Re: RFR: JDK-8164913: JVMTI.agent_load dcmd should show useful error message

[serguei.spit...@oracle.com]

Hi Yasumasa,

We are expected to reduce the risk at the RDP1, not to extend.
So that I'd suggest to reduce you fix instead of extending.
Is it possible to achieve your JVMTI.agent_load dcmd goal without
additional changes in the JvmtiExport::load_agent_library and
the HotSpotVirtualMachine.java ?
Or at least, could we minimize the impact?

I do not like the update in the HotSpotVirtualMachine.java
as it does not look as necessary to fix the bug 8164913.

Thanks,
Serguei


On 9/7/16 20:47, Yasumasa Suenaga wrote:

Hi all,

This changes has been approved. But it was not passed JPRT.

It is caused by checking return value in HotSpotVirtualMachine#loadAgentLibrary().

I've fixed it and uploaded webrev. This changes has been passed JPRT. (Thanks David!)

Could you review again?

hotspot: http://cr.openjdk.java.net/~ysuenaga/JDK-8164913/webrev.02/hotspot/ jdk: http://cr.openjdk.java.net/~ysuenaga/JDK-8164913/webrev.02/jdk/

Thanks,

Yasumasa


On 2016/09/07 16:47, serguei.spit...@oracle.com wrote:

On 9/7/16 00:45, Dmitry Samersoff wrote:

Serguei,

I'm OK with the fix and OK to be listed as a reviewer.

Thanks, Dmitry!
Serguei

-Dmitry

On 2016-09-07 07:08, serguei.spit...@oracle.com wrote:

Hi Dmitry,

As a sponsor I'm going to push this fix if you are Ok with the fix.
Please, let me know if you still have any concerns.
Also, confirm if you are Ok to be in the list of reviewers.


On 9/5/16 06:46, Dmitry Samersoff wrote:

Yasumasa,

I'll look closely to the fix.

Please, notice:

1. We typically avoid printing attach error messages on
the target VM side.

Some message was already printed:

2410 // Agent_OnAttach executed so completion status is JNI_OK
2411 st->print_cr("%d", result);
2412 result = JNI_OK;

It is just a replacement. :)

2. We are in RDP1 for jdk9.

http://mail.openjdk.java.net/pipermail/jdk9-dev/2016-August/004777.html

I've set the priority to P3, so it can be pushed to the jdk9/hs.

Thanks,
Serguei

-Dmitry

On 2016-09-05 16:25, Yasumasa Suenaga wrote:

PING: Could you review and sponsor it?

http://cr.openjdk.java.net/~ysuenaga/JDK-8164913/webrev.01/

Thanks,

Yasumasa


On 2016/09/01 12:47, Yasumasa Suenaga wrote:

Hi all,

I think RDP1 has been started.
Cannot I fix this?

This problem is that jcmd shows incorrect status when JVMTI agent
cannot be attached.
I think this problem should be fixed in 9 GA.

The users who want.to <http://want.to> attach JVMTI agent want to know

whether it succeed.

Yasumasa


2016/08/29 15:42 "Yasumasa Suenaga" <yasue...@gmail.com
<mailto:yasue...@gmail.com>>:

This comment no longer matches the code and should be deleted:

2412 // Agent_OnAttach executed so completion status is

JNI_OK
         2413       st->print_cr("return code: %d", result);


     Thanks David!
     I removed it in new webrev.

http://cr.openjdk.java.net/~ysuenaga/JDK-8164913/webrev.01/
<http://cr.openjdk.java.net/~ysuenaga/JDK-8164913/webrev.01/>


     Yasumasa


     On 2016/08/29 12:59, David Holmes wrote:

         Hi Yasumasa,

         On 28/08/2016 10:47 PM, Yasumasa Suenaga wrote:

             Hi all,

             If we try to attach invalid JVMTI agent via
JVMTI.agent_load dcmd, we
             will get

"Command executed successfully". However, it implies error in

             JVMTIAgentLoadDCmd.

This message is from JCmd.java when jcmd does not receive

output from
             target VM.

So we should send error message from JVMTIAgentLoadDCmd.

             I uploaded a webrev for it. Could you review it?

http://cr.openjdk.java.net/~ysuenaga/JDK-8164913/webrev.00/
<http://cr.openjdk.java.net/~ysuenaga/JDK-8164913/webrev.00/>


         This seems reasonable.

         src/share/vm/prims/jvmtiExport.cpp

This comment no longer matches the code and should be deleted:

2412 // Agent_OnAttach executed so completion status is

JNI_OK
         2413       st->print_cr("return code: %d", result);

         Thanks,
         David

             I cannot access JPRT.
             So I need a sponsor.


             Thanks,

             Yasumasa