2026-10-27T14:24:04.930Z START SHA e5ea25d1292e5342db8508bf48ded67b88b82b82 COMMAND node apps/server/src/bin.ts start --base-dir <fresh isolated home> --port 32853 --dev-url <local origin> --no-browser; runtime-driver.mjs /home/ubuntu/wt/pr-17885-evidence-base base codex
2026-10-27T14:24:05.263Z 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-evidence-base","home":"/tmp/lead-17885-r1/evidence-capture/base-codex-2026-10-27T14-24-04.756Z/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"}
2026-10-27T14:24:05.293Z SPAWN {"pid":2861821}
2026-10-27T14:24:24.116Z PROJECTION {"runs":[{"id":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ordinal":1,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","userMessageId":"message:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1:076898c7-32f3-4963-83ee-bf5eb2b1cd0f","rootNodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1:root","activeAttemptId":"run-attempt:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1:attempt:1","status":"starting","queuePosition":null,"requestedAt":"2026-10-27T14:24:23.442Z","startedAt":null,"completedAt":null,"checkpointId":null,"contextHandoffId":null,"workspacePreparation":{"type":"root"}}],"messages":[{"createdBy":"user","creationSource":"web","id":"message:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1:076898c7-32f3-4963-83ee-bf5eb2b1cd0f","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%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":"2026-10-27T14:24:23.442Z","updatedAt":"2026-10-27T14:24:23.442Z"}],"subagents":[],"providerThreads":[{"id":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","driver":"codex","providerInstanceId":"codex","providerSessionId":"provider-session:provider-instance:codex:shared","appThreadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ownerNodeId":null,"nativeThreadRef":null,"nativeConversationHeadRef":null,"status":"not_loaded","firstRunOrdinal":1,"lastRunOrdinal":1,"handoffIds":[],"forkedFrom":null,"pendingBackgroundTasks":[],"contextUsage":null,"nativeMetadata":null,"goal":null,"createdAt":"2026-10-27T14:24:23.442Z","updatedAt":"2026-10-27T14:24:23.442Z"}]}
2026-10-27T14:24:26.436Z PROJECTION {"runs":[{"id":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ordinal":1,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","userMessageId":"message:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1:076898c7-32f3-4963-83ee-bf5eb2b1cd0f","rootNodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1:root","activeAttemptId":"run-attempt:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1:attempt:1","status":"running","queuePosition":null,"requestedAt":"2026-10-27T14:24:23.442Z","startedAt":"2026-10-27T14:24:25.671Z","completedAt":null,"checkpointId":null,"contextHandoffId":null,"workspacePreparation":{"type":"root"}}],"messages":[{"createdBy":"user","creationSource":"web","id":"message:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1:076898c7-32f3-4963-83ee-bf5eb2b1cd0f","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%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":"2026-10-27T14:24:23.442Z","updatedAt":"2026-10-27T14:24:23.442Z"}],"subagents":[],"providerThreads":[{"id":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","driver":"codex","providerInstanceId":"codex","providerSessionId":"provider-session:provider-instance:codex:shared","appThreadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ownerNodeId":null,"nativeThreadRef":{"driver":"codex","nativeId":"01a17dbf-8317-7fc1-950c-c63c6cd01212","strength":"strong"},"nativeConversationHeadRef":null,"status":"active","firstRunOrdinal":1,"lastRunOrdinal":1,"handoffIds":[],"forkedFrom":null,"pendingBackgroundTasks":[],"contextUsage":null,"nativeMetadata":null,"goal":null,"createdAt":"2026-10-27T14:24:23.442Z","updatedAt":"2026-10-27T14:24:25.671Z"}]}
2026-10-27T14:24:26.438Z STEP {"action":"user RPC dispatch","command":{"type":"message.dispatch","messageId":"519064dd-4cdb-43f2-9488-d4fa4a9d5d55","text":"HELD_Q_17885: When explicitly released, reply exactly HELD_Q_DONE. No tools.","attachments":[],"createdBy":"user","creationSource":"web","dispatchMode":{"type":"queue_after_active"}}}
2026-10-27T14:24:26.804Z PROJECTION {"runs":[{"id":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ordinal":1,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","userMessageId":"message:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1:076898c7-32f3-4963-83ee-bf5eb2b1cd0f","rootNodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1:root","activeAttemptId":"run-attempt:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1:attempt:1","status":"running","queuePosition":null,"requestedAt":"2026-10-27T14:24:23.442Z","startedAt":"2026-10-27T14:24:25.671Z","completedAt":null,"checkpointId":null,"contextHandoffId":null,"workspacePreparation":{"type":"root"}},{"id":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:2","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ordinal":2,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","userMessageId":"519064dd-4cdb-43f2-9488-d4fa4a9d5d55","rootNodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A2:root","activeAttemptId":"run-attempt:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A2:attempt:1","status":"queued","queuePosition":1,"requestedAt":"2026-10-27T14:24:26.567Z","startedAt":null,"completedAt":null,"checkpointId":null,"contextHandoffId":null}],"messages":[{"createdBy":"user","creationSource":"web","id":"message:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1:076898c7-32f3-4963-83ee-bf5eb2b1cd0f","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%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":"2026-10-27T14:24:23.442Z","updatedAt":"2026-10-27T14:24:23.442Z"},{"createdBy":"user","creationSource":"web","id":"519064dd-4cdb-43f2-9488-d4fa4a9d5d55","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:2","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A2:root","role":"user","text":"HELD_Q_17885: When explicitly released, reply exactly HELD_Q_DONE. No tools.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:26.567Z","updatedAt":"2026-10-27T14:24:26.567Z"}],"subagents":[],"providerThreads":[{"id":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","driver":"codex","providerInstanceId":"codex","providerSessionId":"provider-session:provider-instance:codex:shared","appThreadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ownerNodeId":null,"nativeThreadRef":{"driver":"codex","nativeId":"01a17dbf-8317-7fc1-950c-c63c6cd01212","strength":"strong"},"nativeConversationHeadRef":null,"status":"active","firstRunOrdinal":1,"lastRunOrdinal":1,"handoffIds":[],"forkedFrom":null,"pendingBackgroundTasks":[],"contextUsage":null,"nativeMetadata":null,"goal":null,"createdAt":"2026-10-27T14:24:23.442Z","updatedAt":"2026-10-27T14:24:25.671Z"}]}
2026-10-27T14:24:26.810Z STEP {"action":"user RPC dispatch","command":{"type":"thread.stop","reason":"Hold queued synthetic Q"}}
2026-10-27T14:24:27.188Z PROJECTION {"runs":[{"id":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ordinal":1,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","userMessageId":"message:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1:076898c7-32f3-4963-83ee-bf5eb2b1cd0f","rootNodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1:root","activeAttemptId":"run-attempt:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1:attempt:1","status":"interrupted","queuePosition":null,"requestedAt":"2026-10-27T14:24:23.442Z","startedAt":"2026-10-27T14:24:25.671Z","completedAt":"2026-10-27T14:24:26.847Z","checkpointId":null,"contextHandoffId":null,"workspacePreparation":{"type":"root"}},{"id":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:2","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ordinal":2,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","userMessageId":"519064dd-4cdb-43f2-9488-d4fa4a9d5d55","rootNodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A2:root","activeAttemptId":"run-attempt:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A2:attempt:1","status":"queued","queuePosition":1,"queueHeld":true,"requestedAt":"2026-10-27T14:24:26.567Z","startedAt":null,"completedAt":null,"checkpointId":null,"contextHandoffId":null}],"messages":[{"createdBy":"user","creationSource":"web","id":"message:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1:076898c7-32f3-4963-83ee-bf5eb2b1cd0f","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%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":"2026-10-27T14:24:23.442Z","updatedAt":"2026-10-27T14:24:23.442Z"},{"createdBy":"user","creationSource":"web","id":"519064dd-4cdb-43f2-9488-d4fa4a9d5d55","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:2","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A2:root","role":"user","text":"HELD_Q_17885: When explicitly released, reply exactly HELD_Q_DONE. No tools.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:26.567Z","updatedAt":"2026-10-27T14:24:26.567Z"}],"subagents":[],"providerThreads":[{"id":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","driver":"codex","providerInstanceId":"codex","providerSessionId":"provider-session:provider-instance:codex:shared","appThreadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ownerNodeId":null,"nativeThreadRef":{"driver":"codex","nativeId":"01a17dbf-8317-7fc1-950c-c63c6cd01212","strength":"strong"},"nativeConversationHeadRef":null,"status":"active","firstRunOrdinal":1,"lastRunOrdinal":1,"handoffIds":[],"forkedFrom":null,"pendingBackgroundTasks":[],"contextUsage":null,"nativeMetadata":null,"goal":null,"createdAt":"2026-10-27T14:24:23.442Z","updatedAt":"2026-10-27T14:24:25.671Z"}]}
2026-10-27T14:24:27.189Z HELD_Q_BEFORE {"id":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:2","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ordinal":2,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","userMessageId":"519064dd-4cdb-43f2-9488-d4fa4a9d5d55","rootNodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A2:root","activeAttemptId":"run-attempt:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A2:attempt:1","status":"queued","queuePosition":1,"queueHeld":true,"requestedAt":"2026-10-27T14:24:26.567Z","startedAt":null,"completedAt":null,"checkpointId":null,"contextHandoffId":null}
2026-10-27T14:24:27.189Z STEP {"action":"CLI/MCP send; preserves held queue","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","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."}
2026-10-27T14:24:40.403Z PROJECTION {"runs":[{"id":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ordinal":1,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","userMessageId":"message:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1:076898c7-32f3-4963-83ee-bf5eb2b1cd0f","rootNodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1:root","activeAttemptId":"run-attempt:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1:attempt:1","status":"interrupted","queuePosition":null,"requestedAt":"2026-10-27T14:24:23.442Z","startedAt":"2026-10-27T14:24:25.671Z","completedAt":"2026-10-27T14:24:26.847Z","checkpointId":null,"contextHandoffId":null,"workspacePreparation":{"type":"root"}},{"id":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:2","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ordinal":2,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","userMessageId":"519064dd-4cdb-43f2-9488-d4fa4a9d5d55","rootNodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A2:root","activeAttemptId":"run-attempt:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A2:attempt:1","status":"queued","queuePosition":1,"queueHeld":true,"requestedAt":"2026-10-27T14:24:26.567Z","startedAt":null,"completedAt":null,"checkpointId":null,"contextHandoffId":null},{"id":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:3","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ordinal":3,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","userMessageId":"message:mcp:client%3A3615d0b0-29d2-4c83-b8d7-da01992d4840:thread-send:604cddc4-0d14-41f8-8b22-064dc8cb2d50","rootNodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A3:root","activeAttemptId":"run-attempt:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A3:attempt:1","status":"running","queuePosition":null,"requestedAt":"2026-10-27T14:24:39.926Z","startedAt":"2026-10-27T14:24:40.215Z","completedAt":null,"checkpointId":null,"contextHandoffId":null}],"messages":[{"createdBy":"user","creationSource":"web","id":"message:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1:076898c7-32f3-4963-83ee-bf5eb2b1cd0f","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%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":"2026-10-27T14:24:23.442Z","updatedAt":"2026-10-27T14:24:23.442Z"},{"createdBy":"agent","creationSource":"mcp","id":"message:mcp:client%3A3615d0b0-29d2-4c83-b8d7-da01992d4840:thread-send:604cddc4-0d14-41f8-8b22-064dc8cb2d50","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:3","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%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":"2026-10-27T14:24:39.926Z","updatedAt":"2026-10-27T14:24:39.926Z"},{"createdBy":"user","creationSource":"web","id":"519064dd-4cdb-43f2-9488-d4fa4a9d5d55","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:2","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A2:root","role":"user","text":"HELD_Q_17885: When explicitly released, reply exactly HELD_Q_DONE. No tools.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:26.567Z","updatedAt":"2026-10-27T14:24:26.567Z"}],"subagents":[],"providerThreads":[{"id":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","driver":"codex","providerInstanceId":"codex","providerSessionId":"provider-session:provider-instance:codex:shared","appThreadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ownerNodeId":null,"nativeThreadRef":{"driver":"codex","nativeId":"01a17dbf-8317-7fc1-950c-c63c6cd01212","strength":"strong"},"nativeConversationHeadRef":null,"status":"active","firstRunOrdinal":1,"lastRunOrdinal":3,"handoffIds":[],"forkedFrom":null,"pendingBackgroundTasks":[],"contextUsage":null,"nativeMetadata":null,"goal":null,"createdAt":"2026-10-27T14:24:23.442Z","updatedAt":"2026-10-27T14:24:40.215Z"}]}
2026-10-27T14:24:40.532Z CLI_RESULT {"code":0,"out":"{\"threadId\":\"bad21ec5-ff88-4a5a-b1d1-ed69c499695a\",\"link\":\"[Held queue codex evidence](t3-thread://v1/bad21ec5-ff88-4a5a-b1d1-ed69c499695a)\",\"messageId\":\"message:mcp:client%3A3615d0b0-29d2-4c83-b8d7-da01992d4840:thread-send:604cddc4-0d14-41f8-8b22-064dc8cb2d50\",\"runId\":\"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:3\",\"status\":\"starting\",\"delivery\":\"started\"}\n"}
2026-10-27T14:24:40.533Z IDLE_TO_A {"qHeld":{"id":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:2","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ordinal":2,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","userMessageId":"519064dd-4cdb-43f2-9488-d4fa4a9d5d55","rootNodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A2:root","activeAttemptId":"run-attempt:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A2:attempt:1","status":"queued","queuePosition":1,"queueHeld":true,"requestedAt":"2026-10-27T14:24:26.567Z","startedAt":null,"completedAt":null,"checkpointId":null,"contextHandoffId":null},"active":{"id":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:3","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ordinal":3,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","userMessageId":"message:mcp:client%3A3615d0b0-29d2-4c83-b8d7-da01992d4840:thread-send:604cddc4-0d14-41f8-8b22-064dc8cb2d50","rootNodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A3:root","activeAttemptId":"run-attempt:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A3:attempt:1","status":"running","queuePosition":null,"requestedAt":"2026-10-27T14:24:39.926Z","startedAt":"2026-10-27T14:24:40.215Z","completedAt":null,"checkpointId":null,"contextHandoffId":null}}
2026-10-27T14:24:44.227Z PROJECTION {"runs":[{"id":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ordinal":1,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","userMessageId":"message:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1:076898c7-32f3-4963-83ee-bf5eb2b1cd0f","rootNodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1:root","activeAttemptId":"run-attempt:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1:attempt:1","status":"interrupted","queuePosition":null,"requestedAt":"2026-10-27T14:24:23.442Z","startedAt":"2026-10-27T14:24:25.671Z","completedAt":"2026-10-27T14:24:26.847Z","checkpointId":null,"contextHandoffId":null,"workspacePreparation":{"type":"root"}},{"id":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:2","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ordinal":2,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","userMessageId":"519064dd-4cdb-43f2-9488-d4fa4a9d5d55","rootNodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A2:root","activeAttemptId":"run-attempt:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A2:attempt:1","status":"queued","queuePosition":1,"queueHeld":true,"requestedAt":"2026-10-27T14:24:26.567Z","startedAt":null,"completedAt":null,"checkpointId":null,"contextHandoffId":null},{"id":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:3","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ordinal":3,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","userMessageId":"message:mcp:client%3A3615d0b0-29d2-4c83-b8d7-da01992d4840:thread-send:604cddc4-0d14-41f8-8b22-064dc8cb2d50","rootNodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A3:root","activeAttemptId":"run-attempt:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A3:attempt:1","status":"running","queuePosition":null,"requestedAt":"2026-10-27T14:24:39.926Z","startedAt":"2026-10-27T14:24:40.215Z","completedAt":null,"checkpointId":null,"contextHandoffId":null}],"messages":[{"createdBy":"user","creationSource":"web","id":"message:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1:076898c7-32f3-4963-83ee-bf5eb2b1cd0f","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%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":"2026-10-27T14:24:23.442Z","updatedAt":"2026-10-27T14:24:23.442Z"},{"createdBy":"agent","creationSource":"mcp","id":"message:mcp:client%3A3615d0b0-29d2-4c83-b8d7-da01992d4840:thread-send:604cddc4-0d14-41f8-8b22-064dc8cb2d50","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:3","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%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":"2026-10-27T14:24:39.926Z","updatedAt":"2026-10-27T14:24:39.926Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b42bd524819aace1a8cdad9d0eac","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:3","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b42bd524819aace1a8cdad9d0eac","role":"assistant","text":"I’ll start the requested foreground Node process and leave its command session running.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:43.876Z","updatedAt":"2026-10-27T14:24:44.181Z"},{"createdBy":"user","creationSource":"web","id":"519064dd-4cdb-43f2-9488-d4fa4a9d5d55","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:2","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A2:root","role":"user","text":"HELD_Q_17885: When explicitly released, reply exactly HELD_Q_DONE. No tools.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:26.567Z","updatedAt":"2026-10-27T14:24:26.567Z"}],"subagents":[],"providerThreads":[{"id":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","driver":"codex","providerInstanceId":"codex","providerSessionId":"provider-session:provider-instance:codex:shared","appThreadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ownerNodeId":null,"nativeThreadRef":{"driver":"codex","nativeId":"01a17dbf-8317-7fc1-950c-c63c6cd01212","strength":"strong"},"nativeConversationHeadRef":null,"status":"active","firstRunOrdinal":1,"lastRunOrdinal":3,"handoffIds":[],"forkedFrom":null,"pendingBackgroundTasks":[],"contextUsage":null,"nativeMetadata":null,"goal":null,"createdAt":"2026-10-27T14:24:23.442Z","updatedAt":"2026-10-27T14:24:40.215Z"}]}
2026-10-27T14:24:47.712Z PROJECTION {"runs":[{"id":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ordinal":1,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","userMessageId":"message:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1:076898c7-32f3-4963-83ee-bf5eb2b1cd0f","rootNodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1:root","activeAttemptId":"run-attempt:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1:attempt:1","status":"interrupted","queuePosition":null,"requestedAt":"2026-10-27T14:24:23.442Z","startedAt":"2026-10-27T14:24:25.671Z","completedAt":"2026-10-27T14:24:26.847Z","checkpointId":null,"contextHandoffId":null,"workspacePreparation":{"type":"root"}},{"id":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:2","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ordinal":2,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","userMessageId":"519064dd-4cdb-43f2-9488-d4fa4a9d5d55","rootNodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A2:root","activeAttemptId":"run-attempt:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A2:attempt:1","status":"queued","queuePosition":1,"queueHeld":true,"requestedAt":"2026-10-27T14:24:26.567Z","startedAt":null,"completedAt":null,"checkpointId":null,"contextHandoffId":null},{"id":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:3","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ordinal":3,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","userMessageId":"message:mcp:client%3A3615d0b0-29d2-4c83-b8d7-da01992d4840:thread-send:604cddc4-0d14-41f8-8b22-064dc8cb2d50","rootNodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A3:root","activeAttemptId":"run-attempt:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A3:attempt:1","status":"waiting","queuePosition":null,"requestedAt":"2026-10-27T14:24:39.926Z","startedAt":"2026-10-27T14:24:40.215Z","completedAt":null,"checkpointId":null,"contextHandoffId":null}],"messages":[{"createdBy":"user","creationSource":"web","id":"message:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1:076898c7-32f3-4963-83ee-bf5eb2b1cd0f","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%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":"2026-10-27T14:24:23.442Z","updatedAt":"2026-10-27T14:24:23.442Z"},{"createdBy":"agent","creationSource":"mcp","id":"message:mcp:client%3A3615d0b0-29d2-4c83-b8d7-da01992d4840:thread-send:604cddc4-0d14-41f8-8b22-064dc8cb2d50","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:3","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%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":"2026-10-27T14:24:39.926Z","updatedAt":"2026-10-27T14:24:39.926Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b42bd524819aace1a8cdad9d0eac","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:3","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b42bd524819aace1a8cdad9d0eac","role":"assistant","text":"I’ll start the requested foreground Node process and leave its command session running.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:43.876Z","updatedAt":"2026-10-27T14:24:44.181Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b42f6384819aaf98301c46494b00","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:3","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b42f6384819aaf98301c46494b00","role":"assistant","text":"CODEX_ROOT_SETTLED","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:47.463Z","updatedAt":"2026-10-27T14:24:47.504Z"},{"createdBy":"user","creationSource":"web","id":"519064dd-4cdb-43f2-9488-d4fa4a9d5d55","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:2","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A2:root","role":"user","text":"HELD_Q_17885: When explicitly released, reply exactly HELD_Q_DONE. No tools.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:26.567Z","updatedAt":"2026-10-27T14:24:26.567Z"}],"subagents":[],"providerThreads":[{"id":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","driver":"codex","providerInstanceId":"codex","providerSessionId":"provider-session:provider-instance:codex:shared","appThreadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ownerNodeId":null,"nativeThreadRef":{"driver":"codex","nativeId":"01a17dbf-8317-7fc1-950c-c63c6cd01212","strength":"strong"},"nativeConversationHeadRef":null,"status":"idle","firstRunOrdinal":1,"lastRunOrdinal":3,"handoffIds":[],"forkedFrom":null,"pendingBackgroundTasks":[],"contextUsage":null,"nativeMetadata":null,"goal":null,"createdAt":"2026-10-27T14:24:23.442Z","updatedAt":"2026-10-27T14:24:47.595Z"}]}
2026-10-27T14:24:48.625Z PROJECTION {"runs":[{"id":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ordinal":1,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","userMessageId":"message:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1:076898c7-32f3-4963-83ee-bf5eb2b1cd0f","rootNodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1:root","activeAttemptId":"run-attempt:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1:attempt:1","status":"interrupted","queuePosition":null,"requestedAt":"2026-10-27T14:24:23.442Z","startedAt":"2026-10-27T14:24:25.671Z","completedAt":"2026-10-27T14:24:26.847Z","checkpointId":null,"contextHandoffId":null,"workspacePreparation":{"type":"root"}},{"id":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:2","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ordinal":2,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","userMessageId":"519064dd-4cdb-43f2-9488-d4fa4a9d5d55","rootNodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A2:root","activeAttemptId":"run-attempt:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A2:attempt:1","status":"queued","queuePosition":1,"queueHeld":true,"requestedAt":"2026-10-27T14:24:26.567Z","startedAt":null,"completedAt":null,"checkpointId":null,"contextHandoffId":null},{"id":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:3","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ordinal":3,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","userMessageId":"message:mcp:client%3A3615d0b0-29d2-4c83-b8d7-da01992d4840:thread-send:604cddc4-0d14-41f8-8b22-064dc8cb2d50","rootNodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A3:root","activeAttemptId":"run-attempt:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A3:attempt:1","status":"completed","queuePosition":null,"requestedAt":"2026-10-27T14:24:39.926Z","startedAt":"2026-10-27T14:24:40.215Z","completedAt":"2026-10-27T14:24:47.670Z","checkpointId":"checkpoint:scope:checkpoint-scope%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aname%3Aroot:name:3","contextHandoffId":null}],"messages":[{"createdBy":"user","creationSource":"web","id":"message:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1:076898c7-32f3-4963-83ee-bf5eb2b1cd0f","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%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":"2026-10-27T14:24:23.442Z","updatedAt":"2026-10-27T14:24:23.442Z"},{"createdBy":"agent","creationSource":"mcp","id":"message:mcp:client%3A3615d0b0-29d2-4c83-b8d7-da01992d4840:thread-send:604cddc4-0d14-41f8-8b22-064dc8cb2d50","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:3","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%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":"2026-10-27T14:24:39.926Z","updatedAt":"2026-10-27T14:24:39.926Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b42bd524819aace1a8cdad9d0eac","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:3","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b42bd524819aace1a8cdad9d0eac","role":"assistant","text":"I’ll start the requested foreground Node process and leave its command session running.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:43.876Z","updatedAt":"2026-10-27T14:24:44.181Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b42f6384819aaf98301c46494b00","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:3","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b42f6384819aaf98301c46494b00","role":"assistant","text":"CODEX_ROOT_SETTLED","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:47.463Z","updatedAt":"2026-10-27T14:24:47.504Z"},{"createdBy":"user","creationSource":"web","id":"519064dd-4cdb-43f2-9488-d4fa4a9d5d55","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:2","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A2:root","role":"user","text":"HELD_Q_17885: When explicitly released, reply exactly HELD_Q_DONE. No tools.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:26.567Z","updatedAt":"2026-10-27T14:24:26.567Z"}],"subagents":[],"providerThreads":[{"id":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","driver":"codex","providerInstanceId":"codex","providerSessionId":"provider-session:provider-instance:codex:shared","appThreadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ownerNodeId":null,"nativeThreadRef":{"driver":"codex","nativeId":"01a17dbf-8317-7fc1-950c-c63c6cd01212","strength":"strong"},"nativeConversationHeadRef":null,"status":"idle","firstRunOrdinal":1,"lastRunOrdinal":3,"handoffIds":[],"forkedFrom":null,"pendingBackgroundTasks":[],"contextUsage":null,"nativeMetadata":null,"goal":null,"createdAt":"2026-10-27T14:24:23.442Z","updatedAt":"2026-10-27T14:24:47.595Z"}]}
2026-10-27T14:24:48.626Z STEP {"action":"CLI/MCP send; preserves held queue","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","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."}
2026-10-27T14:24:57.318Z PROJECTION {"runs":[{"id":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ordinal":1,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","userMessageId":"message:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1:076898c7-32f3-4963-83ee-bf5eb2b1cd0f","rootNodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1:root","activeAttemptId":"run-attempt:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1:attempt:1","status":"interrupted","queuePosition":null,"requestedAt":"2026-10-27T14:24:23.442Z","startedAt":"2026-10-27T14:24:25.671Z","completedAt":"2026-10-27T14:24:26.847Z","checkpointId":null,"contextHandoffId":null,"workspacePreparation":{"type":"root"}},{"id":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:2","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ordinal":2,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","userMessageId":"519064dd-4cdb-43f2-9488-d4fa4a9d5d55","rootNodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A2:root","activeAttemptId":"run-attempt:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A2:attempt:1","status":"queued","queuePosition":1,"queueHeld":true,"requestedAt":"2026-10-27T14:24:26.567Z","startedAt":null,"completedAt":null,"checkpointId":null,"contextHandoffId":null},{"id":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:3","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ordinal":3,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","userMessageId":"message:mcp:client%3A3615d0b0-29d2-4c83-b8d7-da01992d4840:thread-send:604cddc4-0d14-41f8-8b22-064dc8cb2d50","rootNodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A3:root","activeAttemptId":"run-attempt:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A3:attempt:1","status":"completed","queuePosition":null,"requestedAt":"2026-10-27T14:24:39.926Z","startedAt":"2026-10-27T14:24:40.215Z","completedAt":"2026-10-27T14:24:47.670Z","checkpointId":"checkpoint:scope:checkpoint-scope%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aname%3Aroot:name:3","contextHandoffId":null},{"id":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:4","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ordinal":4,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","userMessageId":"message:mcp:client%3A54049495-6f11-4f1c-89eb-579299a4e0b5:thread-send:e1e87be4-f1df-42fd-9ebb-8db56f3337ba","rootNodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A4:root","activeAttemptId":"run-attempt:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A4:attempt:1","status":"running","queuePosition":null,"requestedAt":"2026-10-27T14:24:57.114Z","startedAt":"2026-10-27T14:24:57.187Z","completedAt":null,"checkpointId":null,"contextHandoffId":null}],"messages":[{"createdBy":"user","creationSource":"web","id":"message:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1:076898c7-32f3-4963-83ee-bf5eb2b1cd0f","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%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":"2026-10-27T14:24:23.442Z","updatedAt":"2026-10-27T14:24:23.442Z"},{"createdBy":"agent","creationSource":"mcp","id":"message:mcp:client%3A3615d0b0-29d2-4c83-b8d7-da01992d4840:thread-send:604cddc4-0d14-41f8-8b22-064dc8cb2d50","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:3","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%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":"2026-10-27T14:24:39.926Z","updatedAt":"2026-10-27T14:24:39.926Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b42bd524819aace1a8cdad9d0eac","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:3","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b42bd524819aace1a8cdad9d0eac","role":"assistant","text":"I’ll start the requested foreground Node process and leave its command session running.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:43.876Z","updatedAt":"2026-10-27T14:24:44.181Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b42f6384819aaf98301c46494b00","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:3","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b42f6384819aaf98301c46494b00","role":"assistant","text":"CODEX_ROOT_SETTLED","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:47.463Z","updatedAt":"2026-10-27T14:24:47.504Z"},{"createdBy":"agent","creationSource":"mcp","id":"message:mcp:client%3A54049495-6f11-4f1c-89eb-579299a4e0b5:thread-send:e1e87be4-f1df-42fd-9ebb-8db56f3337ba","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:4","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%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":"2026-10-27T14:24:57.114Z","updatedAt":"2026-10-27T14:24:57.114Z"},{"createdBy":"user","creationSource":"web","id":"519064dd-4cdb-43f2-9488-d4fa4a9d5d55","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:2","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A2:root","role":"user","text":"HELD_Q_17885: When explicitly released, reply exactly HELD_Q_DONE. No tools.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:26.567Z","updatedAt":"2026-10-27T14:24:26.567Z"}],"subagents":[],"providerThreads":[{"id":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","driver":"codex","providerInstanceId":"codex","providerSessionId":"provider-session:provider-instance:codex:shared","appThreadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ownerNodeId":null,"nativeThreadRef":{"driver":"codex","nativeId":"01a17dbf-8317-7fc1-950c-c63c6cd01212","strength":"strong"},"nativeConversationHeadRef":null,"status":"active","firstRunOrdinal":1,"lastRunOrdinal":4,"handoffIds":[],"forkedFrom":null,"pendingBackgroundTasks":[],"contextUsage":{"usedTokens":20171,"maxTokens":258400},"nativeMetadata":null,"goal":null,"createdAt":"2026-10-27T14:24:23.442Z","updatedAt":"2026-10-27T14:24:57.187Z"}]}
2026-10-27T14:24:57.476Z CLI_RESULT {"code":0,"out":"{\"threadId\":\"bad21ec5-ff88-4a5a-b1d1-ed69c499695a\",\"link\":\"[Held queue codex evidence](t3-thread://v1/bad21ec5-ff88-4a5a-b1d1-ed69c499695a)\",\"messageId\":\"message:mcp:client%3A54049495-6f11-4f1c-89eb-579299a4e0b5:thread-send:e1e87be4-f1df-42fd-9ebb-8db56f3337ba\",\"runId\":\"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:4\",\"status\":\"starting\",\"delivery\":\"started\"}\n"}
2026-10-27T14:24:57.476Z OBSERVATION_WINDOW {"milliseconds":65000,"narration":"Observe real command completions while held Q exists; no release"}
