What core is a given thread running on?

Question

Is there a function or any other way to know, programatically, what core of what processor a given thread of my program (pid) is running on? Both OpenMP or Pthreads solutions would help me, if possible. Thanks.

Answer 1

I think on Linux one can try sched_getcpu().

Answer 2

This is going to be platform-specific, I would think. On Windows you can use NtGetCurrentProcessorNumber, but this is caveat-ed as possibly disappearing.

I expect this is hard to do, because there's nothing to stop the thread being moved to a new core at any time (in most apps, anyway). As soon as you get the result, it could be out of date.