On Thu, 8 Oct 2026 01:56:30 GMT, Shiv Shah <[email protected]> wrote: > referringObjects003 stops its 15 threads, joins them, forces one collection > and expects its ThreadGroup to be gone. That isn't guaranteed. A joined > thread's Thread object is still held by the VM until its handles are released > a bit later, and a terminated Thread keeps its group in holder.group. If the > collection marks while a handle is still there the group survives it, the > parent's weak reference to it stays and instances() counts it. ZGC with > -Xcomp on a slow Windows debug run is where it showed up. > > The test now forces the collection again until no test group or thread is > left, five tries at most, then runs the same checks as before. When something > is still there it prints the object's referrers, today the log only names the > group. The helper querying instances() twice is a separate issue > > -------- > Testing: > > - [x] referringObjects003, heapwalking001, heapwalking002, mixed001 and > mixed002 on linux-x64 debug with the default collector and with -XX:+UseZGC, > on windows-x64 debug with -XX:+UseZGC -Xcomp -XX:-TieredCompilation five > times each, and tier1-3 on linux-x64. > > > > > > --------- > - [x] I confirm that I make this contribution in accordance with the [OpenJDK > Interim AI Policy](https://openjdk.org/legal/ai).
This PR looks good enough to move it out of draft state and publish. ------------- PR Comment: https://git.openjdk.org/jdk/pull/33261#issuecomment-6057655553