2026-10-27T14:25:00.639Z PROJECTION {"runs":[{"id":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ordinal":1,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","userMessageId":"message:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1:076898c7-32f3-4963-83ee-bf5eb2b1cd0f","rootNodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1:root","activeAttemptId":"run-attempt:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1:attempt:1","status":"interrupted","queuePosition":null,"requestedAt":"2026-10-27T14:24:23.442Z","startedAt":"2026-10-27T14:24:25.671Z","completedAt":"2026-10-27T14:24:26.847Z","checkpointId":null,"contextHandoffId":null,"workspacePreparation":{"type":"root"}},{"id":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:2","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ordinal":2,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","userMessageId":"519064dd-4cdb-43f2-9488-d4fa4a9d5d55","rootNodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A2:root","activeAttemptId":"run-attempt:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A2:attempt:1","status":"queued","queuePosition":1,"queueHeld":true,"requestedAt":"2026-10-27T14:24:26.567Z","startedAt":null,"completedAt":null,"checkpointId":null,"contextHandoffId":null},{"id":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:3","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ordinal":3,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","userMessageId":"message:mcp:client%3A3615d0b0-29d2-4c83-b8d7-da01992d4840:thread-send:604cddc4-0d14-41f8-8b22-064dc8cb2d50","rootNodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A3:root","activeAttemptId":"run-attempt:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A3:attempt:1","status":"completed","queuePosition":null,"requestedAt":"2026-10-27T14:24:39.926Z","startedAt":"2026-10-27T14:24:40.215Z","completedAt":"2026-10-27T14:24:47.670Z","checkpointId":"checkpoint:scope:checkpoint-scope%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aname%3Aroot:name:3","contextHandoffId":null},{"id":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:4","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ordinal":4,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","userMessageId":"message:mcp:client%3A54049495-6f11-4f1c-89eb-579299a4e0b5:thread-send:e1e87be4-f1df-42fd-9ebb-8db56f3337ba","rootNodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A4:root","activeAttemptId":"run-attempt:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A4:attempt:1","status":"running","queuePosition":null,"requestedAt":"2026-10-27T14:24:57.114Z","startedAt":"2026-10-27T14:24:57.187Z","completedAt":null,"checkpointId":null,"contextHandoffId":null}],"messages":[{"createdBy":"user","creationSource":"web","id":"message:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1:076898c7-32f3-4963-83ee-bf5eb2b1cd0f","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%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":"2026-10-27T14:24:23.442Z","updatedAt":"2026-10-27T14:24:23.442Z"},{"createdBy":"agent","creationSource":"mcp","id":"message:mcp:client%3A3615d0b0-29d2-4c83-b8d7-da01992d4840:thread-send:604cddc4-0d14-41f8-8b22-064dc8cb2d50","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:3","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%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":"2026-10-27T14:24:39.926Z","updatedAt":"2026-10-27T14:24:39.926Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b42bd524819aace1a8cdad9d0eac","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:3","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b42bd524819aace1a8cdad9d0eac","role":"assistant","text":"I’ll start the requested foreground Node process and leave its command session running.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:43.876Z","updatedAt":"2026-10-27T14:24:44.181Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b42f6384819aaf98301c46494b00","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:3","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b42f6384819aaf98301c46494b00","role":"assistant","text":"CODEX_ROOT_SETTLED","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:47.463Z","updatedAt":"2026-10-27T14:24:47.504Z"},{"createdBy":"agent","creationSource":"mcp","id":"message:mcp:client%3A54049495-6f11-4f1c-89eb-579299a4e0b5:thread-send:e1e87be4-f1df-42fd-9ebb-8db56f3337ba","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:4","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%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":"2026-10-27T14:24:57.114Z","updatedAt":"2026-10-27T14:24:57.114Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b43c77a4819a98bb5eac73b6ae6b","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:4","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b43c77a4819a98bb5eac73b6ae6b","role":"assistant","text":"I’ll start the second foreground Node session, leave it unpolled, then provide the essay without changing files.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:00.542Z","updatedAt":"2026-10-27T14:25:00.609Z"},{"createdBy":"user","creationSource":"web","id":"519064dd-4cdb-43f2-9488-d4fa4a9d5d55","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:2","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A2:root","role":"user","text":"HELD_Q_17885: When explicitly released, reply exactly HELD_Q_DONE. No tools.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:26.567Z","updatedAt":"2026-10-27T14:24:26.567Z"}],"subagents":[],"providerThreads":[{"id":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","driver":"codex","providerInstanceId":"codex","providerSessionId":"provider-session:provider-instance:codex:shared","appThreadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ownerNodeId":null,"nativeThreadRef":{"driver":"codex","nativeId":"01a17dbf-8317-7fc1-950c-c63c6cd01212","strength":"strong"},"nativeConversationHeadRef":null,"status":"active","firstRunOrdinal":1,"lastRunOrdinal":4,"handoffIds":[],"forkedFrom":null,"pendingBackgroundTasks":[],"contextUsage":{"usedTokens":20171,"maxTokens":258400},"nativeMetadata":null,"goal":null,"createdAt":"2026-10-27T14:24:23.442Z","updatedAt":"2026-10-27T14:24:57.187Z"}]}
2026-10-27T14:25:30.299Z PROJECTION {"runs":[{"id":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ordinal":1,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","userMessageId":"message:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1:076898c7-32f3-4963-83ee-bf5eb2b1cd0f","rootNodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1:root","activeAttemptId":"run-attempt:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1:attempt:1","status":"interrupted","queuePosition":null,"requestedAt":"2026-10-27T14:24:23.442Z","startedAt":"2026-10-27T14:24:25.671Z","completedAt":"2026-10-27T14:24:26.847Z","checkpointId":null,"contextHandoffId":null,"workspacePreparation":{"type":"root"}},{"id":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:2","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ordinal":2,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","userMessageId":"519064dd-4cdb-43f2-9488-d4fa4a9d5d55","rootNodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A2:root","activeAttemptId":"run-attempt:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A2:attempt:1","status":"queued","queuePosition":1,"queueHeld":true,"requestedAt":"2026-10-27T14:24:26.567Z","startedAt":null,"completedAt":null,"checkpointId":null,"contextHandoffId":null},{"id":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:3","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ordinal":3,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","userMessageId":"message:mcp:client%3A3615d0b0-29d2-4c83-b8d7-da01992d4840:thread-send:604cddc4-0d14-41f8-8b22-064dc8cb2d50","rootNodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A3:root","activeAttemptId":"run-attempt:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A3:attempt:1","status":"completed","queuePosition":null,"requestedAt":"2026-10-27T14:24:39.926Z","startedAt":"2026-10-27T14:24:40.215Z","completedAt":"2026-10-27T14:24:47.670Z","checkpointId":"checkpoint:scope:checkpoint-scope%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aname%3Aroot:name:3","contextHandoffId":null},{"id":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:4","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ordinal":4,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","userMessageId":"message:mcp:client%3A54049495-6f11-4f1c-89eb-579299a4e0b5:thread-send:e1e87be4-f1df-42fd-9ebb-8db56f3337ba","rootNodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A4:root","activeAttemptId":"run-attempt:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A4:attempt:1","status":"running","queuePosition":null,"requestedAt":"2026-10-27T14:24:57.114Z","startedAt":"2026-10-27T14:24:57.187Z","completedAt":null,"checkpointId":null,"contextHandoffId":null},{"id":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:5","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ordinal":5,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","userMessageId":"message:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1:437b5282-29f1-4188-b3a8-58d8f5a1229d","rootNodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A5:root","activeAttemptId":"run-attempt:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A5:attempt:1","status":"queued","queuePosition":2,"queueHeld":true,"requestedAt":"2026-10-27T14:25:30.253Z","startedAt":null,"completedAt":null,"checkpointId":null,"contextHandoffId":null}],"messages":[{"createdBy":"user","creationSource":"web","id":"message:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1:076898c7-32f3-4963-83ee-bf5eb2b1cd0f","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%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":"2026-10-27T14:24:23.442Z","updatedAt":"2026-10-27T14:24:23.442Z"},{"createdBy":"agent","creationSource":"mcp","id":"message:mcp:client%3A3615d0b0-29d2-4c83-b8d7-da01992d4840:thread-send:604cddc4-0d14-41f8-8b22-064dc8cb2d50","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:3","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%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":"2026-10-27T14:24:39.926Z","updatedAt":"2026-10-27T14:24:39.926Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b42bd524819aace1a8cdad9d0eac","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:3","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b42bd524819aace1a8cdad9d0eac","role":"assistant","text":"I’ll start the requested foreground Node process and leave its command session running.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:43.876Z","updatedAt":"2026-10-27T14:24:44.181Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b42f6384819aaf98301c46494b00","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:3","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b42f6384819aaf98301c46494b00","role":"assistant","text":"CODEX_ROOT_SETTLED","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:47.463Z","updatedAt":"2026-10-27T14:24:47.504Z"},{"createdBy":"agent","creationSource":"mcp","id":"message:mcp:client%3A54049495-6f11-4f1c-89eb-579299a4e0b5:thread-send:e1e87be4-f1df-42fd-9ebb-8db56f3337ba","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:4","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%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":"2026-10-27T14:24:57.114Z","updatedAt":"2026-10-27T14:24:57.114Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b43c77a4819a98bb5eac73b6ae6b","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:4","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b43c77a4819a98bb5eac73b6ae6b","role":"assistant","text":"I’ll start the second foreground Node session, leave it unpolled, then provide the essay without changing files.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:00.542Z","updatedAt":"2026-10-27T14:25:00.609Z"},{"createdBy":"user","creationSource":"web","id":"519064dd-4cdb-43f2-9488-d4fa4a9d5d55","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:2","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A2:root","role":"user","text":"HELD_Q_17885: When explicitly released, reply exactly HELD_Q_DONE. No tools.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:26.567Z","updatedAt":"2026-10-27T14:24:26.567Z"},{"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":"provider","id":"message:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1:437b5282-29f1-4188-b3a8-58d8f5a1229d","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:5","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%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":"2026-10-27T14:25:30.253Z","updatedAt":"2026-10-27T14:25:30.253Z"}],"subagents":[],"providerThreads":[{"id":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","driver":"codex","providerInstanceId":"codex","providerSessionId":"provider-session:provider-instance:codex:shared","appThreadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ownerNodeId":null,"nativeThreadRef":{"driver":"codex","nativeId":"01a17dbf-8317-7fc1-950c-c63c6cd01212","strength":"strong"},"nativeConversationHeadRef":null,"status":"active","firstRunOrdinal":1,"lastRunOrdinal":4,"handoffIds":[],"forkedFrom":null,"pendingBackgroundTasks":[],"contextUsage":{"usedTokens":20171,"maxTokens":258400},"nativeMetadata":null,"goal":null,"createdAt":"2026-10-27T14:24:23.442Z","updatedAt":"2026-10-27T14:24:57.187Z"}]}
2026-10-27T14:25:37.372Z PROJECTION {"runs":[{"id":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ordinal":1,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","userMessageId":"message:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1:076898c7-32f3-4963-83ee-bf5eb2b1cd0f","rootNodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1:root","activeAttemptId":"run-attempt:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1:attempt:1","status":"interrupted","queuePosition":null,"requestedAt":"2026-10-27T14:24:23.442Z","startedAt":"2026-10-27T14:24:25.671Z","completedAt":"2026-10-27T14:24:26.847Z","checkpointId":null,"contextHandoffId":null,"workspacePreparation":{"type":"root"}},{"id":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:2","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ordinal":2,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","userMessageId":"519064dd-4cdb-43f2-9488-d4fa4a9d5d55","rootNodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A2:root","activeAttemptId":"run-attempt:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A2:attempt:1","status":"queued","queuePosition":1,"queueHeld":true,"requestedAt":"2026-10-27T14:24:26.567Z","startedAt":null,"completedAt":null,"checkpointId":null,"contextHandoffId":null},{"id":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:3","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ordinal":3,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","userMessageId":"message:mcp:client%3A3615d0b0-29d2-4c83-b8d7-da01992d4840:thread-send:604cddc4-0d14-41f8-8b22-064dc8cb2d50","rootNodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A3:root","activeAttemptId":"run-attempt:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A3:attempt:1","status":"completed","queuePosition":null,"requestedAt":"2026-10-27T14:24:39.926Z","startedAt":"2026-10-27T14:24:40.215Z","completedAt":"2026-10-27T14:24:47.670Z","checkpointId":"checkpoint:scope:checkpoint-scope%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aname%3Aroot:name:3","contextHandoffId":null},{"id":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:4","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ordinal":4,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","userMessageId":"message:mcp:client%3A54049495-6f11-4f1c-89eb-579299a4e0b5:thread-send:e1e87be4-f1df-42fd-9ebb-8db56f3337ba","rootNodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A4:root","activeAttemptId":"run-attempt:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A4:attempt:1","status":"running","queuePosition":null,"requestedAt":"2026-10-27T14:24:57.114Z","startedAt":"2026-10-27T14:24:57.187Z","completedAt":null,"checkpointId":null,"contextHandoffId":null},{"id":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:5","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ordinal":5,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","userMessageId":"message:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1:437b5282-29f1-4188-b3a8-58d8f5a1229d","rootNodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A5:root","activeAttemptId":"run-attempt:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A5:attempt:1","status":"queued","queuePosition":2,"queueHeld":true,"requestedAt":"2026-10-27T14:25:30.253Z","startedAt":null,"completedAt":null,"checkpointId":null,"contextHandoffId":null}],"messages":[{"createdBy":"user","creationSource":"web","id":"message:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1:076898c7-32f3-4963-83ee-bf5eb2b1cd0f","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%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":"2026-10-27T14:24:23.442Z","updatedAt":"2026-10-27T14:24:23.442Z"},{"createdBy":"agent","creationSource":"mcp","id":"message:mcp:client%3A3615d0b0-29d2-4c83-b8d7-da01992d4840:thread-send:604cddc4-0d14-41f8-8b22-064dc8cb2d50","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:3","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%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":"2026-10-27T14:24:39.926Z","updatedAt":"2026-10-27T14:24:39.926Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b42bd524819aace1a8cdad9d0eac","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:3","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b42bd524819aace1a8cdad9d0eac","role":"assistant","text":"I’ll start the requested foreground Node process and leave its command session running.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:43.876Z","updatedAt":"2026-10-27T14:24:44.181Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b42f6384819aaf98301c46494b00","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:3","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b42f6384819aaf98301c46494b00","role":"assistant","text":"CODEX_ROOT_SETTLED","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:47.463Z","updatedAt":"2026-10-27T14:24:47.504Z"},{"createdBy":"agent","creationSource":"mcp","id":"message:mcp:client%3A54049495-6f11-4f1c-89eb-579299a4e0b5:thread-send:e1e87be4-f1df-42fd-9ebb-8db56f3337ba","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:4","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%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":"2026-10-27T14:24:57.114Z","updatedAt":"2026-10-27T14:24:57.114Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b43c77a4819a98bb5eac73b6ae6b","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:4","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b43c77a4819a98bb5eac73b6ae6b","role":"assistant","text":"I’ll start the second foreground Node session, leave it unpolled, then provide the essay without changing files.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:00.542Z","updatedAt":"2026-10-27T14:25:00.609Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b440f36c819a88511d115ad115f6","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:4","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b440f36c819a88511d115ad115f6","role":"assistant","text":"Serial Queues\n\nA serial queue is one of the simplest tools for organizing concurrent work. It accepts tasks in some order and allows only one task to execute at a time. When the active task finishes, the next task begins. This rule sounds modest, but it provides a powerful guarantee: tasks submitted to the same serial queue never overlap. Systems use that guarantee to coordinate access to shared state, preserve ordering, and make asynchronous programs easier to understand.\n\nConcurrency becomes difficult when several operations can touch the same data simultaneously. Suppose two tasks read a counter, add one, and write the result. If both read the old value before either writes, one increment disappears. Locks can protect the counter, but locks introduce their own obligations. Every access must acquire the correct lock, release it on every path, and avoid incompatible lock ordering. A serial queue offers another model. Code submits all counter operations to one queue, and the queue ensures that each operation observes the effects of its predecessors.\n\nThis arrangement is often described as confinement. The protected state belongs conceptually to the queue, and code may interact with it only through tasks submitted there. Confinement matters more than the queue’s mechanics. If some code bypasses the queue and accesses the state directly, the safety guarantee collapses. A serial queue is therefore not magical synchronization; it is a disciplined boundary. It works when the program consistently respects that boundary.\n\nSerial queues also express ordering. If task A is submitted before task B, a first-in, first-out serial queue starts A first and completes it before B starts. This property is useful for event processing, log writing, protocol handling, and state machines. An application might receive user actions from many threads but funnel them through one queue so that the state changes in a stable sequence. The producers remain concurrent while the sensitive decisions become serialized.\n\nSubmission and execution are different concepts. Asynchronous submission normally places a task on the queue and returns immediately. The caller can continue doing other work while the queued task waits its turn. Synchronous submission blocks the caller until the submitted task completes. Both modes preserve serialization inside the queue, but they have very different effects on the caller. Asynchronous submission promotes responsiveness. Synchronous submission can conveniently retrieve a result, though careless use can cause deadlock.\n\nThe classic deadlock occurs when code already running on a serial queue synchronously submits another task to that same queue. The outer task waits for the inner task to finish, but the queue cannot start the inner task until the outer task finishes. Neither can advance. Queue libraries sometimes detect this mistake, but programs should not depend on detection. Common remedies include executing directly when already on the queue, exposing only asynchronous operations, or restructuring the API so that nested synchronous submission is unnecessary.\n\nA queue need not own a dedicated thread. Many modern runtimes maintain a pool of worker threads and schedule queue tasks onto that pool. The serial property concerns logical execution order, not permanent attachment to a particular operating-system thread. One task may run on one worker and the next task on another, while still never overlapping. Consequently, thread-local storage and thread identity should not be treated as queue identity unless the runtime explicitly promises such behavior.\n\nThis distinction helps explain why serial queues can be inexpensive. Creating thousands of dedicated threads would consume substantial memory and scheduling resources. Creating many lightweight queue objects can be practical because inactive queues need no thread of their own. The runtime activates a queue only when work is available. Queue-based designs can therefore represent many independent domains of serialization without requiring an equally large number of workers.\n\nNevertheless, serialization has a performance cost. A queue can execute no faster than its slowest accumulated workload permits. If producers submit tasks faster than the queue completes them, latency grows and memory may grow with the backlog. One long task delays every task behind it, a phenomenon sometimes called head-of-line blocking. Good serial-queue tasks are usually short, bounded, and focused on the state that truly requires ordered access.\n\nExpensive computation and slow input or output should often happen elsewhere. A task can capture the state needed for an operation, dispatch costly work to a concurrent executor, and later submit a small result-handling task back to the serial queue. This pattern preserves state safety while exploiting parallelism. It also introduces a subtle issue: results may return in a different order from the requests that produced them. The queue serializes result application, but it does not automatically restore semantic ordering. Sequence numbers, version checks, cancellation, or explicit dependencies may be needed.\n\nChoosing the scope of a queue is therefore important. One global serial queue makes reasoning easy but can eliminate useful parallelism. A separate queue for every tiny value can make relationships hard to follow and can create coordination overhead. A useful middle ground is to assign a queue to a coherent ownership domain, such as a document, connection, cache, account, or subsystem. Operations within a domain are ordered, while independent domains can proceed concurrently.\n\nSerial queues resemble mutexes, but their programming styles differ. A mutex protects a critical section executed by the calling thread. A queue usually accepts a unit of work that may execute later on another worker. Mutexes fit small, synchronous accesses and existing data structures. Queues fit ownership-oriented components, asynchronous workflows, and event-driven systems. Neither mechanism is universally superior. The better choice is the one that makes the invariant obvious and difficult to violate.\n\nQueues can also improve encapsulation. Instead of exposing mutable fields and expecting callers to synchronize correctly, a component can expose operations such as update, snapshot, and close. Internally, those operations are submitted to its serial queue. Callers no longer need to know which values require protection. The component becomes an active object: it receives messages, processes them one at a time, and owns its state. Actor systems generalize this idea by providing isolated entities with serial mailboxes.\n\nError handling needs deliberate design. An exception or rejected promise in one task should not silently stop the queue unless that behavior is intentional. Libraries differ in whether errors propagate to submitters, reach a global handler, or become detached failures. A robust queue abstraction defines how each task reports success, how failures affect following tasks, and whether retries preserve order. Retrying a failed operation at the tail may allow later operations to overtake it, while retrying in place may block the entire queue.\n\nCancellation is similarly nuanced. Removing a task that has not started is relatively straightforward, but cancellation may change the meaning of later tasks. If a queued sequence contains open, write, and close, cancelling open while retaining the other operations is probably invalid. Once a task begins, forced interruption may leave protected state inconsistent. Cooperative cancellation is safer: the task checks a token at well-defined points and exits after restoring invariants. Queue APIs should distinguish cancelling interest in a result from cancelling the underlying operation.\n\nFairness and priority complicate the basic FIFO model. Strict submission order is predictable, but urgent work can become trapped behind routine work. Priority queues can reduce urgent latency, yet they weaken ordering and may starve low-priority tasks. Multiple serial queues sharing a worker pool can also experience priority inversion when a high-priority task depends on work waiting in a lower-priority queue. These concerns matter most in interactive, real-time, or heavily loaded systems. For many application components, plain FIFO behavior remains the clearest default.\n\nTesting serial-queue code requires more than verifying final values. Tests should exercise ordering, reentrancy, failure, cancellation, and shutdown. A controllable executor can pause tasks at boundaries and make normally rare schedules reproducible. Assertions can verify that no two tasks enter the protected region simultaneously. Stress tests can submit operations from many producers, but deterministic tests are usually better at explaining a failure. Time-based sleeps are fragile because they confuse scheduler timing with program correctness.\n\nShutdown is an especially important lifecycle transition. A queue may need to reject new tasks, drain accepted work, cancel pending operations, or stop immediately. Each policy is reasonable in a different context. A file writer may need to drain to prevent data loss. A screen controller being discarded may cancel obsolete rendering work. A network service may stop accepting requests but allow in-flight requests to finish before a deadline. The contract must say what happens to queued tasks and how callers learn their outcome.\n\nObservability makes overloaded queues diagnosable. Useful measurements include queue depth, oldest-task age, execution duration, rejection count, and time spent waiting versus running. Task names or correlation identifiers can connect queue activity to higher-level requests. Instrumentation should avoid exposing sensitive task contents and should not add enough synchronized work to become a bottleneck itself. A growing queue is often a symptom rather than the root cause, but without metrics that symptom remains invisible until users notice delays.\n\nSerial queues are most effective when used as precise instruments rather than universal architecture. They simplify one class of problems by turning concurrent mutation into an ordered stream of operations. In exchange, they introduce queuing latency, lifecycle concerns, and the possibility of deadlock or backlog. Their central benefit is intellectual as much as mechanical: they give programmers a place where events happen one at a time. When the ownership boundary is clear, tasks remain short, and ordering semantics are explicit, that simple promise can make a complex concurrent system substantially safer and easier to maintain.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:04.987Z","updatedAt":"2026-10-27T14:25:37.148Z"},{"createdBy":"user","creationSource":"web","id":"519064dd-4cdb-43f2-9488-d4fa4a9d5d55","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:2","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A2:root","role":"user","text":"HELD_Q_17885: When explicitly released, reply exactly HELD_Q_DONE. No tools.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:26.567Z","updatedAt":"2026-10-27T14:24:26.567Z"},{"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":"provider","id":"message:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1:437b5282-29f1-4188-b3a8-58d8f5a1229d","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:5","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%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":"2026-10-27T14:25:30.253Z","updatedAt":"2026-10-27T14:25:30.253Z"}],"subagents":[],"providerThreads":[{"id":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","driver":"codex","providerInstanceId":"codex","providerSessionId":"provider-session:provider-instance:codex:shared","appThreadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ownerNodeId":null,"nativeThreadRef":{"driver":"codex","nativeId":"01a17dbf-8317-7fc1-950c-c63c6cd01212","strength":"strong"},"nativeConversationHeadRef":null,"status":"active","firstRunOrdinal":1,"lastRunOrdinal":4,"handoffIds":[],"forkedFrom":null,"pendingBackgroundTasks":[],"contextUsage":{"usedTokens":20171,"maxTokens":258400},"nativeMetadata":null,"goal":null,"createdAt":"2026-10-27T14:24:23.442Z","updatedAt":"2026-10-27T14:24:57.187Z"}]}
2026-10-27T14:25:37.409Z PROJECTION {"runs":[{"id":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ordinal":1,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","userMessageId":"message:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1:076898c7-32f3-4963-83ee-bf5eb2b1cd0f","rootNodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1:root","activeAttemptId":"run-attempt:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1:attempt:1","status":"interrupted","queuePosition":null,"requestedAt":"2026-10-27T14:24:23.442Z","startedAt":"2026-10-27T14:24:25.671Z","completedAt":"2026-10-27T14:24:26.847Z","checkpointId":null,"contextHandoffId":null,"workspacePreparation":{"type":"root"}},{"id":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:2","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ordinal":2,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","userMessageId":"519064dd-4cdb-43f2-9488-d4fa4a9d5d55","rootNodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A2:root","activeAttemptId":"run-attempt:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A2:attempt:1","status":"queued","queuePosition":1,"queueHeld":true,"requestedAt":"2026-10-27T14:24:26.567Z","startedAt":null,"completedAt":null,"checkpointId":null,"contextHandoffId":null},{"id":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:3","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ordinal":3,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","userMessageId":"message:mcp:client%3A3615d0b0-29d2-4c83-b8d7-da01992d4840:thread-send:604cddc4-0d14-41f8-8b22-064dc8cb2d50","rootNodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A3:root","activeAttemptId":"run-attempt:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A3:attempt:1","status":"completed","queuePosition":null,"requestedAt":"2026-10-27T14:24:39.926Z","startedAt":"2026-10-27T14:24:40.215Z","completedAt":"2026-10-27T14:24:47.670Z","checkpointId":"checkpoint:scope:checkpoint-scope%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aname%3Aroot:name:3","contextHandoffId":null},{"id":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:4","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ordinal":4,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","userMessageId":"message:mcp:client%3A54049495-6f11-4f1c-89eb-579299a4e0b5:thread-send:e1e87be4-f1df-42fd-9ebb-8db56f3337ba","rootNodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A4:root","activeAttemptId":"run-attempt:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A4:attempt:1","status":"waiting","queuePosition":null,"requestedAt":"2026-10-27T14:24:57.114Z","startedAt":"2026-10-27T14:24:57.187Z","completedAt":null,"checkpointId":null,"contextHandoffId":null},{"id":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:5","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ordinal":5,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","userMessageId":"message:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1:437b5282-29f1-4188-b3a8-58d8f5a1229d","rootNodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A5:root","activeAttemptId":"run-attempt:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A5:attempt:1","status":"queued","queuePosition":2,"queueHeld":true,"requestedAt":"2026-10-27T14:25:30.253Z","startedAt":null,"completedAt":null,"checkpointId":null,"contextHandoffId":null}],"messages":[{"createdBy":"user","creationSource":"web","id":"message:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1:076898c7-32f3-4963-83ee-bf5eb2b1cd0f","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%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":"2026-10-27T14:24:23.442Z","updatedAt":"2026-10-27T14:24:23.442Z"},{"createdBy":"agent","creationSource":"mcp","id":"message:mcp:client%3A3615d0b0-29d2-4c83-b8d7-da01992d4840:thread-send:604cddc4-0d14-41f8-8b22-064dc8cb2d50","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:3","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%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":"2026-10-27T14:24:39.926Z","updatedAt":"2026-10-27T14:24:39.926Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b42bd524819aace1a8cdad9d0eac","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:3","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b42bd524819aace1a8cdad9d0eac","role":"assistant","text":"I’ll start the requested foreground Node process and leave its command session running.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:43.876Z","updatedAt":"2026-10-27T14:24:44.181Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b42f6384819aaf98301c46494b00","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:3","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b42f6384819aaf98301c46494b00","role":"assistant","text":"CODEX_ROOT_SETTLED","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:47.463Z","updatedAt":"2026-10-27T14:24:47.504Z"},{"createdBy":"agent","creationSource":"mcp","id":"message:mcp:client%3A54049495-6f11-4f1c-89eb-579299a4e0b5:thread-send:e1e87be4-f1df-42fd-9ebb-8db56f3337ba","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:4","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%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":"2026-10-27T14:24:57.114Z","updatedAt":"2026-10-27T14:24:57.114Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b43c77a4819a98bb5eac73b6ae6b","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:4","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b43c77a4819a98bb5eac73b6ae6b","role":"assistant","text":"I’ll start the second foreground Node session, leave it unpolled, then provide the essay without changing files.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:00.542Z","updatedAt":"2026-10-27T14:25:00.609Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b440f36c819a88511d115ad115f6","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:4","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b440f36c819a88511d115ad115f6","role":"assistant","text":"Serial Queues\n\nA serial queue is one of the simplest tools for organizing concurrent work. It accepts tasks in some order and allows only one task to execute at a time. When the active task finishes, the next task begins. This rule sounds modest, but it provides a powerful guarantee: tasks submitted to the same serial queue never overlap. Systems use that guarantee to coordinate access to shared state, preserve ordering, and make asynchronous programs easier to understand.\n\nConcurrency becomes difficult when several operations can touch the same data simultaneously. Suppose two tasks read a counter, add one, and write the result. If both read the old value before either writes, one increment disappears. Locks can protect the counter, but locks introduce their own obligations. Every access must acquire the correct lock, release it on every path, and avoid incompatible lock ordering. A serial queue offers another model. Code submits all counter operations to one queue, and the queue ensures that each operation observes the effects of its predecessors.\n\nThis arrangement is often described as confinement. The protected state belongs conceptually to the queue, and code may interact with it only through tasks submitted there. Confinement matters more than the queue’s mechanics. If some code bypasses the queue and accesses the state directly, the safety guarantee collapses. A serial queue is therefore not magical synchronization; it is a disciplined boundary. It works when the program consistently respects that boundary.\n\nSerial queues also express ordering. If task A is submitted before task B, a first-in, first-out serial queue starts A first and completes it before B starts. This property is useful for event processing, log writing, protocol handling, and state machines. An application might receive user actions from many threads but funnel them through one queue so that the state changes in a stable sequence. The producers remain concurrent while the sensitive decisions become serialized.\n\nSubmission and execution are different concepts. Asynchronous submission normally places a task on the queue and returns immediately. The caller can continue doing other work while the queued task waits its turn. Synchronous submission blocks the caller until the submitted task completes. Both modes preserve serialization inside the queue, but they have very different effects on the caller. Asynchronous submission promotes responsiveness. Synchronous submission can conveniently retrieve a result, though careless use can cause deadlock.