks for different keys run concurrently. This pattern is sometimes called keyed serialization or partitioned queues. It preserves local consistency without sacrificing all system-wide parallelism. Choosing the partition key is an architectural decision because it defines which operations may safely overlap.\n\nFairness is another concern. A basic first-in, first-out queue treats arrival order as priority, which is often reasonable but not universally desirable. A stream of large background jobs can delay an urgent interactive action. Conversely, continually admitting urgent tasks can starve routine maintenance. Some systems use multiple serial queues with a higher-level scheduler that rotates among them. Others assign priorities, deadlines, or quotas. These policies complicate the clean FIFO model, but the core execution guarantee can remain intact: within the relevant domain, only one task runs at a time.\n\nError handling must be explicit. If a task throws an exception or returns a rejected promise, the queue should record the failure and decide whether subsequent work may continue. Automatically stopping the queue protects dependent operations from running after a broken prerequisite, but it can leave the system permanently wedged. Automatically continuing improves availability, but later tasks may encounter corrupted or incomplete state. A robust queue often classifies failures. Transient errors may trigger bounded retries with backoff. Permanent errors may move the task to a dead-letter store. Invariant violations may pause the queue and alert an operator. Whatever policy is chosen should be observable rather than implicit.\n\nCancellation presents similar questions. Removing a task that has not started is usually straightforward, provided no later task depends on it. Cancelling a running task is harder because arbitrary interruption can leave partial effects. Cooperative cancellation is safer: the task checks a signal at known points and performs cleanup before completing. For externally visible operations, cancellation may be impossible once a request has been accepted. In that case, the system may need a compensating task rather than pretending the original operation never happened. A queue preserves order, but it cannot make irreversible side effects reversible.\n\nBackpressure is essential when producers can outpace the consumer. An unbounded queue hides overload temporarily by accumulating work, then fails through excessive latency or memory exhaustion. A bounded queue makes capacity visible. Producers may block, receive a rejection, shed low-value work, or store tasks durably for later processing. Monitoring should include queue depth, oldest-task age, arrival rate, completion rate, execution duration, and failure count. Depth alone can mislead: ten millisecond-long tasks are harmless, while ten hour-long tasks may indicate a serious incident. Age and service time reveal the user-visible consequences more clearly.\n\nDurability separates in-memory serial queues from persistent job systems. An in-memory queue is fast and appropriate for coordinating state inside a process, but queued tasks disappear if that process crashes. A durable queue stores work before acknowledging acceptance and recovers unfinished tasks after restart. Durability introduces questions about delivery semantics. Most practical systems provide at-least-once execution, meaning a task may run again after ambiguous failure. Tasks must then be idempotent or carry deduplication keys. Exactly-once effects are difficult because the queue and the affected resource may fail independently. Serialization controls order; it does not by itself guarantee unique execution.\n\nReentrancy can cause subtle deadlocks. Imagine a task running on a serial queue that synchronously submits another task to the same queue and waits for its result. The inner task cannot start until the outer task finishes, while the outer task refuses to finish until the inner one runs. Queue APIs should discourage or detect this pattern. Code already executing within the queue can call an internal function directly, submit asynchronously without waiting, or use a reentrant execution rule where appropriate. The safest choice depends on whether immediate nested execution would violate the expected ordering.\n\nSerial queues are especially valuable at boundaries. A user interface often funnels state mutations through one event loop. An actor processes messages sequentially to protect its private state. A database uses ordered logs to establish a history of transactions. A device controller serializes commands because the hardware cannot perform conflicting motions at once. Even systems celebrated for concurrency frequently contain small islands of serialization. Concurrency happens between independent owners, while each owner processes its own stream in order. This combination is more scalable than either total serialization or unrestricted parallelism.\n\nTesting a serial queue should cover more than successful FIFO execution. Tests should confirm behavior after failure, cancellation, timeout, shutdown, and restart. They should verify that a task cannot overlap another task in the same partition and that different partitions can progress independently. Tests should exercise tasks that complete synchronously and asynchronously, because inconsistent completion handling is a common source of accidental concurrency. Shutdown deserves particular attention: the system must decide whether to drain queued work, reject new submissions, persist unfinished tasks, or terminate immediately. Clear lifecycle states prevent tasks from being silently lost.\n\nA serial queue is ultimately a tool for controlling histories. Concurrent systems permit many possible interleavings, and every additional interleaving increases the burden of reasoning, testing, and recovery. Serialization deliberately removes possibilities. That restraint can reduce raw speed, but it often improves correctness, operability, and human understanding. The best designs do not serialize everything. They identify the smallest domains in which order and exclusive ownership matter, place a queue around each domain, and allow concurrency between them. Used this way, the serial queue is not an outdated substitute for parallelism. It is one of the basic structures that makes safe parallelism possible.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:02.856Z","updatedAt":"2026-10-27T14:25:35.210Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b46744e0819ab5f92a182984bcc9","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:6","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b46744e0819ab5f92a182984bcc9","role":"assistant","text":"CODEX_DETAIL_ACK_17885\nCODEX_ACTIVE_17885_DONE","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:43.297Z","updatedAt":"2026-10-27T14:25:43.395Z"},{"createdBy":"user","creationSource":"web","id":"8761646d-95e5-41f4-8794-73e2013e532a","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:2","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A2:root","role":"user","text":"HELD_Q_17885: When explicitly released, reply exactly HELD_Q_DONE. No tools.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:24.188Z","updatedAt":"2026-10-27T14:24:24.188Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b47c71b8819aa241fd13084debfe","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:2","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b47c71b8819aa241fd13084debfe","role":"assistant","text":"HELD_Q_DONE","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:26:04.498Z","updatedAt":"2026-10-27T14:26:04.627Z"},{"notification":{"source":{"kind":"command"},"outcome":"completed","summary":"Command \"/bin/bash -lc \"node -e 'setTimeout(()=>console.log(\\\"CODEX_BACKGROUND_17885_DON…\" finished (exit 0)","detail":"/bin/bash -lc \"node -e 'setTimeout(()=>console.log(\\\"CODEX_BACKGROUND_17885_DONE\\\"),45000)'\""},"createdBy":"agent","creationSource":"server","id":"message:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:1:16e3c6c1-8927-4e29-8dd9-979f6ff5c8b1","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:5","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A5:root","role":"user","text":"Background command completed (exit 0): /bin/bash -lc \"node -e 'setTimeout(()=>console.log(\\\"CODEX_BACKGROUND_17885_DONE\\\"),45000)'\"\n\nOutput tail:\nCODEX_BACKGROUND_17885_DONE","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:27.753Z","updatedAt":"2026-10-27T14:25:27.753Z"}],"subagents":[],"providerThreads":[{"id":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1","driver":"codex","providerInstanceId":"codex","providerSessionId":"provider-session:provider-instance:codex:shared","appThreadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","ownerNodeId":null,"nativeThreadRef":{"driver":"codex","nativeId":"01a17dbf-79ef-7c90-b227-4614d5023bd6","strength":"strong"},"nativeConversationHeadRef":null,"status":"idle","firstRunOrdinal":1,"lastRunOrdinal":7,"handoffIds":[],"forkedFrom":null,"pendingBackgroundTasks":[],"contextUsage":{"usedTokens":22415,"maxTokens":258400},"nativeMetadata":null,"goal":null,"createdAt":"2026-10-27T14:24:20.885Z","updatedAt":"2026-10-27T14:26:04.880Z"}]}
2026-10-27T14:26:07.620Z PROJECTION 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scheduler evidence. Do not change files. Make 60 separate foreground Bash calls strictly sequentially, exactly one echo per call: echo initial-step-1 through echo initial-step-60. No loops, no background commands. After all calls reply INITIAL_DONE.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:20.885Z","updatedAt":"2026-10-27T14:24:20.885Z"},{"createdBy":"agent","creationSource":"mcp","id":"message:mcp:client%3A403306bf-8b12-4c21-8b83-a4274a2d202e:thread-send:e68ed982-aad7-4822-a5f9-4d4166e8cf71","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:3","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A3:root","role":"user","text":"Synthetic scheduler probe, no file edits. Use exec_command to run node -e 'setTimeout(()=>console.log(\"CODEX_BACKGROUND_17885_DONE\"),45000)' with yield_time_ms=1000. It must remain a running command session. Do not use a shell & or redirect. Do not poll or wait for it. Immediately end this turn with CODEX_ROOT_SETTLED. When a real later command-completion notification is delivered, reply exactly CODEX_DETAIL_ACK_17885 followed by the command result. Do not fabricate notifications.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:38.099Z","updatedAt":"2026-10-27T14:24:38.099Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b4299c10819aa33e4779dfefd048","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:3","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b4299c10819aa33e4779dfefd048","role":"assistant","text":"I’ll start the foreground Node timer as a persistent command session, then return immediately without polling it.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:41.681Z","updatedAt":"2026-10-27T14:24:42.113Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b42d1b30819a9fdea2a5e6fccfb3","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:3","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b42d1b30819a9fdea2a5e6fccfb3","role":"assistant","text":"CODEX_ROOT_SETTLED","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:45.195Z","updatedAt":"2026-10-27T14:24:45.218Z"},{"createdBy":"agent","creationSource":"mcp","id":"message:mcp:client%3A23308f20-1e1f-46cd-8b3a-788b4a7900cc:thread-send:0fd04def-0197-42bc-80c0-bd615180c894","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:4","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A4:root","role":"user","text":"Synthetic evidence active companion. Run node -e 'setTimeout(()=>console.log(\"CODEX_ACTIVE_17885_DONE\"),40000)' in exec_command with yield_time_ms=1000. Then write a 1500 word plain essay about serial queues. Do not poll the command session or wait. Do not change files. If a background command detail is already delivered acknowledge it once.