On Thu, 3 Sep 2026 13:56:15 GMT, Jorn Vernee <[email protected]> wrote:
> 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). This pull request has now been integrated. Changeset: 06997248 Author: Jorn Vernee <[email protected]> URL: https://git.openjdk.org/jdk/commit/06997248a8d7b9ac7900a53f9889e6a9ec48e0ed Stats: 248 lines in 5 files changed: 204 ins; 17 del; 27 mod 8391662: Deadlock in UpcallContext dtor when called after JVM shutdown due to System.exit Reviewed-by: dholmes, jsjolen ------------- PR: https://git.openjdk.org/jdk/pull/32686
