incubator-nuttx/sched/timer/timer_getitimer.c

103 lines
3.3 KiB
C

/****************************************************************************
* sched/timer/timer_getitimer.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 <errno.h>
#include <time.h>
#include <sys/time.h>
#include "sched/sched.h"
#ifndef CONFIG_DISABLE_POSIX_TIMERS
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: getitimer
*
* Description:
* The getitimer() function will store the amount of time until the
* specified timer, which, expires and the reload value of the timer
* into the space pointed to by the value argument. The it_value member
* of this structure will contain the amount of time before the timer
* expires, or zero if the timer is disarmed. This value is returned as
* the interval until timer expiration. The it_interval member of value
* will contain the reload value last set by setitime().
*
* Input Parameters:
* which - The predefined timer id
* value - The current timer value
*
* Returned Value:
* If the getitimer() succeeds, a value of 0 (OK) will be returned.
* If an error occurs, the value -1 (ERROR) will be returned, and errno
* set to indicate the error.
*
* EINVAL - The which argument does not correspond to an predefined ID.
*
* Assumptions/Limitations:
* Due to the asynchronous operation of this function, the time reported
* by this function could be significantly more than that actual time
* remaining on the timer at any time.
*
****************************************************************************/
int getitimer(int which, FAR struct itimerval *value)
{
FAR struct tcb_s *rtcb = this_task();
struct itimerspec spec =
{
{0, 0},
{0, 0}
};
int ret = OK;
if (which != ITIMER_REAL || !value)
{
set_errno(EINVAL);
return ERROR;
}
if (rtcb->group->itimer)
{
ret = timer_gettime(rtcb->group->itimer, &spec);
}
if (ret == OK)
{
TIMESPEC_TO_TIMEVAL(&value->it_value, &spec.it_value);
TIMESPEC_TO_TIMEVAL(&value->it_interval, &spec.it_interval);
}
return ret;
}
#endif /* CONFIG_DISABLE_POSIX_TIMERS */