txpool: fix goroutine leak in Fetch on shutdown#20006
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ConnectCore and ConnectSentries spawn goroutines that are not waited on when TxPool.Run returns. After context cancellation, Run exits via the errgroup but the fetch goroutines keep running — they may still be in a retry sleep or blocking on a stream when the DB and other resources are closed. Two fixes: 1. Track all goroutines spawned by ConnectCore/ConnectSentries with a WaitGroup. TxPool.Run defers Wait() so it blocks until they exit. 2. Replace bare time.Sleep calls in retry loops with context-aware selects so the goroutines exit promptly on cancellation instead of sleeping through a 3-second backoff. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Giulio2002
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Mar 19, 2026
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LGTM — clean goroutine leak fix: context-aware sleeps + WaitGroup tracking for ConnectCore/ConnectSentries goroutines
Verifies that goroutines spawned by ConnectCore/ConnectSentries exit promptly after context cancellation, rather than sleeping through a 3-second retry backoff. Fails if any context-aware select is reverted to bare time.Sleep. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
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Summary
ConnectCore/ConnectSentrieswith aWaitGroup;TxPool.RundefersWait()so it blocks until they all exittime.Sleepcalls in retry loops withselectonctx.Done()so goroutines exit promptly on cancellation instead of sleeping through a 3-second backoffThese goroutines were previously fire-and-forget: after context cancellation,
Run()would return via the errgroup while the fetch goroutines were still in retry sleeps or blocking on streams. Downstream cleanup (DB.Close(), etc.) could then race with them.Found while investigating flaky
TestCaplinBlockProductionWithWithdrawalRequestin #19981.Test plan
go test -race ./txnprovider/txpool/passesgo test -race -count=3 ./cl/beacon/handler/ -run TestCaplinBlockProductionWithWithdrawalRequestpasses without goroutine leak🤖 Generated with Claude Code