RFR: 8351142: Add JFR monitor deflation and statistics events [v2]

[Aleksey Shipilev]

On Wed, 5 Mar 2025 06:53:48 GMT, David Holmes <dholmes at openjdk.org> wrote:

>> Aleksey Shipilev has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains seven additional commits since the last revision:
>> 
>>  - Merge branch 'master' into JDK-8351142-jfr-deflate-event
>>  - Test updates
>>  - Rework statistics event to be actually statistics
>>  - Filter JFR HiddenWait consistently
>>  - Event metadata touchups
>>  - Separate statistics event as well
>>  - Fix
>
> src/hotspot/share/runtime/objectMonitor.cpp line 663:
> 
>> 661:                                        const oop obj) {
>> 662:   assert(event != nullptr, "invariant");
>> 663:   event->set_monitorClass(obj->klass());
> 
> Now that I have seen the "hidden wait" logic in the other PR, should inflation/deflation events not also check `is_excluded`?

Good question. I think if we filter waits on JFR "hidden waits", the inflate and deflate should filter them as well. This requires a bit of reshuffling, but I think the thing I have in new version works.

-------------

PR Review Comment: https://git.openjdk.org/jdk/pull/23900#discussion_r1981270242