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

[serguei.spitsyn at oracle.com]

On 1/8/18 20:10, Kim Barrett wrote:
>> On Jan 8, 2018, at 10:57 PM, serguei.spitsyn at oracle.com wrote:
>> Also, this fragment looks strange:
>>
>> 354   if (block->is_empty()) {
>> 355     log_debug(oopstorage, blocks)("%s: block not empty " PTR_FORMAT, name(), p2i(block));
>> 356     --_empty_block_count;
>> 357   }
>>
>>
>> Should the message tell "block is empty" instead of "block not empty”?
> This is logging the transition from empty to non-empty.
>
> I could introduce a bool was_empty flag at line 354 to capture the is_empty state before the allocation,
> and then log the transition and update the counter after the allocation, if was_empty is true.  The current
> code order is just to remove the need for that extra boolean flag.

Got it, thanks!
Serguei