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Concept guides/Concurrency/Check-then-act (TOCTOU)

CodingConcurrency

Check-then-act (TOCTOU)

Medium3 min read

Questions it teaches

Stock race conditionEasy14 min Hit counter reads inconsistentMedium22 min Counter exceeds max limitMedium25 min Connection pool dial and memoizeMedium24 min Cache computes duplicate workMedium20 min Same key computes multiple timesMedium28 min File created by multiple callersHard40 min High water mark check-then-actHard28 min

Related

Concurrency Designing data structures Backend internals Reviewing AI code Correctness review

Builds on: Designing data structures

Queues, deques & ring buffers3 min Database deduplication3 min

Leads to: Backend internals

Encoding and schema evolution4 min MAC addresses4 min

Related: Reviewing AI code

Catching AI mistakes3 min Understanding code & docs with AI3 min

Related: Correctness review

Spotting correctness bugs3 min Structured logging3 min

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