fix(stream): wrap close done ch with sync.Once#2537
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mergify[bot] merged 2 commits intoaws:mainlinefrom Jun 28, 2021
Merged
fix(stream): wrap close done ch with sync.Once#2537mergify[bot] merged 2 commits intoaws:mainlinefrom
mergify[bot] merged 2 commits intoaws:mainlinefrom
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Today, `stream.Stream` is structured as: ```go case <-streamer.Done(): // call Close() case <-time.After(fetchDelay): // call Fetch() ``` The problem is that it's possible that the Done() event is triggered at the same time as time.After(fetchDelay) and in that scenario the behavior is undeterministic. It's possible that we call `Fetch` a second time. For the ECS deployment streamer, this means that we would previous close the `s.done` channel twice. Wrapping the call with a `sync.Once` removes this concern.
huanjani
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Jun 28, 2021
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huanjani
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I'm curious what happens if we try to close it twice.
iamhopaul123
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Jun 28, 2021
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@huanjani PANIC 😱 |
thrau
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Dec 9, 2022
Today, `stream.Stream` is structured as: ```go case <-streamer.Done(): // call Close() case <-time.After(fetchDelay): // call Fetch() ``` The problem is that it's possible that the `Done()` event is triggered at the same time as `time.After(fetchDelay)` and in that scenario the behavior is undeterministic. It's possible that we call `Fetch` a second time. For the ECS deployment streamer, this means that we would previous close the `s.done` channel twice. Wrapping the call with a `sync.Once` removes this concern. By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of your choice.
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Today,
stream.Streamis structured as:The problem is that it's possible that the
Done()event is triggered atthe same time as
time.After(fetchDelay)and in that scenario thebehavior is undeterministic.
It's possible that we call
Fetcha second time. For the ECS deploymentstreamer, this means that we would previous close the
s.donechanneltwice. Wrapping the call with a
sync.Onceremoves this concern.By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of your choice.