On Mon, 12 Oct 2026 22:13:36 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). > > Shiv Shah has updated the pull request incrementally with one additional > commit since the last revision: > > Say why the retry works Looks good. ------------- Marked as reviewed by sspitsyn (Reviewer). PR Review: https://git.openjdk.org/jdk/pull/33261#pullrequestreview-5498256647
