[SharovBot] rpc: fix deadlock in client dispatch when connection lost during write#20898
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[SharovBot] rpc: fix deadlock in client dispatch when connection lost during write#20898erigon-copilot[bot] wants to merge 2 commits intomainfrom
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When a WebSocket server rejects an oversized message (exceeding SetReadLimit), the connection is closed. If the client's read loop detects this closure while a write is still in-flight, cancelAllRequests intentionally excludes the in-flight request (lastOp) to allow a potential reconnection to re-register it. However, if the write completes successfully without triggering a reconnect, no reader exists to deliver a response. The excluded request's resp channel is never closed, causing client.Call to block indefinitely. Fix: when reqSent fires with a successful write but reading is false (no active reader), fail the orphaned request immediately with errDead so the caller doesn't hang. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com> Co-authored-by: Giulio Rebuffo <giulio.rebuffo@gmail.com>
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Summary
Client.dispatchwhen a WebSocket connection is lost while a write is in-flightSetReadLimit),cancelAllRequestsexcludes the in-flight request (lastOp) to allow reconnection. If the write then succeeds without reconnecting, no reader exists to deliver a response, orphaning the request and causingCallto block forever.reqSentcompletes with no error butreading == false, the orphaned request is now immediately failed witherrDeadTest plan
TestWebsocketLargeCallpasses 10 consecutive times with-race -count=1 -timeout 2m./rpc/...package tests pass with-race -count=1 -timeout 5mgo build ./...succeeds🤖 Generated with Claude Code