[11u] RFR: 8212160: JVMTI agent crashes with "assert(_value != 0LL) failed: resolving NULL _value"

[Reingruber, Richard]

Hi Götz,

I'm getting ready to review this.

If I'm not mistaken, your patch has 8173658 as prerequisite which is currently out for review. It took me a few keystrokes and mouse clicks to figure this out. I'd suggest informing about prerequisite patches in the RFR mail.

Cheers, Richard.

-----Original Message-----
From: jdk-updates-dev <jdk-updates-dev-retn at openjdk.java.net> On Behalf Of Lindenmaier, Goetz
Sent: Dienstag, 17. November 2020 15:03
To: jdk-updates-dev at openjdk.java.net
Subject: [CAUTION] RE: [11u] RFR: 8212160: JVMTI agent crashes with "assert(_value != 0LL) failed: resolving NULL _value"

Hi,

I have another update to this change. 
I had to resolve it again because of the Minimal VM fix 8235218 pushed 
after 8173361.
http://cr.openjdk.java.net/~goetz/wr20/8212160-jvmti_crash_resolving-jdk11/03/

Also, I reqested downport for Minimal VM fixes required after this change:
JDK-8236124 Minimal VM slowdebug build failed after JDK-8212160
JDK-8235456 Minimal VM is broken after JDK-8212160
These both are clean downports once this is pushed.

I would appreciate reviews ��

Best regards,
  Goetz.


Hi,

Please look at 
http://cr.openjdk.java.net/~goetz/wr20/8212160-jvmti_crash_resolving-jdk11/02/

I had lost the changes to the test file because of C/C++ mismatch.

Best regards,
  Goetz.


-----Original Message-----
From: Lindenmaier, Goetz 
Sent: Freitag, 6. November 2020 09:39
To: jdk-updates-dev at openjdk.java.net
Subject: [11u] RFR: 8212160: JVMTI agent crashes with "assert(_value != 0LL) failed: resolving NULL _value"

Hi

I am downporting this for parity with 11.0.10-oracle.

http://cr.openjdk.java.net/~goetz/wr20/8212160-jvmti_crash_resolving-jdk11/01/
I had to resolve and fis in quite some places:

src/hotspot/share/code/nmethod.cpp
Resolved. Few differences in code, e.g. MutexLocker --> MutexLockerEx.

Added 'this' to call of JvmtiDeferredEvent::compiled_method_unload_event()

src/hotspot/share/code/nmethod.hpp
Trivial, resolved.

src/hotspot/share/prims/jvmtiCodeBlobEvents.cpp
Resolved. Few differences in code, e.g. MutexLocker --> MutexLockerEx.

I removed NMethodIterator::only_alive_and_not_unloading and call next_alive instead.
The NMethodIterator differs in head a lot.

src/hotspot/share/prims/jvmtiExport.cpp
Resolved. Few differences in code, e.g. MutexLocker --> MutexLockerEx.

I added void JvmtiExport::post_compiled_method_load(JvmtiEnv* env, nmethod *nm)
from head which is called in 

src/hotspot/share/prims/jvmtiExport.hpp
Resolved. Deleted method has different arguments.

src/hotspot/share/prims/jvmtiImpl.hpp
Resolved.

src/hotspot/share/runtime/serviceThread.cpp
Context different.

Please review.
https://bugs.openjdk.java.net/browse/JDK-8212160
https://hg.openjdk.java.net/jdk/jdk/rev/366c0f357ee6

Best regards,
  Goetz