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:55.341Z","updatedAt":"2026-10-27T14:24:55.341Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b439932c819ab7bb9fba46894634","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:4","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b439932c819ab7bb9fba46894634","role":"assistant","text":"I’ll launch the second timer as another persistent foreground session, won’t poll either session, and will use the remaining turn for the requested essay.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:57.606Z","updatedAt":"2026-10-27T14:24:57.835Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b43ecccc819ab970f50660380727","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:4","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b43ecccc819ab970f50660380727","role":"assistant","text":"A serial queue is one of the simplest ways to organize work in a computer system. Tasks enter the queue in some order, and a single worker processes them one at a time. The next task does not begin until the current task has finished, failed, or otherwise released control. This model can look unsophisticated beside thread pools, distributed schedulers, and highly concurrent pipelines, yet its simplicity gives it unusual power. A serial queue turns many difficult coordination problems into ordinary sequencing problems. When the order of operations matters, shared state must remain consistent, or predictability is more valuable than maximum throughput, serial execution is often the clearest design available.\n\nThe defining property of a serial queue is exclusivity. At most one queued task is executing through that queue at any moment. This does not necessarily mean the entire program uses only one thread, nor does it mean every operation is synchronous. A task might begin an asynchronous network request, register a callback, and yield the underlying thread. What matters is the queue’s completion rule. If the queue considers the task complete immediately after the request begins, later tasks may overlap with it. If completion is deferred until the callback arrives, the queue preserves strict logical serialization. Designers must therefore distinguish serial dispatch from serial completion. The former controls when code starts; the latter controls when effects are considered finished.\n\nOrdering is the most obvious benefit. Suppose an application receives commands to create an account, change its email address, and then delete it. If those commands execute concurrently, timing can produce strange outcomes: deletion may finish first, creation may overwrite it, or the email update may fail because the account temporarily does not exist. A serial queue processes the commands in their accepted order and makes the result easier to understand. The same principle applies to writing files, updating a local cache, advancing a workflow, applying database events, or controlling a physical device. The queue becomes a narrow channel through which state transitions occur in a deliberate sequence.\n\nSerial queues also provide a useful form of mutual exclusion. Traditional locking asks every piece of code that touches shared state to acquire and release the correct lock. This is efficient when done carefully, but careful locking is difficult. A forgotten lock creates a race, inconsistent lock ordering creates deadlock, and holding a lock across slow work can stall unrelated operations. Queue confinement offers another approach: shared mutable state belongs to one serial queue, and all access to that state is submitted as work. Since only one task runs at a time, state transitions cannot interleave unexpectedly. The queue acts as both scheduler and ownership boundary.\n\nThis ownership model improves reasoning. A developer can inspect a task and assume that no other task on the same queue is simultaneously changing the protected state. Invariants need to hold at task boundaries rather than at every individual instruction. Tests become more deterministic because fewer outcomes depend on thread timing. Logs naturally reflect a meaningful order. Failures can be tied to particular queue entries, and replay becomes possible when inputs are durable. Serial queues do not eliminate every bug, but they reduce the number of possible histories that a developer must consider.\n\nThe cost is limited throughput. A queue with one active worker cannot execute two independent tasks simultaneously, even when the machine has many available processors. One slow task delays everything behind it, a phenomenon often called head-of-line blocking. If a task waits thirty seconds for an external service, every later task waits as well when strict completion is required. The queue may grow faster than it drains, increasing latency and memory use. This tradeoff is fundamental: serialization buys order and isolation by giving up overlap. A successful design uses that bargain only where ordering or exclusivity is genuinely needed.\n\nQueue scope therefore matters. A single global serial queue is easy to construct but frequently too broad. If one customer’s slow operation blocks every other customer, unrelated work has been coupled unnecessarily. A better design may use one serial queue per account, document, device, or other natural ownership key. Tasks concerning the same key remain ordered, while tasks for different keys run concurrently. This pattern is sometimes called keyed serialization or partitioned queues. It preserves local consistency without sacrificing all system-wide parallelism. Choosing the partition key is an architectural decision because it defines which operations may safely overlap.\n\nFairness is another concern. A basic first-in, first-out queue treats arrival order as priority, which is often reasonable but not universally desirable. A stream of large background jobs can delay an urgent interactive action. Conversely, continually admitting urgent tasks can starve routine maintenance. Some systems use multiple serial queues with a higher-level scheduler that rotates among them. Others assign priorities, deadlines, or quotas. These policies complicate the clean FIFO model, but the core execution guarantee can remain intact: within the relevant domain, only one task runs at a time.\n\nError handling must be explicit. If a task throws an exception or returns a rejected promise, the queue should record the failure and decide whether subsequent work may continue. Automatically stopping the queue protects dependent operations from running after a broken prerequisite, but it can leave the system permanently wedged. Automatically continuing improves availability, but later tasks may encounter corrupted or incomplete state. A robust queue often classifies failures. Transient errors may trigger bounded retries with backoff. Permanent errors may move the task to a dead-letter store. Invariant violations may pause the queue and alert an operator. Whatever policy is chosen should be observable rather than implicit.\n\nCancellation presents similar questions. Removing a task that has not started is usually straightforward, provided no later task depends on it. Cancelling a running task is harder because arbitrary interruption can leave partial effects. Cooperative cancellation is safer: the task checks a signal at known points and performs cleanup before completing. For externally visible operations, cancellation may be impossible once a request has been accepted. In that case, the system may need a compensating task rather than pretending the original operation never happened. A queue preserves order, but it cannot make irreversible side effects reversible.\n\nBackpressure is essential when producers can outpace the consumer. An unbounded queue hides overload temporarily by accumulating work, then fails through excessive latency or memory exhaustion. A bounded queue makes capacity visible. Producers may block, receive a rejection, shed low-value work, or store tasks durably for later processing. Monitoring should include queue depth, oldest-task age, arrival rate, completion rate, execution duration, and failure count. Depth alone can mislead: ten millisecond-long tasks are harmless, while ten hour-long tasks may indicate a serious incident. Age and service time reveal the user-visible consequences more clearly.\n\nDurability separates in-memory serial queues from persistent job systems. An in-memory queue is fast and appropriate for coordinating state inside a process, but queued tasks disappear if that process crashes. A durable queue stores work before acknowledging acceptance and recovers unfinished tasks after restart. Durability introduces questions about delivery semantics. Most practical systems provide at-least-once execution, meaning a task may run again after ambiguous failure. Tasks must then be idempotent or carry deduplication keys. Exactly-once effects are difficult because the queue and the affected resource may fail independently. Serialization controls order; it does not by itself guarantee unique execution.\n\nReentrancy can cause subtle deadlocks. Imagine a task running on a serial queue that synchronously submits another task to the same queue and waits for its result. The inner task cannot start until the outer task finishes, while the outer task refuses to finish until the inner one runs. Queue APIs should discourage or detect this pattern. Code already executing within the queue can call an internal function directly, submit asynchronously without waiting, or use a reentrant execution rule where appropriate. The safest choice depends on whether immediate nested execution would violate the expected ordering.\n\nSerial queues are especially valuable at boundaries. A user interface often funnels state mutations through one event loop. An actor processes messages sequentially to protect its private state. A database uses ordered logs to establish a history of transactions. A device controller serializes commands because the hardware cannot perform conflicting motions at once. Even systems celebrated for concurrency frequently contain small islands of serialization. Concurrency happens between independent owners, while each owner processes its own stream in order. This combination is more scalable than either total serialization or unrestricted parallelism.\n\nTesting a serial queue should cover more than successful FIFO execution. Tests should confirm behavior after failure, cancellation, timeout, shutdown, and restart. They should verify that a task cannot overlap another task in the same partition and that different partitions can progress independently. Tests should exercise tasks that complete synchronously and asynchronously, because inconsistent completion handling is a common source of accidental concurrency. Shutdown deserves particular attention: the system must decide whether to drain queued work, reject new submissions, persist unfinished tasks, or terminate immediately. Clear lifecycle states prevent tasks from being silently lost.\n\nA serial queue is ultimately a tool for controlling histories. Concurrent systems permit many possible interleavings, and every additional interleaving increases the burden of reasoning, testing, and recovery. Serialization deliberately removes possibilities. That restraint can reduce raw speed, but it often improves correctness, operability, and human understanding. The best designs do not serialize everything. They identify the smallest domains in which order and exclusive ownership matter, place a queue around each domain, and allow concurrency between them. Used this way, the serial queue is not an outdated substitute for parallelism. It is one of the basic structures that makes safe parallelism possible.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:02.856Z","updatedAt":"2026-10-27T14:25:35.210Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b46744e0819ab5f92a182984bcc9","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:6","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b46744e0819ab5f92a182984bcc9","role":"assistant","text":"CODEX_DETAIL_ACK_17885\nCODEX_ACTIVE_17885_DONE","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:43.297Z","updatedAt":"2026-10-27T14:25:43.395Z"},{"createdBy":"user","creationSource":"web","id":"8761646d-95e5-41f4-8794-73e2013e532a","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:2","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A2:root","role":"user","text":"HELD_Q_17885: When explicitly released, reply exactly HELD_Q_DONE. No tools.