RFR: 8232649: ZGC: Add callbacks to ZMemoryManager

[erik.osterlund at oracle.com]

Hi Stefan,

Looks good.

Thanks,
/Erik

On 10/21/19 4:06 PM, Stefan Karlsson wrote:
> Hi all,
>
> Please review this patch to add callbacks to ZMemoryManager.
>
> https://cr.openjdk.java.net/~stefank/8232649/webrev.01/
> https://bugs.openjdk.java.net/browse/JDK-8232649
>
> This allows users of ZMemoryManager to get callbacks when memory 
> regions are inserted, removed, split, and coalesced. This is needed to 
> support Windows' stricter requirements for placeholder reserved memory.
>
> Thanks,
> StefanK