[lworld] RFR: 8368274: [lworld] Unsafe.compareAndExchangeFlatValue() wrongly assumes padding bytes are the same for identical value objects [v3]

[Chen Liang]

On Mon, 19 Jan 2026 17:57:26 GMT, Chen Liang <liach at openjdk.org> wrote:

>> Use the raw value get as witness, because the flat value get may ignore garbage value and cause infinite loop as a result. Waiting for a test case.
>
> Chen Liang 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 eight additional commits since the last revision:
> 
>  - Merge branch 'lworld' of https://github.com/openjdk/valhalla into fix/unsafe-flat-cas
>  - Remove test as permitted
>  - Fixes, VHTMHAV now passes
>  - Merge branch 'lworld' of https://github.com/openjdk/valhalla into fix/unsafe-flat-cas
>  - A test
>  - Merge branch 'lworld' of https://github.com/openjdk/valhalla into fix/unsafe-flat-cas
>  - Merge branch 'lworld' of https://github.com/openjdk/valhalla into fix/unsafe-flat-cas
>  - Attempt to fix garbage cas

Ran the VarHandleTestMethodHandleAccessValue test again with no failure.

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PR Comment: https://git.openjdk.org/valhalla/pull/1734#issuecomment-3769783637