graphql-go / graphql / 2019

96%

Build Type

Pull #759

circleci

Committed by hsieh

Commit Message

Fix subscription producer goroutine leak on context cancel

The producer in ExecuteSubscription sent results with a bare unbuffered
send that did not select on p.Context.Done(). When a subscriber
unsubscribes or disconnects and stops reading resultChannel, the producer
blocks forever on the send; cancelling the context cannot unblock it
because the goroutine is not in a select at that moment. This leaks one
goroutine per unsubscribed subscription.

Wrap the send in a select that also observes p.Context.Done(), so a
cancelled context lets the producer exit and close resultChannel even
with no active receiver.

Add TestProducerExitsOnContextCancel as a regression test.

Pull Request Pull Request #759: Fix subscription producer goroutine leak on context cancel

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