blob: 39d47c443f5abd17341dc4696d931e8315eab3f6 [file] [log] [blame]
/*
* Copyright (c) 2018 Friedt Professional Engineering Services, Inc
*
* SPDX-License-Identifier: Apache-2.0
*/
#include <stdint.h>
#include <zephyr/kernel.h>
#include <limits.h>
#include <errno.h>
/* required for struct timespec */
#include <zephyr/posix/time.h>
#include <zephyr/sys/util.h>
#include <zephyr/sys_clock.h>
/**
* @brief Suspend execution for nanosecond intervals.
*
* See IEEE 1003.1
*/
int nanosleep(const struct timespec *rqtp, struct timespec *rmtp)
{
uint64_t ns;
uint64_t us;
const bool update_rmtp = rmtp != NULL;
if (rqtp == NULL) {
errno = EFAULT;
return -1;
}
if (rqtp->tv_sec < 0 || rqtp->tv_nsec < 0
|| rqtp->tv_nsec >= NSEC_PER_SEC) {
errno = EINVAL;
return -1;
}
if (rqtp->tv_sec == 0 && rqtp->tv_nsec == 0) {
goto do_rmtp_update;
}
if (unlikely(rqtp->tv_sec >= ULLONG_MAX / NSEC_PER_SEC)) {
/* If a user passes this in, we could be here a while, but
* at least it's technically correct-ish
*/
ns = rqtp->tv_nsec + NSEC_PER_SEC
+ k_sleep(K_SECONDS(rqtp->tv_sec - 1)) * NSEC_PER_MSEC;
} else {
ns = rqtp->tv_sec * NSEC_PER_SEC + rqtp->tv_nsec;
}
/* TODO: improve upper bound when hr timers are available */
us = DIV_ROUND_UP(ns, NSEC_PER_USEC);
do {
us = k_usleep(us);
} while (us != 0);
do_rmtp_update:
if (update_rmtp) {
rmtp->tv_sec = 0;
rmtp->tv_nsec = 0;
}
return 0;
}