On Tue, 26 Sep 2023 02:42:56 GMT, Chris Plummer <cjplum...@openjdk.org> wrote:
>> Correction, there is one code path where we pop the lockstack first and then
>> update the owner:
>>
>> ObjectMonitor* monitor = inflate(current, object, inflate_cause_vm_internal);
>> if (LockingMode == LM_LIGHTWEIGHT && monitor->is_owner_anonymous()) {
>> // It must be owned by us. Pop lock object from lock stack.
>> LockStack& lock_stack = current->lock_stack();
>> oop popped = lock_stack.pop();
>> assert(popped == object, "must be owned by this thread");
>> monitor->set_owner_from_anonymous(current);
>> }
>> monitor->exit(current);
>>
>> we should probably do this the other way around.
>
> Maybe SA is seeing a monitor in the monitor cache that it is only seeing
> because the monitor cache is currently inconsistent (due to SA not safe
> pointing). So the question is whether the monitor cache can be in a state
> where it still contains a reference to an anonymous monitor, but no thread
> actually owns the monitor (and the anonymous monitor is about to be purged
> from the cache).
Looks like you answered my question while I was asking it.
-------------
PR Review Comment: https://git.openjdk.org/jdk/pull/15907#discussion_r1336566708