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:24.188Z","updatedAt":"2026-10-27T14:24:24.188Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b47c71b8819aa241fd13084debfe","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:2","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b47c71b8819aa241fd13084debfe","role":"assistant","text":"HELD_Q_DONE","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:26:04.498Z","updatedAt":"2026-10-27T14:26:04.627Z"},{"notification":{"source":{"kind":"command"},"outcome":"completed","summary":"Command \"/bin/bash -lc \"node -e 'setTimeout(()=>console.log(\\\"CODEX_BACKGROUND_17885_DON…\" finished (exit 0)","detail":"/bin/bash -lc \"node -e 'setTimeout(()=>console.log(\\\"CODEX_BACKGROUND_17885_DONE\\\"),45000)'\""},"createdBy":"agent","creationSource":"server","id":"message:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:1:16e3c6c1-8927-4e29-8dd9-979f6ff5c8b1","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:5","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A5:root","role":"user","text":"Background command completed (exit 0): /bin/bash -lc \"node -e 'setTimeout(()=>console.log(\\\"CODEX_BACKGROUND_17885_DONE\\\"),45000)'\"\n\nOutput tail:\nCODEX_BACKGROUND_17885_DONE","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:27.753Z","updatedAt":"2026-10-27T14:25:27.753Z"}],"subagents":[],"providerThreads":[{"id":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1","driver":"codex","providerInstanceId":"codex","providerSessionId":"provider-session:provider-instance:codex:shared","appThreadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","ownerNodeId":null,"nativeThreadRef":{"driver":"codex","nativeId":"01a17dbf-79ef-7c90-b227-4614d5023bd6","strength":"strong"},"nativeConversationHeadRef":null,"status":"idle","firstRunOrdinal":1,"lastRunOrdinal":7,"handoffIds":[],"forkedFrom":null,"pendingBackgroundTasks":[],"contextUsage":{"usedTokens":22415,"maxTokens":258400},"nativeMetadata":null,"goal":null,"createdAt":"2026-10-27T14:24:20.885Z","updatedAt":"2026-10-27T14:26:04.880Z"}]}
2026-10-27T14:26:07.654Z PROJECTION 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scheduler evidence. Do not change files. Make 60 separate foreground Bash calls strictly sequentially, exactly one echo per call: echo initial-step-1 through echo initial-step-60. No loops, no background commands. After all calls reply INITIAL_DONE.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:20.885Z","updatedAt":"2026-10-27T14:24:20.885Z"},{"createdBy":"agent","creationSource":"mcp","id":"message:mcp:client%3A403306bf-8b12-4c21-8b83-a4274a2d202e:thread-send:e68ed982-aad7-4822-a5f9-4d4166e8cf71","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:3","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A3:root","role":"user","text":"Synthetic scheduler probe, no file edits. Use exec_command to run node -e 'setTimeout(()=>console.log(\"CODEX_BACKGROUND_17885_DONE\"),45000)' with yield_time_ms=1000. It must remain a running command session. Do not use a shell & or redirect. Do not poll or wait for it. Immediately end this turn with CODEX_ROOT_SETTLED. When a real later command-completion notification is delivered, reply exactly CODEX_DETAIL_ACK_17885 followed by the command result. Do not fabricate notifications.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:38.099Z","updatedAt":"2026-10-27T14:24:38.099Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b4299c10819aa33e4779dfefd048","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:3","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b4299c10819aa33e4779dfefd048","role":"assistant","text":"I’ll start the foreground Node timer as a persistent command session, then return immediately without polling it.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:41.681Z","updatedAt":"2026-10-27T14:24:42.113Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b42d1b30819a9fdea2a5e6fccfb3","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:3","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b42d1b30819a9fdea2a5e6fccfb3","role":"assistant","text":"CODEX_ROOT_SETTLED","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:45.195Z","updatedAt":"2026-10-27T14:24:45.218Z"},{"createdBy":"agent","creationSource":"mcp","id":"message:mcp:client%3A23308f20-1e1f-46cd-8b3a-788b4a7900cc:thread-send:0fd04def-0197-42bc-80c0-bd615180c894","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:4","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A4:root","role":"user","text":"Synthetic evidence active companion. Run node -e 'setTimeout(()=>console.log(\"CODEX_ACTIVE_17885_DONE\"),40000)' in exec_command with yield_time_ms=1000. Then write a 1500 word plain essay about serial queues. Do not poll the command session or wait. Do not change files. If a background command detail is already delivered acknowledge it once.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:55.341Z","updatedAt":"2026-10-27T14:24:55.341Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b439932c819ab7bb9fba46894634","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:4","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b439932c819ab7bb9fba46894634","role":"assistant","text":"I’ll launch the second timer as another persistent foreground session, won’t poll either session, and will use the remaining turn for the requested essay.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:57.606Z","updatedAt":"2026-10-27T14:24:57.835Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b43ecccc819ab970f50660380727","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:4","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b43ecccc819ab970f50660380727","role":"assistant","text":"A serial queue is one of the simplest ways to organize work in a computer system. Tasks enter the queue in some order, and a single worker processes them one at a time. The next task does not begin until the current task has finished, failed, or otherwise released control. This model can look unsophisticated beside thread pools, distributed schedulers, and highly concurrent pipelines, yet its simplicity gives it unusual power. A serial queue turns many difficult coordination problems into ordinary sequencing problems. When the order of operations matters, shared state must remain consistent, or predictability is more valuable than maximum throughput, serial execution is often the clearest design available.\n\nThe defining property of a serial queue is exclusivity. At most one queued task is executing through that queue at any moment. This does not necessarily mean the entire program uses only one thread, nor does it mean every operation is synchronous. A task might begin an asynchronous network request, register a callback, and yield the underlying thread. What matters is the queue’s completion rule. If the queue considers the task complete immediately after the request begins, later tasks may overlap with it. If completion is deferred until the callback arrives, the queue preserves strict logical serialization. Designers must therefore distinguish serial dispatch from serial completion. The former controls when code starts; the latter controls when effects are considered finished.\n\nOrdering is the most obvious benefit. Suppose an application receives commands to create an account, change its email address, and then delete it. If those commands execute concurrently, timing can produce strange outcomes: deletion may finish first, creation may overwrite it, or the email update may fail because the account temporarily does not exist. A serial queue processes the commands in their accepted order and makes the result easier to understand. The same principle applies to writing files, updating a local cache, advancing a workflow, applying database events, or controlling a physical device. The queue becomes a narrow channel through which state transitions occur in a deliberate sequence.\n\nSerial queues also provide a useful form of mutual exclusion. Traditional locking asks every piece of code that touches shared state to acquire and release the correct lock. This is efficient when done carefully, but careful locking is difficult. A forgotten lock creates a race, inconsistent lock ordering creates deadlock, and holding a lock across slow work can stall unrelated operations. Queue confinement offers another approach: shared mutable state belongs to one serial queue, and all access to that state is submitted as work. Since only one task runs at a time, state transitions cannot interleave unexpectedly. The queue acts as both scheduler and ownership boundary.\n\nThis ownership model improves reasoning. A developer can inspect a task and assume that no other task on the same queue is simultaneously changing the protected state. Invariants need to hold at task boundaries rather than at every individual instruction. Tests become more deterministic because fewer outcomes depend on thread timing. Logs naturally reflect a meaningful order. Failures can be tied to particular queue entries, and replay becomes possible when inputs are durable. Serial queues do not eliminate every bug, but they reduce the number of possible histories that a developer must consider.\n\nThe cost is limited throughput. A queue with one active worker cannot execute two independent tasks simultaneously, even when the machine has many available processors. One slow task delays everything behind it, a phenomenon often called head-of-line blocking. If a task waits thirty seconds for an external service, every later task waits as well when strict completion is required. The queue may grow faster than it drains, increasing latency and memory use. This tradeoff is fundamental: serialization buys order and isolation by giving up overlap. A successful design uses that bargain only where ordering or exclusivity is genuinely needed.\n\nQueue scope therefore matters. A single global serial queue is easy to construct but frequently too broad. If one customer’s slow operation blocks every other customer, unrelated work has been coupled unnecessarily. A better design may use one serial queue per account, document, device, or other natural ownership key. Tasks concerning the same key remain ordered, while tasks for different keys run concurrently. This pattern is sometimes called keyed serialization or partitioned queues. It preserves local consistency without sacrificing all system-wide parallelism. Choosing the partition key is an architectural decision because it defines which operations may safely overlap.\n\nFairness is another concern. A basic first-in, first-out queue treats arrival order as priority, which is often reasonable but not universally desirable. A stream of large background jobs can delay an urgent interactive action. Conversely, continually admitting urgent tasks can starve routine maintenance. Some systems use multiple serial queues with a higher-level scheduler that rotates among them. Others assign priorities, deadlines, or quotas. These policies complicate the clean FIFO model, but the core execution guarantee can remain intact: within the relevant domain, only one task runs at a time.\n\nError handling must be explicit. If a task throws an exception or returns a rejected promise, the queue should record the failure and decide whether subsequent work may continue. Automatically stopping the queue protects dependent operations from running after a broken prerequisite, but it can leave the system permanently wedged. Automatically continuing improves availability, but later tasks may encounter corrupted or incomplete state. A robust queue often classifies failures. Transient errors may trigger bounded retries with backoff. Permanent errors may move the task to a dead-letter store. Invariant violations may pause the queue and alert an operator. Whatever policy is chosen should be observable rather than implicit.