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

[Stefan Karlsson]

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.

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
>