competition-race-condition-state-drift

1# Competition Race Condition State Drift
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3Use this skill only as a downstream specialization after `$ctf-sandbox-orchestrator` is already active and has established sandbox assumptions, node ownership, and evidence priorities. If that has not happened yet, return to `$ctf-sandbox-orchestrator` first.
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5Use this skill when the decisive behavior depends on request timing, async ordering, lock gaps, or stale state.
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7Reply in Simplified Chinese unless the user explicitly requests English.
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9## Quick Start
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111. Identify mutable state first: rows, cache keys, queue payloads, session fields, counters, or files.
122. Reproduce with smallest concurrent sequence and fixed timing assumptions.
133. Capture one baseline run and one racing run with only one variable changed.
144. Track read, check, write, enqueue, and commit boundaries separately.
155. Prove final state drift from a clean reset.
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17## Workflow
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19### 1. Map Mutable Boundaries
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21- Record transaction scope, lock behavior, retry logic, idempotency keys, cache invalidation, and queue handoff.
22- Note where read-check-write is split across requests, workers, or services.
23- Keep each boundary tied to exact timestamps or sequence numbers.
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25### 2. Reproduce Timing Window
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27- Build deterministic concurrent inputs with controlled delay, duplicate requests, or reordered worker execution.
28- Compare accepted and rejected paths under identical payloads.
29- Record which condition flips when ordering changes.
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31### 3. Reduce To Decisive Race Chain
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