RFR: 8194312: Support parallel and concurrent JNI global handle processing

[Kim Barrett]

> On Jan 8, 2018, at 7:20 PM, serguei.spitsyn at oracle.com wrote:
> 
> Hi Kim,
> 
> A couple of quick minor comments.

Thanks.

> http://cr.openjdk.java.net/~kbarrett/8194312/open.00/src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/utilities/PointerLocation.java.frames.html
>  241     } else if (isInStrongGlobalJNIHandles() ||
>  242                isInWeakGlobalJNIHandles()) {
> 
>  243       tty.print("In ");
> 
>  244       if (isInStrongGlobalJNIHandles()) {
> 
>  245         tty.print("strong global");
> 
>  246       } else if (isInWeakGlobalJNIHandles()) {
> 
>  247         tty.print("weak global");
>  248       }
> 
>  A suggestion to simplify it a little bit as follows:
>       } else if (isInStrongGlobalJNIHandles()) {
> 
>         tty.print("In strong global");
> 
>       } else if (isInWeakGlobalJNIHandles()) {
> 
>         tty.print("In weak global");
>       }

Good idea.  Will do.

> http://cr.openjdk.java.net/~kbarrett/8194312/open.00/src/hotspot/share/gc/shared/oopStorage.cpp.html
>   61 void OopStorage::BlockList::push_back(const Block& block) {
>   62   const Block* old = _tail;
>   63   if (old == NULL) {
>   64     assert(_tail == NULL, "invariant");
>   65     _head = _tail = █
>   66   } else {
>   67     _get_entry(*old)._next = █
>   68     _get_entry(block)._prev = old;
>   69     _tail = █
>   70   }
>   71 }
> 
>   It seems, the assert should check _head instead of _tail.

Oops!  Will do.