RFR: 8299240: rank of JvmtiVTMSTransition_lock can be safepoint

[Coleen Phillimore]

On Tue, 14 Feb 2023 05:37:51 GMT, Serguei Spitsyn <sspitsyn at openjdk.org> wrote:

> The rank of JvmtiVTMSTransition_lock is better to be safepoint instead of nosafepoint.
> The fix includes removal of the function `check_vthread_and_suspend_at_safepoint` which is not needed anymore.
> 
> Testing:
> mach5 jobs are in progress:
>  Kitchensink, tiers1-6 (all JVMTI, JDWP, JDI and JDB tests have to be included)

I had a couple of nits but otherwise this looks like a good change.

src/hotspot/share/prims/jvmtiEnv.cpp line 932:

> 930:   JavaThread* current = JavaThread::current();
> 931:   HandleMark hm(current);
> 932:   Handle self_tobj = Handle(current, nullptr);

This doesn't have to have the assignment, which the compiler will optimize away anyway.

Handle self_tobj;

does the same thing.

-------------

Marked as reviewed by coleenp (Reviewer).

PR: https://git.openjdk.org/jdk/pull/12550