freebsd man page for sched_yield

SCHED_YIELD(2)						      BSD System Calls Manual						    SCHED_YIELD(2)

NAME
     sched_yield -- yield processor

LIBRARY
     Standard C Library (libc, -lc)

SYNOPSIS
     #include <sched.h>

     int
     sched_yield(void);

DESCRIPTION
     The sched_yield() system call forces the running process to relinquish the processor until it again becomes the head of its process list.	It
     takes no arguments.

RETURN VALUES
     The sched_yield() function returns the value 0 if successful; otherwise the value -1 is returned and the global variable errno is set to
     indicate the error.

ERRORS
     On failure errno will be set to the corresponding value:

     [ENOSYS]		The system is not configured to support this functionality.

STANDARDS
     The sched_yield() system call conforms to IEEE Std 1003.1b-1993 (``POSIX.1'').

BSD
								  March 12, 1998							       BSD