NANOSLEEP(2) System Calls Manual NANOSLEEP(2)

nanosleepsuspend thread execution for an interval measured in nanoseconds

Standard C Library (libc, -lc)

#include <time.h>

nanosleep(const struct timespec *rqtp, struct timespec *rmtp);

The () function causes the calling thread to sleep for the amount of time specified in rqtp (the actual time slept may be longer, due to system latencies and possible limitations in the timer resolution of the hardware). An unmasked signal will cause nanosleep() to terminate the sleep early, regardless of the SA_RESTART value on the interrupting signal.

If nanosleep() returns because the requested time has elapsed, the value returned will be zero.

If nanosleep() returns due to the delivery of a signal, the value returned will be the -1, and the global variable errno will be set to indicate the interruption. If rmtp is non-NULL, the timespec structure it references is updated to contain the unslept amount (the request time minus the time actually slept).

The nanosleep() call fails if:

nanosleep() was interrupted by the delivery of a signal.
rqtp specified a nanosecond value less than zero or greater than or equal to 1000 million.

sigsuspend(2), sleep(3)

The nanosleep() function conforms to IEEE Std 1003.1b-1993 (“POSIX.1b”).

April 17, 1997 macOS 14.4