> There are a few nsk debugger tests that pin multiple virtual threads to > carrier threads when synchronizing. Sometime the default number of carrier > threads (which equals the number of CPUs) is not enough, and the test > deadlocks because virtual threads start to wait forever for an available > carrier thread. This PR fixes this problem by using the > `jdk.virtualThreadScheduler.parallelism` property to change the default > number of carrier threads. I believe the largest number of carrier threads > any test needs is 11, so I chose 15 just to be safe. > > I had initially tried to fix each individual test by using the test support > in `VThreadRunner.setParallism()`. The advantage of this was limiting the > scope of the change to just a few tests, and also being able to specify the > exact number of needed carrier threads. The disadvantage was having to make > quite a few changes to quite a few tests, plus I had one troublesome test > that was still failing, I believe because I didn't fully understand how many > carrier threads it needed. Just giving every test 15 carrier threads in the > end was a lot easier.
Chris Plummer has updated the pull request incrementally with one additional commit since the last revision: Better comments. ------------- Changes: - all: https://git.openjdk.org/jdk/pull/11735/files - new: https://git.openjdk.org/jdk/pull/11735/files/4ea36acd..e079d3bf Webrevs: - full: https://webrevs.openjdk.org/?repo=jdk&pr=11735&range=01 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=11735&range=00-01 Stats: 6 lines in 2 files changed: 4 ins; 2 del; 0 mod Patch: https://git.openjdk.org/jdk/pull/11735.diff Fetch: git fetch https://git.openjdk.org/jdk pull/11735/head:pull/11735 PR: https://git.openjdk.org/jdk/pull/11735
