RFR: 8338383: Implement JEP 491: Synchronize Virtual Threads without Pinning [v13]

[Patricio Chilano Mateo]

On Fri, 25 Oct 2024 22:22:01 GMT, Coleen Phillimore <coleenp at openjdk.org> wrote:

>> Patricio Chilano Mateo has updated the pull request incrementally with four additional commits since the last revision:
>> 
>>  - Simplify set last_sp in prepare_freeze_interpreted_top_frame
>>  - add authenticate_return_address() in StubAssembler::epilogue
>>  - Make member functions in ObjectWaiter const
>>  - Rename inflating_thread to locking_thread
>
> src/hotspot/share/runtime/objectMonitor.hpp line 43:
> 
>> 41: // ParkEvent instead.  Beware, however, that the JVMTI code
>> 42: // knows about ObjectWaiters, so we'll have to reconcile that code.
>> 43: // See next_waiter(), first_waiter(), etc.
> 
> Also a nice cleanup.  Did you reconcile the JVMTI code?

We didn't remove the ObjectWaiter. As for the presence of virtual threads in the list, we skip them in JVMTI get_object_monitor_usage. We already degraded virtual thread support for GetObjectMonitorUsage.

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

PR Review Comment: https://git.openjdk.org/jdk/pull/21565#discussion_r1819463651