evcc-io / ocpp-go

83%

Pull #6

github

fix: prevent client dispatcher deadlock on SendRequest during stop

DefaultClientDispatcher.SendRequest did a blocking send on the requestChannel
notification channel while the caller (chargePoint.SendRequestAsync via the
callback queue) holds the callbacks mutex. Once the message pump has stopped
draining the channel, that send blocks forever, so the mutex is never released
and the concurrent clearCallbacks on teardown deadlocks. The send could also
panic on a closed channel after Stop.

The notification channel is only a wake-up doorbell; the request enqueued in
requestQueue is the source of truth and the pump re-checks the queue on every
wake. Make the doorbell send non-blocking and add a stopped signal so
SendRequest bails out once the dispatcher is stopping instead of blocking or
sending on a closed channel.

Adds a regression test that hangs without the fix.

16 of 18 new or added lines in 1 file covered. (88.89%)

3738 of 4508 relevant lines covered (82.92%)

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