Review Request JDK-8188052: JNI_FindClass needs to specify the class loading context used for library lifecycle hooks

[coleen.phillimore at oracle.com]

http://cr.openjdk.java.net/~mchung/jdk10/webrevs/8188052/webrev.00/src/hotspot/share/prims/jni.cpp.udiff.html

The type Klass has a class_loader() and protection_domain() accessors so 
it is unnecessary to cast to InstanceKlass.  We went through and removed 
many of these unnecessary InstanceKlass::casts.

407     if (loader.is_null() &&

I agree with David's comment that this line will always evaluate to true 
so should be cleaned up also.

413                              thread);
  414       if (HAS_PENDING_EXCEPTION) {
  415         Handle ex(thread, thread->pending_exception());
  416         CLEAR_PENDING_EXCEPTION;
  417         THROW_HANDLE_0(ex);
  418       }


This is strange too.  Why doesn't this just pass CHECK_NULL at line 413, 
which is the same thing as checking for and clearing and throwing the 
pending exception?

Thanks,
Coleen


On 10/4/17 2:12 PM, mandy chung wrote:
> This patch separates the JNI `FindClass` issue from the review thread 
> for JDK-8188052 [1] into a different issue.
>
> webrev: 
> http://cr.openjdk.java.net/~mchung/jdk10/webrevs/8188052/webrev.00/index.html
>
> This patch changes `FindClass` to specify the class loading context 
> used for the load and unload hook. `FindClass` when called from 
> JNI_OnUnload is changed to use the system class loader as the context. 
> This is an incompatible behavioral change and this bumps the version 
> so that a native library can determine the new behavior if desire.  
> This change proposes to defines JNI_VERSION_10 and I expect this name 
> will be revisited along with the version string for the proposed new 
> release cadence [2].
>
> CSR:  https://bugs.openjdk.java.net/browse/JDK-8188069
>
> Thanks David for the suggested spec wordings.
>
> thanks
> Mandy
> [1] 
> http://mail.openjdk.java.net/pipermail/core-libs-dev/2017-September/049292.html
> [2] 
> http://mail.openjdk.java.net/pipermail/discuss/2017-September/004281.html