\n\nThe classic deadlock occurs when code already running on a serial queue synchronously submits another task to that same queue. The outer task waits for the inner task to finish, but the queue cannot start the inner task until the outer task finishes. Neither can advance. Queue libraries sometimes detect this mistake, but programs should not depend on detection. Common remedies include executing directly when already on the queue, exposing only asynchronous operations, or restructuring the API so that nested synchronous submission is unnecessary.\n\nA queue need not own a dedicated thread. Many modern runtimes maintain a pool of worker threads and schedule queue tasks onto that pool. The serial property concerns logical execution order, not permanent attachment to a particular operating-system thread. One task may run on one worker and the next task on another, while still never overlapping. Consequently, thread-local storage and thread identity should not be treated as queue identity unless the runtime explicitly promises such behavior.\n\nThis distinction helps explain why serial queues can be inexpensive. Creating thousands of dedicated threads would consume substantial memory and scheduling resources. Creating many lightweight queue objects can be practical because inactive queues need no thread of their own. The runtime activates a queue only when work is available. Queue-based designs can therefore represent many independent domains of serialization without requiring an equally large number of workers.\n\nNevertheless, serialization has a performance cost. A queue can execute no faster than its slowest accumulated workload permits. If producers submit tasks faster than the queue completes them, latency grows and memory may grow with the backlog. One long task delays every task behind it, a phenomenon sometimes called head-of-line blocking. Good serial-queue tasks are usually short, bounded, and focused on the state that truly requires ordered access.\n\nExpensive computation and slow input or output should often happen elsewhere. A task can capture the state needed for an operation, dispatch costly work to a concurrent executor, and later submit a small result-handling task back to the serial queue. This pattern preserves state safety while exploiting parallelism. It also introduces a subtle issue: results may return in a different order from the requests that produced them. The queue serializes result application, but it does not automatically restore semantic ordering. Sequence numbers, version checks, cancellation, or explicit dependencies may be needed.\n\nChoosing the scope of a queue is therefore important. One global serial queue makes reasoning easy but can eliminate useful parallelism. A separate queue for every tiny value can make relationships hard to follow and can create coordination overhead. A useful middle ground is to assign a queue to a coherent ownership domain, such as a document, connection, cache, account, or subsystem. Operations within a domain are ordered, while independent domains can proceed concurrently.\n\nSerial queues resemble mutexes, but their programming styles differ. A mutex protects a critical section executed by the calling thread. A queue usually accepts a unit of work that may execute later on another worker. Mutexes fit small, synchronous accesses and existing data structures. Queues fit ownership-oriented components, asynchronous workflows, and event-driven systems. Neither mechanism is universally superior. The better choice is the one that makes the invariant obvious and difficult to violate.\n\nQueues can also improve encapsulation. Instead of exposing mutable fields and expecting callers to synchronize correctly, a component can expose operations such as update, snapshot, and close. Internally, those operations are submitted to its serial queue. Callers no longer need to know which values require protection. The component becomes an active object: it receives messages, processes them one at a time, and owns its state. Actor systems generalize this idea by providing isolated entities with serial mailboxes.\n\nError handling needs deliberate design. An exception or rejected promise in one task should not silently stop the queue unless that behavior is intentional. Libraries differ in whether errors propagate to submitters, reach a global handler, or become detached failures. A robust queue abstraction defines how each task reports success, how failures affect following tasks, and whether retries preserve order. Retrying a failed operation at the tail may allow later operations to overtake it, while retrying in place may block the entire queue.\n\nCancellation is similarly nuanced. Removing a task that has not started is relatively straightforward, but cancellation may change the meaning of later tasks. If a queued sequence contains open, write, and close, cancelling open while retaining the other operations is probably invalid. Once a task begins, forced interruption may leave protected state inconsistent. Cooperative cancellation is safer: the task checks a token at well-defined points and exits after restoring invariants. Queue APIs should distinguish cancelling interest in a result from cancelling the underlying operation.\n\nFairness and priority complicate the basic FIFO model. Strict submission order is predictable, but urgent work can become trapped behind routine work. Priority queues can reduce urgent latency, yet they weaken ordering and may starve low-priority tasks. Multiple serial queues sharing a worker pool can also experience priority inversion when a high-priority task depends on work waiting in a lower-priority queue. These concerns matter most in interactive, real-time, or heavily loaded systems. For many application components, plain FIFO behavior remains the clearest default.\n\nTesting serial-queue code requires more than verifying final values. Tests should exercise ordering, reentrancy, failure, cancellation, and shutdown. A controllable executor can pause tasks at boundaries and make normally rare schedules reproducible. Assertions can verify that no two tasks enter the protected region simultaneously. Stress tests can submit operations from many producers, but deterministic tests are usually better at explaining a failure. Time-based sleeps are fragile because they confuse scheduler timing with program correctness.\n\nShutdown is an especially important lifecycle transition. A queue may need to reject new tasks, drain accepted work, cancel pending operations, or stop immediately. Each policy is reasonable in a different context. A file writer may need to drain to prevent data loss. A screen controller being discarded may cancel obsolete rendering work. A network service may stop accepting requests but allow in-flight requests to finish before a deadline. The contract must say what happens to queued tasks and how callers learn their outcome.\n\nObservability makes overloaded queues diagnosable. Useful measurements include queue depth, oldest-task age, execution duration, rejection count, and time spent waiting versus running. Task names or correlation identifiers can connect queue activity to higher-level requests. Instrumentation should avoid exposing sensitive task contents and should not add enough synchronized work to become a bottleneck itself. A growing queue is often a symptom rather than the root cause, but without metrics that symptom remains invisible until users notice delays.\n\nSerial queues are most effective when used as precise instruments rather than universal architecture. They simplify one class of problems by turning concurrent mutation into an ordered stream of operations. In exchange, they introduce queuing latency, lifecycle concerns, and the possibility of deadlock or backlog. Their central benefit is intellectual as much as mechanical: they give programmers a place where events happen one at a time. When the ownership boundary is clear, tasks remain short, and ordering semantics are explicit, that simple promise can make a complex concurrent system substantially safer and easier to maintain.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:04.987Z","updatedAt":"2026-10-27T14:25:37.148Z"},{"createdBy":"user","creationSource":"web","id":"519064dd-4cdb-43f2-9488-d4fa4a9d5d55","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:2","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A2:root","role":"user","text":"HELD_Q_17885: When explicitly released, reply exactly HELD_Q_DONE. No tools.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:26.567Z","updatedAt":"2026-10-27T14:24:26.567Z"},{"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":"provider","id":"message:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1:437b5282-29f1-4188-b3a8-58d8f5a1229d","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:5","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%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":"2026-10-27T14:25:30.253Z","updatedAt":"2026-10-27T14:25:30.253Z"}],"subagents":[],"providerThreads":[{"id":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","driver":"codex","providerInstanceId":"codex","providerSessionId":"provider-session:provider-instance:codex:shared","appThreadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ownerNodeId":null,"nativeThreadRef":{"driver":"codex","nativeId":"01a17dbf-8317-7fc1-950c-c63c6cd01212","strength":"strong"},"nativeConversationHeadRef":null,"status":"idle","firstRunOrdinal":1,"lastRunOrdinal":4,"handoffIds":[],"forkedFrom":null,"pendingBackgroundTasks":[],"contextUsage":{"usedTokens":20171,"maxTokens":258400},"nativeMetadata":null,"goal":null,"createdAt":"2026-10-27T14:24:23.442Z","updatedAt":"2026-10-27T14:25:37.300Z"}]}
2026-10-27T14:25:38.343Z 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":"2026-10-27T14:24:23.442Z","updatedAt":"2026-10-27T14:24:23.442Z"},{"createdBy":"agent","creationSource":"mcp","id":"message:mcp:client%3A3615d0b0-29d2-4c83-b8d7-da01992d4840:thread-send:604cddc4-0d14-41f8-8b22-064dc8cb2d50","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:3","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%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":"2026-10-27T14:24:39.926Z","updatedAt":"2026-10-27T14:24:39.926Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b42bd524819aace1a8cdad9d0eac","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:3","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b42bd524819aace1a8cdad9d0eac","role":"assistant","text":"I’ll start the requested foreground Node process and leave its command session running.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:43.876Z","updatedAt":"2026-10-27T14:24:44.181Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b42f6384819aaf98301c46494b00","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:3","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b42f6384819aaf98301c46494b00","role":"assistant","text":"CODEX_ROOT_SETTLED","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:47.463Z","updatedAt":"2026-10-27T14:24:47.504Z"},{"createdBy":"agent","creationSource":"mcp","id":"message:mcp:client%3A54049495-6f11-4f1c-89eb-579299a4e0b5:thread-send:e1e87be4-f1df-42fd-9ebb-8db56f3337ba","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:4","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%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":"2026-10-27T14:24:57.114Z","updatedAt":"2026-10-27T14:24:57.114Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b43c77a4819a98bb5eac73b6ae6b","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:4","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b43c77a4819a98bb5eac73b6ae6b","role":"assistant","text":"I’ll start the second foreground Node session, leave it unpolled, then provide the essay without changing files.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:00.542Z","updatedAt":"2026-10-27T14:25:00.609Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b440f36c819a88511d115ad115f6","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:4","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b440f36c819a88511d115ad115f6","role":"assistant","text":"Serial Queues\n\nA serial queue is one of the simplest tools for organizing concurrent work. It accepts tasks in some order and allows only one task to execute at a time. When the active task finishes, the next task begins. This rule sounds modest, but it provides a powerful guarantee: tasks submitted to the same serial queue never overlap. Systems use that guarantee to coordinate access to shared state, preserve ordering, and make asynchronous programs easier to understand.\n\nConcurrency becomes difficult when several operations can touch the same data simultaneously. Suppose two tasks read a counter, add one, and write the result. If both read the old value before either writes, one increment disappears. Locks can protect the counter, but locks introduce their own obligations. Every access must acquire the correct lock, release it on every path, and avoid incompatible lock ordering. A serial queue offers another model. Code submits all counter operations to one queue, and the queue ensures that each operation observes the effects of its predecessors.\n\nThis arrangement is often described as confinement. The protected state belongs conceptually to the queue, and code may interact with it only through tasks submitted there. Confinement matters more than the queue’s mechanics. If some code bypasses the queue and accesses the state directly, the safety guarantee collapses. A serial queue is therefore not magical synchronization; it is a disciplined boundary. It works when the program consistently respects that boundary.\n\nSerial queues also express ordering. If task A is submitted before task B, a first-in, first-out serial queue starts A first and completes it before B starts. This property is useful for event processing, log writing, protocol handling, and state machines. An application might receive user actions from many threads but funnel them through one queue so that the state changes in a stable sequence. The producers remain concurrent while the sensitive decisions become serialized.\n\nSubmission and execution are different concepts. Asynchronous submission normally places a task on the queue and returns immediately. The caller can continue doing other work while the queued task waits its turn. Synchronous submission blocks the caller until the submitted task completes. Both modes preserve serialization inside the queue, but they have very different effects on the caller. Asynchronous submission promotes responsiveness. Synchronous submission can conveniently retrieve a result, though careless use can cause deadlock.\n\nThe classic deadlock occurs when code already running on a serial queue synchronously submits another task to that same queue. The outer task waits for the inner task to finish, but the queue cannot start the inner task until the outer task finishes. Neither can advance. Queue libraries sometimes detect this mistake, but programs should not depend on detection. Common remedies include executing directly when already on the queue, exposing only asynchronous operations, or restructuring the API so that nested synchronous submission is unnecessary.\n\nA queue need not own a dedicated thread. Many modern runtimes maintain a pool of worker threads and schedule queue tasks onto that pool. The serial property concerns logical execution order, not permanent attachment to a particular operating-system thread. One task may run on one worker and the next task on another, while still never overlapping. Consequently, thread-local storage and thread identity should not be treated as queue identity unless the runtime explicitly promises such behavior.\n\nThis distinction helps explain why serial queues can be inexpensive. Creating thousands of dedicated threads would consume substantial memory and scheduling resources. Creating many lightweight queue objects can be practical because inactive queues need no thread of their own. The runtime activates a queue only when work is available. Queue-based designs can therefore represent many independent domains of serialization without requiring an equally large number of workers.\n\nNevertheless, serialization has a performance cost. A queue can execute no faster than its slowest accumulated workload permits. If producers submit tasks faster than the queue completes them, latency grows and memory may grow with the backlog. One long task delays every task behind it, a phenomenon sometimes called head-of-line blocking. Good serial-queue tasks are usually short, bounded, and focused on the state that truly requires ordered access.\n\nExpensive computation and slow input or output should often happen elsewhere. A task can capture the state needed for an operation, dispatch costly work to a concurrent executor, and later submit a small result-handling task back to the serial queue. This pattern preserves state safety while exploiting parallelism. It also introduces a subtle issue: results may return in a different order from the requests that produced them. The queue serializes result application, but it does not automatically restore semantic ordering. Sequence numbers, version checks, cancellation, or explicit dependencies may be needed.\n\nChoosing the scope of a queue is therefore important. One global serial queue makes reasoning easy but can eliminate useful parallelism. A separate queue for every tiny value can make relationships hard to follow and can create coordination overhead. A useful middle ground is to assign a queue to a coherent ownership domain, such as a document, connection, cache, account, or subsystem. Operations within a domain are ordered, while independent domains can proceed concurrently.\n\nSerial queues resemble mutexes, but their programming styles differ. A mutex protects a critical section executed by the calling thread. A queue usually accepts a unit of work that may execute later on another worker. Mutexes fit small, synchronous accesses and existing data structures. Queues fit ownership-oriented components, asynchronous workflows, and event-driven systems. Neither mechanism is universally superior. The better choice is the one that makes the invariant obvious and difficult to violate.\n\nQueues can also improve encapsulation. Instead of exposing mutable fields and expecting callers to synchronize correctly, a component can expose operations such as update, snapshot, and close. Internally, those operations are submitted to its serial queue. Callers no longer need to know which values require protection. The component becomes an active object: it receives messages, processes them one at a time, and owns its state. Actor systems generalize this idea by providing isolated entities with serial mailboxes.\n\nError handling needs deliberate design. An exception or rejected promise in one task should not silently stop the queue unless that behavior is intentional. Libraries differ in whether errors propagate to submitters, reach a global handler, or become detached failures. A robust queue abstraction defines how each task reports success, how failures affect following tasks, and whether retries preserve order. Retrying a failed operation at the tail may allow later operations to overtake it, while retrying in place may block the entire queue.\n\nCancellation is similarly nuanced. Removing a task that has not started is relatively straightforward, but cancellation may change the meaning of later tasks. If a queued sequence contains open, write, and close, cancelling open while retaining the other operations is probably invalid. Once a task begins, forced interruption may leave protected state inconsistent. Cooperative cancellation is safer: the task checks a token at well-defined points and exits after restoring invariants. Queue APIs should distinguish cancelling interest in a result from cancelling the underlying operation.\n\nFairness and priority complicate the basic FIFO model. Strict submission order is predictable, but urgent work can become trapped behind routine work. Priority queues can reduce urgent latency, yet they weaken ordering and may starve low-priority tasks. Multiple serial queues sharing a worker pool can also experience priority inversion when a high-priority task depends on work waiting in a lower-priority queue. These concerns matter most in interactive, real-time, or heavily loaded systems. For many application components, plain FIFO behavior remains the clearest default.\n\nTesting serial-queue code requires more than verifying final values. Tests should exercise ordering, reentrancy, failure, cancellation, and shutdown. A controllable executor can pause tasks at boundaries and make normally rare schedules reproducible. Assertions can verify that no two tasks enter the protected region simultaneously. Stress tests can submit operations from many producers, but deterministic tests are usually better at explaining a failure. Time-based sleeps are fragile because they confuse scheduler timing with program correctness.\n\nShutdown is an especially important lifecycle transition. A queue may need to reject new tasks, drain accepted work, cancel pending operations, or stop immediately. Each policy is reasonable in a different context. A file writer may need to drain to prevent data loss. A screen controller being discarded may cancel obsolete rendering work. A network service may stop accepting requests but allow in-flight requests to finish before a deadline. The contract must say what happens to queued tasks and how callers learn their outcome.\n\nObservability makes overloaded queues diagnosable. Useful measurements include queue depth, oldest-task age, execution duration, rejection count, and time spent waiting versus running. Task names or correlation identifiers can connect queue activity to higher-level requests. Instrumentation should avoid exposing sensitive task contents and should not add enough synchronized work to become a bottleneck itself. A growing queue is often a symptom rather than the root cause, but without metrics that symptom remains invisible until users notice delays.\n\nSerial queues are most effective when used as precise instruments rather than universal architecture. They simplify one class of problems by turning concurrent mutation into an ordered stream of operations. In exchange, they introduce queuing latency, lifecycle concerns, and the possibility of deadlock or backlog. Their central benefit is intellectual as much as mechanical: they give programmers a place where events happen one at a time. When the ownership boundary is clear, tasks remain short, and ordering semantics are explicit, that simple promise can make a complex concurrent system substantially safer and easier to maintain.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:04.987Z","updatedAt":"2026-10-27T14:25:37.148Z"},{"createdBy":"user","creationSource":"web","id":"519064dd-4cdb-43f2-9488-d4fa4a9d5d55","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:2","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A2:root","role":"user","text":"HELD_Q_17885: When explicitly released, reply exactly HELD_Q_DONE. No tools.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:26.567Z","updatedAt":"2026-10-27T14:24:26.567Z"},{"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":"provider","id":"message:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1:437b5282-29f1-4188-b3a8-58d8f5a1229d","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:5","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%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":"2026-10-27T14:25:30.253Z","updatedAt":"2026-10-27T14:25:30.253Z"}],"subagents":[],"providerThreads":[{"id":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","driver":"codex","providerInstanceId":"codex","providerSessionId":"provider-session:provider-instance:codex:shared","appThreadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ownerNodeId":null,"nativeThreadRef":{"driver":"codex","nativeId":"01a17dbf-8317-7fc1-950c-c63c6cd01212","strength":"strong"},"nativeConversationHeadRef":null,"status":"idle","firstRunOrdinal":1,"lastRunOrdinal":4,"handoffIds":[],"forkedFrom":null,"pendingBackgroundTasks":[],"contextUsage":{"usedTokens":20171,"maxTokens":258400},"nativeMetadata":null,"goal":null,"createdAt":"2026-10-27T14:24:23.442Z","updatedAt":"2026-10-27T14:25:37.300Z"}]}
2026-10-27T14:25:41.242Z 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":"2026-10-27T14:24:23.442Z","updatedAt":"2026-10-27T14:24:23.442Z"},{"createdBy":"agent","creationSource":"mcp","id":"message:mcp:client%3A3615d0b0-29d2-4c83-b8d7-da01992d4840:thread-send:604cddc4-0d14-41f8-8b22-064dc8cb2d50","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:3","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%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":"2026-10-27T14:24:39.926Z","updatedAt":"2026-10-27T14:24:39.926Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b42bd524819aace1a8cdad9d0eac","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:3","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b42bd524819aace1a8cdad9d0eac","role":"assistant","text":"I’ll start the requested foreground Node process and leave its command session running.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:43.876Z","updatedAt":"2026-10-27T14:24:44.181Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b42f6384819aaf98301c46494b00","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:3","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b42f6384819aaf98301c46494b00","role":"assistant","text":"CODEX_ROOT_SETTLED","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:47.463Z","updatedAt":"2026-10-27T14:24:47.504Z"},{"createdBy":"agent","creationSource":"mcp","id":"message:mcp:client%3A54049495-6f11-4f1c-89eb-579299a4e0b5:thread-send:e1e87be4-f1df-42fd-9ebb-8db56f3337ba","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:4","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%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":"2026-10-27T14:24:57.114Z","updatedAt":"2026-10-27T14:24:57.114Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b43c77a4819a98bb5eac73b6ae6b","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:4","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b43c77a4819a98bb5eac73b6ae6b","role":"assistant","text":"I’ll start the second foreground Node session, leave it unpolled, then provide the essay without changing files.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:00.542Z","updatedAt":"2026-10-27T14:25:00.609Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b440f36c819a88511d115ad115f6","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:4","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b440f36c819a88511d115ad115f6","role":"assistant","text":"Serial Queues\n\nA serial queue is one of the simplest tools for organizing concurrent work. It accepts tasks in some order and allows only one task to execute at a time. When the active task finishes, the next task begins. This rule sounds modest, but it provides a powerful guarantee: tasks submitted to the same serial queue never overlap. Systems use that guarantee to coordinate access to shared state, preserve ordering, and make asynchronous programs easier to understand.\n\nConcurrency becomes difficult when several operations can touch the same data simultaneously. Suppose two tasks read a counter, add one, and write the result. If both read the old value before either writes, one increment disappears. Locks can protect the counter, but locks introduce their own obligations. Every access must acquire the correct lock, release it on every path, and avoid incompatible lock ordering. A serial queue offers another model. Code submits all counter operations to one queue, and the queue ensures that each operation observes the effects of its predecessors.\n\nThis arrangement is often described as confinement. The protected state belongs conceptually to the queue, and code may interact with it only through tasks submitted there. Confinement matters more than the queue’s mechanics. If some code bypasses the queue and accesses the state directly, the safety guarantee collapses. A serial queue is therefore not magical synchronization; it is a disciplined boundary. It works when the program consistently respects that boundary.\n\nSerial queues also express ordering. If task A is submitted before task B, a first-in, first-out serial queue starts A first and completes it before B starts. This property is useful for event processing, log writing, protocol handling, and state machines. An application might receive user actions from many threads but funnel them through one queue so that the state changes in a stable sequence. The producers remain concurrent while the sensitive decisions become serialized.\n\nSubmission and execution are different concepts. Asynchronous submission normally places a task on the queue and returns immediately. The caller can continue doing other work while the queued task waits its turn. Synchronous submission blocks the caller until the submitted task completes. Both modes preserve serialization inside the queue, but they have very different effects on the caller. Asynchronous submission promotes responsiveness. Synchronous submission can conveniently retrieve a result, though careless use can cause deadlock.\n\nThe classic deadlock occurs when code already running on a serial queue synchronously submits another task to that same queue. The outer task waits for the inner task to finish, but the queue cannot start the inner task until the outer task finishes. Neither can advance. Queue libraries sometimes detect this mistake, but programs should not depend on detection. Common remedies include executing directly when already on the queue, exposing only asynchronous operations, or restructuring the API so that nested synchronous submission is unnecessary.\n\nA queue need not own a dedicated thread. Many modern runtimes maintain a pool of worker threads and schedule queue tasks onto that pool. The serial property concerns logical execution order, not permanent attachment to a particular operating-system thread. One task may run on one worker and the next task on another, while still never overlapping. Consequently, thread-local storage and thread identity should not be treated as queue identity unless the runtime explicitly promises such behavior.\n\nThis distinction helps explain why serial queues can be inexpensive. Creating thousands of dedicated threads would consume substantial memory and scheduling resources. Creating many lightweight queue objects can be practical because inactive queues need no thread of their own. The runtime activates a queue only when work is available. Queue-based designs can therefore represent many independent domains of serialization without requiring an equally large number of workers.\n\nNevertheless, serialization has a performance cost. A queue can execute no faster than its slowest accumulated workload permits. If producers submit tasks faster than the queue completes them, latency grows and memory may grow with the backlog. One long task delays every task behind it, a phenomenon sometimes called head-of-line blocking. Good serial-queue tasks are usually short, bounded, and focused on the state that truly requires ordered access.\n\nExpensive computation and slow input or output should often happen elsewhere. A task can capture the state needed for an operation, dispatch costly work to a concurrent executor, and later submit a small result-handling task back to the serial queue. This pattern preserves state safety while exploiting parallelism. It also introduces a subtle issue: results may return in a different order from the requests that produced them. The queue serializes result application, but it does not automatically restore semantic ordering. Sequence numbers, version checks, cancellation, or explicit dependencies may be needed.\n\nChoosing the scope of a queue is therefore important. One global serial queue makes reasoning easy but can eliminate useful parallelism. A separate queue for every tiny value can make relationships hard to follow and can create coordination overhead. A useful middle ground is to assign a queue to a coherent ownership domain, such as a document, connection, cache, account, or subsystem. Operations within a domain are ordered, while independent domains can proceed concurrently.\n\nSerial queues resemble mutexes, but their programming styles differ. A mutex protects a critical section executed by the calling thread. A queue usually accepts a unit of work that may execute later on another worker. Mutexes fit small, synchronous accesses and existing data structures. Queues fit ownership-oriented components, asynchronous workflows, and event-driven systems. Neither mechanism is universally superior. The better choice is the one that makes the invariant obvious and difficult to violate.\n\nQueues can also improve encapsulation. Instead of exposing mutable fields and expecting callers to synchronize correctly, a component can expose operations such as update, snapshot, and close. Internally, those operations are submitted to its serial queue. Callers no longer need to know which values require protection. The component becomes an active object: it receives messages, processes them one at a time, and owns its state. Actor systems generalize this idea by providing isolated entities with serial mailboxes.\n\nError handling needs deliberate design. An exception or rejected promise in one task should not silently stop the queue unless that behavior is intentional. Libraries differ in whether errors propagate to submitters, reach a global handler, or become detached failures. A robust queue abstraction defines how each task reports success, how failures affect following tasks, and whether retries preserve order. Retrying a failed operation at the tail may allow later operations to overtake it, while retrying in place may block the entire queue.\n\nCancellation is similarly nuanced. Removing a task that has not started is relatively straightforward, but cancellation may change the meaning of later tasks. If a queued sequence contains open, write, and close, cancelling open while retaining the other operations is probably invalid. Once a task begins, forced interruption may leave protected state inconsistent. Cooperative cancellation is safer: the task checks a token at well-defined points and exits after restoring invariants. Queue APIs should distinguish cancelling interest in a result from cancelling the underlying operation.\n\nFairness and priority complicate the basic FIFO model. Strict submission order is predictable, but urgent work can become trapped behind routine work. Priority queues can reduce urgent latency, yet they weaken ordering and may starve low-priority tasks. Multiple serial queues sharing a worker pool can also experience priority inversion when a high-priority task depends on work waiting in a lower-priority queue. These concerns matter most in interactive, real-time, or heavily loaded systems. For many application components, plain FIFO behavior remains the clearest default.\n\nTesting serial-queue code requires more than verifying final values. Tests should exercise ordering, reentrancy, failure, cancellation, and shutdown. A controllable executor can pause tasks at boundaries and make normally rare schedules reproducible. Assertions can verify that no two tasks enter the protected region simultaneously. Stress tests can submit operations from many producers, but deterministic tests are usually better at explaining a failure. Time-based sleeps are fragile because they confuse scheduler timing with program correctness.\n\nShutdown is an especially important lifecycle transition. A queue may need to reject new tasks, drain accepted work, cancel pending operations, or stop immediately. Each policy is reasonable in a different context. A file writer may need to drain to prevent data loss. A screen controller being discarded may cancel obsolete rendering work. A network service may stop accepting requests but allow in-flight requests to finish before a deadline. The contract must say what happens to queued tasks and how callers learn their outcome.\n\nObservability makes overloaded queues diagnosable. Useful measurements include queue depth, oldest-task age, execution duration, rejection count, and time spent waiting versus running. Task names or correlation identifiers can connect queue activity to higher-level requests. Instrumentation should avoid exposing sensitive task contents and should not add enough synchronized work to become a bottleneck itself. A growing queue is often a symptom rather than the root cause, but without metrics that symptom remains invisible until users notice delays.\n\nSerial queues are most effective when used as precise instruments rather than universal architecture. They simplify one class of problems by turning concurrent mutation into an ordered stream of operations. In exchange, they introduce queuing latency, lifecycle concerns, and the possibility of deadlock or backlog. Their central benefit is intellectual as much as mechanical: they give programmers a place where events happen one at a time. When the ownership boundary is clear, tasks remain short, and ordering semantics are explicit, that simple promise can make a complex concurrent system substantially safer and easier to maintain.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:04.987Z","updatedAt":"2026-10-27T14:25:37.148Z"},{"createdBy":"user","creationSource":"web","id":"519064dd-4cdb-43f2-9488-d4fa4a9d5d55","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:2","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A2:root","role":"user","text":"HELD_Q_17885: When explicitly released, reply exactly HELD_Q_DONE. No tools.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:26.567Z","updatedAt":"2026-10-27T14:24:26.567Z"},{"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":"provider","id":"message:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1:437b5282-29f1-4188-b3a8-58d8f5a1229d","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:5","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%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":"2026-10-27T14:25:30.253Z","updatedAt":"2026-10-27T14:25:30.253Z"},{"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":"provider","id":"message:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1:f1d90d4f-f3f4-40a7-bbe4-12cae383f473","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:6","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%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":"2026-10-27T14:25:40.904Z","updatedAt":"2026-10-27T14:25:40.904Z"}],"subagents":[],"providerThreads":[{"id":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","driver":"codex","providerInstanceId":"codex","providerSessionId":"provider-session:provider-instance:codex:shared","appThreadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ownerNodeId":null,"nativeThreadRef":{"driver":"codex","nativeId":"01a17dbf-8317-7fc1-950c-c63c6cd01212","strength":"strong"},"nativeConversationHeadRef":null,"status":"active","firstRunOrdinal":1,"lastRunOrdinal":6,"handoffIds":[],"forkedFrom":null,"pendingBackgroundTasks":[],"contextUsage":{"usedTokens":22394,"maxTokens":258400},"nativeMetadata":null,"goal":null,"createdAt":"2026-10-27T14:24:23.442Z","updatedAt":"2026-10-27T14:25:41.087Z"}]}
