Please review the following patch. This fixes a bug in how we handle state changes for the timed `Object.wait` case in `afterYield`, which can leave a virtual thread stuck in the `BLOCKED` state. It can be triggered by two consecutive calls to timed `Object.wait`, if the first call receives a notification and the second call relies on the timeout task to wake up the thread. I added the full sequence of events that leads to the vthread getting stuck in JBS.
The fix is to check for `notified` and attempt to change the state to `BLOCKED` inside the synchronized block. This guarantees that we don't change the state of an already new timed `Object.wait` call. The PR includes a new test which reproduces the issue when run several times in mach5. It's a hybrid of my original repro test and another one created by @AlanBateman. Thanks, Patricio ------------- Commit messages: - v1 Changes: https://git.openjdk.org/jdk/pull/29255/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=29255&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8373120 Stats: 147 lines in 2 files changed: 136 ins; 8 del; 3 mod Patch: https://git.openjdk.org/jdk/pull/29255.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/29255/head:pull/29255 PR: https://git.openjdk.org/jdk/pull/29255
