RFR: 8373839: Disable JVM TI suspension during JNI critical regions

[David Holmes]

On Thu, 18 Dec 2025 13:41:21 GMT, Fredrik Bredberg <fbredberg at openjdk.org> wrote:

>> To ensure JNI critical access to a raw array can't interfere with actions of the debugger, we disable JVM TI suspension whilst JNI critical access is active, as originally suggested by @fisk. We assume the debugger is being operated correctly (ie the thread using the raw array will be suspended), and that the critical section is short so as to not delay debugging too long. 
>> 
>> The mechanism for this already exists courtesy of the virtual thread support.
>> 
>> Testing:
>>  - tiers 1 - 6 sanity
>
> This is a nice fix, regardless of my opinion about pre/post-decrement. Thank you David.

Thanks for looking at this @fbredber

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PR Comment: https://git.openjdk.org/jdk/pull/28884#issuecomment-3672324023