RFR(s): 8223313: Use handshakes for CountStackFrames.

[coleen.phillimore at oracle.com]

I just have a couple of questions.

http://cr.openjdk.java.net/~rehn/8223313/webrev/src/hotspot/share/prims/jvm.cpp.udiff.html

+ JavaThread* jt = (JavaThread*)thread;


Can this add an assert(thread->is_JavaThread(), "");  since there is no 
JavaThread::cast() function that verifies this?

+ int count() { return _count; }
+ int suspended() { return _suspended; }

Nit, these functions should be const.

Nice use of handshakes.

thanks,
Coleen

On 5/15/19 7:17 AM, Robbin Ehn wrote:
> Hi all please review.
>
> This change is part of parent issue:
> Utilize handshakes instead of is_thread_fully_suspended
> https://bugs.openjdk.java.net/browse/JDK-8223312
>
> Issue:
> https://bugs.openjdk.java.net/browse/JDK-8223313
> Change-set:
> http://cr.openjdk.java.net/~rehn/8223313/webrev/
>
> The only test using this seems to be CountStackFramesAtExit.java which 
> passes fine.
>
> Thanks, Robbin