RFR: 8374984: Convert workerUtils to use Atomic<T>

[Stefan Karlsson]

On Wed, 14 Jan 2026 07:16:34 GMT, Aleksey Shipilev <shade at openjdk.org> wrote:

>> Please review this change to make SubTasksDone and SequentialSubTasksDone use
>> Atomic<T> instead of AtomicAccess.
>> 
>> Testing: mach5 tier1
>
> src/hotspot/share/gc/shared/workerUtils.cpp line 120:
> 
>> 118: bool SubTasksDone::try_claim_task(uint t) {
>> 119:   assert(t < _n_tasks, "bad task id.");
>> 120:   return !_tasks[t].load_relaxed() && !_tasks[t].compare_exchange(false, true);
> 
> This is one of those cases where `compare_set` is somewhat cleaner:
> 
> 
>   return !_tasks[t].load_relaxed() && _tasks[t].compare_set(false, true);

And maybe the same for `all_tasks_claimed_impl`?

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PR Review Comment: https://git.openjdk.org/jdk/pull/29201#discussion_r2689449288