RFR: 8373819: Genshen: Control thread can miss allocation failure notification (redux) [v4]

[Y. Srinivas Ramakrishna]

On Mon, 12 Jan 2026 17:22:29 GMT, William Kemper <wkemper 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 14 commits:
>> 
>>  - Merge remote-tracking branch 'jdk/master' into fix-null-generation-crash
>>  - Merge remote-tracking branch 'jdk/master' into fix-null-generation-crash
>>  - Fix typo in assertion message
>>  - Take regulator thread out of STS before requesting GC
>>    
>>    The request may block while it waits for control thread to stop old marking. If workers are already in the STS, and the regulator thread is still in the STS, but cannot yield, the safepoint will not run. Control, worker and regulator threads deadlock each other.
>>  - Add comments
>>  - Revert back to what should be on this branch
>>  - Merge remote-tracking branch 'jdk/master' into fix-null-generation-crash
>>  - Don't know how this file got deleted
>>  - Carry over gc cancellation to gc request
>>  - Do not let allocation failure requests be overwritten by other requests
>>  - ... and 4 more: https://git.openjdk.org/jdk/compare/f5fa9e40...2e57f0ac
>
> We backed out the original "fix" for JDK-8373100 here: https://bugs.openjdk.org/browse/JDK-8374048. I'll remove the issue from the PR and just leave the connections in JBS.

Thanks for your responses/explanation, @earthling-amzn. They all make sense; we can defer the documentation and any refactor/clean-ups for a future PR, since these changes are needed to fix the existing behaviour and it makes sense to land this change sooner rather than later.

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PR Comment: https://git.openjdk.org/jdk/pull/28932#issuecomment-3740894838