RFR: 8364343: Virtual Thread transition management needs to be independent of JVM TI [v4]

[Coleen Phillimore]

On Tue, 25 Nov 2025 19:50:06 GMT, Patricio Chilano Mateo <pchilanomate at openjdk.org> wrote:

>> src/hotspot/share/runtime/mountUnmountDisabler.cpp line 307:
>> 
>>> 305:   // Block while some mount/unmount transitions are in progress.
>>> 306:   // Debug version fails and prints diagnostic information.
>>> 307:   for (JavaThreadIteratorWithHandle jtiwh; JavaThread *jt = jtiwh.next(); ) {
>> 
>> This looks very odd, having an assignment in the loop condition check and no actual loop-update expression.
>
> Yes, from what I see this same construct is used in many places. Seems this is valid because a pointer used in a boolean context evaluates to false if nullptr and true if non-null. :)

This could be a simple cleanup of all these occurrences later.

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PR Review Comment: https://git.openjdk.org/jdk/pull/28361#discussion_r2561991623