Add a watcher (JUnit 3) test rule (JUnit 4) for hanging test logging #774
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Tests may be (and actually are every now and then) hanging for different reasons, such as livelocks or deadlocks. A hanging test does not log anything on its own anymore, which makes it difficult to identify a hanging test and the reasons for that. To this end, it would be useful to have an additional entity that logs the state of all threads, i.e., a thread dump, when a test takes longer than a defined threshold.
Since several tests need to run in the UI thread, the JUnit Timeout rule cannot be used, as it executes a test in a different thread that can even be terminated preemptively after a timeout. Instead, this change introduces a
HangingTestRule
that spawns a watcher thread that writes a thread dump whenever a test (that is run in the UI thread) takes more time than a defined timeout.In total, this change does the following:
TestBarrier2
reusable in a centralTestUtil
HangingTestWatcher
that writes a thread dump if not stopped after a given timeout (compatible with JUnit 3)HangingTestRule
that wraps theHangingTestWatcher
into a JUnit 4 ruleHangingTestWatcher
to the JUnit 3CoreTest
class to apply the logging to all subclasses ofCoreTest
Also see eclipse-platform/eclipse.platform.ui#1229, which discusses some additional logging in Platform UI to help debugging hanging tests. That may be replaced by the proposed watcher/rule.