On Mon, 7 Sep 2026 13:14:41 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). > > Jorn Vernee has updated the pull request incrementally with one additional > commit since the last revision: > > Indentation > > Co-authored-by: David Holmes <[email protected]> test/jdk/java/foreign/detachafterexit/libDetachAfterExit.cpp line 30: > 28: > 29: static TestThread THREAD; > 30: static volatile bool FLAG = false; My C++ is really rusty, but I think `volatile` is much weaker in C++ compared to Java, so I wonder if there is actually any inter-thread synchronization going on here or if we need to use something stronger like `std::atomic<bool> FLAG(false); `? ------------- PR Review Comment: https://git.openjdk.org/jdk/pull/32686#discussion_r3956669914
