RFR: 8373945: vmTestbase eatMemory/ClassUnloader provoke OOME to force GC and might cause GC in other threads [v2]

[SendaoYan]

On Fri, 19 Dec 2025 03:25:34 GMT, SendaoYan <syan at openjdk.org> wrote:

>> Hi all,
>> 
>> This PR use `WhiteBox.getWhiteBox().fullGC()` instead of `eatMemory` to grigger full GC. The OOME trigger by `eatMemory` may cause vmTestbase/nsk/monitoring/stress/classload tests intermittent fails when run those tests simultancely on some machines. The WB.fullGC() might be use for same purpose. It also reduce test execution time.
>> 
>> Change has been verified locally by running tests vmTestbase/nsk/monitoring/stress/classload on linux-x64.
>> 
>> Additional testing:
>> 
>> - [ ] All jtreg tests by fastdebug build
>
> SendaoYan has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains three additional commits since the last revision:
> 
>  - Merge branch 'openjdk:master' into jbs8373945
>  - Remove unnecessary unloadClass
>  - 8373945: vmTestbase eatMemory/ClassUnloader provoke OOME to force GC and might cause GC in other threads

There are other 36 tests need to be updated since the change of `unloadClass`

[tests.txt](https://github.com/user-attachments/files/24250041/tests.txt)

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PR Comment: https://git.openjdk.org/jdk/pull/28891#issuecomment-3673373828