On Mon, 5 Jun 2023 20:05:24 GMT, Chris Plummer <cjplum...@openjdk.org> wrote:
> The following commit in loom heavily modified this file with a lot of added > expected methods. There are other related tests with similar changes. I'm not > so sure I understand the need for so many additions, and also why > expectedLength is so out of sync with the number of added method. I don't > believe this commit was reviewed individually, but was just part of the > overall loom review when merge into jdk. Perhaps it should be revisited. These tests aren't easy to read or maintain, it would be good to re-visit them. In some cases, the tests capture the stack trace asynchronously so the test needs to know about all code paths. As regards ThreadController, used by the nsk/monitoring/stress/thread/straceXXX tests, the main thread waits at a barrier (a CountDownLatch) until all sleeping threads are ready to sleep. Once the main thread is released, it checks all the sleepers are in TIMED_WAITING state and samples their stack traces with the ThreadMXBean and related APIs. The test fails if there are frames corresponding to methods that the test doesn't know about. If a thread is sleeping then we shouldn't see frames for beforeSleep/afterSlee. My reading of these tests is that the main thread could poll a SleepingThread after it counts down and before it parks in sleep. It's doing an expensive ThreadMXBean::getAllThreadIds once released and that may explain why it hasn't been seen. ------------- PR Review Comment: https://git.openjdk.org/jdk/pull/14303#discussion_r1219348675
