RFR: 8349094: GenShen: Race between control and regulator threads may violate assertions [v14]

[William Kemper]

On Tue, 25 Feb 2025 23:22:48 GMT, Y. Srinivas Ramakrishna <ysr 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 32 commits:
>> 
>>  - Merge tag 'jdk-25+11' into fix-control-regulator-threads
>>    
>>    Added tag jdk-25+11 for changeset 0131c1bf
>>  - Address review feedback (better comments, better names)
>>  - Merge remote-tracking branch 'jdk/master' into fix-control-regulator-threads
>>  - Old gen bootstrap cycle must make it to init mark
>>  - Merge remote-tracking branch 'jdk/master' into fix-control-regulator-threads
>>  - Improve message for assertion
>>  - Make shutdown safer for threads requesting (or expecting) gc
>>  - Do not accept requests if control thread is terminating
>>  - Notify waiters when control thread terminates
>>  - Add event for control thread state changes
>>  - ... and 22 more: https://git.openjdk.org/jdk/compare/0131c1bf...d7858deb
>
> src/hotspot/share/gc/shenandoah/shenandoahGenerationalControlThread.hpp line 150:
> 
>> 148:   GCMode prepare_for_explicit_gc_request(ShenandoahGCRequest &request);
>> 149: 
>> 150:   GCMode prepare_for_concurrent_gc_request(ShenandoahGCRequest &request);
> 
> Documentation of private APIs.
> 
> Bit of a nit: These all seem to take a request type, fill in some yet unfilled fields, and return a GC mode. So they look to me like `prepare_request_for_<action>` rather than `pepare_for_<action>_request`.

Hmm, they do modify the request, so I see your point. But they also touch `ShenandoahHeap` , `ShenandoahPolicy` and `ShenandoahHeuristics`. How about we just drop `_request` from their name?

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PR Review Comment: https://git.openjdk.org/jdk/pull/23475#discussion_r1972319562