RFR: 8232651: Add implementation of os::processor_id() for Windows

[David Holmes]

Hi Stefan,

This fix looks good.

One comment below ...

On 22/10/2019 6:24 am, Stefan Karlsson wrote:
> Hi Thomas,
> 
> On 2019-10-21 16:34, Thomas Stüfe wrote:
>> Hi Stefan,
>>
>> looks good to me.
> 
> Thanks.
> 
>>
>> Note that according to the documentation we should have to include 
>> processthreadsapi.h. I wonder why this works without it.
> 
> Good catch. My guess is that it gets included by one of the other 
> included header files. I'll add processthreadsapi.h and make sure that 
> it compiles as expected.

It isn't needed as you just include Windows.h to get it:

"Header 	processthreadsapi.h (include Windows Vista, Windows 7, Windows 
Server 2008 Windows Server 2008 R2, Windows.h)"

Thanks,
David

> Thanks for reviewing,
> StefanK
> 
>>
>> Cheers, Thomas
>>
>>
>> On Mon, Oct 21, 2019 at 4:23 PM Stefan Karlsson 
>> <stefan.karlsson at oracle.com <mailto:stefan.karlsson at oracle.com>> wrote:
>>
>>     Hi all,
>>
>>     Please review this patch to add an implementation of
>>     os::processor_id()
>>     for Windows.
>>
>>     https://cr.openjdk.java.net/~stefank/8232651/webrev.01/
>>     https://bugs.openjdk.java.net/browse/JDK-8232651
>>
>>     We need an implementation of this function on Windows, to be able
>>     to run
>>     ZGC there.
>>
>>     Note that GetCurrentProcessorNumber only "returns the processor
>>     number
>>     within the processor group to which the logical processor is
>>     assigned".
>>     AFAICT, there's no support for multi-groups in HotSpot, and therefore
>>     this seems like an adequate function to use.
>>
>>     See this page for more information about processor groups:
>>     
>> https://docs.microsoft.com/en-us/windows/win32/procthread/processor-groups 
>>
>>
>>     Thanks,
>>     StefanK
>>
>