2026-10-27T14:25:45.067Z PROJECTION 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1ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1:f1d90d4f-f3f4-40a7-bbe4-12cae383f473","rootNodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A6:root","activeAttemptId":"run-attempt:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A6:attempt:1","status":"running","queuePosition":null,"requestedAt":"2026-10-27T14:25:40.904Z","startedAt":"2026-10-27T14:25:41.087Z","completedAt":null,"checkpointId":null,"contextHandoffId":null,"workStartedAt":"2026-10-27T14:24:57.187Z"}],"messages":[{"createdBy":"user","creationSource":"web","id":"message:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1:076898c7-32f3-4963-83ee-bf5eb2b1cd0f","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%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":"2026-10-27T14:24:23.442Z","updatedAt":"2026-10-27T14:24:23.442Z"},{"createdBy":"agent","creationSource":"mcp","id":"message:mcp:client%3A3615d0b0-29d2-4c83-b8d7-da01992d4840:thread-send:604cddc4-0d14-41f8-8b22-064dc8cb2d50","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:3","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%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":"2026-10-27T14:24:39.926Z","updatedAt":"2026-10-27T14:24:39.926Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b42bd524819aace1a8cdad9d0eac","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:3","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b42bd524819aace1a8cdad9d0eac","role":"assistant","text":"I’ll start the requested foreground Node process and leave its command session running.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:43.876Z","updatedAt":"2026-10-27T14:24:44.181Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b42f6384819aaf98301c46494b00","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:3","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b42f6384819aaf98301c46494b00","role":"assistant","text":"CODEX_ROOT_SETTLED","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:47.463Z","updatedAt":"2026-10-27T14:24:47.504Z"},{"createdBy":"agent","creationSource":"mcp","id":"message:mcp:client%3A54049495-6f11-4f1c-89eb-579299a4e0b5:thread-send:e1e87be4-f1df-42fd-9ebb-8db56f3337ba","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:4","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%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":"2026-10-27T14:24:57.114Z","updatedAt":"2026-10-27T14:24:57.114Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b43c77a4819a98bb5eac73b6ae6b","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:4","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b43c77a4819a98bb5eac73b6ae6b","role":"assistant","text":"I’ll start the second foreground Node session, leave it unpolled, then provide the essay without changing files.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:00.542Z","updatedAt":"2026-10-27T14:25:00.609Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b440f36c819a88511d115ad115f6","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:4","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b440f36c819a88511d115ad115f6","role":"assistant","text":"Serial Queues\n\nA serial queue is one of the simplest tools for organizing concurrent work. It accepts tasks in some order and allows only one task to execute at a time. When the active task finishes, the next task begins. This rule sounds modest, but it provides a powerful guarantee: tasks submitted to the same serial queue never overlap. Systems use that guarantee to coordinate access to shared state, preserve ordering, and make asynchronous programs easier to understand.\n\nConcurrency becomes difficult when several operations can touch the same data simultaneously. Suppose two tasks read a counter, add one, and write the result. If both read the old value before either writes, one increment disappears. Locks can protect the counter, but locks introduce their own obligations. Every access must acquire the correct lock, release it on every path, and avoid incompatible lock ordering. A serial queue offers another model. Code submits all counter operations to one queue, and the queue ensures that each operation observes the effects of its predecessors.\n\nThis arrangement is often described as confinement. The protected state belongs conceptually to the queue, and code may interact with it only through tasks submitted there. Confinement matters more than the queue’s mechanics. If some code bypasses the queue and accesses the state directly, the safety guarantee collapses. A serial queue is therefore not magical synchronization; it is a disciplined boundary. It works when the program consistently respects that boundary.\n\nSerial queues also express ordering. If task A is submitted before task B, a first-in, first-out serial queue starts A first and completes it before B starts. This property is useful for event processing, log writing, protocol handling, and state machines. An application might receive user actions from many threads but funnel them through one queue so that the state changes in a stable sequence. The producers remain concurrent while the sensitive decisions become serialized.\n\nSubmission and execution are different concepts. Asynchronous submission normally places a task on the queue and returns immediately. The caller can continue doing other work while the queued task waits its turn. Synchronous submission blocks the caller until the submitted task completes. Both modes preserve serialization inside the queue, but they have very different effects on the caller. Asynchronous submission promotes responsiveness. Synchronous submission can conveniently retrieve a result, though careless use can cause deadlock.\n\nThe classic deadlock occurs when code already running on a serial queue synchronously submits another task to that same queue. The outer task waits for the inner task to finish, but the queue cannot start the inner task until the outer task finishes. Neither can advance. Queue libraries sometimes detect this mistake, but programs should not depend on detection. Common remedies include executing directly when already on the queue, exposing only asynchronous operations, or restructuring the API so that nested synchronous submission is unnecessary.\n\nA queue need not own a dedicated thread. Many modern runtimes maintain a pool of worker threads and schedule queue tasks onto that pool. The serial property concerns logical execution order, not permanent attachment to a particular operating-system thread. One task may run on one worker and the next task on another, while still never overlapping. Consequently, thread-local storage and thread identity should not be treated as queue identity unless the runtime explicitly promises such behavior.\n\nThis distinction helps explain why serial queues can be inexpensive. Creating thousands of dedicated threads would consume substantial memory and scheduling resources. Creating many lightweight queue objects can be practical because inactive queues need no thread of their own. The runtime activates a queue only when work is available. Queue-based designs can therefore represent many independent domains of serialization without requiring an equally large number of workers.\n\nNevertheless, serialization has a performance cost. A queue can execute no faster than its slowest accumulated workload permits. If producers submit tasks faster than the queue completes them, latency grows and memory may grow with the backlog. One long task delays every task behind it, a phenomenon sometimes called head-of-line blocking. Good serial-queue tasks are usually short, bounded, and focused on the state that truly requires ordered access.\n\nExpensive computation and slow input or output should often happen elsewhere. A task can capture the state needed for an operation, dispatch costly work to a concurrent executor, and later submit a small result-handling task back to the serial queue. This pattern preserves state safety while exploiting parallelism. It also introduces a subtle issue: results may return in a different order from the requests that produced them. The queue serializes result application, but it does not automatically restore semantic ordering. Sequence numbers, version checks, cancellation, or explicit dependencies may be needed.\n\nChoosing the scope of a queue is therefore important. One global serial queue makes reasoning easy but can eliminate useful parallelism. A separate queue for every tiny value can make relationships hard to follow and can create coordination overhead. A useful middle ground is to assign a queue to a coherent ownership domain, such as a document, connection, cache, account, or subsystem. Operations within a domain are ordered, while independent domains can proceed concurrently.\n\nSerial queues resemble mutexes, but their programming styles differ. A mutex protects a critical section executed by the calling thread. A queue usually accepts a unit of work that may execute later on another worker. Mutexes fit small, synchronous accesses and existing data structures. Queues fit ownership-oriented components, asynchronous workflows, and event-driven systems. Neither mechanism is universally superior. The better choice is the one that makes the invariant obvious and difficult to violate.\n\nQueues can also improve encapsulation. Instead of exposing mutable fields and expecting callers to synchronize correctly, a component can expose operations such as update, snapshot, and close. Internally, those operations are submitted to its serial queue. Callers no longer need to know which values require protection. The component becomes an active object: it receives messages, processes them one at a time, and owns its state. Actor systems generalize this idea by providing isolated entities with serial mailboxes.\n\nError handling needs deliberate design. An exception or rejected promise in one task should not silently stop the queue unless that behavior is intentional. Libraries differ in whether errors propagate to submitters, reach a global handler, or become detached failures. A robust queue abstraction defines how each task reports success, how failures affect following tasks, and whether retries preserve order. Retrying a failed operation at the tail may allow later operations to overtake it, while retrying in place may block the entire queue.\n\nCancellation is similarly nuanced. Removing a task that has not started is relatively straightforward, but cancellation may change the meaning of later tasks. If a queued sequence contains open, write, and close, cancelling open while retaining the other operations is probably invalid. Once a task begins, forced interruption may leave protected state inconsistent. Cooperative cancellation is safer: the task checks a token at well-defined points and exits after restoring invariants. Queue APIs should distinguish cancelling interest in a result from cancelling the underlying operation.\n\nFairness and priority complicate the basic FIFO model. Strict submission order is predictable, but urgent work can become trapped behind routine work. Priority queues can reduce urgent latency, yet they weaken ordering and may starve low-priority tasks. Multiple serial queues sharing a worker pool can also experience priority inversion when a high-priority task depends on work waiting in a lower-priority queue. These concerns matter most in interactive, real-time, or heavily loaded systems. For many application components, plain FIFO behavior remains the clearest default.\n\nTesting serial-queue code requires more than verifying final values. Tests should exercise ordering, reentrancy, failure, cancellation, and shutdown. A controllable executor can pause tasks at boundaries and make normally rare schedules reproducible. Assertions can verify that no two tasks enter the protected region simultaneously. Stress tests can submit operations from many producers, but deterministic tests are usually better at explaining a failure. Time-based sleeps are fragile because they confuse scheduler timing with program correctness.\n\nShutdown is an especially important lifecycle transition. A queue may need to reject new tasks, drain accepted work, cancel pending operations, or stop immediately. Each policy is reasonable in a different context. A file writer may need to drain to prevent data loss. A screen controller being discarded may cancel obsolete rendering work. A network service may stop accepting requests but allow in-flight requests to finish before a deadline. The contract must say what happens to queued tasks and how callers learn their outcome.\n\nObservability makes overloaded queues diagnosable. Useful measurements include queue depth, oldest-task age, execution duration, rejection count, and time spent waiting versus running. Task names or correlation identifiers can connect queue activity to higher-level requests. Instrumentation should avoid exposing sensitive task contents and should not add enough synchronized work to become a bottleneck itself. A growing queue is often a symptom rather than the root cause, but without metrics that symptom remains invisible until users notice delays.\n\nSerial queues are most effective when used as precise instruments rather than universal architecture. They simplify one class of problems by turning concurrent mutation into an ordered stream of operations. In exchange, they introduce queuing latency, lifecycle concerns, and the possibility of deadlock or backlog. Their central benefit is intellectual as much as mechanical: they give programmers a place where events happen one at a time. When the ownership boundary is clear, tasks remain short, and ordering semantics are explicit, that simple promise can make a complex concurrent system substantially safer and easier to maintain.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:04.987Z","updatedAt":"2026-10-27T14:25:37.148Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b468a3b4819aa4e0361dca94ed51","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:6","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b468a3b4819aa4e0361dca94ed51","role":"assistant","text":"CODEX_DETAIL_ACK_17885\nCODEX_ACTIVE_17885_DONE","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:44.691Z","updatedAt":"2026-10-27T14:25:44.949Z"},{"createdBy":"user","creationSource":"web","id":"519064dd-4cdb-43f2-9488-d4fa4a9d5d55","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:2","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A2:root","role":"user","text":"HELD_Q_17885: When explicitly released, reply exactly HELD_Q_DONE. No tools.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:26.567Z","updatedAt":"2026-10-27T14:24:26.567Z"},{"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":"provider","id":"message:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1:437b5282-29f1-4188-b3a8-58d8f5a1229d","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:5","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%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":"2026-10-27T14:25:30.253Z","updatedAt":"2026-10-27T14:25:30.253Z"},{"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":"provider","id":"message:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1:f1d90d4f-f3f4-40a7-bbe4-12cae383f473","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:6","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%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":"2026-10-27T14:25:40.904Z","updatedAt":"2026-10-27T14:25:40.904Z"}],"subagents":[],"providerThreads":[{"id":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","driver":"codex","providerInstanceId":"codex","providerSessionId":"provider-session:provider-instance:codex:shared","appThreadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ownerNodeId":null,"nativeThreadRef":{"driver":"codex","nativeId":"01a17dbf-8317-7fc1-950c-c63c6cd01212","strength":"strong"},"nativeConversationHeadRef":null,"status":"active","firstRunOrdinal":1,"lastRunOrdinal":6,"handoffIds":[],"forkedFrom":null,"pendingBackgroundTasks":[],"contextUsage":{"usedTokens":22394,"maxTokens":258400},"nativeMetadata":null,"goal":null,"createdAt":"2026-10-27T14:24:23.442Z","updatedAt":"2026-10-27T14:25:41.087Z"}]}
2026-10-27T14:25:45.182Z PROJECTION {"runs":[{"id":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ordinal":1,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","userMessageId":"message:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1:076898c7-32f3-4963-83ee-bf5eb2b1cd0f","rootNodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1:root","activeAttemptId":"run-attempt:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1:attempt:1","status":"interrupted","queuePosition":null,"requestedAt":"2026-10-27T14:24:23.442Z","startedAt":"2026-10-27T14:24:25.671Z","completedAt":"2026-10-27T14:24:26.847Z","checkpointId":null,"contextHandoffId":null,"workspacePreparation":{"type":"root"}},{"id":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:2","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ordinal":2,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","userMessageId":"519064dd-4cdb-43f2-9488-d4fa4a9d5d55","rootNodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A2:root","activeAttemptId":"run-attempt:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A2:attempt:1","status":"queued","queuePosition":1,"queueHeld":true,"requestedAt":"2026-10-27T14:24:26.567Z","startedAt":null,"completedAt":null,"checkpointId":null,"contextHandoffId":null},{"id":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:3","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ordinal":3,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","userMessageId":"message:mcp:client%3A3615d0b0-29d2-4c83-b8d7-da01992d4840:thread-send:604cddc4-0d14-41f8-8b22-064dc8cb2d50","rootNodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A3:root","activeAttemptId":"run-attempt:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A3:attempt:1","status":"completed","queuePosition":null,"requestedAt":"2026-10-27T14:24:39.926Z","startedAt":"2026-10-27T14:24:40.215Z","completedAt":"2026-10-27T14:24:47.670Z","checkpointId":"checkpoint:scope:checkpoint-scope%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aname%3Aroot:name:3","contextHandoffId":null},{"id":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:4","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ordinal":4,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","userMessageId":"message:mcp:client%3A54049495-6f11-4f1c-89eb-579299a4e0b5:thread-send:e1e87be4-f1df-42fd-9ebb-8db56f3337ba","rootNodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A4:root","activeAttemptId":"run-attempt:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A4:attempt:1","status":"completed","queuePosition":null,"requestedAt":"2026-10-27T14:24:57.114Z","startedAt":"2026-10-27T14:24:57.187Z","completedAt":"2026-10-27T14:25:37.354Z","checkpointId":"checkpoint:scope:checkpoint-scope%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aname%3Aroot:name:4","contextHandoffId":null},{"id":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:5","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ordinal":5,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","userMessageId":"message:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1:437b5282-29f1-4188-b3a8-58d8f5a1229d","rootNodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A5:root","activeAttemptId":"run-attempt:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A5:attempt:1","status":"queued","queuePosition":2,"queueHeld":true,"requestedAt":"2026-10-27T14:25:30.253Z","startedAt":null,"completedAt":null,"checkpointId":null,"contextHandoffId":null},{"id":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:6","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ordinal":6,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","userMessageId":"message:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1:f1d90d4f-f3f4-40a7-bbe4-12cae383f473","rootNodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A6:root","activeAttemptId":"run-attempt:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A6:attempt:1","status":"waiting","queuePosition":null,"requestedAt":"2026-10-27T14:25:40.904Z","startedAt":"2026-10-27T14:25:41.087Z","completedAt":null,"checkpointId":null,"contextHandoffId":null,"workStartedAt":"2026-10-27T14:24:57.187Z"}],"messages":[{"createdBy":"user","creationSource":"web","id":"message:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1:076898c7-32f3-4963-83ee-bf5eb2b1cd0f","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%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":"2026-10-27T14:24:23.442Z","updatedAt":"2026-10-27T14:24:23.442Z"},{"createdBy":"agent","creationSource":"mcp","id":"message:mcp:client%3A3615d0b0-29d2-4c83-b8d7-da01992d4840:thread-send:604cddc4-0d14-41f8-8b22-064dc8cb2d50","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:3","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%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":"2026-10-27T14:24:39.926Z","updatedAt":"2026-10-27T14:24:39.926Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b42bd524819aace1a8cdad9d0eac","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:3","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b42bd524819aace1a8cdad9d0eac","role":"assistant","text":"I’ll start the requested foreground Node process and leave its command session running.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:43.876Z","updatedAt":"2026-10-27T14:24:44.181Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b42f6384819aaf98301c46494b00","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:3","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b42f6384819aaf98301c46494b00","role":"assistant","text":"CODEX_ROOT_SETTLED","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:47.463Z","updatedAt":"2026-10-27T14:24:47.504Z"},{"createdBy":"agent","creationSource":"mcp","id":"message:mcp:client%3A54049495-6f11-4f1c-89eb-579299a4e0b5:thread-send:e1e87be4-f1df-42fd-9ebb-8db56f3337ba","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:4","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%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":"2026-10-27T14:24:57.114Z","updatedAt":"2026-10-27T14:24:57.114Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b43c77a4819a98bb5eac73b6ae6b","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:4","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b43c77a4819a98bb5eac73b6ae6b","role":"assistant","text":"I’ll start the second foreground Node session, leave it unpolled, then provide the essay without changing files.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:00.542Z","updatedAt":"2026-10-27T14:25:00.609Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b440f36c819a88511d115ad115f6","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:4","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b440f36c819a88511d115ad115f6","role":"assistant","text":"Serial Queues\n\nA serial queue is one of the simplest tools for organizing concurrent work. It accepts tasks in some order and allows only one task to execute at a time. When the active task finishes, the next task begins. This rule sounds modest, but it provides a powerful guarantee: tasks submitted to the same serial queue never overlap. Systems use that guarantee to coordinate access to shared state, preserve ordering, and make asynchronous programs easier to understand.\n\nConcurrency becomes difficult when several operations can touch the same data simultaneously. Suppose two tasks read a counter, add one, and write the result. If both read the old value before either writes, one increment disappears. Locks can protect the counter, but locks introduce their own obligations. Every access must acquire the correct lock, release it on every path, and avoid incompatible lock ordering. A serial queue offers another model. Code submits all counter operations to one queue, and the queue ensures that each operation observes the effects of its predecessors.\n\nThis arrangement is often described as confinement. The protected state belongs conceptually to the queue, and code may interact with it only through tasks submitted there. Confinement matters more than the queue’s mechanics. If some code bypasses the queue and accesses the state directly, the safety guarantee collapses. A serial queue is therefore not magical synchronization; it is a disciplined boundary. It works when the program consistently respects that boundary.\n\nSerial queues also express ordering. If task A is submitted before task B, a first-in, first-out serial queue starts A first and completes it before B starts. This property is useful for event processing, log writing, protocol handling, and state machines. An application might receive user actions from many threads but funnel them through one queue so that the state changes in a stable sequence. The producers remain concurrent while the sensitive decisions become serialized.\n\nSubmission and execution are different concepts. Asynchronous submission normally places a task on the queue and returns immediately. The caller can continue doing other work while the queued task waits its turn. Synchronous submission blocks the caller until the submitted task completes. Both modes preserve serialization inside the queue, but they have very different effects on the caller. Asynchronous submission promotes responsiveness. Synchronous submission can conveniently retrieve a result, though careless use can cause deadlock.\n\nThe classic deadlock occurs when code already running on a serial queue synchronously submits another task to that same queue. The outer task waits for the inner task to finish, but the queue cannot start the inner task until the outer task finishes. Neither can advance. Queue libraries sometimes detect this mistake, but programs should not depend on detection. Common remedies include executing directly when already on the queue, exposing only asynchronous operations, or restructuring the API so that nested synchronous submission is unnecessary.\n\nA queue need not own a dedicated thread. Many modern runtimes maintain a pool of worker threads and schedule queue tasks onto that pool. The serial property concerns logical execution order, not permanent attachment to a particular operating-system thread. One task may run on one worker and the next task on another, while still never overlapping. Consequently, thread-local storage and thread identity should not be treated as queue identity unless the runtime explicitly promises such behavior.\n\nThis distinction helps explain why serial queues can be inexpensive. Creating thousands of dedicated threads would consume substantial memory and scheduling resources. Creating many lightweight queue objects can be practical because inactive queues need no thread of their own. The runtime activates a queue only when work is available. Queue-based designs can therefore represent many independent domains of serialization without requiring an equally large number of workers.\n\nNevertheless, serialization has a performance cost. A queue can execute no faster than its slowest accumulated workload permits. If producers submit tasks faster than the queue completes them, latency grows and memory may grow with the backlog. One long task delays every task behind it, a phenomenon sometimes called head-of-line blocking. Good serial-queue tasks are usually short, bounded, and focused on the state that truly requires ordered access.\n\nExpensive computation and slow input or output should often happen elsewhere. A task can capture the state needed for an operation, dispatch costly work to a concurrent executor, and later submit a small result-handling task back to the serial queue. This pattern preserves state safety while exploiting parallelism. It also introduces a subtle issue: results may return in a different order from the requests that produced them. The queue serializes result application, but it does not automatically restore semantic ordering. Sequence numbers, version checks, cancellation, or explicit dependencies may be needed.\n\nChoosing the scope of a queue is therefore important. One global serial queue makes reasoning easy but can eliminate useful parallelism. A separate queue for every tiny value can make relationships hard to follow and can create coordination overhead. A useful middle ground is to assign a queue to a coherent ownership domain, such as a document, connection, cache, account, or subsystem. Operations within a domain are ordered, while independent domains can proceed concurrently.\n\nSerial queues resemble mutexes, but their programming styles differ. A mutex protects a critical section executed by the calling thread. A queue usually accepts a unit of work that may execute later on another worker. Mutexes fit small, synchronous accesses and existing data structures. Queues fit ownership-oriented components, asynchronous workflows, and event-driven systems. Neither mechanism is universally superior. The better choice is the one that makes the invariant obvious and difficult to violate.\n\nQueues can also improve encapsulation. Instead of exposing mutable fields and expecting callers to synchronize correctly, a component can expose operations such as update, snapshot, and close. Internally, those operations are submitted to its serial queue. Callers no longer need to know which values require protection. The component becomes an active object: it receives messages, processes them one at a time, and owns its state. Actor systems generalize this idea by providing isolated entities with serial mailboxes.\n\nError handling needs deliberate design. An exception or rejected promise in one task should not silently stop the queue unless that behavior is intentional. Libraries differ in whether errors propagate to submitters, reach a global handler, or become detached failures. A robust queue abstraction defines how each task reports success, how failures affect following tasks, and whether retries preserve order. Retrying a failed operation at the tail may allow later operations to overtake it, while retrying in place may block the entire queue.\n\nCancellation is similarly nuanced. Removing a task that has not started is relatively straightforward, but cancellation may change the meaning of later tasks. If a queued sequence contains open, write, and close, cancelling open while retaining the other operations is probably invalid. Once a task begins, forced interruption may leave protected state inconsistent. Cooperative cancellation is safer: the task checks a token at well-defined points and exits after restoring invariants. Queue APIs should distinguish cancelling interest in a result from cancelling the underlying operation.\n\nFairness and priority complicate the basic FIFO model. Strict submission order is predictable, but urgent work can become trapped behind routine work. Priority queues can reduce urgent latency, yet they weaken ordering and may starve low-priority tasks. Multiple serial queues sharing a worker pool can also experience priority inversion when a high-priority task depends on work waiting in a lower-priority queue. These concerns matter most in interactive, real-time, or heavily loaded systems. For many application components, plain FIFO behavior remains the clearest default.\n\nTesting serial-queue code requires more than verifying final values. Tests should exercise ordering, reentrancy, failure, cancellation, and shutdown. A controllable executor can pause tasks at boundaries and make normally rare schedules reproducible. Assertions can verify that no two tasks enter the protected region simultaneously. Stress tests can submit operations from many producers, but deterministic tests are usually better at explaining a failure. Time-based sleeps are fragile because they confuse scheduler timing with program correctness.\n\nShutdown is an especially important lifecycle transition. A queue may need to reject new tasks, drain accepted work, cancel pending operations, or stop immediately. Each policy is reasonable in a different context. A file writer may need to drain to prevent data loss. A screen controller being discarded may cancel obsolete rendering work. A network service may stop accepting requests but allow in-flight requests to finish before a deadline. The contract must say what happens to queued tasks and how callers learn their outcome.\n\nObservability makes overloaded queues diagnosable. Useful measurements include queue depth, oldest-task age, execution duration, rejection count, and time spent waiting versus running. Task names or correlation identifiers can connect queue activity to higher-level requests. Instrumentation should avoid exposing sensitive task contents and should not add enough synchronized work to become a bottleneck itself. A growing queue is often a symptom rather than the root cause, but without metrics that symptom remains invisible until users notice delays.\n\nSerial queues are most effective when used as precise instruments rather than universal architecture. They simplify one class of problems by turning concurrent mutation into an ordered stream of operations. In exchange, they introduce queuing latency, lifecycle concerns, and the possibility of deadlock or backlog. Their central benefit is intellectual as much as mechanical: they give programmers a place where events happen one at a time. When the ownership boundary is clear, tasks remain short, and ordering semantics are explicit, that simple promise can make a complex concurrent system substantially safer and easier to maintain.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:04.987Z","updatedAt":"2026-10-27T14:25:37.148Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b468a3b4819aa4e0361dca94ed51","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:6","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b468a3b4819aa4e0361dca94ed51","role":"assistant","text":"CODEX_DETAIL_ACK_17885\nCODEX_ACTIVE_17885_DONE","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:44.691Z","updatedAt":"2026-10-27T14:25:44.949Z"},{"createdBy":"user","creationSource":"web","id":"519064dd-4cdb-43f2-9488-d4fa4a9d5d55","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:2","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A2:root","role":"user","text":"HELD_Q_17885: When explicitly released, reply exactly HELD_Q_DONE. No tools.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:26.567Z","updatedAt":"2026-10-27T14:24:26.567Z"},{"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":"provider","id":"message:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1:437b5282-29f1-4188-b3a8-58d8f5a1229d","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:5","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%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":"2026-10-27T14:25:30.253Z","updatedAt":"2026-10-27T14:25:30.253Z"},{"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":"provider","id":"message:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1:f1d90d4f-f3f4-40a7-bbe4-12cae383f473","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:6","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%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":"2026-10-27T14:25:40.904Z","updatedAt":"2026-10-27T14:25:40.904Z"}],"subagents":[],"providerThreads":[{"id":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","driver":"codex","providerInstanceId":"codex","providerSessionId":"provider-session:provider-instance:codex:shared","appThreadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ownerNodeId":null,"nativeThreadRef":{"driver":"codex","nativeId":"01a17dbf-8317-7fc1-950c-c63c6cd01212","strength":"strong"},"nativeConversationHeadRef":null,"status":"idle","firstRunOrdinal":1,"lastRunOrdinal":6,"handoffIds":[],"forkedFrom":null,"pendingBackgroundTasks":[],"contextUsage":{"usedTokens":22394,"maxTokens":258400},"nativeMetadata":null,"goal":null,"createdAt":"2026-10-27T14:24:23.442Z","updatedAt":"2026-10-27T14:25:45.082Z"}]}
