[SharovBot] fix: resolve WebSocket client deadlock on oversized message#20897
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[SharovBot] fix: resolve WebSocket client deadlock on oversized message#20897erigon-copilot[bot] wants to merge 2 commits intomainfrom
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Fix a race condition in the RPC client dispatch loop that could cause TestWebsocketLargeCall (and real clients) to hang indefinitely. When a client sends a message that exceeds the server's read limit, the server closes the connection. If the client's write succeeds (data was TCP-buffered) while the read loop has already detected the closed connection, the in-flight request was orphaned: cancelAllRequests intentionally skipped it (to allow re-registration on reconnect), but no reconnect occurred because the write didn't fail. The request's resp channel was never closed, causing op.wait() to block forever. The fix detects this specific scenario in the reqSent handler: if the write succeeded (err == nil) but the read loop is already dead (!reading), the in-flight request is explicitly failed with errDead. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com> Co-authored-by: Giulio Rebuffo <giulio.rebuffo@gmail.com>
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Summary
dispatchloop that causedTestWebsocketLargeCallto hang indefinitely (deadlock)cancelAllRequestsskipped it (for potential reconnect reuse), but no reconnect happened, leavingop.respunclosed andop.wait()blocking foreverreqSenthandler: if the write succeeded but the read loop is dead, the in-flight request is explicitly failed witherrDeadTest plan
go build ./...passesgo test -race -count=1 -timeout 2m ./rpc -run TestWebsocketLargeCallpasses 10/10 consecutive runsgo test -race -count=1 -timeout 5m ./rpc/...full package suite passes🤖 Generated with Claude Code