Question

I spent a good long while looking for info on the differences between time.h::sleep() and pthread.h::pthread_yield() but was unable to find any solid reference material and so I am posting this question.

What is the difference between time.h::sleep() and pthread.h::pthread_yield()?

Update:

The reason I ask is because I was using sleep() to sleep() each individual thread… and my application started having issues when there was 8 threads vs 4 threads. When I went online to see if sleep() only affects each thread, I couldn’t find any good reference stating whether Sleep() affects the entire process OR sleep() only affects the individual thread.

Answer 1

From pthread_yield:

The pthread_yield subroutine forces the calling thread to relinquish use of its processor, and to wait in the run queue before it is scheduled again. If the run queue is empty when the pthread_yield subroutine is called, the calling thread is immediately rescheduled.

From the sleep manpage:

sleep() makes the calling process sleep until seconds seconds have elapsed or a signal arrives which is not ignored.

If you don’t want to have a real time delay in your threads and just want to allow other threads to do their work, then pthread_yield is better suited than sleep.