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Prevent a transaction from being added to the wait queue multiple times across retry attempts by tracking `addedToWaitQueue`. Also clean up the wait queue and dependency graph when the retry loop times out, avoiding stale state in subsequent lock acquisitions.
Documents the 2PL protocol, supported lock modes, internal subsystems (LockTable, WaitQueue, DependencyGraph, LockGrantor), the lock acquisition flow, deadlock detection strategy, and the invariants the package upholds.
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Fix duplicate wait-queue entries and timeout leak in lock manager
Title: Fix duplicate wait-queue entries and timeout leak in lock manager
Summary:
LockManager.attemptToAcquireLockwas re-adding the same transaction to the wait queue and dependency graph on every failed attempt, causing duplicate entries and incorrect deadlock detection.FuzzLexerCI step was removed (it no longer exists or is covered elsewhere).pkg/concurrency/lockdocumenting the 2PL protocol, components, lock acquisition flow, and invariants.Changes:
pkg/concurrency/lock/manager.go— guard wait-queue insertion and dependency tracking behind anaddedToWaitQueueflag so they only run once per acquisition attempt; clean up queue and graph on timeout.pkg/concurrency/lock/docs.go— new file with package-level godoc coveringLockManager,LockTable,WaitQueue,DependencyGraph,LockGrantor, and all relevant invariants..github/workflows/ci.yml— remove theFuzzLexerfuzz step from the CI workflow.