How is sleep implemented at the OS level?

Question

I am just interested how sleep(time in ms) is implemented in a C library or basically at the OS level...

I am guessing...

1. May be the based

Answer 1

The answer to your question is completely operating-system and implementation-dependent.

A simple way to think about it: When you call sleep(), the OS calculates the wakeup time, then sticks your process on a priority queue somewhere. It then just doesn't schedule your process to get any execution time until enough real time has passed for it to get popped off the queue.