RFR: 8329699: GenShen: Move promotion logic out of shHeap and shHeapRegion [v2]

[Kelvin Nilsen]

On Thu, 4 Apr 2024 18:40:25 GMT, William Kemper <wkemper at openjdk.org> wrote:

>> The code to handle promotions during evacuation has been moved into a new class in its own files: `shGenerationalEvacuationTask`
>> 
>> The methods for managing `plabs` have been moved into `shGenerationalHeap`. `plabs` are now also only created when running the generational mode.
>> 
>> 
>> -  inline HeapWord* allocate_from_plab(Thread* thread, size_t size, bool is_promotion);
>> -  HeapWord* allocate_from_plab_slow(Thread* thread, size_t size, bool is_promotion);
>> -  HeapWord* allocate_new_plab(size_t min_size, size_t word_size, size_t* actual_size);
>> -  void retire_plab(PLAB* plab);
>> -  void retire_plab(PLAB* plab, Thread* thread);
>> 
>> 
>> The code to handle promotion in place has been moved from `shHeapRegion` into `shGenerationalEvacuationTask`:
>> 
>> -  void promote_humongous();
>> -  void promote_in_place();
>> 
>> 
>> Unused methods related to global coalesce and fill have been deleted from `shHeapRegion`:
>> 
>> -  void global_oop_iterate_and_fill_dead(OopIterateClosure* cl);
>> -  void global_oop_iterate_objects_and_fill_dead(OopIterateClosure* cl);
>> -  void oop_iterate_humongous(OopIterateClosure* cl);
>> -  void oop_iterate_humongous(OopIterateClosure* cl, HeapWord* start, size_t words);
>> 
>> 
>> Additionally, these methods in `shHeap` which just delegated to old or young generation instances have more or less been inlined at the usage site (many `includes` have been fixed):
>> 
>> -  ShenandoahOldHeuristics* old_heuristics();
>> -  ShenandoahYoungHeuristics* young_heuristics();
>> -
>> -  bool doing_mixed_evacuations();
>> -  bool is_old_bitmap_stable() const;
>> -  bool is_gc_generation_young() const;
>> 
>> 
>> The boolean `is_promotion` that was passed through all of the allocation calls has been moved into `shAllocRequest` to reduce the upstream delta for `shHeap`.
>
> William Kemper has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Fix mac build

Very nice cleanup.  Thanks for your work on this.

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Marked as reviewed by kdnilsen (Committer).

PR Review: https://git.openjdk.org/shenandoah/pull/415#pullrequestreview-1995168043