incubator-nuttx/sched/timer/timer_gettime.c

96 lines
3.5 KiB
C

/****************************************************************************
* sched/timer/timer_gettime.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 <errno.h>
#include "clock/clock.h"
#include "timer/timer.h"
#ifndef CONFIG_DISABLE_POSIX_TIMERS
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: timer_gettime
*
* Description:
* The timer_gettime() function will store the amount of time until the
* specified timer, timerid, 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, even if the timer was armed with
* absolute time. The it_interval member of value will contain the reload
* value last set by timer_settime().
*
* Input Parameters:
* timerid - The pre-thread timer, previously created by the call to
* timer_create(), whose remaining time count will be returned..
*
* Returned Value:
* If the timer_gettime() 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 timerid argument does not correspond to an ID returned by
* timer_create() but not yet deleted by timer_delete().
*
* 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 timer_gettime(timer_t timerid, FAR struct itimerspec *value)
{
FAR struct posix_timer_s *timer = timer_gethandle(timerid);
sclock_t ticks;
if (!timer || !value)
{
set_errno(EINVAL);
return ERROR;
}
/* Get the number of ticks before the underlying watchdog expires */
ticks = wd_gettime(&timer->pt_wdog);
/* Convert that to a struct timespec and return it */
clock_ticks2time(&value->it_value, ticks);
clock_ticks2time(&value->it_interval, timer->pt_delay);
return OK;
}
#endif /* CONFIG_DISABLE_POSIX_TIMERS */