\n\nCancellation presents similar questions. Removing a task that has not started is usually straightforward, provided no later task depends on it. Cancelling a running task is harder because arbitrary interruption can leave partial effects. Cooperative cancellation is safer: the task checks a signal at known points and performs cleanup before completing. For externally visible operations, cancellation may be impossible once a request has been accepted. In that case, the system may need a compensating task rather than pretending the original operation never happened. A queue preserves order, but it cannot make irreversible side effects reversible.\n\nBackpressure is essential when producers can outpace the consumer. An unbounded queue hides overload temporarily by accumulating work, then fails through excessive latency or memory exhaustion. A bounded queue makes capacity visible. Producers may block, receive a rejection, shed low-value work, or store tasks durably for later processing. Monitoring should include queue depth, oldest-task age, arrival rate, completion rate, execution duration, and failure count. Depth alone can mislead: ten millisecond-long tasks are harmless, while ten hour-long tasks may indicate a serious incident. Age and service time reveal the user-visible consequences more clearly.\n\nDurability separates in-memory serial queues from persistent job systems. An in-memory queue is fast and appropriate for coordinating state inside a process, but queued tasks disappear if that process crashes. A durable queue stores work before acknowledging acceptance and recovers unfinished tasks after restart. Durability introduces questions about delivery semantics. Most practical systems provide at-least-once execution, meaning a task may run again after ambiguous failure. Tasks must then be idempotent or carry deduplication keys. Exactly-once effects are difficult because the queue and the affected resource may fail independently. Serialization controls order; it does not by itself guarantee unique execution.\n\nReentrancy can cause subtle deadlocks. Imagine a task running on a serial queue that synchronously submits another task to the same queue and waits for its result. The inner task cannot start until the outer task finishes, while the outer task refuses to finish until the inner one runs. Queue APIs should discourage or detect this pattern. Code already executing within the queue can call an internal function directly, submit asynchronously without waiting, or use a reentrant execution rule where appropriate. The safest choice depends on whether immediate nested execution would violate the expected ordering.\n\nSerial queues are especially valuable at boundaries. A user interface often funnels state mutations through one event loop. An actor processes messages sequentially to protect its private state. A database uses ordered logs to establish a history of transactions. A device controller serializes commands because the hardware cannot perform conflicting motions at once. Even systems celebrated for concurrency frequently contain small islands of serialization. Concurrency happens between independent owners, while each owner processes its own stream in order. This combination is more scalable than either total serialization or unrestricted parallelism.\n\nTesting a serial queue should cover more than successful FIFO execution. Tests should confirm behavior after failure, cancellation, timeout, shutdown, and restart. They should verify that a task cannot overlap another task in the same partition and that different partitions can progress independently. Tests should exercise tasks that complete synchronously and asynchronously, because inconsistent completion handling is a common source of accidental concurrency. Shutdown deserves particular attention: the system must decide whether to drain queued work, reject new submissions, persist unfinished tasks, or terminate immediately. Clear lifecycle states prevent tasks from being silently lost.\n\nA serial queue is ultimately a tool for controlling histories. Concurrent systems permit many possible interleavings, and every additional interleaving increases the burden of reasoning, testing, and recovery. Serialization deliberately removes possibilities. That restraint can reduce raw speed, but it often improves correctness, operability, and human understanding. The best designs do not serialize everything. They identify the smallest domains in which order and exclusive ownership matter, place a queue around each domain, and allow concurrency between them. Used this way, the serial queue is not an outdated substitute for parallelism. It is one of the basic structures that makes safe parallelism possible.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:02.856Z","updatedAt":"2026-10-27T14:25:35.210Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b46744e0819ab5f92a182984bcc9","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:6","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b46744e0819ab5f92a182984bcc9","role":"assistant","text":"CODEX_DETAIL_ACK_17885\nCODEX_ACTIVE_17885_DONE","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:43.297Z","updatedAt":"2026-10-27T14:25:43.395Z"},{"createdBy":"user","creationSource":"web","id":"8761646d-95e5-41f4-8794-73e2013e532a","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:2","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A2:root","role":"user","text":"HELD_Q_17885: When explicitly released, reply exactly HELD_Q_DONE. No tools.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:24.188Z","updatedAt":"2026-10-27T14:24:24.188Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b47c71b8819aa241fd13084debfe","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:2","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b47c71b8819aa241fd13084debfe","role":"assistant","text":"HELD_Q_DONE","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:26:04.498Z","updatedAt":"2026-10-27T14:26:04.627Z"},{"notification":{"source":{"kind":"command"},"outcome":"completed","summary":"Command \"/bin/bash -lc \"node -e 'setTimeout(()=>console.log(\\\"CODEX_BACKGROUND_17885_DON…\" finished (exit 0)","detail":"/bin/bash -lc \"node -e 'setTimeout(()=>console.log(\\\"CODEX_BACKGROUND_17885_DONE\\\"),45000)'\""},"createdBy":"agent","creationSource":"server","id":"message:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:1:16e3c6c1-8927-4e29-8dd9-979f6ff5c8b1","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:5","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A5:root","role":"user","text":"Background command completed (exit 0): /bin/bash -lc \"node -e 'setTimeout(()=>console.log(\\\"CODEX_BACKGROUND_17885_DONE\\\"),45000)'\"\n\nOutput tail:\nCODEX_BACKGROUND_17885_DONE","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:27.753Z","updatedAt":"2026-10-27T14:25:27.753Z"}],"subagents":[],"providerThreads":[{"id":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1","driver":"codex","providerInstanceId":"codex","providerSessionId":"provider-session:provider-instance:codex:shared","appThreadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","ownerNodeId":null,"nativeThreadRef":{"driver":"codex","nativeId":"01a17dbf-79ef-7c90-b227-4614d5023bd6","strength":"strong"},"nativeConversationHeadRef":null,"status":"not_loaded","firstRunOrdinal":1,"lastRunOrdinal":8,"handoffIds":[],"forkedFrom":null,"pendingBackgroundTasks":[],"contextUsage":{"usedTokens":22415,"maxTokens":258400},"nativeMetadata":null,"goal":null,"createdAt":"2026-10-27T14:24:20.885Z","updatedAt":"2026-10-27T14:26:07.583Z"}]}
2026-10-27T14:26:09.395Z PROJECTION 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scheduler evidence. Do not change files. Make 60 separate foreground Bash calls strictly sequentially, exactly one echo per call: echo initial-step-1 through echo initial-step-60. No loops, no background commands. After all calls reply INITIAL_DONE.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:20.885Z","updatedAt":"2026-10-27T14:24:20.885Z"},{"createdBy":"agent","creationSource":"mcp","id":"message:mcp:client%3A403306bf-8b12-4c21-8b83-a4274a2d202e:thread-send:e68ed982-aad7-4822-a5f9-4d4166e8cf71","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:3","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A3:root","role":"user","text":"Synthetic scheduler probe, no file edits. Use exec_command to run node -e 'setTimeout(()=>console.log(\"CODEX_BACKGROUND_17885_DONE\"),45000)' with yield_time_ms=1000. It must remain a running command session. Do not use a shell & or redirect. Do not poll or wait for it. Immediately end this turn with CODEX_ROOT_SETTLED. When a real later command-completion notification is delivered, reply exactly CODEX_DETAIL_ACK_17885 followed by the command result. Do not fabricate notifications.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:38.099Z","updatedAt":"2026-10-27T14:24:38.099Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b4299c10819aa33e4779dfefd048","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:3","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b4299c10819aa33e4779dfefd048","role":"assistant","text":"I’ll start the foreground Node timer as a persistent command session, then return immediately without polling it.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:41.681Z","updatedAt":"2026-10-27T14:24:42.113Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b42d1b30819a9fdea2a5e6fccfb3","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:3","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b42d1b30819a9fdea2a5e6fccfb3","role":"assistant","text":"CODEX_ROOT_SETTLED","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:45.195Z","updatedAt":"2026-10-27T14:24:45.218Z"},{"createdBy":"agent","creationSource":"mcp","id":"message:mcp:client%3A23308f20-1e1f-46cd-8b3a-788b4a7900cc:thread-send:0fd04def-0197-42bc-80c0-bd615180c894","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:4","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A4:root","role":"user","text":"Synthetic evidence active companion. Run node -e 'setTimeout(()=>console.log(\"CODEX_ACTIVE_17885_DONE\"),40000)' in exec_command with yield_time_ms=1000. Then write a 1500 word plain essay about serial queues. Do not poll the command session or wait. Do not change files. If a background command detail is already delivered acknowledge it once.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:55.341Z","updatedAt":"2026-10-27T14:24:55.341Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b439932c819ab7bb9fba46894634","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:4","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b439932c819ab7bb9fba46894634","role":"assistant","text":"I’ll launch the second timer as another persistent foreground session, won’t poll either session, and will use the remaining turn for the requested essay.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:57.606Z","updatedAt":"2026-10-27T14:24:57.835Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b43ecccc819ab970f50660380727","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:4","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b43ecccc819ab970f50660380727","role":"assistant","text":"A serial queue is one of the simplest ways to organize work in a computer system. Tasks enter the queue in some order, and a single worker processes them one at a time. The next task does not begin until the current task has finished, failed, or otherwise released control. This model can look unsophisticated beside thread pools, distributed schedulers, and highly concurrent pipelines, yet its simplicity gives it unusual power. A serial queue turns many difficult coordination problems into ordinary sequencing problems. When the order of operations matters, shared state must remain consistent, or predictability is more valuable than maximum throughput, serial execution is often the clearest design available.