RFR: 8343840: Rewrite the ObjectMonitor lists [v2]

[Patricio Chilano Mateo]

On Wed, 5 Mar 2025 12:40:41 GMT, Fredrik Bredberg <fbredberg at openjdk.org> wrote:

>> src/hotspot/share/runtime/objectMonitor.cpp line 1509:
>> 
>>> 1507:     // is no successor, so it appears that an heir-presumptive
>>> 1508:     // (successor) must be made ready. Only the current lock owner can
>>> 1509:     // detach threads from the entry_list, therefore we need to
>> 
>> We don't detach threads here, so maybe manipulate would be better.
>
> Maybe, but manipulate may also include "pushing to the head", which is fine to do without holding the lock.
> I'll keep the comment as is for now, maybe this sentence will be deleted if we find a way of running exit without holding the lock, as we have talked about. If that's not possible I'll rephrase this sentence in a follow up PR.

You could use the same wording we have in the comment above already just to make it consistent: `manipulate the _entry_list (except for pushing new threads to the head)`.

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PR Review Comment: https://git.openjdk.org/jdk/pull/23421#discussion_r1981553339