RFR(S) 8206183: Possible construct EMPTY_STACK and allocation stack, etc. on first use

[Zhengyu Gu]

>>> Okay but this relies on C+11 thread-safe static initialization. 
>>> That's only available in VS2015 and above (which should be okay for 
>>> JDK 12+). What about other compilers? Does it have to be enabled via 
>>> any compilation flags?
>>
>> Thanks for pointing out.
>>
>> NMT is always initialized while JVM is still in single-thread mode, so 
>> I think it is safe even without language support, or I miss something 
>> here?
> 
> Okay - that sounds alright then.

Thanks, David.

-Zhengyu

> 
> Thanks,
> David
> 
>> -Zhengyu
>>
>>
>>>
>>> I'm currently running this through some additional internal build/tests.
>>>
>>> Thanks,
>>> David
>>> -----
>>>
>>>>
>>>> Bug: https://bugs.openjdk.java.net/browse/JDK-8206183
>>>> Webrev: http://cr.openjdk.java.net/~zgu/8206183/webrev.00/
>>>>
>>>> Test:
>>>>
>>>>    hotspot_nmt on Linux 64 (fastdebug and release)
>>>>    Submit-test.
>>>>
>>>>
>>>> Thanks,
>>>>
>>>> -Zhengyu