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