2026-10-27T14:25:45.909Z PROJECTION {"runs":[{"id":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ordinal":1,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","userMessageId":"message:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1:076898c7-32f3-4963-83ee-bf5eb2b1cd0f","rootNodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1:root","activeAttemptId":"run-attempt:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1:attempt:1","status":"interrupted","queuePosition":null,"requestedAt":"2026-10-27T14:24:23.442Z","startedAt":"2026-10-27T14:24:25.671Z","completedAt":"2026-10-27T14:24:26.847Z","checkpointId":null,"contextHandoffId":null,"workspacePreparation":{"type":"root"}},{"id":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:2","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ordinal":2,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","userMessageId":"519064dd-4cdb-43f2-9488-d4fa4a9d5d55","rootNodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A2:root","activeAttemptId":"run-attempt:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A2:attempt:1","status":"queued","queuePosition":1,"queueHeld":true,"requestedAt":"2026-10-27T14:24:26.567Z","startedAt":null,"completedAt":null,"checkpointId":null,"contextHandoffId":null},{"id":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:3","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ordinal":3,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","userMessageId":"message:mcp:client%3A3615d0b0-29d2-4c83-b8d7-da01992d4840:thread-send:604cddc4-0d14-41f8-8b22-064dc8cb2d50","rootNodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A3:root","activeAttemptId":"run-attempt:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A3:attempt:1","status":"completed","queuePosition":null,"requestedAt":"2026-10-27T14:24:39.926Z","startedAt":"2026-10-27T14:24:40.215Z","completedAt":"2026-10-27T14:24:47.670Z","checkpointId":"checkpoint:scope:checkpoint-scope%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aname%3Aroot:name:3","contextHandoffId":null},{"id":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:4","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ordinal":4,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","userMessageId":"message:mcp:client%3A54049495-6f11-4f1c-89eb-579299a4e0b5:thread-send:e1e87be4-f1df-42fd-9ebb-8db56f3337ba","rootNodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A4:root","activeAttemptId":"run-attempt:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A4:attempt:1","status":"completed","queuePosition":null,"requestedAt":"2026-10-27T14:24:57.114Z","startedAt":"2026-10-27T14:24:57.187Z","completedAt":"2026-10-27T14:25:37.354Z","checkpointId":"checkpoint:scope:checkpoint-scope%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aname%3Aroot:name:4","contextHandoffId":null},{"id":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:5","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ordinal":5,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","userMessageId":"message:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1:437b5282-29f1-4188-b3a8-58d8f5a1229d","rootNodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A5:root","activeAttemptId":"run-attempt:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A5:attempt:1","status":"queued","queuePosition":2,"queueHeld":true,"requestedAt":"2026-10-27T14:25:30.253Z","startedAt":null,"completedAt":null,"checkpointId":null,"contextHandoffId":null},{"id":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:6","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ordinal":6,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","userMessageId":"message:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1:f1d90d4f-f3f4-40a7-bbe4-12cae383f473","rootNodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A6:root","activeAttemptId":"run-attempt:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A6:attempt:1","status":"completed","queuePosition":null,"requestedAt":"2026-10-27T14:25:40.904Z","startedAt":"2026-10-27T14:25:41.087Z","completedAt":"2026-10-27T14:25:45.153Z","checkpointId":"checkpoint:scope:checkpoint-scope%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aname%3Aroot:name:6","contextHandoffId":null,"workStartedAt":"2026-10-27T14:24:57.187Z"}],"messages":[{"createdBy":"user","creationSource":"web","id":"message:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1:076898c7-32f3-4963-83ee-bf5eb2b1cd0f","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%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":"2026-10-27T14:24:23.442Z","updatedAt":"2026-10-27T14:24:23.442Z"},{"createdBy":"agent","creationSource":"mcp","id":"message:mcp:client%3A3615d0b0-29d2-4c83-b8d7-da01992d4840:thread-send:604cddc4-0d14-41f8-8b22-064dc8cb2d50","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:3","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%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":"2026-10-27T14:24:39.926Z","updatedAt":"2026-10-27T14:24:39.926Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b42bd524819aace1a8cdad9d0eac","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:3","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b42bd524819aace1a8cdad9d0eac","role":"assistant","text":"I’ll start the requested foreground Node process and leave its command session running.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:43.876Z","updatedAt":"2026-10-27T14:24:44.181Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b42f6384819aaf98301c46494b00","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:3","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b42f6384819aaf98301c46494b00","role":"assistant","text":"CODEX_ROOT_SETTLED","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:47.463Z","updatedAt":"2026-10-27T14:24:47.504Z"},{"createdBy":"agent","creationSource":"mcp","id":"message:mcp:client%3A54049495-6f11-4f1c-89eb-579299a4e0b5:thread-send:e1e87be4-f1df-42fd-9ebb-8db56f3337ba","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:4","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%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":"2026-10-27T14:24:57.114Z","updatedAt":"2026-10-27T14:24:57.114Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b43c77a4819a98bb5eac73b6ae6b","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:4","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b43c77a4819a98bb5eac73b6ae6b","role":"assistant","text":"I’ll start the second foreground Node session, leave it unpolled, then provide the essay without changing files.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:00.542Z","updatedAt":"2026-10-27T14:25:00.609Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b440f36c819a88511d115ad115f6","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:4","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b440f36c819a88511d115ad115f6","role":"assistant","text":"Serial Queues\n\nA serial queue is one of the simplest tools for organizing concurrent work. It accepts tasks in some order and allows only one task to execute at a time. When the active task finishes, the next task begins. This rule sounds modest, but it provides a powerful guarantee: tasks submitted to the same serial queue never overlap. Systems use that guarantee to coordinate access to shared state, preserve ordering, and make asynchronous programs easier to understand.\n\nConcurrency becomes difficult when several operations can touch the same data simultaneously. Suppose two tasks read a counter, add one, and write the result. If both read the old value before either writes, one increment disappears. Locks can protect the counter, but locks introduce their own obligations. Every access must acquire the correct lock, release it on every path, and avoid incompatible lock ordering. A serial queue offers another model. Code submits all counter operations to one queue, and the queue ensures that each operation observes the effects of its predecessors.\n\nThis arrangement is often described as confinement. The protected state belongs conceptually to the queue, and code may interact with it only through tasks submitted there. Confinement matters more than the queue’s mechanics. If some code bypasses the queue and accesses the state directly, the safety guarantee collapses. A serial queue is therefore not magical synchronization; it is a disciplined boundary. It works when the program consistently respects that boundary.\n\nSerial queues also express ordering. If task A is submitted before task B, a first-in, first-out serial queue starts A first and completes it before B starts. This property is useful for event processing, log writing, protocol handling, and state machines. An application might receive user actions from many threads but funnel them through one queue so that the state changes in a stable sequence. The producers remain concurrent while the sensitive decisions become serialized.\n\nSubmission and execution are different concepts. Asynchronous submission normally places a task on the queue and returns immediately. The caller can continue doing other work while the queued task waits its turn. Synchronous submission blocks the caller until the submitted task completes. Both modes preserve serialization inside the queue, but they have very different effects on the caller. Asynchronous submission promotes responsiveness. Synchronous submission can conveniently retrieve a result, though careless use can cause deadlock.\n\nThe classic deadlock occurs when code already running on a serial queue synchronously submits another task to that same queue. The outer task waits for the inner task to finish, but the queue cannot start the inner task until the outer task finishes. Neither can advance. Queue libraries sometimes detect this mistake, but programs should not depend on detection. Common remedies include executing directly when already on the queue, exposing only asynchronous operations, or restructuring the API so that nested synchronous submission is unnecessary.\n\nA queue need not own a dedicated thread. Many modern runtimes maintain a pool of worker threads and schedule queue tasks onto that pool. The serial property concerns logical execution order, not permanent attachment to a particular operating-system thread. One task may run on one worker and the next task on another, while still never overlapping. Consequently, thread-local storage and thread identity should not be treated as queue identity unless the runtime explicitly promises such behavior.\n\nThis distinction helps explain why serial queues can be inexpensive. Creating thousands of dedicated threads would consume substantial memory and scheduling resources. Creating many lightweight queue objects can be practical because inactive queues need no thread of their own. The runtime activates a queue only when work is available. Queue-based designs can therefore represent many independent domains of serialization without requiring an equally large number of workers.\n\nNevertheless, serialization has a performance cost. A queue can execute no faster than its slowest accumulated workload permits. If producers submit tasks faster than the queue completes them, latency grows and memory may grow with the backlog. One long task delays every task behind it, a phenomenon sometimes called head-of-line blocking. Good serial-queue tasks are usually short, bounded, and focused on the state that truly requires ordered access.\n\nExpensive computation and slow input or output should often happen elsewhere. A task can capture the state needed for an operation, dispatch costly work to a concurrent executor, and later submit a small result-handling task back to the serial queue. This pattern preserves state safety while exploiting parallelism. It also introduces a subtle issue: results may return in a different order from the requests that produced them. The queue serializes result application, but it does not automatically restore semantic ordering. Sequence numbers, version checks, cancellation, or explicit dependencies may be needed.\n\nChoosing the scope of a queue is therefore important. One global serial queue makes reasoning easy but can eliminate useful parallelism. A separate queue for every tiny value can make relationships hard to follow and can create coordination overhead. A useful middle ground is to assign a queue to a coherent ownership domain, such as a document, connection, cache, account, or subsystem. Operations within a domain are ordered, while independent domains can proceed concurrently.\n\nSerial queues resemble mutexes, but their programming styles differ. A mutex protects a critical section executed by the calling thread. A queue usually accepts a unit of work that may execute later on another worker. Mutexes fit small, synchronous accesses and existing data structures. Queues fit ownership-oriented components, asynchronous workflows, and event-driven systems. Neither mechanism is universally superior. The better choice is the one that makes the invariant obvious and difficult to violate.\n\nQueues can also improve encapsulation. Instead of exposing mutable fields and expecting callers to synchronize correctly, a component can expose operations such as update, snapshot, and close. Internally, those operations are submitted to its serial queue. Callers no longer need to know which values require protection. The component becomes an active object: it receives messages, processes them one at a time, and owns its state. Actor systems generalize this idea by providing isolated entities with serial mailboxes.\n\nError handling needs deliberate design. An exception or rejected promise in one task should not silently stop the queue unless that behavior is intentional. Libraries differ in whether errors propagate to submitters, reach a global handler, or become detached failures. A robust queue abstraction defines how each task reports success, how failures affect following tasks, and whether retries preserve order. Retrying a failed operation at the tail may allow later operations to overtake it, while retrying in place may block the entire queue.\n\nCancellation is similarly nuanced. Removing a task that has not started is relatively straightforward, but cancellation may change the meaning of later tasks. If a queued sequence contains open, write, and close, cancelling open while retaining the other operations is probably invalid. Once a task begins, forced interruption may leave protected state inconsistent. Cooperative cancellation is safer: the task checks a token at well-defined points and exits after restoring invariants. Queue APIs should distinguish cancelling interest in a result from cancelling the underlying operation.\n\nFairness and priority complicate the basic FIFO model. Strict submission order is predictable, but urgent work can become trapped behind routine work. Priority queues can reduce urgent latency, yet they weaken ordering and may starve low-priority tasks. Multiple serial queues sharing a worker pool can also experience priority inversion when a high-priority task depends on work waiting in a lower-priority queue. These concerns matter most in interactive, real-time, or heavily loaded systems. For many application components, plain FIFO behavior remains the clearest default.\n\nTesting serial-queue code requires more than verifying final values. Tests should exercise ordering, reentrancy, failure, cancellation, and shutdown. A controllable executor can pause tasks at boundaries and make normally rare schedules reproducible. Assertions can verify that no two tasks enter the protected region simultaneously. Stress tests can submit operations from many producers, but deterministic tests are usually better at explaining a failure. Time-based sleeps are fragile because they confuse scheduler timing with program correctness.\n\nShutdown is an especially important lifecycle transition. A queue may need to reject new tasks, drain accepted work, cancel pending operations, or stop immediately. Each policy is reasonable in a different context. A file writer may need to drain to prevent data loss. A screen controller being discarded may cancel obsolete rendering work. A network service may stop accepting requests but allow in-flight requests to finish before a deadline. The contract must say what happens to queued tasks and how callers learn their outcome.\n\nObservability makes overloaded queues diagnosable. Useful measurements include queue depth, oldest-task age, execution duration, rejection count, and time spent waiting versus running. Task names or correlation identifiers can connect queue activity to higher-level requests. Instrumentation should avoid exposing sensitive task contents and should not add enough synchronized work to become a bottleneck itself. A growing queue is often a symptom rather than the root cause, but without metrics that symptom remains invisible until users notice delays.\n\nSerial queues are most effective when used as precise instruments rather than universal architecture. They simplify one class of problems by turning concurrent mutation into an ordered stream of operations. In exchange, they introduce queuing latency, lifecycle concerns, and the possibility of deadlock or backlog. Their central benefit is intellectual as much as mechanical: they give programmers a place where events happen one at a time. When the ownership boundary is clear, tasks remain short, and ordering semantics are explicit, that simple promise can make a complex concurrent system substantially safer and easier to maintain.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:04.987Z","updatedAt":"2026-10-27T14:25:37.148Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b468a3b4819aa4e0361dca94ed51","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:6","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b468a3b4819aa4e0361dca94ed51","role":"assistant","text":"CODEX_DETAIL_ACK_17885\nCODEX_ACTIVE_17885_DONE","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:44.691Z","updatedAt":"2026-10-27T14:25:44.949Z"},{"createdBy":"user","creationSource":"web","id":"519064dd-4cdb-43f2-9488-d4fa4a9d5d55","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:2","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A2:root","role":"user","text":"HELD_Q_17885: When explicitly released, reply exactly HELD_Q_DONE. No tools.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:26.567Z","updatedAt":"2026-10-27T14:24:26.567Z"},{"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":"provider","id":"message:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1:437b5282-29f1-4188-b3a8-58d8f5a1229d","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:5","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%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":"2026-10-27T14:25:30.253Z","updatedAt":"2026-10-27T14:25:30.253Z"}],"subagents":[],"providerThreads":[{"id":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","driver":"codex","providerInstanceId":"codex","providerSessionId":"provider-session:provider-instance:codex:shared","appThreadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ownerNodeId":null,"nativeThreadRef":{"driver":"codex","nativeId":"01a17dbf-8317-7fc1-950c-c63c6cd01212","strength":"strong"},"nativeConversationHeadRef":null,"status":"idle","firstRunOrdinal":1,"lastRunOrdinal":6,"handoffIds":[],"forkedFrom":null,"pendingBackgroundTasks":[],"contextUsage":{"usedTokens":22394,"maxTokens":258400},"nativeMetadata":null,"goal":null,"createdAt":"2026-10-27T14:24:23.442Z","updatedAt":"2026-10-27T14:25:45.082Z"}]}
2026-10-27T14:26:02.482Z 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":"2026-10-27T14:24:23.442Z","updatedAt":"2026-10-27T14:24:23.442Z"},{"createdBy":"agent","creationSource":"mcp","id":"message:mcp:client%3A3615d0b0-29d2-4c83-b8d7-da01992d4840:thread-send:604cddc4-0d14-41f8-8b22-064dc8cb2d50","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:3","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%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":"2026-10-27T14:24:39.926Z","updatedAt":"2026-10-27T14:24:39.926Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b42bd524819aace1a8cdad9d0eac","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:3","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b42bd524819aace1a8cdad9d0eac","role":"assistant","text":"I’ll start the requested foreground Node process and leave its command session running.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:43.876Z","updatedAt":"2026-10-27T14:24:44.181Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b42f6384819aaf98301c46494b00","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:3","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b42f6384819aaf98301c46494b00","role":"assistant","text":"CODEX_ROOT_SETTLED","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:47.463Z","updatedAt":"2026-10-27T14:24:47.504Z"},{"createdBy":"agent","creationSource":"mcp","id":"message:mcp:client%3A54049495-6f11-4f1c-89eb-579299a4e0b5:thread-send:e1e87be4-f1df-42fd-9ebb-8db56f3337ba","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:4","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%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":"2026-10-27T14:24:57.114Z","updatedAt":"2026-10-27T14:24:57.114Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b43c77a4819a98bb5eac73b6ae6b","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:4","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b43c77a4819a98bb5eac73b6ae6b","role":"assistant","text":"I’ll start the second foreground Node session, leave it unpolled, then provide the essay without changing files.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:00.542Z","updatedAt":"2026-10-27T14:25:00.609Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b440f36c819a88511d115ad115f6","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:4","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b440f36c819a88511d115ad115f6","role":"assistant","text":"Serial Queues\n\nA serial queue is one of the simplest tools for organizing concurrent work. It accepts tasks in some order and allows only one task to execute at a time. When the active task finishes, the next task begins. This rule sounds modest, but it provides a powerful guarantee: tasks submitted to the same serial queue never overlap. Systems use that guarantee to coordinate access to shared state, preserve ordering, and make asynchronous programs easier to understand.\n\nConcurrency becomes difficult when several operations can touch the same data simultaneously. Suppose two tasks read a counter, add one, and write the result. If both read the old value before either writes, one increment disappears. Locks can protect the counter, but locks introduce their own obligations. Every access must acquire the correct lock, release it on every path, and avoid incompatible lock ordering. A serial queue offers another model. Code submits all counter operations to one queue, and the queue ensures that each operation observes the effects of its predecessors.\n\nThis arrangement is often described as confinement. The protected state belongs conceptually to the queue, and code may interact with it only through tasks submitted there. Confinement matters more than the queue’s mechanics. If some code bypasses the queue and accesses the state directly, the safety guarantee collapses. A serial queue is therefore not magical synchronization; it is a disciplined boundary. It works when the program consistently respects that boundary.\n\nSerial queues also express ordering. If task A is submitted before task B, a first-in, first-out serial queue starts A first and completes it before B starts. This property is useful for event processing, log writing, protocol handling, and state machines. An application might receive user actions from many threads but funnel them through one queue so that the state changes in a stable sequence. The producers remain concurrent while the sensitive decisions become serialized.\n\nSubmission and execution are different concepts. Asynchronous submission normally places a task on the queue and returns immediately. The caller can continue doing other work while the queued task waits its turn. Synchronous submission blocks the caller until the submitted task completes. Both modes preserve serialization inside the queue, but they have very different effects on the caller. Asynchronous submission promotes responsiveness. Synchronous submission can conveniently retrieve a result, though careless use can cause deadlock.\n\nThe classic deadlock occurs when code already running on a serial queue synchronously submits another task to that same queue. The outer task waits for the inner task to finish, but the queue cannot start the inner task until the outer task finishes. Neither can advance. Queue libraries sometimes detect this mistake, but programs should not depend on detection. Common remedies include executing directly when already on the queue, exposing only asynchronous operations, or restructuring the API so that nested synchronous submission is unnecessary.\n\nA queue need not own a dedicated thread. Many modern runtimes maintain a pool of worker threads and schedule queue tasks onto that pool. The serial property concerns logical execution order, not permanent attachment to a particular operating-system thread. One task may run on one worker and the next task on another, while still never overlapping. Consequently, thread-local storage and thread identity should not be treated as queue identity unless the runtime explicitly promises such behavior.\n\nThis distinction helps explain why serial queues can be inexpensive. Creating thousands of dedicated threads would consume substantial memory and scheduling resources. Creating many lightweight queue objects can be practical because inactive queues need no thread of their own. The runtime activates a queue only when work is available. Queue-based designs can therefore represent many independent domains of serialization without requiring an equally large number of workers.\n\nNevertheless, serialization has a performance cost. A queue can execute no faster than its slowest accumulated workload permits. If producers submit tasks faster than the queue completes them, latency grows and memory may grow with the backlog. One long task delays every task behind it, a phenomenon sometimes called head-of-line blocking. Good serial-queue tasks are usually short, bounded, and focused on the state that truly requires ordered access.\n\nExpensive computation and slow input or output should often happen elsewhere. A task can capture the state needed for an operation, dispatch costly work to a concurrent executor, and later submit a small result-handling task back to the serial queue. This pattern preserves state safety while exploiting parallelism. It also introduces a subtle issue: results may return in a different order from the requests that produced them. The queue serializes result application, but it does not automatically restore semantic ordering. Sequence numbers, version checks, cancellation, or explicit dependencies may be needed.\n\nChoosing the scope of a queue is therefore important. One global serial queue makes reasoning easy but can eliminate useful parallelism. A separate queue for every tiny value can make relationships hard to follow and can create coordination overhead. A useful middle ground is to assign a queue to a coherent ownership domain, such as a document, connection, cache, account, or subsystem. Operations within a domain are ordered, while independent domains can proceed concurrently.\n\nSerial queues resemble mutexes, but their programming styles differ. A mutex protects a critical section executed by the calling thread. A queue usually accepts a unit of work that may execute later on another worker. Mutexes fit small, synchronous accesses and existing data structures. Queues fit ownership-oriented components, asynchronous workflows, and event-driven systems. Neither mechanism is universally superior. The better choice is the one that makes the invariant obvious and difficult to violate.\n\nQueues can also improve encapsulation. Instead of exposing mutable fields and expecting callers to synchronize correctly, a component can expose operations such as update, snapshot, and close. Internally, those operations are submitted to its serial queue. Callers no longer need to know which values require protection. The component becomes an active object: it receives messages, processes them one at a time, and owns its state. Actor systems generalize this idea by providing isolated entities with serial mailboxes.\n\nError handling needs deliberate design. An exception or rejected promise in one task should not silently stop the queue unless that behavior is intentional. Libraries differ in whether errors propagate to submitters, reach a global handler, or become detached failures. A robust queue abstraction defines how each task reports success, how failures affect following tasks, and whether retries preserve order. Retrying a failed operation at the tail may allow later operations to overtake it, while retrying in place may block the entire queue.\n\nCancellation is similarly nuanced. Removing a task that has not started is relatively straightforward, but cancellation may change the meaning of later tasks. If a queued sequence contains open, write, and close, cancelling open while retaining the other operations is probably invalid. Once a task begins, forced interruption may leave protected state inconsistent. Cooperative cancellation is safer: the task checks a token at well-defined points and exits after restoring invariants. Queue APIs should distinguish cancelling interest in a result from cancelling the underlying operation.\n\nFairness and priority complicate the basic FIFO model. Strict submission order is predictable, but urgent work can become trapped behind routine work. Priority queues can reduce urgent latency, yet they weaken ordering and may starve low-priority tasks. Multiple serial queues sharing a worker pool can also experience priority inversion when a high-priority task depends on work waiting in a lower-priority queue. These concerns matter most in interactive, real-time, or heavily loaded systems. For many application components, plain FIFO behavior remains the clearest default.\n\nTesting serial-queue code requires more than verifying final values. Tests should exercise ordering, reentrancy, failure, cancellation, and shutdown. A controllable executor can pause tasks at boundaries and make normally rare schedules reproducible. Assertions can verify that no two tasks enter the protected region simultaneously. Stress tests can submit operations from many producers, but deterministic tests are usually better at explaining a failure. Time-based sleeps are fragile because they confuse scheduler timing with program correctness.\n\nShutdown is an especially important lifecycle transition. A queue may need to reject new tasks, drain accepted work, cancel pending operations, or stop immediately. Each policy is reasonable in a different context. A file writer may need to drain to prevent data loss. A screen controller being discarded may cancel obsolete rendering work. A network service may stop accepting requests but allow in-flight requests to finish before a deadline. The contract must say what happens to queued tasks and how callers learn their outcome.\n\nObservability makes overloaded queues diagnosable. Useful measurements include queue depth, oldest-task age, execution duration, rejection count, and time spent waiting versus running. Task names or correlation identifiers can connect queue activity to higher-level requests. Instrumentation should avoid exposing sensitive task contents and should not add enough synchronized work to become a bottleneck itself. A growing queue is often a symptom rather than the root cause, but without metrics that symptom remains invisible until users notice delays.\n\nSerial queues are most effective when used as precise instruments rather than universal architecture. They simplify one class of problems by turning concurrent mutation into an ordered stream of operations. In exchange, they introduce queuing latency, lifecycle concerns, and the possibility of deadlock or backlog. Their central benefit is intellectual as much as mechanical: they give programmers a place where events happen one at a time. When the ownership boundary is clear, tasks remain short, and ordering semantics are explicit, that simple promise can make a complex concurrent system substantially safer and easier to maintain.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:04.987Z","updatedAt":"2026-10-27T14:25:37.148Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b468a3b4819aa4e0361dca94ed51","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:6","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b468a3b4819aa4e0361dca94ed51","role":"assistant","text":"CODEX_DETAIL_ACK_17885\nCODEX_ACTIVE_17885_DONE","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:44.691Z","updatedAt":"2026-10-27T14:25:44.949Z"},{"createdBy":"user","creationSource":"web","id":"519064dd-4cdb-43f2-9488-d4fa4a9d5d55","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:2","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A2:root","role":"user","text":"HELD_Q_17885: When explicitly released, reply exactly HELD_Q_DONE. No tools.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:26.567Z","updatedAt":"2026-10-27T14:24:26.567Z"},{"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":"provider","id":"message:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1:437b5282-29f1-4188-b3a8-58d8f5a1229d","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:5","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%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":"2026-10-27T14:25:30.253Z","updatedAt":"2026-10-27T14:25:30.253Z"}]}
2026-10-27T14:26:02.483Z STEP {"action":"user RPC dispatch","command":{"type":"queue.resume"}}
2026-10-27T14:26:02.667Z OBSERVATION_WINDOW {"milliseconds":45000,"narration":"Observe one fresh prompt for each released notification and queued Q"}
