playwright-community / playwright-go / 28143035874

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Pull #601

github

fix: prevent jsonPipe deadlock that hung remote connections

The remote-connection transport (jsonPipe) delivered incoming messages into
a bounded channel (buffer 10) from the outer connection's dispatch goroutine.
When more than 10 messages queued before the inner connection drained them,
that blocking send stalled the dispatch goroutine — which is also the only
goroutine that delivers replies. Any in-flight Send() awaiting a reply then
blocked forever.

This surfaced as a flaky hang in TestShouldUploadAFolderRemote: streaming
files to a remote server produces a burst of write/close responses plus async
page events, occasionally exceeding the buffer and deadlocking until the test
timeout. Reproduced deterministically by shrinking the buffer to 1; goroutine
dump showed the dispatch goroutine blocked on 'chan send' at jsonPipe while the
test goroutine blocked on 'chan receive' in jsonPipe.Send.

Replace the bounded channel with an unbounded, order-preserving queue drained
by Poll(), so the dispatch goroutine never blocks. Add unit tests covering the
non-blocking guarantee, ordering, blocking Poll, close, and drain-before-close.

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