Re: RFR(MS): 8222072: JVMTI GenerateEvents() sends CompiledMethodLoad events to wrong jvmtiEnv

[serguei . spitsyn]

Hi Jc,

Thank you a lot for looking at this!
On 4/9/19 9:29 AM, Jean Christophe Beyler wrote:
Hi Serguei,

I saw a nit here:

http://cr.openjdk.java.net/~sspitsyn/webrevs/2019/8222072-jvmti-GenerateEvents.1/test/hotspot/jtreg/serviceability/jvmti/GenerateEvents/MyPackage/GenerateEventsTest.java.html 
<http://cr.openjdk.java.net/%7Esspitsyn/webrevs/2019/8222072-jvmti-GenerateEvents.1/test/hotspot/jtreg/serviceability/jvmti/GenerateEvents/MyPackage/GenerateEventsTest.java.html>

arei -> are

Nice catch, fixed.

- I'm not sure you needed two files for the agents, you could have 
re-used some of the code and just called twice GetEnv but that is a 
detail.

Right.
I initially wanted to use this way but then decided to use two real 
agent libraries.
Wanted to exercise this path.

- I thought JNIEnv was not supposed to be really kept because it 
should not be used by another thread, is there not a risk that you are 
doing that? It doesn't look like it but I've been surprised in the past

You are right.
Tried to fix it in new webrev version below.


- Isn't there a chance that your second agent gets a normal 
JVMTI_EVENT_COMPILED_METHOD_LOAD before the GenerateEvents call and 
increments its counter?
   - I guess we'd see if it becomes flaky at some point? :)
Yes, it is expected.
But they should be posted on threads other than Main thread.
The callback should ignore them.


The updated fix version is:
http://cr.openjdk.java.net/~sspitsyn/webrevs/2019/8222072-jvmti-GenerateEvents.2/


Thanks!
Serguei


Thanks!
Jc


On Mon, Apr 8, 2019 at 12:29 PM serguei.spit...@oracle.com 
<mailto:serguei.spit...@oracle.com> <serguei.spit...@oracle.com 
<mailto:serguei.spit...@oracle.com>> wrote:

    Please, review a fix for:
    https://bugs.openjdk.java.net/browse/JDK-8222072

    Webrev:
    
http://cr.openjdk.java.net/~sspitsyn/webrevs/2019/8222072-jvmti-GenerateEvents.1/
    
<http://cr.openjdk.java.net/%7Esspitsyn/webrevs/2019/8222072-jvmti-GenerateEvents.1/>


    Summary:
      The JVMTI GenerateEvents() must send CompiledMethodLoad events
    only to the agent which called it.
      However, it sends events to all agents (jvmti environements)
    which violates the JVMTI spec.
      The webrev above fixes this issue and adds new jtreg test:
        test/hotspot/jtreg/serviceability/jvmti/GenerateEvents


    Testing:
      Mach5 submission for:
       - JVMTI tests: open/test/hotspot/jtreg/vmTestbase/nsk/jvmti
    - new test: test/hotspot/jtreg/serviceability/jvmti/GenerateEvents

    Thanks,
    Serguei



--

Thanks,
Jc