See the JBS issue for the extended problem description. Native threads that were attached to the JVM through an FFM upcall are automatically detached from the VM when they join/terminate. However, if a native thread tries to terminate after the VM has exited without going through `DestroyJavaVm` (e.g. as a result of calling `System.exit`), they will block in `VM_Exit::block_if_vm_exited` inside `DetachCurrentThread`. This may happen for instance when they try to join after the JVM has exited in an `atexit` handler.
This patch adds a check before trying to detach the thread to see if the VM has exited and bails out if it has. This does not prevent issues as a result of a race between the VM exiting and the thread joining, but it does prevent issues in the more comment case where a thread simply outlives the VM. --------- - [X] I confirm that I make this contribution in accordance with the [OpenJDK Interim AI Policy](https://openjdk.org/legal/ai). ------------- Commit messages: - cleanup PROCEDURE typedef - Improve TestThread callback data management - Refactor test helper lib - Add detach after exit test Changes: https://git.openjdk.org/jdk/pull/32686/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=32686&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8391662 Stats: 258 lines in 5 files changed: 214 ins; 17 del; 27 mod Patch: https://git.openjdk.org/jdk/pull/32686.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/32686/head:pull/32686 PR: https://git.openjdk.org/jdk/pull/32686
