/**************************************************************************** * libs/libc/time/nanosleep.c * * Copyright (C) 2017 Gregory Nutt. All rights reserved. * Author: Gregory Nutt * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in * the documentation and/or other materials provided with the * distribution. * 3. Neither the name NuttX nor the names of its contributors may be * used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. * ****************************************************************************/ /**************************************************************************** * Included Files ****************************************************************************/ #include #include /**************************************************************************** * Public Functions ****************************************************************************/ /**************************************************************************** * Name: nanosleep * * Description: * The nanosleep() function causes the current thread to be suspended from * execution until either the time interval specified by the rqtp argument * has elapsed or a signal is delivered to the calling thread and its * action is to invoke a signal-catching function or to terminate the * process. The suspension time may be longer than requested because the * argument value is rounded up to an integer multiple of the sleep * resolution or because of the scheduling of other activity by the * system. But, except for the case of being interrupted by a signal, the * suspension time will not be less than the time specified by rqtp, as * measured by the system clock, CLOCK_REALTIME. * * The use of the nanosleep() function has no effect on the action or * blockage of any signal. * * Input Parameters: * rqtp - The amount of time to be suspended from execution. * rmtp - If the rmtp argument is non-NULL, the timespec structure * referenced by it is updated to contain the amount of time * remaining in the interval (the requested time minus the time * actually slept) * * Returned Value: * If the nanosleep() function returns because the requested time has * elapsed, its return value is zero. * * If the nanosleep() function returns because it has been interrupted by * a signal, the function returns a value of -1 and sets errno to indicate * the interruption. If the rmtp argument is non-NULL, the timespec * structure referenced by it is updated to contain the amount of time * remaining in the interval (the requested time minus the time actually * slept). If the rmtp argument is NULL, the remaining time is not * returned. * * If nanosleep() fails, it returns a value of -1 and sets errno to * indicate the error. The nanosleep() function will fail if: * * EINTR - The nanosleep() function was interrupted by a signal. * EINVAL - The rqtp argument specified a nanosecond value less than * zero or greater than or equal to 1000 million. * ENOSYS - The nanosleep() function is not supported by this * implementation. * ****************************************************************************/ int nanosleep(FAR const struct timespec *rqtp, FAR struct timespec *rmtp) { /* Calling clock_nanosleep() with the value TIMER_ABSTIME not set in the * flags argument and with a clock_id of CLOCK_REALTIME is equivalent t * calling nanosleep() with the same rqtp and rmtp arguments. */ return clock_nanosleep(CLOCK_REALTIME, 0, rqtp, rmtp); }