\n\nThe defining property of a serial queue is exclusivity. At most one queued task is executing through that queue at any moment. This does not necessarily mean the entire program uses only one thread, nor does it mean every operation is synchronous. A task might begin an asynchronous network request, register a callback, and yield the underlying thread. What matters is the queue’s completion rule. If the queue considers the task complete immediately after the request begins, later tasks may overlap with it. If completion is deferred until the callback arrives, the queue preserves strict logical serialization. Designers must therefore distinguish serial dispatch from serial completion. The former controls when code starts; the latter controls when effects are considered finished.\n\nOrdering is the most obvious benefit. Suppose an application receives commands to create an account, change its email address, and then delete it. If those commands execute concurrently, timing can produce strange outcomes: deletion may finish first, creation may overwrite it, or the email update may fail because the account temporarily does not exist. A serial queue processes the commands in their accepted order and makes the result easier to understand. The same principle applies to writing files, updating a local cache, advancing a workflow, applying database events, or controlling a physical device. The queue becomes a narrow channel through which state transitions occur in a deliberate sequence.\n\nSerial queues also provide a useful form of mutual exclusion. Traditional locking asks every piece of code that touches shared state to acquire and release the correct lock. This is efficient when done carefully, but careful locking is difficult. A forgotten lock creates a race, inconsistent lock ordering creates deadlock, and holding a lock across slow work can stall unrelated operations. Queue confinement offers another approach: shared mutable state belongs to one serial queue, and all access to that state is submitted as work. Since only one task runs at a time, state transitions cannot interleave unexpectedly. The queue acts as both scheduler and ownership boundary.\n\nThis ownership model improves reasoning. A developer can inspect a task and assume that no other task on the same queue is simultaneously changing the protected state. Invariants need to hold at task boundaries rather than at every individual instruction. Tests become more deterministic because fewer outcomes depend on thread timing. Logs naturally reflect a meaningful order. Failures can be tied to particular queue entries, and replay becomes possible when inputs are durable. Serial queues do not eliminate every bug, but they reduce the number of possible histories that a developer must consider.\n\nThe cost is limited throughput. A queue with one active worker cannot execute two independent tasks simultaneously, even when the machine has many available processors. One slow task delays everything behind it, a phenomenon often called head-of-line blocking. If a task waits thirty seconds for an external service, every later task waits as well when strict completion is required. The queue may grow faster than it drains, increasing latency and memory use. This tradeoff is fundamental: serialization buys order and isolation by giving up overlap. A successful design uses that bargain only where ordering or exclusivity is genuinely needed.\n\nQueue scope therefore matters. A single global serial queue is easy to construct but frequently too broad. If one customer’s slow operation blocks every other customer, unrelated work has been coupled unnecessarily. A better design may use one serial queue per account, document, device, or other natural ownership key. Tasks concerning the same key remain ordered, while tasks for different keys run concurrently. This pattern is sometimes called keyed serialization or partitioned queues. It preserves local consistency without sacrificing all system-wide parallelism. Choosing the partition key is an architectural decision because it defines which operations may safely overlap.\n\nFairness is another concern. A basic first-in, first-out queue treats arrival order as priority, which is often reasonable but not universally desirable. A stream of large background jobs can delay an urgent interactive action. Conversely, continually admitting urgent tasks can starve routine maintenance. Some systems use multiple serial queues with a higher-level scheduler that rotates among them. Others assign priorities, deadlines, or quotas. These policies complicate the clean FIFO model, but the core execution guarantee can remain intact: within the relevant domain, only one task runs at a time.\n\nError handling must be explicit. If a task throws an exception or returns a rejected promise, the queue should record the failure and decide whether subsequent work may continue. Automatically stopping the queue protects dependent operations from running after a broken prerequisite, but it can leave the system permanently wedged. Automatically continuing improves availability, but later tasks may encounter corrupted or incomplete state. A robust queue often classifies failures. Transient errors may trigger bounded retries with backoff. Permanent errors may move the task to a dead-letter store. Invariant violations may pause the queue and alert an operator. Whatever policy is chosen should be observable rather than implicit.\n\nCancellation presents similar questions. Removing a task that has not started is usually straightforward, provided no later task depends on it. Cancelling a running task is harder because arbitrary interruption can leave partial effects. Cooperative cancellation is safer: the task checks a signal at known points and performs cleanup before completing. For externally visible operations, cancellation may be impossible once a request has been accepted. In that case, the system may need a compensating task rather than pretending the original operation never happened. A queue preserves order, but it cannot make irreversible side effects reversible.\n\nBackpressure is essential when producers can outpace the consumer. An unbounded queue hides overload temporarily by accumulating work, then fails through excessive latency or memory exhaustion. A bounded queue makes capacity visible. Producers may block, receive a rejection, shed low-value work, or store tasks durably for later processing. Monitoring should include queue depth, oldest-task age, arrival rate, completion rate, execution duration, and failure count. Depth alone can mislead: ten millisecond-long tasks are harmless, while ten hour-long tasks may indicate a serious incident. Age and service time reveal the user-visible consequences more clearly.\n\nDurability separates in-memory serial queues from persistent job systems. An in-memory queue is fast and appropriate for coordinating state inside a process, but queued tasks disappear if that process crashes. A durable queue stores work before acknowledging acceptance and recovers unfinished tasks after restart. Durability introduces questions about delivery semantics. Most practical systems provide at-least-once execution, meaning a task may run again after ambiguous failure. Tasks must then be idempotent or carry deduplication keys. Exactly-once effects are difficult because the queue and the affected resource may fail independently. Serialization controls order; it does not by itself guarantee unique execution.\n\nReentrancy can cause subtle deadlocks. Imagine a task running on a serial queue that synchronously submits another task to the same queue and waits for its result. The inner task cannot start until the outer task finishes, while the outer task refuses to finish until the inner one runs. Queue APIs should discourage or detect this pattern. Code already executing within the queue can call an internal function directly, submit asynchronously without waiting, or use a reentrant execution rule where appropriate. The safest choice depends on whether immediate nested execution would violate the expected ordering.\n\nSerial queues are especially valuable at boundaries. A user interface often funnels state mutations through one event loop. An actor processes messages sequentially to protect its private state. A database uses ordered logs to establish a history of transactions. A device controller serializes commands because the hardware cannot perform conflicting motions at once. Even systems celebrated for concurrency frequently contain small islands of serialization. Concurrency happens between independent owners, while each owner processes its own stream in order. This combination is more scalable than either total serialization or unrestricted parallelism.\n\nTesting a serial queue should cover more than successful FIFO execution. Tests should confirm behavior after failure, cancellation, timeout, shutdown, and restart. They should verify that a task cannot overlap another task in the same partition and that different partitions can progress independently. Tests should exercise tasks that complete synchronously and asynchronously, because inconsistent completion handling is a common source of accidental concurrency. Shutdown deserves particular attention: the system must decide whether to drain queued work, reject new submissions, persist unfinished tasks, or terminate immediately. Clear lifecycle states prevent tasks from being silently lost.\n\nA serial queue is ultimately a tool for controlling histories. Concurrent systems permit many possible interleavings, and every additional interleaving increases the burden of reasoning, testing, and recovery. Serialization deliberately removes possibilities. That restraint can reduce raw speed, but it often improves correctness, operability, and human understanding. The best designs do not serialize everything. They identify the smallest domains in which order and exclusive ownership matter, place a queue around each domain, and allow concurrency between them. Used this way, the serial queue is not an outdated substitute for parallelism. It is one of the basic structures that makes safe parallelism possible.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:02.856Z","updatedAt":"2026-10-27T14:25:35.210Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b46744e0819ab5f92a182984bcc9","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:6","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b46744e0819ab5f92a182984bcc9","role":"assistant","text":"CODEX_DETAIL_ACK_17885\nCODEX_ACTIVE_17885_DONE","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:43.297Z","updatedAt":"2026-10-27T14:25:43.395Z"},{"createdBy":"user","creationSource":"web","id":"8761646d-95e5-41f4-8794-73e2013e532a","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:2","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A2:root","role":"user","text":"HELD_Q_17885: When explicitly released, reply exactly HELD_Q_DONE. No tools.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:24.188Z","updatedAt":"2026-10-27T14:24:24.188Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b47c71b8819aa241fd13084debfe","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:2","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b47c71b8819aa241fd13084debfe","role":"assistant","text":"HELD_Q_DONE","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:26:04.498Z","updatedAt":"2026-10-27T14:26:04.627Z"},{"notification":{"source":{"kind":"command"},"outcome":"completed","summary":"Command \"/bin/bash -lc \"node -e 'setTimeout(()=>console.log(\\\"CODEX_BACKGROUND_17885_DON…\" finished (exit 0)","detail":"/bin/bash -lc \"node -e 'setTimeout(()=>console.log(\\\"CODEX_BACKGROUND_17885_DONE\\\"),45000)'\""},"createdBy":"agent","creationSource":"server","id":"message:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:1:16e3c6c1-8927-4e29-8dd9-979f6ff5c8b1","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:5","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A5:root","role":"user","text":"Background command completed (exit 0): /bin/bash -lc \"node -e 'setTimeout(()=>console.log(\\\"CODEX_BACKGROUND_17885_DONE\\\"),45000)'\"\n\nOutput tail:\nCODEX_BACKGROUND_17885_DONE","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:27.753Z","updatedAt":"2026-10-27T14:25:27.753Z"}],"subagents":[],"providerThreads":[{"id":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1","driver":"codex","providerInstanceId":"codex","providerSessionId":"provider-session:provider-instance:codex:shared","appThreadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","ownerNodeId":null,"nativeThreadRef":{"driver":"codex","nativeId":"01a17dbf-79ef-7c90-b227-4614d5023bd6","strength":"strong"},"nativeConversationHeadRef":null,"status":"active","firstRunOrdinal":1,"lastRunOrdinal":8,"handoffIds":[],"forkedFrom":null,"pendingBackgroundTasks":[],"contextUsage":{"usedTokens":22528,"maxTokens":258400},"nativeMetadata":null,"goal":null,"createdAt":"2026-10-27T14:24:20.885Z","updatedAt":"2026-10-27T14:26:09.220Z"}]}
