90 lines
4.0 KiB
C
90 lines
4.0 KiB
C
/****************************************************************************
|
|
* libs/libc/time/lib_nanosleep.c
|
|
*
|
|
* Licensed to the Apache Software Foundation (ASF) under one or more
|
|
* contributor license agreements. See the NOTICE file distributed with
|
|
* this work for additional information regarding copyright ownership. The
|
|
* ASF licenses this file to you under the Apache License, Version 2.0 (the
|
|
* "License"); you may not use this file except in compliance with the
|
|
* License. You may obtain a copy of the License at
|
|
*
|
|
* http://www.apache.org/licenses/LICENSE-2.0
|
|
*
|
|
* Unless required by applicable law or agreed to in writing, software
|
|
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
|
|
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
|
|
* License for the specific language governing permissions and limitations
|
|
* under the License.
|
|
*
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Included Files
|
|
****************************************************************************/
|
|
|
|
#include <nuttx/config.h>
|
|
|
|
#include <time.h>
|
|
|
|
/****************************************************************************
|
|
* 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);
|
|
}
|