Cygwin: Implement sched_[gs]etaffinity() commit breaks RTEMS port

[Mark Geisert]

Corinna Vinschen wrote:
> On Jun 28 10:06, Yaakov Selkowitz wrote:
>> On Fri, 2019-06-28 at 03:17 -0700, Mark Geisert wrote:
>>> We can call it a day, with review and release of the current patch state.
>>> If you think it's worthwhile to implement CPU_SET on Cygwin now, rather
>>> than later, I can look into it but it's not strictly necessary at this
>>> time.
>>
>> We shouldn't be do things half-way.  taskset may not require it, but
>> any use of CPU sets could very well expect this to be present:
>>
>> http://man7.org/linux/man-pages/man3/CPU_SET.3.html
> 
> Agreed.  We shouldn't release 3.1 without it.

Fair enough on the requirement.  Just FYI I'll be AFK for two weeks beginning 
July 4, so will try to get this done before I leave.  No big worry there.

Please forgive my ignorance of licensing details...  Are we allowed to copy GNU 
library source into Cygwin?  Or is re-implementation from documentation the way 
to go?  In either case, must the glibc file organization be followed or is 
platform-specific rejiggering acceptable?

I'd like to just add the CPU_SET macros to Cygwin's new sys/cpuset.h and any 
needed support code to our sched.cc but am willing to hear other options.
Thanks,

..mark