2026-10-27T14:26:11.602Z PROJECTION 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scheduler evidence. Do not change files. Make 60 separate foreground Bash calls strictly sequentially, exactly one echo per call: echo initial-step-1 through echo initial-step-60. No loops, no background commands. After all calls reply INITIAL_DONE.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:20.885Z","updatedAt":"2026-10-27T14:24:20.885Z"},{"createdBy":"agent","creationSource":"mcp","id":"message:mcp:client%3A403306bf-8b12-4c21-8b83-a4274a2d202e:thread-send:e68ed982-aad7-4822-a5f9-4d4166e8cf71","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:3","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A3:root","role":"user","text":"Synthetic scheduler probe, no file edits. Use exec_command to run node -e 'setTimeout(()=>console.log(\"CODEX_BACKGROUND_17885_DONE\"),45000)' with yield_time_ms=1000. It must remain a running command session. Do not use a shell & or redirect. Do not poll or wait for it. Immediately end this turn with CODEX_ROOT_SETTLED. When a real later command-completion notification is delivered, reply exactly CODEX_DETAIL_ACK_17885 followed by the command result. Do not fabricate notifications.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:38.099Z","updatedAt":"2026-10-27T14:24:38.099Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b4299c10819aa33e4779dfefd048","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:3","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b4299c10819aa33e4779dfefd048","role":"assistant","text":"I’ll start the foreground Node timer as a persistent command session, then return immediately without polling it.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:41.681Z","updatedAt":"2026-10-27T14:24:42.113Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b42d1b30819a9fdea2a5e6fccfb3","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:3","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b42d1b30819a9fdea2a5e6fccfb3","role":"assistant","text":"CODEX_ROOT_SETTLED","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:45.195Z","updatedAt":"2026-10-27T14:24:45.218Z"},{"createdBy":"agent","creationSource":"mcp","id":"message:mcp:client%3A23308f20-1e1f-46cd-8b3a-788b4a7900cc:thread-send:0fd04def-0197-42bc-80c0-bd615180c894","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:4","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A4:root","role":"user","text":"Synthetic evidence active companion. Run node -e 'setTimeout(()=>console.log(\"CODEX_ACTIVE_17885_DONE\"),40000)' in exec_command with yield_time_ms=1000. Then write a 1500 word plain essay about serial queues. Do not poll the command session or wait. Do not change files. If a background command detail is already delivered acknowledge it once.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:55.341Z","updatedAt":"2026-10-27T14:24:55.341Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b439932c819ab7bb9fba46894634","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:4","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b439932c819ab7bb9fba46894634","role":"assistant","text":"I’ll launch the second timer as another persistent foreground session, won’t poll either session, and will use the remaining turn for the requested essay.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:57.606Z","updatedAt":"2026-10-27T14:24:57.835Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b43ecccc819ab970f50660380727","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:4","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b43ecccc819ab970f50660380727","role":"assistant","text":"A serial queue is one of the simplest ways to organize work in a computer system. Tasks enter the queue in some order, and a single worker processes them one at a time. The next task does not begin until the current task has finished, failed, or otherwise released control. This model can look unsophisticated beside thread pools, distributed schedulers, and highly concurrent pipelines, yet its simplicity gives it unusual power. A serial queue turns many difficult coordination problems into ordinary sequencing problems. When the order of operations matters, shared state must remain consistent, or predictability is more valuable than maximum throughput, serial execution is often the clearest design available.\n\nThe defining property of a serial queue is exclusivity. At most one queued task is executing through that queue at any moment. This does not necessarily mean the entire program uses only one thread, nor does it mean every operation is synchronous. A task might begin an asynchronous network request, register a callback, and yield the underlying thread. What matters is the queue’s completion rule. If the queue considers the task complete immediately after the request begins, later tasks may overlap with it. If completion is deferred until the callback arrives, the queue preserves strict logical serialization. Designers must therefore distinguish serial dispatch from serial completion. The former controls when code starts; the latter controls when effects are considered finished.\n\nOrdering is the most obvious benefit. Suppose an application receives commands to create an account, change its email address, and then delete it. If those commands execute concurrently, timing can produce strange outcomes: deletion may finish first, creation may overwrite it, or the email update may fail because the account temporarily does not exist. A serial queue processes the commands in their accepted order and makes the result easier to understand. The same principle applies to writing files, updating a local cache, advancing a workflow, applying database events, or controlling a physical device. The queue becomes a narrow channel through which state transitions occur in a deliberate sequence.\n\nSerial queues also provide a useful form of mutual exclusion. Traditional locking asks every piece of code that touches shared state to acquire and release the correct lock. This is efficient when done carefully, but careful locking is difficult. A forgotten lock creates a race, inconsistent lock ordering creates deadlock, and holding a lock across slow work can stall unrelated operations. Queue confinement offers another approach: shared mutable state belongs to one serial queue, and all access to that state is submitted as work. Since only one task runs at a time, state transitions cannot interleave unexpectedly. The queue acts as both scheduler and ownership boundary.\n\nThis ownership model improves reasoning. A developer can inspect a task and assume that no other task on the same queue is simultaneously changing the protected state. Invariants need to hold at task boundaries rather than at every individual instruction. Tests become more deterministic because fewer outcomes depend on thread timing. Logs naturally reflect a meaningful order. Failures can be tied to particular queue entries, and replay becomes possible when inputs are durable. Serial queues do not eliminate every bug, but they reduce the number of possible histories that a developer must consider.\n\nThe cost is limited throughput. A queue with one active worker cannot execute two independent tasks simultaneously, even when the machine has many available processors. One slow task delays everything behind it, a phenomenon often called head-of-line blocking. If a task waits thirty seconds for an external service, every later task waits as well when strict completion is required. The queue may grow faster than it drains, increasing latency and memory use. This tradeoff is fundamental: serialization buys order and isolation by giving up overlap. A successful design uses that bargain only where ordering or exclusivity is genuinely needed.\n\nQueue scope therefore matters. A single global serial queue is easy to construct but frequently too broad. If one customer’s slow operation blocks every other customer, unrelated work has been coupled unnecessarily. A better design may use one serial queue per account, document, device, or other natural ownership key. Tasks concerning the same key remain ordered, while tasks for different keys run concurrently. This pattern is sometimes called keyed serialization or partitioned queues. It preserves local consistency without sacrificing all system-wide parallelism. Choosing the partition key is an architectural decision because it defines which operations may safely overlap.\n\nFairness is another concern. A basic first-in, first-out queue treats arrival order as priority, which is often reasonable but not universally desirable. A stream of large background jobs can delay an urgent interactive action. Conversely, continually admitting urgent tasks can starve routine maintenance. Some systems use multiple serial queues with a higher-level scheduler that rotates among them. Others assign priorities, deadlines, or quotas. These policies complicate the clean FIFO model, but the core execution guarantee can remain intact: within the relevant domain, only one task runs at a time.\n\nError handling must be explicit. If a task throws an exception or returns a rejected promise, the queue should record the failure and decide whether subsequent work may continue. Automatically stopping the queue protects dependent operations from running after a broken prerequisite, but it can leave the system permanently wedged. Automatically continuing improves availability, but later tasks may encounter corrupted or incomplete state. A robust queue often classifies failures. Transient errors may trigger bounded retries with backoff. Permanent errors may move the task to a dead-letter store. Invariant violations may pause the queue and alert an operator. Whatever policy is chosen should be observable rather than implicit.\n\nCancellation presents similar questions. Removing a task that has not started is usually straightforward, provided no later task depends on it. Cancelling a running task is harder because arbitrary interruption can leave partial effects. Cooperative cancellation is safer: the task checks a signal at known points and performs cleanup before completing. For externally visible operations, cancellation may be impossible once a request has been accepted. In that case, the system may need a compensating task rather than pretending the original operation never happened. A queue preserves order, but it cannot make irreversible side effects reversible.\n\nBackpressure is essential when producers can outpace the consumer. An unbounded queue hides overload temporarily by accumulating work, then fails through excessive latency or memory exhaustion. A bounded queue makes capacity visible. Producers may block, receive a rejection, shed low-value work, or store tasks durably for later processing. Monitoring should include queue depth, oldest-task age, arrival rate, completion rate, execution duration, and failure count. Depth alone can mislead: ten millisecond-long tasks are harmless, while ten hour-long tasks may indicate a serious incident. Age and service time reveal the user-visible consequences more clearly.