RFR: 8264711: More runtime TRAPS cleanups

[David Holmes]

On 6/04/2021 5:14 am, Patricio Chilano Mateo wrote:
> src/hotspot/share/prims/jni.cpp line 2738:
> 
>> 2736:
>> 2737:   Handle obj(THREAD, JNIHandles::resolve_non_null(jobj));
>> 2738:   ObjectSynchronizer::jni_exit(THREAD->as_Java_thread(), obj());
> 
> Here we would return JNI_ERR if we throw IMSE from jni_exit().

Strictly speaking we probably should return JNI_ERR in that case, but 
the spec (as usual) is non-specific about the relationship between error 
codes and throwing exceptions. I would not suggest making such a change 
now. Note that we would have to be careful to only return JNI_ERR in the 
single case of IMSE, and even then we would have to be certain that the 
IMSE came from the actual "exit" and not e.g.

err = MonitorEnter(obj);
...
throwIMSE()
...
err = MonitorExit(obj)

Cheers,
David

> src/hotspot/share/runtime/synchronizer.cpp line 609:
> 
>> 607:   // intentionally do not use CHECK on check_owner because we must exit the
>> 608:   // monitor even if an exception was already pending.
>> 609:   if (monitor->check_owner(current)) {
> 
> We can actually throw IMSE from check_owner() if this thread is not the real owner.
> 
> -------------
> 
> PR: https://git.openjdk.java.net/jdk/pull/3345
>