incubator-nuttx/sched/signal/sig_nanosleep.c

214 lines
8.8 KiB
C

/****************************************************************************
* sched/signal/sig_nanosleep.c
*
* SPDX-License-Identifier: Apache-2.0
*
* 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>
#include <signal.h>
#include <assert.h>
#include <errno.h>
#include <nuttx/clock.h>
#include <nuttx/irq.h>
#include <nuttx/signal.h>
#include <nuttx/cancelpt.h>
#include "clock/clock.h"
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: nxsig_nanosleep
*
* Description:
* The nxsig_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 nxsig_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 nxsig_nanosleep() function returns because the requested time
* has elapsed, its return value is zero.
*
* If the nxsig_nanosleep() function returns because it has been
* interrupted by a signal, the function returns a negated errno value
* 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 nxsig_nanosleep() fails, it returns a negated errno indicating the
* cause of the failure. The nxsig_nanosleep() function will fail if:
*
* EINTR - The nxsig_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 nxsig_nanosleep() function is not supported by this
* implementation.
*
****************************************************************************/
int nxsig_nanosleep(FAR const struct timespec *rqtp,
FAR struct timespec *rmtp)
{
int ret;
ret = nxsig_clockwait(CLOCK_REALTIME, 0, rqtp, rmtp);
return ret == -EAGAIN ? 0 : ret;
}
/****************************************************************************
* Name: clock_nanosleep
*
* Description:
* If the flag TIMER_ABSTIME is not set in the flags argument, the
* clock_nanosleep() function will cause 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 the process
* is terminated. The clock used to measure the time will be the clock
* specified by clock_id.
*
* If the flag TIMER_ABSTIME is set in the flags argument, the
* clock_nanosleep() function will cause the current thread to be
* suspended from execution until either the time value of the clock
* specified by clock_id reaches the absolute time specified by the rqtp
* argument, or a signal is delivered to the calling thread and its action
* is to invoke a signal-catching function, or the process is terminated.
* If, at the time of the call, the time value specified by rqtp is less
* than or equal to the time value of the specified clock, then
* clock_nanosleep() will return immediately and the calling process will
* not be suspended.
*
* The suspension time caused by this function 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 for the relative clock_nanosleep() function (that is,
* with the TIMER_ABSTIME flag not set) will not be less than the time
* interval specified by rqtp, as measured by the corresponding clock. The
* suspension for the absolute clock_nanosleep() function (that is, with
* the TIMER_ABSTIME flag set) will be in effect at least until the value
* of the corresponding clock reaches the absolute time specified by rqtp,
* except for the case of being interrupted by a signal.
*
* The use of the clock_nanosleep() function will have no effect on the
* action or blockage of any signal.
*
* The clock_nanosleep() function will fail if the clock_id argument refers
* to the CPU-time clock of the calling thread. It is unspecified whether
* clock_id values of other CPU-time clocks are allowed.
*
* Input Parameters:
* clockid - The clock to use to interpret the absolute time
* flags - Open flags. TIMER_ABSTIME is the only supported flag.
* 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 clock_nanosleep() function returns because the requested time has
* elapsed, its return value is zero.
*
* If the clock_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 clock_nanosleep() fails, it returns a value of errno. The
* clock_nanosleep() function will fail if:
*
* EINTR - The clock_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. Or the clockid that
* does not specify a known clock.
* ENOSYS - The clock_nanosleep() function is not supported by this
* implementation.
*
****************************************************************************/
int clock_nanosleep(clockid_t clockid, int flags,
FAR const struct timespec *rqtp,
FAR struct timespec *rmtp)
{
int ret;
/* clock_nanosleep() is a cancellation point */
enter_cancellation_point();
if (clockid < CLOCK_REALTIME || clockid > CLOCK_BOOTTIME)
{
leave_cancellation_point();
return EINVAL;
}
/* Just a wrapper around nxsig_clockwait() */
ret = nxsig_clockwait(clockid, flags, rqtp, rmtp);
/* Check if nxsig_clockwait() succeeded */
if (ret == -EAGAIN)
{
ret = OK;
}
else if (ret < 0)
{
/* If not return the errno */
ret = -ret;
}
leave_cancellation_point();
return ret;
}