Question

I am following the examples given here. While I am able to successfully create threads, these threads have default affinity to all the processes.

How do I set affinity? Can someone please provide an example on how can I use SetThreadAffinityMask with the examples given on above link?

Answer 1

Ok, I’m going to assume you want affinity. The second parameter of SetThreadAffinityMask is a bit mask representing on which processors the thread is allowed to run. The bits are set to 1 on the corresponding processors. For example:

// binary 01, so it allows this thread to run on CPU 0
SetThreadAffinityMask(hThread, 0x01); 
// binary 10, so it allows this thread to run on CPU 1
SetThreadAffinityMask(hThread, 0x02); 
// binary 11, so it allows this thread to run on CPU 0 or CPU 1
SetThreadAffinityMask(hThread, 0x03);