RFR: 8370039: GenShen: array copy SATB barrier improvements [v3]

[Aleksey Shipilev]

On Tue, 18 Nov 2025 17:01:13 GMT, William Kemper <wkemper at openjdk.org> wrote:

>> src/hotspot/share/gc/shenandoah/shenandoahBarrierSet.inline.hpp line 428:
>> 
>>> 426: 
>>> 427:   const char gc_state = ShenandoahThreadLocalData::gc_state(Thread::current());
>>> 428:   if ((gc_state & ShenandoahHeap::MARKING) != 0) {
>> 
>> A question on sequencing. Can we have marking and update-refs at the same time? If so, should update-refs happen first, and then marking should be doing the walk over (fixed-up) objects?
>
> I can change the sequencing, though I'm not sure it's necessary. Old marking shouldn't be following references into the young generation, so updating references in old that point to young shouldn't matter to old marking.

Okay.

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PR Review Comment: https://git.openjdk.org/jdk/pull/28183#discussion_r2539036634