2026-10-27T14:26:03.132Z PROJECTION 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modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","userMessageId":"519064dd-4cdb-43f2-9488-d4fa4a9d5d55","rootNodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A2:root","activeAttemptId":"run-attempt:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A2:attempt:1","status":"running","queuePosition":null,"queueHeld":false,"requestedAt":"2026-10-27T14:24:26.567Z","startedAt":"2026-10-27T14:26:02.712Z","completedAt":null,"checkpointId":null,"contextHandoffId":null}],"messages":[{"createdBy":"user","creationSource":"web","id":"message:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1:076898c7-32f3-4963-83ee-bf5eb2b1cd0f","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%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":"2026-10-27T14:24:23.442Z","updatedAt":"2026-10-27T14:24:23.442Z"},{"createdBy":"agent","creationSource":"mcp","id":"message:mcp:client%3A3615d0b0-29d2-4c83-b8d7-da01992d4840:thread-send:604cddc4-0d14-41f8-8b22-064dc8cb2d50","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:3","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%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":"2026-10-27T14:24:39.926Z","updatedAt":"2026-10-27T14:24:39.926Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b42bd524819aace1a8cdad9d0eac","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:3","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b42bd524819aace1a8cdad9d0eac","role":"assistant","text":"I’ll start the requested foreground Node process and leave its command session running.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:43.876Z","updatedAt":"2026-10-27T14:24:44.181Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b42f6384819aaf98301c46494b00","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:3","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b42f6384819aaf98301c46494b00","role":"assistant","text":"CODEX_ROOT_SETTLED","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:47.463Z","updatedAt":"2026-10-27T14:24:47.504Z"},{"createdBy":"agent","creationSource":"mcp","id":"message:mcp:client%3A54049495-6f11-4f1c-89eb-579299a4e0b5:thread-send:e1e87be4-f1df-42fd-9ebb-8db56f3337ba","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:4","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%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":"2026-10-27T14:24:57.114Z","updatedAt":"2026-10-27T14:24:57.114Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b43c77a4819a98bb5eac73b6ae6b","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:4","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b43c77a4819a98bb5eac73b6ae6b","role":"assistant","text":"I’ll start the second foreground Node session, leave it unpolled, then provide the essay without changing files.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:00.542Z","updatedAt":"2026-10-27T14:25:00.609Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b440f36c819a88511d115ad115f6","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:4","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b440f36c819a88511d115ad115f6","role":"assistant","text":"Serial Queues\n\nA serial queue is one of the simplest tools for organizing concurrent work. It accepts tasks in some order and allows only one task to execute at a time. When the active task finishes, the next task begins. This rule sounds modest, but it provides a powerful guarantee: tasks submitted to the same serial queue never overlap. Systems use that guarantee to coordinate access to shared state, preserve ordering, and make asynchronous programs easier to understand.\n\nConcurrency becomes difficult when several operations can touch the same data simultaneously. Suppose two tasks read a counter, add one, and write the result. If both read the old value before either writes, one increment disappears. Locks can protect the counter, but locks introduce their own obligations. Every access must acquire the correct lock, release it on every path, and avoid incompatible lock ordering. A serial queue offers another model. Code submits all counter operations to one queue, and the queue ensures that each operation observes the effects of its predecessors.\n\nThis arrangement is often described as confinement. The protected state belongs conceptually to the queue, and code may interact with it only through tasks submitted there. Confinement matters more than the queue’s mechanics. If some code bypasses the queue and accesses the state directly, the safety guarantee collapses. A serial queue is therefore not magical synchronization; it is a disciplined boundary. It works when the program consistently respects that boundary.\n\nSerial queues also express ordering. If task A is submitted before task B, a first-in, first-out serial queue starts A first and completes it before B starts. This property is useful for event processing, log writing, protocol handling, and state machines. An application might receive user actions from many threads but funnel them through one queue so that the state changes in a stable sequence. The producers remain concurrent while the sensitive decisions become serialized.\n\nSubmission and execution are different concepts. Asynchronous submission normally places a task on the queue and returns immediately. The caller can continue doing other work while the queued task waits its turn. Synchronous submission blocks the caller until the submitted task completes. Both modes preserve serialization inside the queue, but they have very different effects on the caller. Asynchronous submission promotes responsiveness. Synchronous submission can conveniently retrieve a result, though careless use can cause deadlock.\n\nThe classic deadlock occurs when code already running on a serial queue synchronously submits another task to that same queue. The outer task waits for the inner task to finish, but the queue cannot start the inner task until the outer task finishes. Neither can advance. Queue libraries sometimes detect this mistake, but programs should not depend on detection. Common remedies include executing directly when already on the queue, exposing only asynchronous operations, or restructuring the API so that nested synchronous submission is unnecessary.\n\nA queue need not own a dedicated thread. Many modern runtimes maintain a pool of worker threads and schedule queue tasks onto that pool. The serial property concerns logical execution order, not permanent attachment to a particular operating-system thread. One task may run on one worker and the next task on another, while still never overlapping. Consequently, thread-local storage and thread identity should not be treated as queue identity unless the runtime explicitly promises such behavior.\n\nThis distinction helps explain why serial queues can be inexpensive. Creating thousands of dedicated threads would consume substantial memory and scheduling resources. Creating many lightweight queue objects can be practical because inactive queues need no thread of their own. The runtime activates a queue only when work is available. Queue-based designs can therefore represent many independent domains of serialization without requiring an equally large number of workers.\n\nNevertheless, serialization has a performance cost. A queue can execute no faster than its slowest accumulated workload permits. If producers submit tasks faster than the queue completes them, latency grows and memory may grow with the backlog. One long task delays every task behind it, a phenomenon sometimes called head-of-line blocking. Good serial-queue tasks are usually short, bounded, and focused on the state that truly requires ordered access.\n\nExpensive computation and slow input or output should often happen elsewhere. A task can capture the state needed for an operation, dispatch costly work to a concurrent executor, and later submit a small result-handling task back to the serial queue. This pattern preserves state safety while exploiting parallelism. It also introduces a subtle issue: results may return in a different order from the requests that produced them. The queue serializes result application, but it does not automatically restore semantic ordering. Sequence numbers, version checks, cancellation, or explicit dependencies may be needed.\n\nChoosing the scope of a queue is therefore important. One global serial queue makes reasoning easy but can eliminate useful parallelism. A separate queue for every tiny value can make relationships hard to follow and can create coordination overhead. A useful middle ground is to assign a queue to a coherent ownership domain, such as a document, connection, cache, account, or subsystem. Operations within a domain are ordered, while independent domains can proceed concurrently.\n\nSerial queues resemble mutexes, but their programming styles differ. A mutex protects a critical section executed by the calling thread. A queue usually accepts a unit of work that may execute later on another worker. Mutexes fit small, synchronous accesses and existing data structures. Queues fit ownership-oriented components, asynchronous workflows, and event-driven systems. Neither mechanism is universally superior. The better choice is the one that makes the invariant obvious and difficult to violate.\n\nQueues can also improve encapsulation. Instead of exposing mutable fields and expecting callers to synchronize correctly, a component can expose operations such as update, snapshot, and close. Internally, those operations are submitted to its serial queue. Callers no longer need to know which values require protection. The component becomes an active object: it receives messages, processes them one at a time, and owns its state. Actor systems generalize this idea by providing isolated entities with serial mailboxes.\n\nError handling needs deliberate design. An exception or rejected promise in one task should not silently stop the queue unless that behavior is intentional. Libraries differ in whether errors propagate to submitters, reach a global handler, or become detached failures. A robust queue abstraction defines how each task reports success, how failures affect following tasks, and whether retries preserve order. Retrying a failed operation at the tail may allow later operations to overtake it, while retrying in place may block the entire queue.\n\nCancellation is similarly nuanced. Removing a task that has not started is relatively straightforward, but cancellation may change the meaning of later tasks. If a queued sequence contains open, write, and close, cancelling open while retaining the other operations is probably invalid. Once a task begins, forced interruption may leave protected state inconsistent. Cooperative cancellation is safer: the task checks a token at well-defined points and exits after restoring invariants. Queue APIs should distinguish cancelling interest in a result from cancelling the underlying operation.\n\nFairness and priority complicate the basic FIFO model. Strict submission order is predictable, but urgent work can become trapped behind routine work. Priority queues can reduce urgent latency, yet they weaken ordering and may starve low-priority tasks. Multiple serial queues sharing a worker pool can also experience priority inversion when a high-priority task depends on work waiting in a lower-priority queue. These concerns matter most in interactive, real-time, or heavily loaded systems. For many application components, plain FIFO behavior remains the clearest default.\n\nTesting serial-queue code requires more than verifying final values. Tests should exercise ordering, reentrancy, failure, cancellation, and shutdown. A controllable executor can pause tasks at boundaries and make normally rare schedules reproducible. Assertions can verify that no two tasks enter the protected region simultaneously. Stress tests can submit operations from many producers, but deterministic tests are usually better at explaining a failure. Time-based sleeps are fragile because they confuse scheduler timing with program correctness.\n\nShutdown is an especially important lifecycle transition. A queue may need to reject new tasks, drain accepted work, cancel pending operations, or stop immediately. Each policy is reasonable in a different context. A file writer may need to drain to prevent data loss. A screen controller being discarded may cancel obsolete rendering work. A network service may stop accepting requests but allow in-flight requests to finish before a deadline. The contract must say what happens to queued tasks and how callers learn their outcome.\n\nObservability makes overloaded queues diagnosable. Useful measurements include queue depth, oldest-task age, execution duration, rejection count, and time spent waiting versus running. Task names or correlation identifiers can connect queue activity to higher-level requests. Instrumentation should avoid exposing sensitive task contents and should not add enough synchronized work to become a bottleneck itself. A growing queue is often a symptom rather than the root cause, but without metrics that symptom remains invisible until users notice delays.\n\nSerial queues are most effective when used as precise instruments rather than universal architecture. They simplify one class of problems by turning concurrent mutation into an ordered stream of operations. In exchange, they introduce queuing latency, lifecycle concerns, and the possibility of deadlock or backlog. Their central benefit is intellectual as much as mechanical: they give programmers a place where events happen one at a time. When the ownership boundary is clear, tasks remain short, and ordering semantics are explicit, that simple promise can make a complex concurrent system substantially safer and easier to maintain.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:04.987Z","updatedAt":"2026-10-27T14:25:37.148Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b468a3b4819aa4e0361dca94ed51","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:6","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b468a3b4819aa4e0361dca94ed51","role":"assistant","text":"CODEX_DETAIL_ACK_17885\nCODEX_ACTIVE_17885_DONE","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:44.691Z","updatedAt":"2026-10-27T14:25:44.949Z"},{"createdBy":"user","creationSource":"web","id":"519064dd-4cdb-43f2-9488-d4fa4a9d5d55","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:2","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A2:root","role":"user","text":"HELD_Q_17885: When explicitly released, reply exactly HELD_Q_DONE. No tools.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:26.567Z","updatedAt":"2026-10-27T14:24:26.567Z"},{"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":"provider","id":"message:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1:437b5282-29f1-4188-b3a8-58d8f5a1229d","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:5","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%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":"2026-10-27T14:25:30.253Z","updatedAt":"2026-10-27T14:25:30.253Z"}],"subagents":[],"providerThreads":[{"id":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","driver":"codex","providerInstanceId":"codex","providerSessionId":"provider-session:provider-instance:codex:shared","appThreadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ownerNodeId":null,"nativeThreadRef":{"driver":"codex","nativeId":"01a17dbf-8317-7fc1-950c-c63c6cd01212","strength":"strong"},"nativeConversationHeadRef":null,"status":"active","firstRunOrdinal":1,"lastRunOrdinal":7,"handoffIds":[],"forkedFrom":null,"pendingBackgroundTasks":[],"contextUsage":{"usedTokens":22561,"maxTokens":258400},"nativeMetadata":null,"goal":null,"createdAt":"2026-10-27T14:24:23.442Z","updatedAt":"2026-10-27T14:26:02.712Z"}]}
2026-10-27T14:26:07.395Z 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":"2026-10-27T14:24:23.442Z","updatedAt":"2026-10-27T14:24:23.442Z"},{"createdBy":"agent","creationSource":"mcp","id":"message:mcp:client%3A3615d0b0-29d2-4c83-b8d7-da01992d4840:thread-send:604cddc4-0d14-41f8-8b22-064dc8cb2d50","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:3","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%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":"2026-10-27T14:24:39.926Z","updatedAt":"2026-10-27T14:24:39.926Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b42bd524819aace1a8cdad9d0eac","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:3","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b42bd524819aace1a8cdad9d0eac","role":"assistant","text":"I’ll start the requested foreground Node process and leave its command session running.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:43.876Z","updatedAt":"2026-10-27T14:24:44.181Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b42f6384819aaf98301c46494b00","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:3","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b42f6384819aaf98301c46494b00","role":"assistant","text":"CODEX_ROOT_SETTLED","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:47.463Z","updatedAt":"2026-10-27T14:24:47.504Z"},{"createdBy":"agent","creationSource":"mcp","id":"message:mcp:client%3A54049495-6f11-4f1c-89eb-579299a4e0b5:thread-send:e1e87be4-f1df-42fd-9ebb-8db56f3337ba","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:4","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%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":"2026-10-27T14:24:57.114Z","updatedAt":"2026-10-27T14:24:57.114Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b43c77a4819a98bb5eac73b6ae6b","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:4","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b43c77a4819a98bb5eac73b6ae6b","role":"assistant","text":"I’ll start the second foreground Node session, leave it unpolled, then provide the essay without changing files.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:00.542Z","updatedAt":"2026-10-27T14:25:00.609Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b440f36c819a88511d115ad115f6","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:4","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b440f36c819a88511d115ad115f6","role":"assistant","text":"Serial Queues\n\nA serial queue is one of the simplest tools for organizing concurrent work. It accepts tasks in some order and allows only one task to execute at a time. When the active task finishes, the next task begins. This rule sounds modest, but it provides a powerful guarantee: tasks submitted to the same serial queue never overlap. Systems use that guarantee to coordinate access to shared state, preserve ordering, and make asynchronous programs easier to understand.\n\nConcurrency becomes difficult when several operations can touch the same data simultaneously. Suppose two tasks read a counter, add one, and write the result. If both read the old value before either writes, one increment disappears. Locks can protect the counter, but locks introduce their own obligations. Every access must acquire the correct lock, release it on every path, and avoid incompatible lock ordering. A serial queue offers another model. Code submits all counter operations to one queue, and the queue ensures that each operation observes the effects of its predecessors.\n\nThis arrangement is often described as confinement. The protected state belongs conceptually to the queue, and code may interact with it only through tasks submitted there. Confinement matters more than the queue’s mechanics. If some code bypasses the queue and accesses the state directly, the safety guarantee collapses. A serial queue is therefore not magical synchronization; it is a disciplined boundary. It works when the program consistently respects that boundary.\n\nSerial queues also express ordering. If task A is submitted before task B, a first-in, first-out serial queue starts A first and completes it before B starts. This property is useful for event processing, log writing, protocol handling, and state machines. An application might receive user actions from many threads but funnel them through one queue so that the state changes in a stable sequence. The producers remain concurrent while the sensitive decisions become serialized.\n\nSubmission and execution are different concepts. Asynchronous submission normally places a task on the queue and returns immediately. The caller can continue doing other work while the queued task waits its turn. Synchronous submission blocks the caller until the submitted task completes. Both modes preserve serialization inside the queue, but they have very different effects on the caller. Asynchronous submission promotes responsiveness. Synchronous submission can conveniently retrieve a result, though careless use can cause deadlock.\n\nThe classic deadlock occurs when code already running on a serial queue synchronously submits another task to that same queue. The outer task waits for the inner task to finish, but the queue cannot start the inner task until the outer task finishes. Neither can advance. Queue libraries sometimes detect this mistake, but programs should not depend on detection. Common remedies include executing directly when already on the queue, exposing only asynchronous operations, or restructuring the API so that nested synchronous submission is unnecessary.\n\nA queue need not own a dedicated thread. Many modern runtimes maintain a pool of worker threads and schedule queue tasks onto that pool. The serial property concerns logical execution order, not permanent attachment to a particular operating-system thread. One task may run on one worker and the next task on another, while still never overlapping. Consequently, thread-local storage and thread identity should not be treated as queue identity unless the runtime explicitly promises such behavior.\n\nThis distinction helps explain why serial queues can be inexpensive. Creating thousands of dedicated threads would consume substantial memory and scheduling resources. Creating many lightweight queue objects can be practical because inactive queues need no thread of their own. The runtime activates a queue only when work is available. Queue-based designs can therefore represent many independent domains of serialization without requiring an equally large number of workers.\n\nNevertheless, serialization has a performance cost. A queue can execute no faster than its slowest accumulated workload permits. If producers submit tasks faster than the queue completes them, latency grows and memory may grow with the backlog. One long task delays every task behind it, a phenomenon sometimes called head-of-line blocking. Good serial-queue tasks are usually short, bounded, and focused on the state that truly requires ordered access.\n\nExpensive computation and slow input or output should often happen elsewhere. A task can capture the state needed for an operation, dispatch costly work to a concurrent executor, and later submit a small result-handling task back to the serial queue. This pattern preserves state safety while exploiting parallelism. It also introduces a subtle issue: results may return in a different order from the requests that produced them. The queue serializes result application, but it does not automatically restore semantic ordering. Sequence numbers, version checks, cancellation, or explicit dependencies may be needed.\n\nChoosing the scope of a queue is therefore important. One global serial queue makes reasoning easy but can eliminate useful parallelism. A separate queue for every tiny value can make relationships hard to follow and can create coordination overhead. A useful middle ground is to assign a queue to a coherent ownership domain, such as a document, connection, cache, account, or subsystem. Operations within a domain are ordered, while independent domains can proceed concurrently.\n\nSerial queues resemble mutexes, but their programming styles differ. A mutex protects a critical section executed by the calling thread. A queue usually accepts a unit of work that may execute later on another worker. Mutexes fit small, synchronous accesses and existing data structures. Queues fit ownership-oriented components, asynchronous workflows, and event-driven systems. Neither mechanism is universally superior. The better choice is the one that makes the invariant obvious and difficult to violate.\n\nQueues can also improve encapsulation. Instead of exposing mutable fields and expecting callers to synchronize correctly, a component can expose operations such as update, snapshot, and close. Internally, those operations are submitted to its serial queue. Callers no longer need to know which values require protection. The component becomes an active object: it receives messages, processes them one at a time, and owns its state. Actor systems generalize this idea by providing isolated entities with serial mailboxes.\n\nError handling needs deliberate design. An exception or rejected promise in one task should not silently stop the queue unless that behavior is intentional. Libraries differ in whether errors propagate to submitters, reach a global handler, or become detached failures. A robust queue abstraction defines how each task reports success, how failures affect following tasks, and whether retries preserve order. Retrying a failed operation at the tail may allow later operations to overtake it, while retrying in place may block the entire queue.\n\nCancellation is similarly nuanced. Removing a task that has not started is relatively straightforward, but cancellation may change the meaning of later tasks. If a queued sequence contains open, write, and close, cancelling open while retaining the other operations is probably invalid. Once a task begins, forced interruption may leave protected state inconsistent. Cooperative cancellation is safer: the task checks a token at well-defined points and exits after restoring invariants. Queue APIs should distinguish cancelling interest in a result from cancelling the underlying operation.\n\nFairness and priority complicate the basic FIFO model. Strict submission order is predictable, but urgent work can become trapped behind routine work. Priority queues can reduce urgent latency, yet they weaken ordering and may starve low-priority tasks. Multiple serial queues sharing a worker pool can also experience priority inversion when a high-priority task depends on work waiting in a lower-priority queue. These concerns matter most in interactive, real-time, or heavily loaded systems. For many application components, plain FIFO behavior remains the clearest default.\n\nTesting serial-queue code requires more than verifying final values. Tests should exercise ordering, reentrancy, failure, cancellation, and shutdown. A controllable executor can pause tasks at boundaries and make normally rare schedules reproducible. Assertions can verify that no two tasks enter the protected region simultaneously. Stress tests can submit operations from many producers, but deterministic tests are usually better at explaining a failure. Time-based sleeps are fragile because they confuse scheduler timing with program correctness.\n\nShutdown is an especially important lifecycle transition. A queue may need to reject new tasks, drain accepted work, cancel pending operations, or stop immediately. Each policy is reasonable in a different context. A file writer may need to drain to prevent data loss. A screen controller being discarded may cancel obsolete rendering work. A network service may stop accepting requests but allow in-flight requests to finish before a deadline. The contract must say what happens to queued tasks and how callers learn their outcome.\n\nObservability makes overloaded queues diagnosable. Useful measurements include queue depth, oldest-task age, execution duration, rejection count, and time spent waiting versus running. Task names or correlation identifiers can connect queue activity to higher-level requests. Instrumentation should avoid exposing sensitive task contents and should not add enough synchronized work to become a bottleneck itself. A growing queue is often a symptom rather than the root cause, but without metrics that symptom remains invisible until users notice delays.\n\nSerial queues are most effective when used as precise instruments rather than universal architecture. They simplify one class of problems by turning concurrent mutation into an ordered stream of operations. In exchange, they introduce queuing latency, lifecycle concerns, and the possibility of deadlock or backlog. Their central benefit is intellectual as much as mechanical: they give programmers a place where events happen one at a time. When the ownership boundary is clear, tasks remain short, and ordering semantics are explicit, that simple promise can make a complex concurrent system substantially safer and easier to maintain.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:04.987Z","updatedAt":"2026-10-27T14:25:37.148Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b468a3b4819aa4e0361dca94ed51","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:6","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b468a3b4819aa4e0361dca94ed51","role":"assistant","text":"CODEX_DETAIL_ACK_17885\nCODEX_ACTIVE_17885_DONE","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:44.691Z","updatedAt":"2026-10-27T14:25:44.949Z"},{"createdBy":"user","creationSource":"web","id":"519064dd-4cdb-43f2-9488-d4fa4a9d5d55","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:2","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A2:root","role":"user","text":"HELD_Q_17885: When explicitly released, reply exactly HELD_Q_DONE. No tools.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:26.567Z","updatedAt":"2026-10-27T14:24:26.567Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b47e3b64819a8ae42911ff303eb1","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:2","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b47e3b64819a8ae42911ff303eb1","role":"assistant","text":"HELD_Q_17885 held.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:26:07.008Z","updatedAt":"2026-10-27T14:26:07.195Z"},{"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":"provider","id":"message:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1:437b5282-29f1-4188-b3a8-58d8f5a1229d","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:5","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%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":"2026-10-27T14:25:30.253Z","updatedAt":"2026-10-27T14:25:30.253Z"}],"subagents":[],"providerThreads":[{"id":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","driver":"codex","providerInstanceId":"codex","providerSessionId":"provider-session:provider-instance:codex:shared","appThreadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ownerNodeId":null,"nativeThreadRef":{"driver":"codex","nativeId":"01a17dbf-8317-7fc1-950c-c63c6cd01212","strength":"strong"},"nativeConversationHeadRef":null,"status":"idle","firstRunOrdinal":1,"lastRunOrdinal":7,"handoffIds":[],"forkedFrom":null,"pendingBackgroundTasks":[],"contextUsage":{"usedTokens":22561,"maxTokens":258400},"nativeMetadata":null,"goal":null,"createdAt":"2026-10-27T14:24:23.442Z","updatedAt":"2026-10-27T14:26:07.247Z"}]}
2026-10-27T14:26:09.832Z PROJECTION {"runs":[{"id":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ordinal":1,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","userMessageId":"message:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1:076898c7-32f3-4963-83ee-bf5eb2b1cd0f","rootNodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1:root","activeAttemptId":"run-attempt:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1:attempt:1","status":"interrupted","queuePosition":null,"requestedAt":"2026-10-27T14:24:23.442Z","startedAt":"2026-10-27T14:24:25.671Z","completedAt":"2026-10-27T14:24:26.847Z","checkpointId":null,"contextHandoffId":null,"workspacePreparation":{"type":"root"}},{"id":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:3","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ordinal":3,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","userMessageId":"message:mcp:client%3A3615d0b0-29d2-4c83-b8d7-da01992d4840:thread-send:604cddc4-0d14-41f8-8b22-064dc8cb2d50","rootNodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A3:root","activeAttemptId":"run-attempt:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A3:attempt:1","status":"completed","queuePosition":null,"requestedAt":"2026-10-27T14:24:39.926Z","startedAt":"2026-10-27T14:24:40.215Z","completedAt":"2026-10-27T14:24:47.670Z","checkpointId":"checkpoint:scope:checkpoint-scope%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aname%3Aroot:name:3","contextHandoffId":null},{"id":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:4","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ordinal":4,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","userMessageId":"message:mcp:client%3A54049495-6f11-4f1c-89eb-579299a4e0b5:thread-send:e1e87be4-f1df-42fd-9ebb-8db56f3337ba","rootNodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A4:root","activeAttemptId":"run-attempt:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A4:attempt:1","status":"completed","queuePosition":null,"requestedAt":"2026-10-27T14:24:57.114Z","startedAt":"2026-10-27T14:24:57.187Z","completedAt":"2026-10-27T14:25:37.354Z","checkpointId":"checkpoint:scope:checkpoint-scope%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aname%3Aroot:name:4","contextHandoffId":null},{"id":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:6","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ordinal":6,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","userMessageId":"message:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1:f1d90d4f-f3f4-40a7-bbe4-12cae383f473","rootNodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A6:root","activeAttemptId":"run-attempt:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A6:attempt:1","status":"completed","queuePosition":null,"requestedAt":"2026-10-27T14:25:40.904Z","startedAt":"2026-10-27T14:25:41.087Z","completedAt":"2026-10-27T14:25:45.153Z","checkpointId":"checkpoint:scope:checkpoint-scope%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aname%3Aroot:name:6","contextHandoffId":null,"workStartedAt":"2026-10-27T14:24:57.187Z"},{"id":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:2","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ordinal":7,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","userMessageId":"519064dd-4cdb-43f2-9488-d4fa4a9d5d55","rootNodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A2:root","activeAttemptId":"run-attempt:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A2:attempt:1","status":"completed","queuePosition":null,"queueHeld":false,"requestedAt":"2026-10-27T14:24:26.567Z","startedAt":"2026-10-27T14:26:02.712Z","completedAt":"2026-10-27T14:26:07.362Z","checkpointId":"checkpoint:scope:checkpoint-scope%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aname%3Aroot:name:7","contextHandoffId":null},{"id":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:5","thr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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":"2026-10-27T14:24:23.442Z","updatedAt":"2026-10-27T14:24:23.442Z"},{"createdBy":"agent","creationSource":"mcp","id":"message:mcp:client%3A3615d0b0-29d2-4c83-b8d7-da01992d4840:thread-send:604cddc4-0d14-41f8-8b22-064dc8cb2d50","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:3","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%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":"2026-10-27T14:24:39.926Z","updatedAt":"2026-10-27T14:24:39.926Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b42bd524819aace1a8cdad9d0eac","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:3","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b42bd524819aace1a8cdad9d0eac","role":"assistant","text":"I’ll start the requested foreground Node process and leave its command session running.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:43.876Z","updatedAt":"2026-10-27T14:24:44.181Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b42f6384819aaf98301c46494b00","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:3","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b42f6384819aaf98301c46494b00","role":"assistant","text":"CODEX_ROOT_SETTLED","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:47.463Z","updatedAt":"2026-10-27T14:24:47.504Z"},{"createdBy":"agent","creationSource":"mcp","id":"message:mcp:client%3A54049495-6f11-4f1c-89eb-579299a4e0b5:thread-send:e1e87be4-f1df-42fd-9ebb-8db56f3337ba","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:4","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%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":"2026-10-27T14:24:57.114Z","updatedAt":"2026-10-27T14:24:57.114Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b43c77a4819a98bb5eac73b6ae6b","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:4","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b43c77a4819a98bb5eac73b6ae6b","role":"assistant","text":"I’ll start the second foreground Node session, leave it unpolled, then provide the essay without changing files.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:00.542Z","updatedAt":"2026-10-27T14:25:00.609Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b440f36c819a88511d115ad115f6","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:4","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b440f36c819a88511d115ad115f6","role":"assistant","text":"Serial Queues\n\nA serial queue is one of the simplest tools for organizing concurrent work. It accepts tasks in some order and allows only one task to execute at a time. When the active task finishes, the next task begins. This rule sounds modest, but it provides a powerful guarantee: tasks submitted to the same serial queue never overlap. Systems use that guarantee to coordinate access to shared state, preserve ordering, and make asynchronous programs easier to understand.\n\nConcurrency becomes difficult when several operations can touch the same data simultaneously. Suppose two tasks read a counter, add one, and write the result. If both read the old value before either writes, one increment disappears. Locks can protect the counter, but locks introduce their own obligations. Every access must acquire the correct lock, release it on every path, and avoid incompatible lock ordering. A serial queue offers another model. Code submits all counter operations to one queue, and the queue ensures that each operation observes the effects of its predecessors.\n\nThis arrangement is often described as confinement. The protected state belongs conceptually to the queue, and code may interact with it only through tasks submitted there. Confinement matters more than the queue’s mechanics. If some code bypasses the queue and accesses the state directly, the safety guarantee collapses. A serial queue is therefore not magical synchronization; it is a disciplined boundary. It works when the program consistently respects that boundary.\n\nSerial queues also express ordering. If task A is submitted before task B, a first-in, first-out serial queue starts A first and completes it before B starts. This property is useful for event processing, log writing, protocol handling, and state machines. An application might receive user actions from many threads but funnel them through one queue so that the state changes in a stable sequence. The producers remain concurrent while the sensitive decisions become serialized.\n\nSubmission and execution are different concepts. Asynchronous submission normally places a task on the queue and returns immediately. The caller can continue doing other work while the queued task waits its turn. Synchronous submission blocks the caller until the submitted task completes. Both modes preserve serialization inside the queue, but they have very different effects on the caller. Asynchronous submission promotes responsiveness. Synchronous submission can conveniently retrieve a result, though careless use can cause deadlock.\n\nThe classic deadlock occurs when code already running on a serial queue synchronously submits another task to that same queue. The outer task waits for the inner task to finish, but the queue cannot start the inner task until the outer task finishes. Neither can advance. Queue libraries sometimes detect this mistake, but programs should not depend on detection. Common remedies include executing directly when already on the queue, exposing only asynchronous operations, or restructuring the API so that nested synchronous submission is unnecessary.\n\nA queue need not own a dedicated thread. Many modern runtimes maintain a pool of worker threads and schedule queue tasks onto that pool. The serial property concerns logical execution order, not permanent attachment to a particular operating-system thread. One task may run on one worker and the next task on another, while still never overlapping. Consequently, thread-local storage and thread identity should not be treated as queue identity unless the runtime explicitly promises such behavior.\n\nThis distinction helps explain why serial queues can be inexpensive. Creating thousands of dedicated threads would consume substantial memory and scheduling resources. Creating many lightweight queue objects can be practical because inactive queues need no thread of their own. The runtime activates a queue only when work is available. Queue-based designs can therefore represent many independent domains of serialization without requiring an equally large number of workers.\n\nNevertheless, serialization has a performance cost. A queue can execute no faster than its slowest accumulated workload permits. If producers submit tasks faster than the queue completes them, latency grows and memory may grow with the backlog. One long task delays every task behind it, a phenomenon sometimes called head-of-line blocking. Good serial-queue tasks are usually short, bounded, and focused on the state that truly requires ordered access.