Hi Amir,
As a work around, could you try to enable the
can_generate_breakpoint_events capability?
This capability should disable the fast get/putfiled bytecodes generation.
Adding this line to the MyAgent.cpp should do it:
capa.can_generate_breakpoint_events = 1;
Thanks,
Serguei
On 12/20/17 05:40, Amir Rapson wrote:
Hi,
If you could please remove my phone number from the comments of the bug.
Thanks,
Amir
-----Original Message-----
From: Amir Rapson [mailto:a...@vfunction.com]
Sent: Tuesday, December 12, 2017 3:24 PM
To: 'daniel.daughe...@oracle.com' <daniel.daughe...@oracle.com>; 'Vladimir
Ivanov' <vladimir.x.iva...@oracle.com>;
'serviceability-dev@openjdk.java.net' <serviceability-dev@openjdk.java.net>
Cc: 'coleen.phillim...@oracle.com' <coleen.phillim...@oracle.com>
Subject: RE: JVMTI not receiving field access events with fast_getfield
Thank you Dan. Much appreciated.
Again, let me know if I can assist with anything.
Best,
Amir
-----Original Message-----
From: Daniel D. Daugherty [mailto:daniel.daughe...@oracle.com]
Sent: Tuesday, December 12, 2017 3:13 PM
To: Amir Rapson <a...@vfunction.com>; Vladimir Ivanov
<vladimir.x.iva...@oracle.com>; serviceability-dev@openjdk.java.net
Cc: coleen.phillim...@oracle.com
Subject: Re: JVMTI not receiving field access events with fast_getfield
Amir,
Your https://bugs.openjdk.java.net/browse/JI-9051849 bug has been moved to
https://bugs.openjdk.java.net/browse/JDK-8193369.
Someone on the Serviceability team should pick up this thread from here, but
we're right at the end game for JDK10 so it might take some time...
Dan
On 12/12/17 8:03 AM, Amir Rapson wrote:
Hi,
I know the code has some relevant code, but it doesn't seem to work.
You will see some differences: the CALL_VM to the post function has
only 2 arguments and not 3, I'm not sure it matters.
The platform is x86_64, Java version is 1.8.0-152. I can try other
versions if you wish.
Please find the attached MyAgent.cpp MyAgent.h and
com_vfunction_Main.h to compile the agent.
Please also find the attached com.vfunction.zip that holds the simple
java util to reproduce the problem.
You'll see the problem on ArrayList.add(item) where you'll get events
only on codes #16 and #22 and not on #2 and #11 (see attached
bytecode.txt of said function).
Please let me know once you managed to reproduce it. I can also send
you a patch file to disable the fast_getfield (and fast putfield) to
show that the problem disappears.
I'm currently looking at the actual assembly of the add function, both
with the modified hotspot and without and will try to assist will
offering a fix for this issue.
One last thing. I saw a very old issue (resolved by Daniel Daugherty)
stating that fast_getfield was not completely addressed with the
resolution on this issue. The bug ID is
https://bugs.openjdk.java.net/browse/JDK-4300409
I'll be happy to assist further.
Best regards,
Amir
-----Original Message-----
From: Vladimir Ivanov [mailto:vladimir.x.iva...@oracle.com]
Sent: Tuesday, December 12, 2017 2:46 PM
To: Amir Rapson <a...@vfunction.com>
Cc: coleen.phillim...@oracle.com; daniel.daughe...@oracle.com
Subject: Re: JVMTI not receiving field access events with
fast_getfield
Thanks for the report, Amir!
Unfortunately, I can't access the bug you filed.
Can you, please, share the test case and instructions how to reproduce
the problem?
Also, what Java version & platform do you observe the bug on?
I briefly looked into template interpreter code on x86 and it does
have relevant code to post JVMTI events in fast accessors.
Best regards,
Vladimir Ivanov
On 12/12/17 11:12 AM, Amir Rapson wrote:
Hi Daniel, Coleen and Vladimir,
I tracked your email addresses from some mailing lists and hopefully
one of you is a relevant person for my problem.
I also filed a bug request (ID 9051849) but since I don’t have an
option to add information I decided to email you.
The problem I’m seeing is that JMTI does not receive field access
events (and probably field modification events) when /fast_getfield/
is used instead of /get_field/.
I verified this by disabling all the
/patch_bytecode(Bytecodes::_fast_?getfield, bc, rbx)/ in
/TemplateTable::getfield_or_static()/ and made sure that JVMTI
receives all the correct events.
I have the agent code and a short java program that can reproduce the
problem and would be happy to assist in fixing and or debugging this
issue.
I would appreciate any feedback.
Best regards,
Amir
Amir Rapson | Founder & VP Eng @ *vFunction* | 7 HaPelech St.
Tel-Aviv | +972-522650968
