RFR: 8369913: Parallel: Refactor PSAdjustTask

[Stefan Karlsson]

On Fri, 31 Oct 2025 11:50:14 GMT, Joel Sikström <jsikstro at openjdk.org> wrote:

>> Cleanup roots processing (adjusting/remapping) during the adjust-phase of full-gc, so that relevant roots are grouped together with some documentations. Also, the use of `SubTasksDone` is replaced with a `volatile bool`, which is more transparent in the context.
>> 
>> Test: tier1-5
>
> src/hotspot/share/gc/parallel/psParallelCompact.cpp line 1383:
> 
>> 1381:     _weak_proc_task(nworkers),
>> 1382:     _nworkers(nworkers),
>> 1383:     _code_cache_claimed(false) {
> 
> Looks weird that we're not calling the constructor for `_oop_storage_iter`, but it's fine since it only has a default-ctor anyway. Up to you if we add it.

We should explicitly spell them out when we go over and adjust old code. We have been doing that for ZGC code, but it would be good to fix this in other GCs as well.

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PR Review Comment: https://git.openjdk.org/jdk/pull/27822#discussion_r2481225615