\n\nExpensive computation and slow input or output should often happen elsewhere. A task can capture the state needed for an operation, dispatch costly work to a concurrent executor, and later submit a small result-handling task back to the serial queue. This pattern preserves state safety while exploiting parallelism. It also introduces a subtle issue: results may return in a different order from the requests that produced them. The queue serializes result application, but it does not automatically restore semantic ordering. Sequence numbers, version checks, cancellation, or explicit dependencies may be needed.\n\nChoosing the scope of a queue is therefore important. One global serial queue makes reasoning easy but can eliminate useful parallelism. A separate queue for every tiny value can make relationships hard to follow and can create coordination overhead. A useful middle ground is to assign a queue to a coherent ownership domain, such as a document, connection, cache, account, or subsystem. Operations within a domain are ordered, while independent domains can proceed concurrently.\n\nSerial queues resemble mutexes, but their programming styles differ. A mutex protects a critical section executed by the calling thread. A queue usually accepts a unit of work that may execute later on another worker. Mutexes fit small, synchronous accesses and existing data structures. Queues fit ownership-oriented components, asynchronous workflows, and event-driven systems. Neither mechanism is universally superior. The better choice is the one that makes the invariant obvious and difficult to violate.\n\nQueues can also improve encapsulation. Instead of exposing mutable fields and expecting callers to synchronize correctly, a component can expose operations such as update, snapshot, and close. Internally, those operations are submitted to its serial queue. Callers no longer need to know which values require protection. The component becomes an active object: it receives messages, processes them one at a time, and owns its state. Actor systems generalize this idea by providing isolated entities with serial mailboxes.\n\nError handling needs deliberate design. An exception or rejected promise in one task should not silently stop the queue unless that behavior is intentional. Libraries differ in whether errors propagate to submitters, reach a global handler, or become detached failures. A robust queue abstraction defines how each task reports success, how failures affect following tasks, and whether retries preserve order. Retrying a failed operation at the tail may allow later operations to overtake it, while retrying in place may block the entire queue.\n\nCancellation is similarly nuanced. Removing a task that has not started is relatively straightforward, but cancellation may change the meaning of later tasks. If a queued sequence contains open, write, and close, cancelling open while retaining the other operations is probably invalid. Once a task begins, forced interruption may leave protected state inconsistent. Cooperative cancellation is safer: the task checks a token at well-defined points and exits after restoring invariants. Queue APIs should distinguish cancelling interest in a result from cancelling the underlying operation.\n\nFairness and priority complicate the basic FIFO model. Strict submission order is predictable, but urgent work can become trapped behind routine work. Priority queues can reduce urgent latency, yet they weaken ordering and may starve low-priority tasks. Multiple serial queues sharing a worker pool can also experience priority inversion when a high-priority task depends on work waiting in a lower-priority queue. These concerns matter most in interactive, real-time, or heavily loaded systems. For many application components, plain FIFO behavior remains the clearest default.\n\nTesting serial-queue code requires more than verifying final values. Tests should exercise ordering, reentrancy, failure, cancellation, and shutdown. A controllable executor can pause tasks at boundaries and make normally rare schedules reproducible. Assertions can verify that no two tasks enter the protected region simultaneously. Stress tests can submit operations from many producers, but deterministic tests are usually better at explaining a failure. Time-based sleeps are fragile because they confuse scheduler timing with program correctness.\n\nShutdown is an especially important lifecycle transition. A queue may need to reject new tasks, drain accepted work, cancel pending operations, or stop immediately. Each policy is reasonable in a different context. A file writer may need to drain to prevent data loss. A screen controller being discarded may cancel obsolete rendering work. A network service may stop accepting requests but allow in-flight requests to finish before a deadline. The contract must say what happens to queued tasks and how callers learn their outcome.\n\nObservability makes overloaded queues diagnosable. Useful measurements include queue depth, oldest-task age, execution duration, rejection count, and time spent waiting versus running. Task names or correlation identifiers can connect queue activity to higher-level requests. Instrumentation should avoid exposing sensitive task contents and should not add enough synchronized work to become a bottleneck itself. A growing queue is often a symptom rather than the root cause, but without metrics that symptom remains invisible until users notice delays.\n\nSerial queues are most effective when used as precise instruments rather than universal architecture. They simplify one class of problems by turning concurrent mutation into an ordered stream of operations. In exchange, they introduce queuing latency, lifecycle concerns, and the possibility of deadlock or backlog. Their central benefit is intellectual as much as mechanical: they give programmers a place where events happen one at a time. When the ownership boundary is clear, tasks remain short, and ordering semantics are explicit, that simple promise can make a complex concurrent system substantially safer and easier to maintain.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:04.987Z","updatedAt":"2026-10-27T14:25:37.148Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b468a3b4819aa4e0361dca94ed51","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:6","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b468a3b4819aa4e0361dca94ed51","role":"assistant","text":"CODEX_DETAIL_ACK_17885\nCODEX_ACTIVE_17885_DONE","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:44.691Z","updatedAt":"2026-10-27T14:25:44.949Z"},{"createdBy":"user","creationSource":"web","id":"519064dd-4cdb-43f2-9488-d4fa4a9d5d55","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:2","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A2:root","role":"user","text":"HELD_Q_17885: When explicitly released, reply exactly HELD_Q_DONE. No tools.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:26.567Z","updatedAt":"2026-10-27T14:24:26.567Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b47e3b64819a8ae42911ff303eb1","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:2","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b47e3b64819a8ae42911ff303eb1","role":"assistant","text":"HELD_Q_17885 held.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:26:07.008Z","updatedAt":"2026-10-27T14:26:07.195Z"},{"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":"provider","id":"message:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1:437b5282-29f1-4188-b3a8-58d8f5a1229d","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:5","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%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":"2026-10-27T14:25:30.253Z","updatedAt":"2026-10-27T14:25:30.253Z"}],"subagents":[],"providerThreads":[{"id":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","driver":"codex","providerInstanceId":"codex","providerSessionId":"provider-session:provider-instance:codex:shared","appThreadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ownerNodeId":null,"nativeThreadRef":{"driver":"codex","nativeId":"01a17dbf-8317-7fc1-950c-c63c6cd01212","strength":"strong"},"nativeConversationHeadRef":null,"status":"not_loaded","firstRunOrdinal":1,"lastRunOrdinal":8,"handoffIds":[],"forkedFrom":null,"pendingBackgroundTasks":[],"contextUsage":{"usedTokens":22561,"maxTokens":258400},"nativeMetadata":null,"goal":null,"createdAt":"2026-10-27T14:24:23.442Z","updatedAt":"2026-10-27T14:26:09.303Z"}]}
2026-10-27T14:26:10.741Z PROJECTION {"runs":[{"id":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ordinal":1,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","userMessageId":"message:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1:076898c7-32f3-4963-83ee-bf5eb2b1cd0f","rootNodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1:root","activeAttemptId":"run-attempt:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1:attempt:1","status":"interrupted","queuePosition":null,"requestedAt":"2026-10-27T14:24:23.442Z","startedAt":"2026-10-27T14:24:25.671Z","completedAt":"2026-10-27T14:24:26.847Z","checkpointId":null,"contextHandoffId":null,"workspacePreparation":{"type":"root"}},{"id":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:3","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ordinal":3,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","userMessageId":"message:mcp:client%3A3615d0b0-29d2-4c83-b8d7-da01992d4840:thread-send:604cddc4-0d14-41f8-8b22-064dc8cb2d50","rootNodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A3:root","activeAttemptId":"run-attempt:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A3:attempt:1","status":"completed","queuePosition":null,"requestedAt":"2026-10-27T14:24:39.926Z","startedAt":"2026-10-27T14:24:40.215Z","completedAt":"2026-10-27T14:24:47.670Z","checkpointId":"checkpoint:scope:checkpoint-scope%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aname%3Aroot:name:3","contextHandoffId":null},{"id":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:4","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ordinal":4,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","userMessageId":"message:mcp:client%3A54049495-6f11-4f1c-89eb-579299a4e0b5:thread-send:e1e87be4-f1df-42fd-9ebb-8db56f3337ba","rootNodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A4:root","activeAttemptId":"run-attempt:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A4:attempt:1","status":"completed","queuePosition":null,"requestedAt":"2026-10-27T14:24:57.114Z","startedAt":"2026-10-27T14:24:57.187Z","completedAt":"2026-10-27T14:25:37.354Z","checkpointId":"checkpoint:scope:checkpoint-scope%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aname%3Aroot:name:4","contextHandoffId":null},{"id":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:6","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ordinal":6,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","userMessageId":"message:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1:f1d90d4f-f3f4-40a7-bbe4-12cae383f473","rootNodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A6:root","activeAttemptId":"run-attempt:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A6:attempt:1","status":"completed","queuePosition":null,"requestedAt":"2026-10-27T14:25:40.904Z","startedAt":"2026-10-27T14:25:41.087Z","completedAt":"2026-10-27T14:25:45.153Z","checkpointId":"checkpoint:scope:checkpoint-scope%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aname%3Aroot:name:6","contextHandoffId":null,"workStartedAt":"2026-10-27T14:24:57.187Z"},{"id":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:2","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ordinal":7,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","userMessageId":"519064dd-4cdb-43f2-9488-d4fa4a9d5d55","rootNodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A2:root","activeAttemptId":"run-attempt:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A2:attempt:1","status":"completed","queuePosition":null,"queueHeld":false,"requestedAt":"2026-10-27T14:24:26.567Z","startedAt":"2026-10-27T14:26:02.712Z","completedAt":"2026-10-27T14:26:07.362Z","checkpointId":"checkpoint:scope:checkpoint-scope%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aname%3Aroot:name:7","contextHandoffId":null},{"id":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:5","thr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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":"2026-10-27T14:24:23.442Z","updatedAt":"2026-10-27T14:24:23.442Z"},{"createdBy":"agent","creationSource":"mcp","id":"message:mcp:client%3A3615d0b0-29d2-4c83-b8d7-da01992d4840:thread-send:604cddc4-0d14-41f8-8b22-064dc8cb2d50","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:3","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%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":"2026-10-27T14:24:39.926Z","updatedAt":"2026-10-27T14:24:39.926Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b42bd524819aace1a8cdad9d0eac","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:3","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b42bd524819aace1a8cdad9d0eac","role":"assistant","text":"I’ll start the requested foreground Node process and leave its command session running.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:43.876Z","updatedAt":"2026-10-27T14:24:44.181Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b42f6384819aaf98301c46494b00","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:3","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b42f6384819aaf98301c46494b00","role":"assistant","text":"CODEX_ROOT_SETTLED","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:47.463Z","updatedAt":"2026-10-27T14:24:47.504Z"},{"createdBy":"agent","creationSource":"mcp","id":"message:mcp:client%3A54049495-6f11-4f1c-89eb-579299a4e0b5:thread-send:e1e87be4-f1df-42fd-9ebb-8db56f3337ba","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:4","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%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":"2026-10-27T14:24:57.114Z","updatedAt":"2026-10-27T14:24:57.114Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b43c77a4819a98bb5eac73b6ae6b","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:4","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b43c77a4819a98bb5eac73b6ae6b","role":"assistant","text":"I’ll start the second foreground Node session, leave it unpolled, then provide the essay without changing files.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:00.542Z","updatedAt":"2026-10-27T14:25:00.609Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b440f36c819a88511d115ad115f6","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:4","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b440f36c819a88511d115ad115f6","role":"assistant","text":"Serial Queues\n\nA serial queue is one of the simplest tools for organizing concurrent work. It accepts tasks in some order and allows only one task to execute at a time. When the active task finishes, the next task begins. This rule sounds modest, but it provides a powerful guarantee: tasks submitted to the same serial queue never overlap. Systems use that guarantee to coordinate access to shared state, preserve ordering, and make asynchronous programs easier to understand.\n\nConcurrency becomes difficult when several operations can touch the same data simultaneously. Suppose two tasks read a counter, add one, and write the result. If both read the old value before either writes, one increment disappears. Locks can protect the counter, but locks introduce their own obligations. Every access must acquire the correct lock, release it on every path, and avoid incompatible lock ordering. A serial queue offers another model. Code submits all counter operations to one queue, and the queue ensures that each operation observes the effects of its predecessors.\n\nThis arrangement is often described as confinement. The protected state belongs conceptually to the queue, and code may interact with it only through tasks submitted there. Confinement matters more than the queue’s mechanics. If some code bypasses the queue and accesses the state directly, the safety guarantee collapses. A serial queue is therefore not magical synchronization; it is a disciplined boundary. It works when the program consistently respects that boundary.\n\nSerial queues also express ordering. If task A is submitted before task B, a first-in, first-out serial queue starts A first and completes it before B starts. This property is useful for event processing, log writing, protocol handling, and state machines. An application might receive user actions from many threads but funnel them through one queue so that the state changes in a stable sequence. The producers remain concurrent while the sensitive decisions become serialized.\n\nSubmission and execution are different concepts. Asynchronous submission normally places a task on the queue and returns immediately. The caller can continue doing other work while the queued task waits its turn. Synchronous submission blocks the caller until the submitted task completes. Both modes preserve serialization inside the queue, but they have very different effects on the caller. Asynchronous submission promotes responsiveness. Synchronous submission can conveniently retrieve a result, though careless use can cause deadlock.\n\nThe classic deadlock occurs when code already running on a serial queue synchronously submits another task to that same queue. The outer task waits for the inner task to finish, but the queue cannot start the inner task until the outer task finishes. Neither can advance. Queue libraries sometimes detect this mistake, but programs should not depend on detection. Common remedies include executing directly when already on the queue, exposing only asynchronous operations, or restructuring the API so that nested synchronous submission is unnecessary.\n\nA queue need not own a dedicated thread. Many modern runtimes maintain a pool of worker threads and schedule queue tasks onto that pool. The serial property concerns logical execution order, not permanent attachment to a particular operating-system thread. One task may run on one worker and the next task on another, while still never overlapping. Consequently, thread-local storage and thread identity should not be treated as queue identity unless the runtime explicitly promises such behavior.\n\nThis distinction helps explain why serial queues can be inexpensive. Creating thousands of dedicated threads would consume substantial memory and scheduling resources. Creating many lightweight queue objects can be practical because inactive queues need no thread of their own. The runtime activates a queue only when work is available. Queue-based designs can therefore represent many independent domains of serialization without requiring an equally large number of workers.\n\nNevertheless, serialization has a performance cost. A queue can execute no faster than its slowest accumulated workload permits. If producers submit tasks faster than the queue completes them, latency grows and memory may grow with the backlog. One long task delays every task behind it, a phenomenon sometimes called head-of-line blocking. Good serial-queue tasks are usually short, bounded, and focused on the state that truly requires ordered access.\n\nExpensive computation and slow input or output should often happen elsewhere. A task can capture the state needed for an operation, dispatch costly work to a concurrent executor, and later submit a small result-handling task back to the serial queue. This pattern preserves state safety while exploiting parallelism. It also introduces a subtle issue: results may return in a different order from the requests that produced them. The queue serializes result application, but it does not automatically restore semantic ordering. Sequence numbers, version checks, cancellation, or explicit dependencies may be needed.\n\nChoosing the scope of a queue is therefore important. One global serial queue makes reasoning easy but can eliminate useful parallelism. A separate queue for every tiny value can make relationships hard to follow and can create coordination overhead. A useful middle ground is to assign a queue to a coherent ownership domain, such as a document, connection, cache, account, or subsystem. Operations within a domain are ordered, while independent domains can proceed concurrently.\n\nSerial queues resemble mutexes, but their programming styles differ. A mutex protects a critical section executed by the calling thread. A queue usually accepts a unit of work that may execute later on another worker. Mutexes fit small, synchronous accesses and existing data structures. Queues fit ownership-oriented components, asynchronous workflows, and event-driven systems. Neither mechanism is universally superior. The better choice is the one that makes the invariant obvious and difficult to violate.\n\nQueues can also improve encapsulation. Instead of exposing mutable fields and expecting callers to synchronize correctly, a component can expose operations such as update, snapshot, and close. Internally, those operations are submitted to its serial queue. Callers no longer need to know which values require protection. The component becomes an active object: it receives messages, processes them one at a time, and owns its state. Actor systems generalize this idea by providing isolated entities with serial mailboxes.\n\nError handling needs deliberate design. An exception or rejected promise in one task should not silently stop the queue unless that behavior is intentional. Libraries differ in whether errors propagate to submitters, reach a global handler, or become detached failures. A robust queue abstraction defines how each task reports success, how failures affect following tasks, and whether retries preserve order. Retrying a failed operation at the tail may allow later operations to overtake it, while retrying in place may block the entire queue.\n\nCancellation is similarly nuanced. Removing a task that has not started is relatively straightforward, but cancellation may change the meaning of later tasks. If a queued sequence contains open, write, and close, cancelling open while retaining the other operations is probably invalid. Once a task begins, forced interruption may leave protected state inconsistent. Cooperative cancellation is safer: the task checks a token at well-defined points and exits after restoring invariants. Queue APIs should distinguish cancelling interest in a result from cancelling the underlying operation.\n\nFairness and priority complicate the basic FIFO model. Strict submission order is predictable, but urgent work can become trapped behind routine work. Priority queues can reduce urgent latency, yet they weaken ordering and may starve low-priority tasks. Multiple serial queues sharing a worker pool can also experience priority inversion when a high-priority task depends on work waiting in a lower-priority queue. These concerns matter most in interactive, real-time, or heavily loaded systems. For many application components, plain FIFO behavior remains the clearest default.\n\nTesting serial-queue code requires more than verifying final values. Tests should exercise ordering, reentrancy, failure, cancellation, and shutdown. A controllable executor can pause tasks at boundaries and make normally rare schedules reproducible. Assertions can verify that no two tasks enter the protected region simultaneously. Stress tests can submit operations from many producers, but deterministic tests are usually better at explaining a failure. Time-based sleeps are fragile because they confuse scheduler timing with program correctness.\n\nShutdown is an especially important lifecycle transition. A queue may need to reject new tasks, drain accepted work, cancel pending operations, or stop immediately. Each policy is reasonable in a different context. A file writer may need to drain to prevent data loss. A screen controller being discarded may cancel obsolete rendering work. A network service may stop accepting requests but allow in-flight requests to finish before a deadline. The contract must say what happens to queued tasks and how callers learn their outcome.\n\nObservability makes overloaded queues diagnosable. Useful measurements include queue depth, oldest-task age, execution duration, rejection count, and time spent waiting versus running. Task names or correlation identifiers can connect queue activity to higher-level requests. Instrumentation should avoid exposing sensitive task contents and should not add enough synchronized work to become a bottleneck itself. A growing queue is often a symptom rather than the root cause, but without metrics that symptom remains invisible until users notice delays.\n\nSerial queues are most effective when used as precise instruments rather than universal architecture. They simplify one class of problems by turning concurrent mutation into an ordered stream of operations. In exchange, they introduce queuing latency, lifecycle concerns, and the possibility of deadlock or backlog. Their central benefit is intellectual as much as mechanical: they give programmers a place where events happen one at a time. When the ownership boundary is clear, tasks remain short, and ordering semantics are explicit, that simple promise can make a complex concurrent system substantially safer and easier to maintain.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:04.987Z","updatedAt":"2026-10-27T14:25:37.148Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b468a3b4819aa4e0361dca94ed51","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:6","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b468a3b4819aa4e0361dca94ed51","role":"assistant","text":"CODEX_DETAIL_ACK_17885\nCODEX_ACTIVE_17885_DONE","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:44.691Z","updatedAt":"2026-10-27T14:25:44.949Z"},{"createdBy":"user","creationSource":"web","id":"519064dd-4cdb-43f2-9488-d4fa4a9d5d55","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:2","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A2:root","role":"user","text":"HELD_Q_17885: When explicitly released, reply exactly HELD_Q_DONE. No tools.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:26.567Z","updatedAt":"2026-10-27T14:24:26.567Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b47e3b64819a8ae42911ff303eb1","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:2","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b47e3b64819a8ae42911ff303eb1","role":"assistant","text":"HELD_Q_17885 held.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:26:07.008Z","updatedAt":"2026-10-27T14:26:07.195Z"},{"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":"provider","id":"message:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1:437b5282-29f1-4188-b3a8-58d8f5a1229d","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:5","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%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":"2026-10-27T14:25:30.253Z","updatedAt":"2026-10-27T14:25:30.253Z"}],"subagents":[],"providerThreads":[{"id":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","driver":"codex","providerInstanceId":"codex","providerSessionId":"provider-session:provider-instance:codex:shared","appThreadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ownerNodeId":null,"nativeThreadRef":{"driver":"codex","nativeId":"01a17dbf-8317-7fc1-950c-c63c6cd01212","strength":"strong"},"nativeConversationHeadRef":null,"status":"active","firstRunOrdinal":1,"lastRunOrdinal":8,"handoffIds":[],"forkedFrom":null,"pendingBackgroundTasks":[],"contextUsage":{"usedTokens":22640,"maxTokens":258400},"nativeMetadata":null,"goal":null,"createdAt":"2026-10-27T14:24:23.442Z","updatedAt":"2026-10-27T14:26:10.624Z"}]}
2026-10-27T14:26:13.189Z 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":"2026-10-27T14:24:23.442Z","updatedAt":"2026-10-27T14:24:23.442Z"},{"createdBy":"agent","creationSource":"mcp","id":"message:mcp:client%3A3615d0b0-29d2-4c83-b8d7-da01992d4840:thread-send:604cddc4-0d14-41f8-8b22-064dc8cb2d50","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:3","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%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":"2026-10-27T14:24:39.926Z","updatedAt":"2026-10-27T14:24:39.926Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b42bd524819aace1a8cdad9d0eac","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:3","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b42bd524819aace1a8cdad9d0eac","role":"assistant","text":"I’ll start the requested foreground Node process and leave its command session running.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:43.876Z","updatedAt":"2026-10-27T14:24:44.181Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b42f6384819aaf98301c46494b00","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:3","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b42f6384819aaf98301c46494b00","role":"assistant","text":"CODEX_ROOT_SETTLED","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:47.463Z","updatedAt":"2026-10-27T14:24:47.504Z"},{"createdBy":"agent","creationSource":"mcp","id":"message:mcp:client%3A54049495-6f11-4f1c-89eb-579299a4e0b5:thread-send:e1e87be4-f1df-42fd-9ebb-8db56f3337ba","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:4","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%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":"2026-10-27T14:24:57.114Z","updatedAt":"2026-10-27T14:24:57.114Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b43c77a4819a98bb5eac73b6ae6b","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:4","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b43c77a4819a98bb5eac73b6ae6b","role":"assistant","text":"I’ll start the second foreground Node session, leave it unpolled, then provide the essay without changing files.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:00.542Z","updatedAt":"2026-10-27T14:25:00.609Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b440f36c819a88511d115ad115f6","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:4","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b440f36c819a88511d115ad115f6","role":"assistant","text":"Serial Queues\n\nA serial queue is one of the simplest tools for organizing concurrent work. It accepts tasks in some order and allows only one task to execute at a time. When the active task finishes, the next task begins. This rule sounds modest, but it provides a powerful guarantee: tasks submitted to the same serial queue never overlap. Systems use that guarantee to coordinate access to shared state, preserve ordering, and make asynchronous programs easier to understand.\n\nConcurrency becomes difficult when several operations can touch the same data simultaneously. Suppose two tasks read a counter, add one, and write the result. If both read the old value before either writes, one increment disappears. Locks can protect the counter, but locks introduce their own obligations. Every access must acquire the correct lock, release it on every path, and avoid incompatible lock ordering. A serial queue offers another model. Code submits all counter operations to one queue, and the queue ensures that each operation observes the effects of its predecessors.\n\nThis arrangement is often described as confinement. The protected state belongs conceptually to the queue, and code may interact with it only through tasks submitted there. Confinement matters more than the queue’s mechanics. If some code bypasses the queue and accesses the state directly, the safety guarantee collapses. A serial queue is therefore not magical synchronization; it is a disciplined boundary. It works when the program consistently respects that boundary.\n\nSerial queues also express ordering. If task A is submitted before task B, a first-in, first-out serial queue starts A first and completes it before B starts. This property is useful for event processing, log writing, protocol handling, and state machines. An application might receive user actions from many threads but funnel them through one queue so that the state changes in a stable sequence. The producers remain concurrent while the sensitive decisions become serialized.\n\nSubmission and execution are different concepts. Asynchronous submission normally places a task on the queue and returns immediately. The caller can continue doing other work while the queued task waits its turn. Synchronous submission blocks the caller until the submitted task completes. Both modes preserve serialization inside the queue, but they have very different effects on the caller. Asynchronous submission promotes responsiveness. Synchronous submission can conveniently retrieve a result, though careless use can cause deadlock.\n\nThe classic deadlock occurs when code already running on a serial queue synchronously submits another task to that same queue. The outer task waits for the inner task to finish, but the queue cannot start the inner task until the outer task finishes. Neither can advance. Queue libraries sometimes detect this mistake, but programs should not depend on detection. Common remedies include executing directly when already on the queue, exposing only asynchronous operations, or restructuring the API so that nested synchronous submission is unnecessary.\n\nA queue need not own a dedicated thread. Many modern runtimes maintain a pool of worker threads and schedule queue tasks onto that pool. The serial property concerns logical execution order, not permanent attachment to a particular operating-system thread. One task may run on one worker and the next task on another, while still never overlapping. Consequently, thread-local storage and thread identity should not be treated as queue identity unless the runtime explicitly promises such behavior.\n\nThis distinction helps explain why serial queues can be inexpensive. Creating thousands of dedicated threads would consume substantial memory and scheduling resources. Creating many lightweight queue objects can be practical because inactive queues need no thread of their own. The runtime activates a queue only when work is available. Queue-based designs can therefore represent many independent domains of serialization without requiring an equally large number of workers.\n\nNevertheless, serialization has a performance cost. A queue can execute no faster than its slowest accumulated workload permits. If producers submit tasks faster than the queue completes them, latency grows and memory may grow with the backlog. One long task delays every task behind it, a phenomenon sometimes called head-of-line blocking. Good serial-queue tasks are usually short, bounded, and focused on the state that truly requires ordered access.\n\nExpensive computation and slow input or output should often happen elsewhere. A task can capture the state needed for an operation, dispatch costly work to a concurrent executor, and later submit a small result-handling task back to the serial queue. This pattern preserves state safety while exploiting parallelism. It also introduces a subtle issue: results may return in a different order from the requests that produced them. The queue serializes result application, but it does not automatically restore semantic ordering. Sequence numbers, version checks, cancellation, or explicit dependencies may be needed.\n\nChoosing the scope of a queue is therefore important. One global serial queue makes reasoning easy but can eliminate useful parallelism. A separate queue for every tiny value can make relationships hard to follow and can create coordination overhead. A useful middle ground is to assign a queue to a coherent ownership domain, such as a document, connection, cache, account, or subsystem. Operations within a domain are ordered, while independent domains can proceed concurrently.\n\nSerial queues resemble mutexes, but their programming styles differ. A mutex protects a critical section executed by the calling thread. A queue usually accepts a unit of work that may execute later on another worker. Mutexes fit small, synchronous accesses and existing data structures. Queues fit ownership-oriented components, asynchronous workflows, and event-driven systems. Neither mechanism is universally superior. The better choice is the one that makes the invariant obvious and difficult to violate.\n\nQueues can also improve encapsulation. Instead of exposing mutable fields and expecting callers to synchronize correctly, a component can expose operations such as update, snapshot, and close. Internally, those operations are submitted to its serial queue. Callers no longer need to know which values require protection. The component becomes an active object: it receives messages, processes them one at a time, and owns its state. Actor systems generalize this idea by providing isolated entities with serial mailboxes.\n\nError handling needs deliberate design. An exception or rejected promise in one task should not silently stop the queue unless that behavior is intentional. Libraries differ in whether errors propagate to submitters, reach a global handler, or become detached failures. A robust queue abstraction defines how each task reports success, how failures affect following tasks, and whether retries preserve order. Retrying a failed operation at the tail may allow later operations to overtake it, while retrying in place may block the entire queue.\n\nCancellation is similarly nuanced. Removing a task that has not started is relatively straightforward, but cancellation may change the meaning of later tasks. If a queued sequence contains open, write, and close, cancelling open while retaining the other operations is probably invalid. Once a task begins, forced interruption may leave protected state inconsistent. Cooperative cancellation is safer: the task checks a token at well-defined points and exits after restoring invariants. Queue APIs should distinguish cancelling interest in a result from cancelling the underlying operation.\n\nFairness and priority complicate the basic FIFO model. Strict submission order is predictable, but urgent work can become trapped behind routine work. Priority queues can reduce urgent latency, yet they weaken ordering and may starve low-priority tasks. Multiple serial queues sharing a worker pool can also experience priority inversion when a high-priority task depends on work waiting in a lower-priority queue. These concerns matter most in interactive, real-time, or heavily loaded systems. For many application components, plain FIFO behavior remains the clearest default.\n\nTesting serial-queue code requires more than verifying final values. Tests should exercise ordering, reentrancy, failure, cancellation, and shutdown. A controllable executor can pause tasks at boundaries and make normally rare schedules reproducible. Assertions can verify that no two tasks enter the protected region simultaneously. Stress tests can submit operations from many producers, but deterministic tests are usually better at explaining a failure. Time-based sleeps are fragile because they confuse scheduler timing with program correctness.\n\nShutdown is an especially important lifecycle transition. A queue may need to reject new tasks, drain accepted work, cancel pending operations, or stop immediately. Each policy is reasonable in a different context. A file writer may need to drain to prevent data loss. A screen controller being discarded may cancel obsolete rendering work. A network service may stop accepting requests but allow in-flight requests to finish before a deadline. The contract must say what happens to queued tasks and how callers learn their outcome.\n\nObservability makes overloaded queues diagnosable. Useful measurements include queue depth, oldest-task age, execution duration, rejection count, and time spent waiting versus running. Task names or correlation identifiers can connect queue activity to higher-level requests. Instrumentation should avoid exposing sensitive task contents and should not add enough synchronized work to become a bottleneck itself. A growing queue is often a symptom rather than the root cause, but without metrics that symptom remains invisible until users notice delays.\n\nSerial queues are most effective when used as precise instruments rather than universal architecture. They simplify one class of problems by turning concurrent mutation into an ordered stream of operations. In exchange, they introduce queuing latency, lifecycle concerns, and the possibility of deadlock or backlog. Their central benefit is intellectual as much as mechanical: they give programmers a place where events happen one at a time. When the ownership boundary is clear, tasks remain short, and ordering semantics are explicit, that simple promise can make a complex concurrent system substantially safer and easier to maintain.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:04.987Z","updatedAt":"2026-10-27T14:25:37.148Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b468a3b4819aa4e0361dca94ed51","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:6","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b468a3b4819aa4e0361dca94ed51","role":"assistant","text":"CODEX_DETAIL_ACK_17885\nCODEX_ACTIVE_17885_DONE","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:44.691Z","updatedAt":"2026-10-27T14:25:44.949Z"},{"createdBy":"user","creationSource":"web","id":"519064dd-4cdb-43f2-9488-d4fa4a9d5d55","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:2","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A2:root","role":"user","text":"HELD_Q_17885: When explicitly released, reply exactly HELD_Q_DONE. No tools.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:26.567Z","updatedAt":"2026-10-27T14:24:26.567Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b47e3b64819a8ae42911ff303eb1","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:2","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b47e3b64819a8ae42911ff303eb1","role":"assistant","text":"HELD_Q_17885 held.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:26:07.008Z","updatedAt":"2026-10-27T14:26:07.195Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b484dc9c819a9037122182ea8a81","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:5","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b484dc9c819a9037122182ea8a81","role":"assistant","text":"CODEX_DETAIL_ACK_17885\nCODEX_BACKGROUND_17885_DONE","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:26:12.903Z","updatedAt":"2026-10-27T14:26:13.038Z"},{"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":"provider","id":"message:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1:437b5282-29f1-4188-b3a8-58d8f5a1229d","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:5","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%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":"2026-10-27T14:25:30.253Z","updatedAt":"2026-10-27T14:25:30.253Z"}],"subagents":[],"providerThreads":[{"id":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","driver":"codex","providerInstanceId":"codex","providerSessionId":"provider-session:provider-instance:codex:shared","appThreadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ownerNodeId":null,"nativeThreadRef":{"driver":"codex","nativeId":"01a17dbf-8317-7fc1-950c-c63c6cd01212","strength":"strong"},"nativeConversationHeadRef":null,"status":"active","firstRunOrdinal":1,"lastRunOrdinal":8,"handoffIds":[],"forkedFrom":null,"pendingBackgroundTasks":[],"contextUsage":{"usedTokens":22640,"maxTokens":258400},"nativeMetadata":null,"goal":null,"createdAt":"2026-10-27T14:24:23.442Z","updatedAt":"2026-10-27T14:26:10.624Z"}]}
