Fix two flaky tests #30278
Fix two flaky tests #30278
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| @@ -165,6 +165,7 @@ public void testCloseVisibleToAwaitCompletionCallerAndProducer() throws Exceptio | |||
| Future<?> future2 = | |||
| executor.submit( | |||
| () -> { | |||
| Thread.sleep(500); // give the previous future some time to reach the inf while loop | |||
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Busy sleep is generally not preferable. Consider use wait/notify which sounds exactly what we need here? That is block this thread until future1 reaches while(true)
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sdks/java/core/src/test/java/org/apache/beam/sdk/fn/data/BeamFnDataInboundObserverTest.java
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| @@ -553,7 +553,7 @@ public void testThreadsAreAddedOnlyAsNeededWithContention() throws Exception { | |||
| LOG.info("Created {} threads to execute at most 100 parallel tasks", largestPool); | |||
| // Ideally we would never create more than 100, however with contention it is still possible | |||
| // some extra threads will be created. | |||
| assertTrue(largestPool <= 104); | |||
| assertTrue(largestPool <= 110); | |||
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out of curiosity, you mind explain briefly about the change
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As the comment above the change says, there could be more than 100 threads created in the UnboundedScheduledExecutorService. The previous threshold is set to 104 but it causes some flakiness recently. I attempt to increase to a little bit more to see if it can stop or at least reduce the chance of failure.
| @@ -165,6 +171,11 @@ public void testCloseVisibleToAwaitCompletionCallerAndProducer() throws Exceptio | |||
| Future<?> future2 = | |||
| executor.submit( | |||
| () -> { | |||
| synchronized (isReady) { | |||
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sorry, actually this cannot be synchronized (either using this or isReady). Because synchronized block will block other thread's same synchronized block. Here it will wait for signal indefinitely and cause deadlock.
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Using synchronized block on isReady works here. I don't see there is a deadlock.
(1) If it runs the first synchronized block first, then it will call notify() and isReady is set to true. Then when the second synchronized block is executed, it will not reach the wait() call because isReady is true.
(2) If it runs the second synchronized block first, then it will wait() and give up the lock. Then in the first synchronized block, it will pick up the lock, set isReady to true, and then call notify().
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You are right, I confused myself, LGTM
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Looks like the second flaky test is still there after the fix, though the frequency seems lower. |
For test of
testCloseVisibleToAwaitCompletionCallerAndProducerBeamFnDataInboundObserver.CloseExceptionthrown at callingfuture.get().For test
testThreadsAreAddedOnlyAsNeededWithContention, my attempt is to increase the threshold so we can allow more extra threads being created.Thank you for your contribution! Follow this checklist to help us incorporate your contribution quickly and easily:
addresses #123), if applicable. This will automatically add a link to the pull request in the issue. If you would like the issue to automatically close on merging the pull request, commentfixes #<ISSUE NUMBER>instead.CHANGES.mdwith noteworthy changes.See the Contributor Guide for more tips on how to make review process smoother.
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