DefaultExecutor can never exit on IDLE #856
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Any fix for this? |
dkhalanskyjb
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Mar 23, 2020
qwwdfsad
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Apr 24, 2020
* Fix DefaultExecutor not being able to exit. * Also adds the performance optimization. See the discussion on the PR. * Add a stress test for the DefaultExecutor worker shutting down. * Make `testDelayChannelBackpressure2` not fail: This test could in theory already fail on the second `checkNotEmpty`: after the first `checkNotEmpty` has passed, first, the ticker channel awakens to produce a new element, and then the main thread awakens to check if it's there. However, if the ticker channel is sufficiently slowed down, it may not produce the element in time for the main thread to find it. After introducing the change that allows the worker thread in `DefaultExecutor` to shut down, the initial delay of 2500 ms is sufficient for the worker to shut down (which, by default, happens after 1000 ms of inactivity), and then the aforementioned race condition worsens: additional time is required to launch a new worker thread and it's much easier to miss the deadline. Now, the delays are much shorter, meaning that the worker thread is never inactive long enough to shut down. Fixes #856
recheej
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Dec 28, 2020
* Fix DefaultExecutor not being able to exit. * Also adds the performance optimization. See the discussion on the PR. * Add a stress test for the DefaultExecutor worker shutting down. * Make `testDelayChannelBackpressure2` not fail: This test could in theory already fail on the second `checkNotEmpty`: after the first `checkNotEmpty` has passed, first, the ticker channel awakens to produce a new element, and then the main thread awakens to check if it's there. However, if the ticker channel is sufficiently slowed down, it may not produce the element in time for the main thread to find it. After introducing the change that allows the worker thread in `DefaultExecutor` to shut down, the initial delay of 2500 ms is sufficient for the worker to shut down (which, by default, happens after 1000 ms of inactivity), and then the aforementioned race condition worsens: additional time is required to launch a new worker thread and it's much easier to miss the deadline. Now, the delays are much shorter, meaning that the worker thread is never inactive long enough to shut down. Fixes Kotlin#856
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DefaultExecutor.run. According to it's source, if there are no tasks thenprocessNextEvent()returnsLong.MAX_VALUE. Then we checkshutdownNanosand if not yet initialized then we check it again for the same condition (that is always true) and computeparkNanostime. After parking forKEEP_ALIVE_NANOSwe respin here again but we are falling into the second case whereparkNanos = parkNanos.coerceAtMost(KEEP_ALIVE_NANOS)is executed and the same after one more respin so we will never exit but spin every second instead.Also it looks like we need to reset
shutdownNanosif there was a task scheduled but we don't do it.The text was updated successfully, but these errors were encountered: