fix: prevent deadlock in server Write and websocket Close/WriteManual#408
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rishabhvaish wants to merge 1 commit intolorenzodonini:masterfrom
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fix: prevent deadlock in server Write and websocket Close/WriteManual#408rishabhvaish wants to merge 1 commit intolorenzodonini:masterfrom
rishabhvaish wants to merge 1 commit intolorenzodonini:masterfrom
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The server's Write method held connMutex.RLock while calling webSocket.Write, which in turn held webSocket.mutex.RLock while sending on the outQueue channel. If the channel was full, the goroutine blocked while holding both locks. Meanwhile, cleanup() needed webSocket.mutex.Lock and handleDisconnect needed connMutex.Lock, creating a deadlock. The fix releases each lock immediately after the map/nil-check lookup, before any potentially-blocking channel send. A deferred recover guards against the race where cleanup closes the channel between the nil check and the send. Fixes lorenzodonini#291
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Summary
Fixes #291
server.WriteheldconnMutex.RLockwhile callingwebSocket.WriteManual, which heldwebSocket.mutex.RLockwhile sending onoutQueue. If the channel buffer was full, the goroutine blocked holding both read locks. Concurrently,cleanup()needed both write locks — deadlock.The fix releases each lock immediately after the map lookup / nil check, before any channel send. A deferred
recoverhandles the race wherecleanup()closes the channel between the nil check and the send.Changes:
server.Write: releaseconnMutex.RLockright after map lookupwebSocket.WriteManual: releasemutex.RLockafter nil check, add recoverwebSocket.Close: same pattern as WriteManualTest plan
go test ./ws/... -v -racepasses🤖 Generated with Claude Code