Hi,
JDK-8240918 has been pushed, so I made a patch for
GetCurrentContendedMonitor(). How about this?
http://cr.openjdk.java.net/~ysuenaga/jvmti-thread-local-handshake/2/
An observation, it seems to me that calling_thread is not used when this is not
a VMOperation.
calling_thread is used for creating JNI reference:
```
*monitor_ptr = jni_reference(calling_thread, hobj);
```
If it is ok, I will make patches for other JVMTI functions.
However the patch might be bigger, so I want to separate as below. What do you
think?
(I think we can file them as subtask under JDK-8201641)
* Monitor operation
- VM_GetOwnedMonitorInfo
- VM_GetCurrentContendedMonitor
* Frame operation
- VM_UpdateForPopTopFrame
- VM_SetFramePop
* Thread operation
- VM_GetFrameCount
- VM_GetFrameLocation
- VM_GetThreadListStackTraces
- VM_GetCurrentLocation
- VM_EnterInterpOnlyMode
Thanks,
Yasumasa
On 2020/04/01 21:29, Yasumasa Suenaga wrote:
Thanks David!
If JDK-8201641 is not assigned when JDK-8240918 is resolved, I will start to
work for JDK-8201641.
(It would be large patch...)
Cheers,
Yasumasa
On 2020/04/01 19:05, David Holmes wrote:
On 1/04/2020 11:02 am, Yasumasa Suenaga wrote:
Thanks Dan and Serguei!
I added a comment for this to JDK-8201641.
David, can you share Bug ID for thread-to-thread handshake?
I want to record it to JDK-8201641 as a blocker.
https://bugs.openjdk.java.net/browse/JDK-8240918
I heard the RFR could be as soon as tomorrow :)
Cheers,
David
Yasumasa
On 2020/04/01 1:59, serguei.spit...@oracle.com wrote:
Hi Yasumasa,
Yes, this works needs to be done.
I'll take look at you webrev.
Thanks,
Serguei
On 3/31/20 07:41, Daniel D. Daugherty wrote:
Add Robbin to this thread...
This reminded of the following RFE that Robbin filed:
JDK-8201641 JVMTI: GetThreadListStackTraces should use Thread-Local
Handshakes
https://bugs.openjdk.java.net/browse/JDK-8201641
We could update 8201641 to include everything that Yasumasa-san is requesting.
Would be a good place to track it...
Dan
On 3/31/20 7:40 AM, Yasumasa Suenaga wrote:
Hi David,
On 2020/03/31 19:16, David Holmes wrote:
Hi Yasumasa,
On 31/03/2020 8:06 pm, Yasumasa Suenaga wrote:
Hi all,
Many JVMTI functions uses VM Operation to get information. However some of them
need to stop only one thread - they don't need to stop all threads.
So I think we can use Thread Local Handshake as this webrev. It is example for
GetOneCurrentContendedMonitor().
True, but at the moment handshakes involve the VMThread. There is work being
done to support direct thread-to-thread handshakes and once that is done this
kind of conversion should be more easily done. It might be worth waiting for
that.
Thanks, I will be back to this topic when thread-to-thread handshake is done.
I wondered at first why VMThread involves handshake. Its improvement is welcome
for me ;)
Cheers,
Yasumasa
http://cr.openjdk.java.net/~ysuenaga/jvmti-thread-local-handshake/
An observation, it seems to me that calling_thread is not used when this is not
a VMOperation.
Cheers,
David
Also I think we can replace following VM Operations to Thread Local Handshake:
class VM_GetCurrentLocation
class VM_EnterInterpOnlyMode
class VM_UpdateForPopTopFrame
class VM_SetFramePop
class VM_GetOwnedMonitorInfo
class VM_GetCurrentContendedMonitor
class VM_GetFrameCount
class VM_GetFrameLocation
What do you think?
It it is acceptable, I will file it to JBS and send review request.
Thanks,
Yasumasa