\n\nDurability separates in-memory serial queues from persistent job systems. An in-memory queue is fast and appropriate for coordinating state inside a process, but queued tasks disappear if that process crashes. A durable queue stores work before acknowledging acceptance and recovers unfinished tasks after restart. Durability introduces questions about delivery semantics. Most practical systems provide at-least-once execution, meaning a task may run again after ambiguous failure. Tasks must then be idempotent or carry deduplication keys. Exactly-once effects are difficult because the queue and the affected resource may fail independently. Serialization controls order; it does not by itself guarantee unique execution.\n\nReentrancy can cause subtle deadlocks. Imagine a task running on a serial queue that synchronously submits another task to the same queue and waits for its result. The inner task cannot start until the outer task finishes, while the outer task refuses to finish until the inner one runs. Queue APIs should discourage or detect this pattern. Code already executing within the queue can call an internal function directly, submit asynchronously without waiting, or use a reentrant execution rule where appropriate. The safest choice depends on whether immediate nested execution would violate the expected ordering.\n\nSerial queues are especially valuable at boundaries. A user interface often funnels state mutations through one event loop. An actor processes messages sequentially to protect its private state. A database uses ordered logs to establish a history of transactions. A device controller serializes commands because the hardware cannot perform conflicting motions at once. Even systems celebrated for concurrency frequently contain small islands of serialization. Concurrency happens between independent owners, while each owner processes its own stream in order. This combination is more scalable than either total serialization or unrestricted parallelism.\n\nTesting a serial queue should cover more than successful FIFO execution. Tests should confirm behavior after failure, cancellation, timeout, shutdown, and restart. They should verify that a task cannot overlap another task in the same partition and that different partitions can progress independently. Tests should exercise tasks that complete synchronously and asynchronously, because inconsistent completion handling is a common source of accidental concurrency. Shutdown deserves particular attention: the system must decide whether to drain queued work, reject new submissions, persist unfinished tasks, or terminate immediately. Clear lifecycle states prevent tasks from being silently lost.\n\nA serial queue is ultimately a tool for controlling histories. Concurrent systems permit many possible interleavings, and every additional interleaving increases the burden of reasoning, testing, and recovery. Serialization deliberately removes possibilities. That restraint can reduce raw speed, but it often improves correctness, operability, and human understanding. The best designs do not serialize everything. They identify the smallest domains in which order and exclusive ownership matter, place a queue around each domain, and allow concurrency between them. Used this way, the serial queue is not an outdated substitute for parallelism. It is one of the basic structures that makes safe parallelism possible.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:02.856Z","updatedAt":"2026-10-27T14:25:35.210Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b46744e0819ab5f92a182984bcc9","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:6","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b46744e0819ab5f92a182984bcc9","role":"assistant","text":"CODEX_DETAIL_ACK_17885\nCODEX_ACTIVE_17885_DONE","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:43.297Z","updatedAt":"2026-10-27T14:25:43.395Z"},{"createdBy":"user","creationSource":"web","id":"8761646d-95e5-41f4-8794-73e2013e532a","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:2","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A2:root","role":"user","text":"HELD_Q_17885: When explicitly released, reply exactly HELD_Q_DONE. No tools.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:24.188Z","updatedAt":"2026-10-27T14:24:24.188Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b47c71b8819aa241fd13084debfe","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:2","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b47c71b8819aa241fd13084debfe","role":"assistant","text":"HELD_Q_DONE","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:26:04.498Z","updatedAt":"2026-10-27T14:26:04.627Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b4830c6c819aae8945cb56481081","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:5","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b4830c6c819aae8945cb56481081","role":"assistant","text":"CODEX_DETAIL_ACK_17885\nCODEX_BACKGROUND_17885_DONE","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:26:11.321Z","updatedAt":"2026-10-27T14:26:11.356Z"},{"notification":{"source":{"kind":"command"},"outcome":"completed","summary":"Command \"/bin/bash -lc \"node -e 'setTimeout(()=>console.log(\\\"CODEX_BACKGROUND_17885_DON…\" finished (exit 0)","detail":"/bin/bash -lc \"node -e 'setTimeout(()=>console.log(\\\"CODEX_BACKGROUND_17885_DONE\\\"),45000)'\""},"createdBy":"agent","creationSource":"server","id":"message:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:1:16e3c6c1-8927-4e29-8dd9-979f6ff5c8b1","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:5","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A5:root","role":"user","text":"Background command completed (exit 0): /bin/bash -lc \"node -e 'setTimeout(()=>console.log(\\\"CODEX_BACKGROUND_17885_DONE\\\"),45000)'\"\n\nOutput tail:\nCODEX_BACKGROUND_17885_DONE","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:27.753Z","updatedAt":"2026-10-27T14:25:27.753Z"}],"subagents":[],"providerThreads":[{"id":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1","driver":"codex","providerInstanceId":"codex","providerSessionId":"provider-session:provider-instance:codex:shared","appThreadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","ownerNodeId":null,"nativeThreadRef":{"driver":"codex","nativeId":"01a17dbf-79ef-7c90-b227-4614d5023bd6","strength":"strong"},"nativeConversationHeadRef":null,"status":"idle","firstRunOrdinal":1,"lastRunOrdinal":8,"handoffIds":[],"forkedFrom":null,"pendingBackgroundTasks":[],"contextUsage":{"usedTokens":22528,"maxTokens":258400},"nativeMetadata":null,"goal":null,"createdAt":"2026-10-27T14:24:20.885Z","updatedAt":"2026-10-27T14:26:11.506Z"}]}
2026-10-27T14:26:12.805Z PROJECTION 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scheduler evidence. Do not change files. Make 60 separate foreground Bash calls strictly sequentially, exactly one echo per call: echo initial-step-1 through echo initial-step-60. No loops, no background commands. After all calls reply INITIAL_DONE.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:20.885Z","updatedAt":"2026-10-27T14:24:20.885Z"},{"createdBy":"agent","creationSource":"mcp","id":"message:mcp:client%3A403306bf-8b12-4c21-8b83-a4274a2d202e:thread-send:e68ed982-aad7-4822-a5f9-4d4166e8cf71","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:3","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A3:root","role":"user","text":"Synthetic scheduler probe, no file edits. Use exec_command to run node -e 'setTimeout(()=>console.log(\"CODEX_BACKGROUND_17885_DONE\"),45000)' with yield_time_ms=1000. It must remain a running command session. Do not use a shell & or redirect. Do not poll or wait for it. Immediately end this turn with CODEX_ROOT_SETTLED. When a real later command-completion notification is delivered, reply exactly CODEX_DETAIL_ACK_17885 followed by the command result. Do not fabricate notifications.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:38.099Z","updatedAt":"2026-10-27T14:24:38.099Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b4299c10819aa33e4779dfefd048","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:3","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b4299c10819aa33e4779dfefd048","role":"assistant","text":"I’ll start the foreground Node timer as a persistent command session, then return immediately without polling it.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:41.681Z","updatedAt":"2026-10-27T14:24:42.113Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b42d1b30819a9fdea2a5e6fccfb3","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:3","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b42d1b30819a9fdea2a5e6fccfb3","role":"assistant","text":"CODEX_ROOT_SETTLED","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:45.195Z","updatedAt":"2026-10-27T14:24:45.218Z"},{"createdBy":"agent","creationSource":"mcp","id":"message:mcp:client%3A23308f20-1e1f-46cd-8b3a-788b4a7900cc:thread-send:0fd04def-0197-42bc-80c0-bd615180c894","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:4","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A4:root","role":"user","text":"Synthetic evidence active companion. Run node -e 'setTimeout(()=>console.log(\"CODEX_ACTIVE_17885_DONE\"),40000)' in exec_command with yield_time_ms=1000. Then write a 1500 word plain essay about serial queues. Do not poll the command session or wait. Do not change files. If a background command detail is already delivered acknowledge it once.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:55.341Z","updatedAt":"2026-10-27T14:24:55.341Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b439932c819ab7bb9fba46894634","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:4","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b439932c819ab7bb9fba46894634","role":"assistant","text":"I’ll launch the second timer as another persistent foreground session, won’t poll either session, and will use the remaining turn for the requested essay.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:57.606Z","updatedAt":"2026-10-27T14:24:57.835Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b43ecccc819ab970f50660380727","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:4","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b43ecccc819ab970f50660380727","role":"assistant","text":"A serial queue is one of the simplest ways to organize work in a computer system. Tasks enter the queue in some order, and a single worker processes them one at a time. The next task does not begin until the current task has finished, failed, or otherwise released control. This model can look unsophisticated beside thread pools, distributed schedulers, and highly concurrent pipelines, yet its simplicity gives it unusual power. A serial queue turns many difficult coordination problems into ordinary sequencing problems. When the order of operations matters, shared state must remain consistent, or predictability is more valuable than maximum throughput, serial execution is often the clearest design available.\n\nThe defining property of a serial queue is exclusivity. At most one queued task is executing through that queue at any moment. This does not necessarily mean the entire program uses only one thread, nor does it mean every operation is synchronous. A task might begin an asynchronous network request, register a callback, and yield the underlying thread. What matters is the queue’s completion rule. If the queue considers the task complete immediately after the request begins, later tasks may overlap with it. If completion is deferred until the callback arrives, the queue preserves strict logical serialization. Designers must therefore distinguish serial dispatch from serial completion. The former controls when code starts; the latter controls when effects are considered finished.\n\nOrdering is the most obvious benefit. Suppose an application receives commands to create an account, change its email address, and then delete it. If those commands execute concurrently, timing can produce strange outcomes: deletion may finish first, creation may overwrite it, or the email update may fail because the account temporarily does not exist. A serial queue processes the commands in their accepted order and makes the result easier to understand. The same principle applies to writing files, updating a local cache, advancing a workflow, applying database events, or controlling a physical device. The queue becomes a narrow channel through which state transitions occur in a deliberate sequence.