RFR: 8242425: JVMTI monitor operations should use Thread-Local Handshakes

[Yasumasa Suenaga]

Hi Serguei,

I use current_jt in this webrev. Could you review again?

   http://cr.openjdk.java.net/~ysuenaga/JDK-8242425/webrev.02/

I tested this change with vmTestbase/nsk/jvmti, they are fine on my Linux x64.


Thanks,

Yasumasa


On 2020/04/10 17:21, serguei.spitsyn at oracle.com wrote:
> Hi Yasumasa,
> 
> Thank you for the update.
> 
> Minor:
> http://cr.openjdk.java.net/~ysuenaga/JDK-8242425/webrev.01/src/hotspot/share/prims/jvmtiEnvBase.cpp.udiff.html
> 
> + err = get_locked_objects_in_frame(JavaThread::current(), java_thread, jvf, owned_monitors_list, depth-1); . . .
> 
> + JvmtiMonitorClosure jmc(java_thread, JavaThread::current(), owned_monitors_list, this);
> 
> You can use current_jt instead of JavaThread::current() above.
> 
> There is also some test coverage in the vmTestbase/nsk/jvmti/scenarios tests.
> This one as well:
> test/hotspot/jtreg/vmTestbase/nsk/jvmti/unit/functions/nosuspendMonitorInfo/JvmtiTest
> Probably it is easier to run all vmTestbase/nsk/jvmti tests.
> 
> Thanks,
> Serguei
> 
> 
> On 4/10/20 01:05, Yasumasa Suenaga wrote:
>> Hi Serguei,
>>
>> Thanks for your comment!
>> I uploaded new webrev:
>>
>> http://cr.openjdk.java.net/~ysuenaga/JDK-8242425/webrev.01/
>>
>> I ran following tests, and all of them were passed on my Linux x64.
>>
>>  - vmTestbase/nsk/jvmti/GetCurrentContendedMonitor
>>  - vmTestbase/nsk/jvmti/GetOwnedMonitorInfo
>>  - vmTestbase/nsk/jdi
>>  - vmTestbase/nsk/jdwp
>>  - serviceability/jvmti/GetOwnedMonitorInfo
>>  - serviceability/jvmti/GetOwnedMonitorStackDepthInfo
>>  - serviceability/jdwp
>>
>>
>> Thanks,
>>
>> Yasumasa
>>
>>
>> On 2020/04/10 14:50, serguei.spitsyn at oracle.com wrote:
>>> Hi Yasumasa,
>>>
>>> It looks pretty good in general.
>>> A couple of comments though.
>>>
>>> http://cr.openjdk.java.net/~ysuenaga/JDK-8242425/webrev.00/src/hotspot/share/prims/jvmtiEnvBase.cpp.frames.html
>>>
>>> 650 JvmtiEnvBase::get_current_contended_monitor(JavaThread *java_thread, jobject *monitor_ptr) {
>>> 651 assert(!Thread::current()->is_VM_thread() &&
>>> 652 (Thread::current() == java_thread ||
>>> 653 Thread::current() == java_thread->active_handshaker()),
>>> 654 "call by myself or at direct handshake");
>>>
>>>   ...
>>>
>>> 685 JvmtiEnvBase::get_owned_monitors(JavaThread* java_thread,
>>>   686 GrowableArray<jvmtiMonitorStackDepthInfo*> *owned_monitors_list) {
>>>   687   jvmtiError err = JVMTI_ERROR_NONE;
>>> 688 assert(!Thread::current()->is_VM_thread() &&
>>> 689 (Thread::current() == java_thread ||
>>> 690 Thread::current() == java_thread->active_handshaker()),
>>> 691 "call by myself or at direct handshake");
>>>
>>> I'd suggest to add this at the beginning:
>>>    JavaThread *current_jt = JavaThread::current();
>>>
>>>
>>> 676 JavaThread *current_jt = reinterpret_cast<JavaThread *>(JavaThread::current());
>>>
>>> There is not need in reinterpret_cast<JavaThread *>. Also, you can use the current_jt defined above.
>>>
>>> Also, please, removed these two definitions as they became unused with your fix:
>>>     src/hotspot/share/runtime/vmOperations.hpp: template(GGetCurrentContendedMonitoretOwnedMonitorInfo) \
>>>     src/hotspot/share/runtime/vmOperations.hpp: template()            \
>>>
>>> The impacted JVMTI monitor functions are used in the JDWP agent to support the JDI ThreadReference implementation.
>>> To be safe the JDI & JDWP tests have to be run as well. It is well covered by the tier-5.
>>>
>>> Thanks,
>>> Serguei
>>>
>>>
>>> On 4/9/20 21:46, Yasumasa Suenaga wrote:
>>>> Hi all,
>>>>
>>>> Please review this change:
>>>>
>>>>   JBS: https://bugs.openjdk.java.net/browse/JDK-8242425
>>>>   webrev: http://cr.openjdk.java.net/~ysuenaga/JDK-8242425/webrev.00/
>>>>
>>>> We've discussed to use Thread-Local Handshake in some JVMTI functions [1].
>>>> This change is for monitor functions. It affects GetOwnedMonitorInfo(), GetOwnedMonitorStackDepthInfo(), GetCurrentContendedMonitor().
>>>>
>>>> It passed tests on submit repo (mach5-one-ysuenaga-JDK-8242425-20200410-0228-10075639), and also I confirmed to pass following tests:
>>>>
>>>>  - serviceability/jvmti/GetOwnedMonitorInfo
>>>>  - serviceability/jvmti/GetOwnedMonitorStackDepthInfo
>>>>  - vmTestbase/nsk/jvmti/GetCurrentContendedMonitor
>>>>  - vmTestbase/nsk/jvmti/GetOwnedMonitorInfo
>>>>
>>>>
>>>> Thanks,
>>>>
>>>> Yasumasa
>>>>
>>>>
>>>> [1] https://mail.openjdk.java.net/pipermail/serviceability-dev/2020-March/030890.html
>>>
>