WaitForMultipleObjects is fascinating behind the scenes. A single thread can wait on up to 64 independent events, which is done by plumbing the KTHREAD data structure with literally 64 slots for dispatcher header stuff, plus all the supporting Ke/dispatcher logic in the kernel.

There’s never been a POSIX equivalent to this. It requires sophisticated kernel support and the exact same parity can’t be achieved in user space alone.

Yeah I was wondering if some native Linux apps might want to use it, since it is clearly useful and hard to emulate.

This comes up often, but what can it do that poll can't?