RFR: 8320318: ObjectMonitor Responsible thread [v2]

[Coleen Phillimore]

On Tue, 17 Sep 2024 12:03:57 GMT, Fredrik Bredberg <fbredberg at openjdk.org> wrote:

>> src/hotspot/share/runtime/objectMonitor.hpp line 360:
>> 
>>> 358: 
>>> 359:   enum class TryLockResult { Interference = -1, HasOwner = 0, Success = 1 };
>>> 360:   TryLockResult  TryLock(JavaThread* current);
>> 
>> This CamelCase syntax is used for private methods. We should change it to try_lock now that we are calling it from SharedRuntime code. Another alternative is to keep it private and just use the already available try_enter(). That has the benefit of not having to make TryLockResult public either. If we want to skip the checks after TryLock in try_enter we could add a check_owner_already boolean.
>
> Good suggestion! I'll go with the "Another alternative...".

Yes, that's a good suggestion.  try_enter() is already exported.  Also change the comment in try_enter():

      // TryLock avoids the CAS and handles deflation.

because it used to be a try_set_owner_from(), and now there's two reasons it can't go back.

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PR Review Comment: https://git.openjdk.org/jdk/pull/19454#discussion_r1763225745