RFR: 8337511: Implement JEP 404: Generational Shenandoah (Experimental) [v5]

[William Kemper]

On Sat, 26 Oct 2024 02:05:28 GMT, Zhengyu Gu <zgu at openjdk.org> wrote:

>> William Kemper has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains 492 commits:
>> 
>>  - Merge remote-tracking branch 'shenandoah/master' into great-genshen-pr-redux
>>  - Merge
>>  - 8342560: GenShen: Fix confusing method name
>>    
>>    Reviewed-by: ysr
>>  - 8342564: GenShen: Only reference young/old generation names in generational mode
>>    
>>    Reviewed-by: xpeng, ysr
>>  - Merge remote-tracking branch 'jdk/master' into great-genshen-pr-redux
>>  - Merge remote-tracking branch 'shenandoah/master' into great-genshen-pr-redux
>>  - 8342214: GenShen: Reduce code duplication in shFreeSet with iterator abstraction
>>    
>>    Reviewed-by: kdnilsen, ysr
>>  - 8342239: GenShen: Revert changes in adaptive heuristic to avoid overflow on 32 bit
>>    
>>    Reviewed-by: ysr
>>  - 8342278: GenShen: Move non-generational mode test out of generational test configuration
>>    
>>    Reviewed-by: ysr
>>  - 8342255: GenShen: Remove unnecessary enum initial values
>>    
>>    Reviewed-by: ysr
>>  - ... and 482 more: https://git.openjdk.org/jdk/compare/71583222...2a2aa408
>
> src/hotspot/share/gc/shenandoah/shenandoahGeneration.cpp line 701:
> 
>> 699:       // Seed the collection set with resource area-allocated
>> 700:       // preselected regions, which are removed when we exit this scope.
>> 701:       ResourceMark rm;
> 
> You can fold `ResourceMark` into `ShenandoahCollectionSetPreselector` class.

This makes sense: https://bugs.openjdk.org/browse/JDK-8343227

-------------

PR Review Comment: https://git.openjdk.org/jdk/pull/21273#discussion_r1821368739