NAME

nanosleep — high resolution sleep

LIBRARY

Standard C Library (libc, -lc)

SYNOPSIS

#include <time.h>

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

DESCRIPTION

The nanosleep() suspends execution of the calling process until either the number of seconds and nanoseconds specified by rqtp have elapsed or a signal is delivered to the calling process and its action is to invoke a signal catching function or to terminate the process. The suspension time may be longer than requested due to the scheduling of other activity by the system. The struct timespec is described in timespec(3).

RETURN VALUES

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

If the nanosleep() function 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).

ERRORS

If any of the following conditions occur, the nanosleep function shall return -1 and set errno to the corresponding value.

[EFAULT]

Either rqtp or rmtp points to memory that is not a valid part of the process address space.

[EINTR]

nanosleep was interrupted by the delivery of a signal.

[EINVAL]

rqtp specified a nanosecond value less than zero or greater than 1000 million.

[ENOSYS]

nanosleep is not supported by this implementation.

SEE ALSO

sleep(3), timespec(3)

STANDARDS

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