On Wed, 15 Jun 2022 17:21:25 GMT, Chris Plummer <cjplum...@openjdk.org> wrote:
>> Currently, jdi only check and process class unloading event when it detects >> a new GC cycle. >> >> After [JDK-8212879](https://bugs.openjdk.org/browse/JDK-8212879), posting >> class events can overlap with GC finish event, that results, sometimes, it >> only captures partial or even empty unloaded class list. The pending list >> usually can be flushed out at next GC cycle. But for the classes unloaded >> during the last GC cycle, the class unloading events may lost forever. >> >> This patch checks and processes class unloading events unconditionally, >> suggested by @kbarrett, the last pending unloaded class list can be flushed >> by other events, such as `VM_DEATH`. >> >> It also performs `commonRef_compact()` only when there are classes unloaded. >> >> New test failed about 20% without patch, none with patch. > > src/jdk.jdwp.agent/share/native/libjdwp/eventHandler.c line 637: > >> 635: * been collected. >> 636: */ >> 637: commonRef_compact(); > > I think you want to be doing the `commonRef_compact()` after every gc, not > just if some classes were unloaded. You may need to re-add the > `garbageCollected` flag to accomplish this. If so, should `cbGarbageCollectionFinish()` be a better place for the call? ------------- PR: https://git.openjdk.org/jdk/pull/9168
