[jdk11u-dev] RFR: 8310176: JDK 11 G1 crash during full GC with +UseStringDeduplication [v2]

[Man Cao]

On Fri, 16 Jun 2023 09:14:47 GMT, Man Cao <manc at openjdk.org> wrote:

>> Hi all,
>> 
>> Could anyone review this bug fix to G1's full GC for JDK 11. See https://bugs.openjdk.org/browse/JDK-8310176 for details.
>> This issue only affects JDK 11 and 12, and is not a backport.
>> 
>> -Man
>
> Man Cao has updated the pull request incrementally with two additional commits since the last revision:
> 
>  - Update copyright year
>  - Add a jtreg test

Thanks for the quick review. Initially I validated the fix with an internal application that exposes this bug, as I didn't find any jtreg test failing. With a closer look I discovered the jtreg test `TestStringDeduplicationFullGC.java`, and the flag `-XX:+StringDeduplicationRehashALot`. Running both together can expose this bug. Added a new test that is similar to `TestStringDeduplicationTableResize.java`. 

The rehashing mechanism together with `-XX:+StringDeduplicationRehashALot` were deleted in https://bugs.openjdk.org/browse/JDK-8254598, so this test is also JDK11-only.

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PR Comment: https://git.openjdk.org/jdk11u-dev/pull/1948#issuecomment-1594378899