\n\nSerial queues also provide a useful form of mutual exclusion. Traditional locking asks every piece of code that touches shared state to acquire and release the correct lock. This is efficient when done carefully, but careful locking is difficult. A forgotten lock creates a race, inconsistent lock ordering creates deadlock, and holding a lock across slow work can stall unrelated operations. Queue confinement offers another approach: shared mutable state belongs to one serial queue, and all access to that state is submitted as work. Since only one task runs at a time, state transitions cannot interleave unexpectedly. The queue acts as both scheduler and ownership boundary.\n\nThis ownership model improves reasoning. A developer can inspect a task and assume that no other task on the same queue is simultaneously changing the protected state. Invariants need to hold at task boundaries rather than at every individual instruction. Tests become more deterministic because fewer outcomes depend on thread timing. Logs naturally reflect a meaningful order. Failures can be tied to particular queue entries, and replay becomes possible when inputs are durable. Serial queues do not eliminate every bug, but they reduce the number of possible histories that a developer must consider.\n\nThe cost is limited throughput. A queue with one active worker cannot execute two independent tasks simultaneously, even when the machine has many available processors. One slow task delays everything behind it, a phenomenon often called head-of-line blocking. If a task waits thirty seconds for an external service, every later task waits as well when strict completion is required. The queue may grow faster than it drains, increasing latency and memory use. This tradeoff is fundamental: serialization buys order and isolation by giving up overlap. A successful design uses that bargain only where ordering or exclusivity is genuinely needed.\n\nQueue scope therefore matters. A single global serial queue is easy to construct but frequently too broad. If one customer’s slow operation blocks every other customer, unrelated work has been coupled unnecessarily. A better design may use one serial queue per account, document, device, or other natural ownership key. Tasks concerning the same key remain ordered, while tasks for different keys run concurrently. This pattern is sometimes called keyed serialization or partitioned queues. It preserves local consistency without sacrificing all system-wide parallelism. Choosing the partition key is an architectural decision because it defines which operations may safely overlap.\n\nFairness is another concern. A basic first-in, first-out queue treats arrival order as priority, which is often reasonable but not universally desirable. A stream of large background jobs can delay an urgent interactive action. Conversely, continually admitting urgent tasks can starve routine maintenance. Some systems use multiple serial queues with a higher-level scheduler that rotates among them. Others assign priorities, deadlines, or quotas. These policies complicate the clean FIFO model, but the core execution guarantee can remain intact: within the relevant domain, only one task runs at a time.\n\nError handling must be explicit. If a task throws an exception or returns a rejected promise, the queue should record the failure and decide whether subsequent work may continue. Automatically stopping the queue protects dependent operations from running after a broken prerequisite, but it can leave the system permanently wedged. Automatically continuing improves availability, but later tasks may encounter corrupted or incomplete state. A robust queue often classifies failures. Transient errors may trigger bounded retries with backoff. Permanent errors may move the task to a dead-letter store. Invariant violations may pause the queue and alert an operator. Whatever policy is chosen should be observable rather than implicit.\n\nCancellation presents similar questions. Removing a task that has not started is usually straightforward, provided no later task depends on it. Cancelling a running task is harder because arbitrary interruption can leave partial effects. Cooperative cancellation is safer: the task checks a signal at known points and performs cleanup before completing. For externally visible operations, cancellation may be impossible once a request has been accepted. In that case, the system may need a compensating task rather than pretending the original operation never happened. A queue preserves order, but it cannot make irreversible side effects reversible.\n\nBackpressure is essential when producers can outpace the consumer. An unbounded queue hides overload temporarily by accumulating work, then fails through excessive latency or memory exhaustion. A bounded queue makes capacity visible. Producers may block, receive a rejection, shed low-value work, or store tasks durably for later processing. Monitoring should include queue depth, oldest-task age, arrival rate, completion rate, execution duration, and failure count. Depth alone can mislead: ten millisecond-long tasks are harmless, while ten hour-long tasks may indicate a serious incident. Age and service time reveal the user-visible consequences more clearly.\n\nDurability separates in-memory serial queues from persistent job systems. An in-memory queue is fast and appropriate for coordinating state inside a process, but queued tasks disappear if that process crashes. A durable queue stores work before acknowledging acceptance and recovers unfinished tasks after restart. Durability introduces questions about delivery semantics. Most practical systems provide at-least-once execution, meaning a task may run again after ambiguous failure. Tasks must then be idempotent or carry deduplication keys. Exactly-once effects are difficult because the queue and the affected resource may fail independently. Serialization controls order; it does not by itself guarantee unique execution.\n\nReentrancy can cause subtle deadlocks. Imagine a task running on a serial queue that synchronously submits another task to the same queue and waits for its result. The inner task cannot start until the outer task finishes, while the outer task refuses to finish until the inner one runs. Queue APIs should discourage or detect this pattern. Code already executing within the queue can call an internal function directly, submit asynchronously without waiting, or use a reentrant execution rule where appropriate. The safest choice depends on whether immediate nested execution would violate the expected ordering.\n\nSerial queues are especially valuable at boundaries. A user interface often funnels state mutations through one event loop. An actor processes messages sequentially to protect its private state. A database uses ordered logs to establish a history of transactions. A device controller serializes commands because the hardware cannot perform conflicting motions at once. Even systems celebrated for concurrency frequently contain small islands of serialization. Concurrency happens between independent owners, while each owner processes its own stream in order. This combination is more scalable than either total serialization or unrestricted parallelism.\n\nTesting a serial queue should cover more than successful FIFO execution. Tests should confirm behavior after failure, cancellation, timeout, shutdown, and restart. They should verify that a task cannot overlap another task in the same partition and that different partitions can progress independently. Tests should exercise tasks that complete synchronously and asynchronously, because inconsistent completion handling is a common source of accidental concurrency. Shutdown deserves particular attention: the system must decide whether to drain queued work, reject new submissions, persist unfinished tasks, or terminate immediately. Clear lifecycle states prevent tasks from being silently lost.\n\nA serial queue is ultimately a tool for controlling histories. Concurrent systems permit many possible interleavings, and every additional interleaving increases the burden of reasoning, testing, and recovery. Serialization deliberately removes possibilities. That restraint can reduce raw speed, but it often improves correctness, operability, and human understanding. The best designs do not serialize everything. They identify the smallest domains in which order and exclusive ownership matter, place a queue around each domain, and allow concurrency between them. Used this way, the serial queue is not an outdated substitute for parallelism. It is one of the basic structures that makes safe parallelism possible.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:02.856Z","updatedAt":"2026-10-27T14:25:35.210Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b46744e0819ab5f92a182984bcc9","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:6","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b46744e0819ab5f92a182984bcc9","role":"assistant","text":"CODEX_DETAIL_ACK_17885\nCODEX_ACTIVE_17885_DONE","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:43.297Z","updatedAt":"2026-10-27T14:25:43.395Z"},{"createdBy":"user","creationSource":"web","id":"8761646d-95e5-41f4-8794-73e2013e532a","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:2","nodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A2:root","role":"user","text":"HELD_Q_17885: When explicitly released, reply exactly HELD_Q_DONE. No tools.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:24.188Z","updatedAt":"2026-10-27T14:24:24.188Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b47c71b8819aa241fd13084debfe","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:2","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b47c71b8819aa241fd13084debfe","role":"assistant","text":"HELD_Q_DONE","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:26:04.498Z","updatedAt":"2026-10-27T14:26:04.627Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b4830c6c819aae8945cb56481081","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","runId":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:5","nodeId":"node:provider:codex:native-item:msg_0cb2083fb19368c0016ae0b4830c6c819aae8945cb56481081","role":"assistant","text":"CODEX_DETAIL_ACK_17885\nCODEX_BACKGROUND_17885_DONE","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:26:11.321Z","updatedAt":"2026-10-27T14:26:11.356Z"}],"subagents":[],"providerThreads":[{"id":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1","driver":"codex","providerInstanceId":"codex","providerSessionId":"provider-session:provider-instance:codex:shared","appThreadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","ownerNodeId":null,"nativeThreadRef":{"driver":"codex","nativeId":"01a17dbf-79ef-7c90-b227-4614d5023bd6","strength":"strong"},"nativeConversationHeadRef":null,"status":"idle","firstRunOrdinal":1,"lastRunOrdinal":8,"handoffIds":[],"forkedFrom":null,"pendingBackgroundTasks":[],"contextUsage":{"usedTokens":22528,"maxTokens":258400},"nativeMetadata":null,"goal":null,"createdAt":"2026-10-27T14:24:20.885Z","updatedAt":"2026-10-27T14:26:11.506Z"}]}
2026-10-27T14:26:45.949Z HELD_Q_FINAL {"before":{"id":"run:thread:b0b36ab1-aa99-4e65-9f48-86022b42ccb1:ordinal:2","threadId":"b0b36ab1-aa99-4e65-9f48-86022b42ccb1","ordinal":2,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A1","userMessageId":"8761646d-95e5-41f4-8794-73e2013e532a","rootNodeId":"node:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A2:root","activeAttemptId":"run-attempt:run:run%3Athread%3Ab0b36ab1-aa99-4e65-9f48-86022b42ccb1%3Aordinal%3A2:attempt:1","status":"queued","queuePosition":1,"queueHeld":true,"requestedAt":"2026-10-27T14:24:24.188Z","startedAt":null,"completedAt":null,"checkpointId":null,"contextHandoffId":null},"byteEqual":false}
2026-10-27T14:26:45.950Z FINAL 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2026-10-27T14:26:45.993Z STOP_SERVER {"pid":2861777}
2026-10-27T14:26:47.145Z END SHA c740ee52fabfabea61f16a43a1591c5777d54eca COMMAND runtime-driver.mjs /home/ubuntu/wt/pr-17885 head codex