2026-10-27T14:26:13.310Z 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":"2026-10-27T14:24:23.442Z","updatedAt":"2026-10-27T14:24:23.442Z"},{"createdBy":"agent","creationSource":"mcp","id":"message:mcp:client%3A3615d0b0-29d2-4c83-b8d7-da01992d4840:thread-send:604cddc4-0d14-41f8-8b22-064dc8cb2d50","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:3","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%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":"2026-10-27T14:24:39.926Z","updatedAt":"2026-10-27T14:24:39.926Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b42bd524819aace1a8cdad9d0eac","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:3","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b42bd524819aace1a8cdad9d0eac","role":"assistant","text":"I’ll start the requested foreground Node process and leave its command session running.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:43.876Z","updatedAt":"2026-10-27T14:24:44.181Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b42f6384819aaf98301c46494b00","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:3","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b42f6384819aaf98301c46494b00","role":"assistant","text":"CODEX_ROOT_SETTLED","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:47.463Z","updatedAt":"2026-10-27T14:24:47.504Z"},{"createdBy":"agent","creationSource":"mcp","id":"message:mcp:client%3A54049495-6f11-4f1c-89eb-579299a4e0b5:thread-send:e1e87be4-f1df-42fd-9ebb-8db56f3337ba","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:4","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%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":"2026-10-27T14:24:57.114Z","updatedAt":"2026-10-27T14:24:57.114Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b43c77a4819a98bb5eac73b6ae6b","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:4","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b43c77a4819a98bb5eac73b6ae6b","role":"assistant","text":"I’ll start the second foreground Node session, leave it unpolled, then provide the essay without changing files.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:00.542Z","updatedAt":"2026-10-27T14:25:00.609Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b440f36c819a88511d115ad115f6","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:4","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b440f36c819a88511d115ad115f6","role":"assistant","text":"Serial Queues\n\nA serial queue is one of the simplest tools for organizing concurrent work. It accepts tasks in some order and allows only one task to execute at a time. When the active task finishes, the next task begins. This rule sounds modest, but it provides a powerful guarantee: tasks submitted to the same serial queue never overlap. Systems use that guarantee to coordinate access to shared state, preserve ordering, and make asynchronous programs easier to understand.\n\nConcurrency becomes difficult when several operations can touch the same data simultaneously. Suppose two tasks read a counter, add one, and write the result. If both read the old value before either writes, one increment disappears. Locks can protect the counter, but locks introduce their own obligations. Every access must acquire the correct lock, release it on every path, and avoid incompatible lock ordering. A serial queue offers another model. Code submits all counter operations to one queue, and the queue ensures that each operation observes the effects of its predecessors.\n\nThis arrangement is often described as confinement. The protected state belongs conceptually to the queue, and code may interact with it only through tasks submitted there. Confinement matters more than the queue’s mechanics. If some code bypasses the queue and accesses the state directly, the safety guarantee collapses. A serial queue is therefore not magical synchronization; it is a disciplined boundary. It works when the program consistently respects that boundary.\n\nSerial queues also express ordering. If task A is submitted before task B, a first-in, first-out serial queue starts A first and completes it before B starts. This property is useful for event processing, log writing, protocol handling, and state machines. An application might receive user actions from many threads but funnel them through one queue so that the state changes in a stable sequence. The producers remain concurrent while the sensitive decisions become serialized.\n\nSubmission and execution are different concepts. Asynchronous submission normally places a task on the queue and returns immediately. The caller can continue doing other work while the queued task waits its turn. Synchronous submission blocks the caller until the submitted task completes. Both modes preserve serialization inside the queue, but they have very different effects on the caller. Asynchronous submission promotes responsiveness. Synchronous submission can conveniently retrieve a result, though careless use can cause deadlock.\n\nThe classic deadlock occurs when code already running on a serial queue synchronously submits another task to that same queue. The outer task waits for the inner task to finish, but the queue cannot start the inner task until the outer task finishes. Neither can advance. Queue libraries sometimes detect this mistake, but programs should not depend on detection. Common remedies include executing directly when already on the queue, exposing only asynchronous operations, or restructuring the API so that nested synchronous submission is unnecessary.\n\nA queue need not own a dedicated thread. Many modern runtimes maintain a pool of worker threads and schedule queue tasks onto that pool. The serial property concerns logical execution order, not permanent attachment to a particular operating-system thread. One task may run on one worker and the next task on another, while still never overlapping. Consequently, thread-local storage and thread identity should not be treated as queue identity unless the runtime explicitly promises such behavior.\n\nThis distinction helps explain why serial queues can be inexpensive. Creating thousands of dedicated threads would consume substantial memory and scheduling resources. Creating many lightweight queue objects can be practical because inactive queues need no thread of their own. The runtime activates a queue only when work is available. Queue-based designs can therefore represent many independent domains of serialization without requiring an equally large number of workers.\n\nNevertheless, serialization has a performance cost. A queue can execute no faster than its slowest accumulated workload permits. If producers submit tasks faster than the queue completes them, latency grows and memory may grow with the backlog. One long task delays every task behind it, a phenomenon sometimes called head-of-line blocking. Good serial-queue tasks are usually short, bounded, and focused on the state that truly requires ordered access.\n\nExpensive computation and slow input or output should often happen elsewhere. A task can capture the state needed for an operation, dispatch costly work to a concurrent executor, and later submit a small result-handling task back to the serial queue. This pattern preserves state safety while exploiting parallelism. It also introduces a subtle issue: results may return in a different order from the requests that produced them. The queue serializes result application, but it does not automatically restore semantic ordering. Sequence numbers, version checks, cancellation, or explicit dependencies may be needed.\n\nChoosing the scope of a queue is therefore important. One global serial queue makes reasoning easy but can eliminate useful parallelism. A separate queue for every tiny value can make relationships hard to follow and can create coordination overhead. A useful middle ground is to assign a queue to a coherent ownership domain, such as a document, connection, cache, account, or subsystem. Operations within a domain are ordered, while independent domains can proceed concurrently.\n\nSerial queues resemble mutexes, but their programming styles differ. A mutex protects a critical section executed by the calling thread. A queue usually accepts a unit of work that may execute later on another worker. Mutexes fit small, synchronous accesses and existing data structures. Queues fit ownership-oriented components, asynchronous workflows, and event-driven systems. Neither mechanism is universally superior. The better choice is the one that makes the invariant obvious and difficult to violate.\n\nQueues can also improve encapsulation. Instead of exposing mutable fields and expecting callers to synchronize correctly, a component can expose operations such as update, snapshot, and close. Internally, those operations are submitted to its serial queue. Callers no longer need to know which values require protection. The component becomes an active object: it receives messages, processes them one at a time, and owns its state. Actor systems generalize this idea by providing isolated entities with serial mailboxes.\n\nError handling needs deliberate design. An exception or rejected promise in one task should not silently stop the queue unless that behavior is intentional. Libraries differ in whether errors propagate to submitters, reach a global handler, or become detached failures. A robust queue abstraction defines how each task reports success, how failures affect following tasks, and whether retries preserve order. Retrying a failed operation at the tail may allow later operations to overtake it, while retrying in place may block the entire queue.\n\nCancellation is similarly nuanced. Removing a task that has not started is relatively straightforward, but cancellation may change the meaning of later tasks. If a queued sequence contains open, write, and close, cancelling open while retaining the other operations is probably invalid. Once a task begins, forced interruption may leave protected state inconsistent. Cooperative cancellation is safer: the task checks a token at well-defined points and exits after restoring invariants. Queue APIs should distinguish cancelling interest in a result from cancelling the underlying operation.\n\nFairness and priority complicate the basic FIFO model. Strict submission order is predictable, but urgent work can become trapped behind routine work. Priority queues can reduce urgent latency, yet they weaken ordering and may starve low-priority tasks. Multiple serial queues sharing a worker pool can also experience priority inversion when a high-priority task depends on work waiting in a lower-priority queue. These concerns matter most in interactive, real-time, or heavily loaded systems. For many application components, plain FIFO behavior remains the clearest default.\n\nTesting serial-queue code requires more than verifying final values. Tests should exercise ordering, reentrancy, failure, cancellation, and shutdown. A controllable executor can pause tasks at boundaries and make normally rare schedules reproducible. Assertions can verify that no two tasks enter the protected region simultaneously. Stress tests can submit operations from many producers, but deterministic tests are usually better at explaining a failure. Time-based sleeps are fragile because they confuse scheduler timing with program correctness.\n\nShutdown is an especially important lifecycle transition. A queue may need to reject new tasks, drain accepted work, cancel pending operations, or stop immediately. Each policy is reasonable in a different context. A file writer may need to drain to prevent data loss. A screen controller being discarded may cancel obsolete rendering work. A network service may stop accepting requests but allow in-flight requests to finish before a deadline. The contract must say what happens to queued tasks and how callers learn their outcome.\n\nObservability makes overloaded queues diagnosable. Useful measurements include queue depth, oldest-task age, execution duration, rejection count, and time spent waiting versus running. Task names or correlation identifiers can connect queue activity to higher-level requests. Instrumentation should avoid exposing sensitive task contents and should not add enough synchronized work to become a bottleneck itself. A growing queue is often a symptom rather than the root cause, but without metrics that symptom remains invisible until users notice delays.\n\nSerial queues are most effective when used as precise instruments rather than universal architecture. They simplify one class of problems by turning concurrent mutation into an ordered stream of operations. In exchange, they introduce queuing latency, lifecycle concerns, and the possibility of deadlock or backlog. Their central benefit is intellectual as much as mechanical: they give programmers a place where events happen one at a time. When the ownership boundary is clear, tasks remain short, and ordering semantics are explicit, that simple promise can make a complex concurrent system substantially safer and easier to maintain.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:04.987Z","updatedAt":"2026-10-27T14:25:37.148Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b468a3b4819aa4e0361dca94ed51","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:6","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b468a3b4819aa4e0361dca94ed51","role":"assistant","text":"CODEX_DETAIL_ACK_17885\nCODEX_ACTIVE_17885_DONE","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:44.691Z","updatedAt":"2026-10-27T14:25:44.949Z"},{"createdBy":"user","creationSource":"web","id":"519064dd-4cdb-43f2-9488-d4fa4a9d5d55","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:2","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A2:root","role":"user","text":"HELD_Q_17885: When explicitly released, reply exactly HELD_Q_DONE. No tools.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:26.567Z","updatedAt":"2026-10-27T14:24:26.567Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b47e3b64819a8ae42911ff303eb1","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:2","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b47e3b64819a8ae42911ff303eb1","role":"assistant","text":"HELD_Q_17885 held.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:26:07.008Z","updatedAt":"2026-10-27T14:26:07.195Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b484dc9c819a9037122182ea8a81","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:5","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b484dc9c819a9037122182ea8a81","role":"assistant","text":"CODEX_DETAIL_ACK_17885\nCODEX_BACKGROUND_17885_DONE","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:26:12.903Z","updatedAt":"2026-10-27T14:26:13.038Z"},{"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":"provider","id":"message:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:1:437b5282-29f1-4188-b3a8-58d8f5a1229d","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:5","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%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":"2026-10-27T14:25:30.253Z","updatedAt":"2026-10-27T14:25:30.253Z"}],"subagents":[],"providerThreads":[{"id":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","driver":"codex","providerInstanceId":"codex","providerSessionId":"provider-session:provider-instance:codex:shared","appThreadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ownerNodeId":null,"nativeThreadRef":{"driver":"codex","nativeId":"01a17dbf-8317-7fc1-950c-c63c6cd01212","strength":"strong"},"nativeConversationHeadRef":null,"status":"idle","firstRunOrdinal":1,"lastRunOrdinal":8,"handoffIds":[],"forkedFrom":null,"pendingBackgroundTasks":[],"contextUsage":{"usedTokens":22640,"maxTokens":258400},"nativeMetadata":null,"goal":null,"createdAt":"2026-10-27T14:24:23.442Z","updatedAt":"2026-10-27T14:26:13.212Z"}]}
2026-10-27T14:26:14.461Z 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":"2026-10-27T14:24:23.442Z","updatedAt":"2026-10-27T14:24:23.442Z"},{"createdBy":"agent","creationSource":"mcp","id":"message:mcp:client%3A3615d0b0-29d2-4c83-b8d7-da01992d4840:thread-send:604cddc4-0d14-41f8-8b22-064dc8cb2d50","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:3","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%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":"2026-10-27T14:24:39.926Z","updatedAt":"2026-10-27T14:24:39.926Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b42bd524819aace1a8cdad9d0eac","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:3","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b42bd524819aace1a8cdad9d0eac","role":"assistant","text":"I’ll start the requested foreground Node process and leave its command session running.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:43.876Z","updatedAt":"2026-10-27T14:24:44.181Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b42f6384819aaf98301c46494b00","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:3","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b42f6384819aaf98301c46494b00","role":"assistant","text":"CODEX_ROOT_SETTLED","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:47.463Z","updatedAt":"2026-10-27T14:24:47.504Z"},{"createdBy":"agent","creationSource":"mcp","id":"message:mcp:client%3A54049495-6f11-4f1c-89eb-579299a4e0b5:thread-send:e1e87be4-f1df-42fd-9ebb-8db56f3337ba","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:4","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%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":"2026-10-27T14:24:57.114Z","updatedAt":"2026-10-27T14:24:57.114Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b43c77a4819a98bb5eac73b6ae6b","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:4","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b43c77a4819a98bb5eac73b6ae6b","role":"assistant","text":"I’ll start the second foreground Node session, leave it unpolled, then provide the essay without changing files.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:00.542Z","updatedAt":"2026-10-27T14:25:00.609Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b440f36c819a88511d115ad115f6","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:4","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b440f36c819a88511d115ad115f6","role":"assistant","text":"Serial Queues\n\nA serial queue is one of the simplest tools for organizing concurrent work. It accepts tasks in some order and allows only one task to execute at a time. When the active task finishes, the next task begins. This rule sounds modest, but it provides a powerful guarantee: tasks submitted to the same serial queue never overlap. Systems use that guarantee to coordinate access to shared state, preserve ordering, and make asynchronous programs easier to understand.\n\nConcurrency becomes difficult when several operations can touch the same data simultaneously. Suppose two tasks read a counter, add one, and write the result. If both read the old value before either writes, one increment disappears. Locks can protect the counter, but locks introduce their own obligations. Every access must acquire the correct lock, release it on every path, and avoid incompatible lock ordering. A serial queue offers another model. Code submits all counter operations to one queue, and the queue ensures that each operation observes the effects of its predecessors.\n\nThis arrangement is often described as confinement. The protected state belongs conceptually to the queue, and code may interact with it only through tasks submitted there. Confinement matters more than the queue’s mechanics. If some code bypasses the queue and accesses the state directly, the safety guarantee collapses. A serial queue is therefore not magical synchronization; it is a disciplined boundary. It works when the program consistently respects that boundary.\n\nSerial queues also express ordering. If task A is submitted before task B, a first-in, first-out serial queue starts A first and completes it before B starts. This property is useful for event processing, log writing, protocol handling, and state machines. An application might receive user actions from many threads but funnel them through one queue so that the state changes in a stable sequence. The producers remain concurrent while the sensitive decisions become serialized.\n\nSubmission and execution are different concepts. Asynchronous submission normally places a task on the queue and returns immediately. The caller can continue doing other work while the queued task waits its turn. Synchronous submission blocks the caller until the submitted task completes. Both modes preserve serialization inside the queue, but they have very different effects on the caller. Asynchronous submission promotes responsiveness. Synchronous submission can conveniently retrieve a result, though careless use can cause deadlock.\n\nThe classic deadlock occurs when code already running on a serial queue synchronously submits another task to that same queue. The outer task waits for the inner task to finish, but the queue cannot start the inner task until the outer task finishes. Neither can advance. Queue libraries sometimes detect this mistake, but programs should not depend on detection. Common remedies include executing directly when already on the queue, exposing only asynchronous operations, or restructuring the API so that nested synchronous submission is unnecessary.\n\nA queue need not own a dedicated thread. Many modern runtimes maintain a pool of worker threads and schedule queue tasks onto that pool. The serial property concerns logical execution order, not permanent attachment to a particular operating-system thread. One task may run on one worker and the next task on another, while still never overlapping. Consequently, thread-local storage and thread identity should not be treated as queue identity unless the runtime explicitly promises such behavior.\n\nThis distinction helps explain why serial queues can be inexpensive. Creating thousands of dedicated threads would consume substantial memory and scheduling resources. Creating many lightweight queue objects can be practical because inactive queues need no thread of their own. The runtime activates a queue only when work is available. Queue-based designs can therefore represent many independent domains of serialization without requiring an equally large number of workers.\n\nNevertheless, serialization has a performance cost. A queue can execute no faster than its slowest accumulated workload permits. If producers submit tasks faster than the queue completes them, latency grows and memory may grow with the backlog. One long task delays every task behind it, a phenomenon sometimes called head-of-line blocking. Good serial-queue tasks are usually short, bounded, and focused on the state that truly requires ordered access.\n\nExpensive computation and slow input or output should often happen elsewhere. A task can capture the state needed for an operation, dispatch costly work to a concurrent executor, and later submit a small result-handling task back to the serial queue. This pattern preserves state safety while exploiting parallelism. It also introduces a subtle issue: results may return in a different order from the requests that produced them. The queue serializes result application, but it does not automatically restore semantic ordering. Sequence numbers, version checks, cancellation, or explicit dependencies may be needed.\n\nChoosing the scope of a queue is therefore important. One global serial queue makes reasoning easy but can eliminate useful parallelism. A separate queue for every tiny value can make relationships hard to follow and can create coordination overhead. A useful middle ground is to assign a queue to a coherent ownership domain, such as a document, connection, cache, account, or subsystem. Operations within a domain are ordered, while independent domains can proceed concurrently.\n\nSerial queues resemble mutexes, but their programming styles differ. A mutex protects a critical section executed by the calling thread. A queue usually accepts a unit of work that may execute later on another worker. Mutexes fit small, synchronous accesses and existing data structures. Queues fit ownership-oriented components, asynchronous workflows, and event-driven systems. Neither mechanism is universally superior. The better choice is the one that makes the invariant obvious and difficult to violate.\n\nQueues can also improve encapsulation. Instead of exposing mutable fields and expecting callers to synchronize correctly, a component can expose operations such as update, snapshot, and close. Internally, those operations are submitted to its serial queue. Callers no longer need to know which values require protection. The component becomes an active object: it receives messages, processes them one at a time, and owns its state. Actor systems generalize this idea by providing isolated entities with serial mailboxes.\n\nError handling needs deliberate design. An exception or rejected promise in one task should not silently stop the queue unless that behavior is intentional. Libraries differ in whether errors propagate to submitters, reach a global handler, or become detached failures. A robust queue abstraction defines how each task reports success, how failures affect following tasks, and whether retries preserve order. Retrying a failed operation at the tail may allow later operations to overtake it, while retrying in place may block the entire queue.\n\nCancellation is similarly nuanced. Removing a task that has not started is relatively straightforward, but cancellation may change the meaning of later tasks. If a queued sequence contains open, write, and close, cancelling open while retaining the other operations is probably invalid. Once a task begins, forced interruption may leave protected state inconsistent. Cooperative cancellation is safer: the task checks a token at well-defined points and exits after restoring invariants. Queue APIs should distinguish cancelling interest in a result from cancelling the underlying operation.\n\nFairness and priority complicate the basic FIFO model. Strict submission order is predictable, but urgent work can become trapped behind routine work. Priority queues can reduce urgent latency, yet they weaken ordering and may starve low-priority tasks. Multiple serial queues sharing a worker pool can also experience priority inversion when a high-priority task depends on work waiting in a lower-priority queue. These concerns matter most in interactive, real-time, or heavily loaded systems. For many application components, plain FIFO behavior remains the clearest default.\n\nTesting serial-queue code requires more than verifying final values. Tests should exercise ordering, reentrancy, failure, cancellation, and shutdown. A controllable executor can pause tasks at boundaries and make normally rare schedules reproducible. Assertions can verify that no two tasks enter the protected region simultaneously. Stress tests can submit operations from many producers, but deterministic tests are usually better at explaining a failure. Time-based sleeps are fragile because they confuse scheduler timing with program correctness.\n\nShutdown is an especially important lifecycle transition. A queue may need to reject new tasks, drain accepted work, cancel pending operations, or stop immediately. Each policy is reasonable in a different context. A file writer may need to drain to prevent data loss. A screen controller being discarded may cancel obsolete rendering work. A network service may stop accepting requests but allow in-flight requests to finish before a deadline. The contract must say what happens to queued tasks and how callers learn their outcome.\n\nObservability makes overloaded queues diagnosable. Useful measurements include queue depth, oldest-task age, execution duration, rejection count, and time spent waiting versus running. Task names or correlation identifiers can connect queue activity to higher-level requests. Instrumentation should avoid exposing sensitive task contents and should not add enough synchronized work to become a bottleneck itself. A growing queue is often a symptom rather than the root cause, but without metrics that symptom remains invisible until users notice delays.\n\nSerial queues are most effective when used as precise instruments rather than universal architecture. They simplify one class of problems by turning concurrent mutation into an ordered stream of operations. In exchange, they introduce queuing latency, lifecycle concerns, and the possibility of deadlock or backlog. Their central benefit is intellectual as much as mechanical: they give programmers a place where events happen one at a time. When the ownership boundary is clear, tasks remain short, and ordering semantics are explicit, that simple promise can make a complex concurrent system substantially safer and easier to maintain.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:04.987Z","updatedAt":"2026-10-27T14:25:37.148Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b468a3b4819aa4e0361dca94ed51","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:6","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b468a3b4819aa4e0361dca94ed51","role":"assistant","text":"CODEX_DETAIL_ACK_17885\nCODEX_ACTIVE_17885_DONE","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:25:44.691Z","updatedAt":"2026-10-27T14:25:44.949Z"},{"createdBy":"user","creationSource":"web","id":"519064dd-4cdb-43f2-9488-d4fa4a9d5d55","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:2","nodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A2:root","role":"user","text":"HELD_Q_17885: When explicitly released, reply exactly HELD_Q_DONE. No tools.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:24:26.567Z","updatedAt":"2026-10-27T14:24:26.567Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b47e3b64819a8ae42911ff303eb1","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:2","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b47e3b64819a8ae42911ff303eb1","role":"assistant","text":"HELD_Q_17885 held.","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:26:07.008Z","updatedAt":"2026-10-27T14:26:07.195Z"},{"createdBy":"agent","creationSource":"provider","id":"message:provider:codex:native-item:msg_058d4cad80000c1c016ae0b484dc9c819a9037122182ea8a81","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","runId":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:5","nodeId":"node:provider:codex:native-item:msg_058d4cad80000c1c016ae0b484dc9c819a9037122182ea8a81","role":"assistant","text":"CODEX_DETAIL_ACK_17885\nCODEX_BACKGROUND_17885_DONE","attachments":[],"streaming":false,"createdAt":"2026-10-27T14:26:12.903Z","updatedAt":"2026-10-27T14:26:13.038Z"}],"subagents":[],"providerThreads":[{"id":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","driver":"codex","providerInstanceId":"codex","providerSessionId":"provider-session:provider-instance:codex:shared","appThreadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ownerNodeId":null,"nativeThreadRef":{"driver":"codex","nativeId":"01a17dbf-8317-7fc1-950c-c63c6cd01212","strength":"strong"},"nativeConversationHeadRef":null,"status":"idle","firstRunOrdinal":1,"lastRunOrdinal":8,"handoffIds":[],"forkedFrom":null,"pendingBackgroundTasks":[],"contextUsage":{"usedTokens":22640,"maxTokens":258400},"nativeMetadata":null,"goal":null,"createdAt":"2026-10-27T14:24:23.442Z","updatedAt":"2026-10-27T14:26:13.212Z"}]}
2026-10-27T14:26:47.670Z HELD_Q_FINAL {"before":{"id":"run:thread:bad21ec5-ff88-4a5a-b1d1-ed69c499695a:ordinal:2","threadId":"bad21ec5-ff88-4a5a-b1d1-ed69c499695a","ordinal":2,"providerInstanceId":"codex","modelSelection":{"instanceId":"codex","model":"gpt-5.6-sol"},"providerThreadId":"provider-thread:provider:codex:native-thread:pending%3Arun%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A1","userMessageId":"519064dd-4cdb-43f2-9488-d4fa4a9d5d55","rootNodeId":"node:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A2:root","activeAttemptId":"run-attempt:run:run%3Athread%3Abad21ec5-ff88-4a5a-b1d1-ed69c499695a%3Aordinal%3A2:attempt:1","status":"queued","queuePosition":1,"queueHeld":true,"requestedAt":"2026-10-27T14:24:26.567Z","startedAt":null,"completedAt":null,"checkpointId":null,"contextHandoffId":null},"byteEqual":false}
2026-10-27T14:26:47.672Z FINAL 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2026-10-27T14:26:47.722Z STOP_SERVER {"pid":2861821}
2026-10-27T14:26:48.482Z END SHA e5ea25d1292e5342db8508bf48ded67b88b82b82 COMMAND runtime-driver.mjs /home/ubuntu/wt/pr-17885-evidence-base base codex
