RFR: 8329726: Use non-short forward jumps in lightweight locking [v3]

[Tobias Hartmann]

On Mon, 8 Apr 2024 08:19:32 GMT, Roman Kennke <rkennke at openjdk.org> wrote:

>> This turns a few short-jumps to long-jumps in x86 lightweight locking code paths. When running with -XX:+ShowMessageBoxOnError, MA::stop() generates more code and jccb is not sufficient to address this.
>> 
>> Two of the jccb are in ASSERT path anyway. However, another is also in a product path. We *could* generate jccb or jcc conditionally on ShowMessageBoxOnError, however, I don't think it is worth the trouble. WDYT?
>> 
>> Unfortunately, I could not make a simple test-case, because ShowMessageBoxOnError stops and waits on error, which would make jtreg time-out.
>> 
>> Testing:
>>  - [x] manual test with dacapo as provided in the bug report
>>  - [ ] tier1
>
> Roman Kennke has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Add test-case

Looks good but I think it's safer to use the default timeout because otherwise we risk a false-positive timeout on slow machines when running with additional flags like -XX:+DeoptimizeALot.

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PR Comment: https://git.openjdk.org/jdk/pull/18657#issuecomment-2042551146