causes the calling thread to relinquish the CPU.
The thread is placed at the end of the run queue for its static
priority and another thread is scheduled to run.
For further details, see
on error, it returns an error number.
On Linux, this call always succeeds
(but portable and future-proof applications should nevertheless
handle a possible error return).
This call is nonstandard, but present on several other systems.
Use the standardized
On Linux, this function is implemented as a call to