RFR: 8242428: JVMTI thread operations should use Thread-Local Handshake

[Yasumasa Suenaga]

Hi David, Serguei,

I updated webrev for 8242428. Could you review again?
This change migrate to use direct handshake for GetStackTrace() and GetThreadListStackTraces() (when thread_count == 1).

   http://cr.openjdk.java.net/~ysuenaga/JDK-8242428/webrev.01/

VM_GetThreadListStackTrace (for GetThreadListStackTraces) and VM_GetAllStackTraces (for GetAllStackTraces) have inherited VM_GetMultipleStackTraces VM operation which provides the feature to generate jvmtiStackInfo. I modified  VM_GetMultipleStackTraces to a normal C++ class to share with HandshakeClosure for GetThreadListStackTraces (GetSingleStackTraceClosure).

Also I added new testcases which test GetThreadListStackTraces() with thread_count == 1 and with all threads.

This change has been tested in serviceability/jvmti serviceability/jdwp vmTestbase/nsk/jvmti vmTestbase/nsk/jdi vmTestbase/nsk/jdwp.


Thanks,

Yasumasa


On 2020/06/24 15:50, Yasumasa Suenaga wrote:
> Hi all,
> 
> Please review this change:
> 
>    JBS: https://bugs.openjdk.java.net/browse/JDK-8242428
>    webrev: http://cr.openjdk.java.net/~ysuenaga/JDK-8242428/webrev.00/
> 
> This change replace following VM operations to direct handshake.
> 
>   - VM_GetFrameCount (GetFrameCount())
>   - VM_GetFrameLocation (GetFrameLocation())
>   - VM_GetThreadListStackTraces (GetThreadListStackTrace())
>   - VM_GetCurrentLocation
> 
> GetThreadListStackTrace() uses direct handshake if thread count == 1. In other case (thread count > 1), it would be performed as VM operation (VM_GetThreadListStackTraces).
> Caller of VM_GetCurrentLocation (JvmtiEnvThreadState::reset_current_location()) might be called at safepoint. So I added safepoint check in its caller.
> 
> This change has been tested in serviceability/jvmti serviceability/jdwp vmTestbase/nsk/jvmti vmTestbase/nsk/jdi vmTestbase/ns
> k/jdwp.
> 
> Also I tested it on submit repo, then it has execution error (mach5-one-ysuenaga-JDK-8242428-20200624-0054-12034717) due to dependency error. So I think it does not occur by this change.
> 
> 
> Thanks,
> 
> Yasumasa