RFR: 8295849: Consolidate Threads::owning_thread* [v3]

[Daniel D. Daugherty]

On Fri, 28 Oct 2022 15:28:42 GMT, Roman Kennke <rkennke at openjdk.org> wrote:

>> There are several users and even mostly-identical implementations of Threads::owning_thread_from_monitor_owner(), which I would like to consolidate a little in preparation of JDK-8291555:
>> - JvmtiEnvBase::get_monitor_usage(): As the comment in ObjectSynchronizer::get_lock_owner() suggests, the JVMTI code should call the ObjectSynchronizer method. The only real difference is that JVMTI loads the object header directly while OS spins to avoid INFLATING. This is harmless, because JVMTI calls from safepoint, where INFLATING does not occur, and would just do a simple load of the header. A little care must be taken to fetch the monitor if exists a few lines below, to fill in monitor info.
>> - Two ThreadService methods call Threads::owning_thread_from_monitor_owner(), but always only ever from a monitor. I would like to extract that special case because with fast-locking this can be treated differently (with fast-locking, monitor owners can only be JavaThread* or 'anonynmous'). It's also a little cleaner IMO.
>> 
>> Testing:
>>  - [x] GHA (x86 and x-compile failures look like infra glitch)
>>  - [x] tier1
>>  - [x] tier2
>>  - [x] tier3
>>  - [x] tier4
>
> Roman Kennke 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 five additional commits since the last revision:
> 
>  - Merge branch 'master' into JDK-8295849
>  - Fix has_owner() condition
>  - Improve condition in OM::has_owner()
>  - Fix OM::has_owner()
>  - 8295849: Consolidate Threads::owning_thread*

Mach5 testing for the v02 version of this fix:

Mach5 Tier1:
- no test or task failures

Mach5 Tier2:
- no test or task failures

Mach5 Tier3:
- no test or task failures

Mach5 Tier4:
- 1 known, unrelated test failure:
- no task failures

Mach5 Tier5:
- 1 test suite issue due to a corrupted download that resulted in 240 test failures
- no tasks failed

Mach5 Tier6:
- no test failures and no task failures

Mach5 Tier7:
- 1 known, unrelated test failure
- no task failures

Mach5 Tier8:
- skipped for the v02 version since the PR is already integrated

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

PR: https://git.openjdk.org/jdk/pull/10849