RFR: 8364343: Virtual Thread transition management needs to be independent of JVM TI [v7]

[Coleen Phillimore]

On Wed, 26 Nov 2025 22:46:37 GMT, Patricio Chilano Mateo <pchilanomate at openjdk.org> wrote:

>> src/hotspot/share/prims/jvm.cpp line 3671:
>> 
>>> 3669: 
>>> 3670: JVM_ENTRY(void, JVM_VirtualThreadStartFinalTransition(JNIEnv* env, jobject vthread))
>>> 3671:   oop vt = JNIHandles::resolve_external_guard(vthread);
>> 
>> Why do the opto runtime versions set is_in_VTMTS_transition in both the java.lang.Thread and JavaThread and these don't?
>
> Because we set them in the intrinsic when trying to start the transition. Method `MountUnmountDisabler::start_transition` expects them to be false so we need to clear them in the opto versions.

Not sure what I was looking at when I made this comment.

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PR Review Comment: https://git.openjdk.org/jdk/pull/28361#discussion_r2578213839