RFR(s): 8247248: JVM TI might create JNI locals in another thread when using handshakes.

[Daniel D. Daugherty]

On 6/10/20 9:57 AM, Robbin Ehn wrote:
> Hi David and Serguei, (Dan feel free to chime in)
>
>> Honestly I think I'd like to see things reverted to the use of 
>> calling_thread as done for the VMOperation previously. We know it is 
>> functionally correct and it should also have the same performance 
>> profile.
>
> Done:
> http://cr.openjdk.java.net/~rehn/8247248/v2/webrev/

src/hotspot/share/prims/jvmtiEnvBase.hpp
     No comments.

src/hotspot/share/prims/jvmtiEnvBase.cpp
     No comments.

src/hotspot/share/prims/jvmtiEnv.cpp
     L1248:   JavaThread* calling_thread  = JavaThread::current();
     L1296:   JavaThread* calling_thread  = JavaThread::current();
         nit - please delete extra space before '='.

Thumbs up. I like the switch back to use of calling_thread. Thanks!

Dan


>
> Passes: hotspot jdi/jvmti testing, running mach5.
>
> I'll push tomorrow morning if test is ok and you all are happy (+- 
> nits). (and no objection to break the 24h rule)
> I started this patch with reverting "8242425: JVMTI monitor operations 
> should use Thread-Local Handshakes".
> And work my way forward.
>
> Thanks, Robbin
>
>>
>> Thanks,
>> David
>>
>>> Thanks, Robbin
>>>
>>>>
>>>> Thanks,
>>>> David
>>>> -----
>>>>
>>>>> Issue:
>>>>> https://bugs.openjdk.java.net/browse/JDK-8247248
>>>>>
>>>>> Local testing of JDI/JVMTI and t1-5.
>>>>> (no real crash so there is nothing to reproduce)
>>>>>
>>>>> Thanks, Robbin