RFR: 8364343: Virtual Thread transition management needs to be independent of JVM TI [v3]

[David Holmes]

On Tue, 25 Nov 2025 19:45:08 GMT, Patricio Chilano Mateo <pchilanomate at openjdk.org> wrote:

>> src/hotspot/share/classfile/javaClasses.cpp line 1764:
>> 
>>> 1762:   jint* addr = java_thread->field_addr<jint>(_VTMS_transition_disable_count_offset);
>>> 1763:   int val = AtomicAccess::load(addr);
>>> 1764:   AtomicAccess::store(addr, val - 1);
>> 
>> Suggestion:
>> 
>>   AtomicAccess::dec(addr);
>
> I’d prefer to leave it as a plain store to avoid the unnecessary extra fence.

But it isn't then an atomic update.

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PR Review Comment: https://git.openjdk.org/jdk/pull/28361#discussion_r2563699480