px4-firmware/nuttx/sched/timer_gettime.c

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/********************************************************************************
* timer_gettime.c
*
* Copyright (C) 2007 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* 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 <nuttx/config.h>
#include <time.h>
#include <errno.h>
#include "clock_internal.h"
#include "timer_internal.h"
#ifndef CONFIG_DISABLE_POSIX_TIMERS
/********************************************************************************
* Definitions
********************************************************************************/
/********************************************************************************
* Private Data
********************************************************************************/
/********************************************************************************
* Public Data
********************************************************************************/
/********************************************************************************
* Private Functions
********************************************************************************/
/********************************************************************************
* 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().
*
* Parameters:
* timerid - The pre-thread timer, previously created by the call to
* timer_create(), whose remaining time count will be returned..
*
* Return 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 = (FAR struct posix_timer_s *)timerid;
int 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 */
(void)clock_ticks2time(ticks, &value->it_value);
(void)clock_ticks2time(timer->pt_last, &value->it_interval);
return OK;
}
#endif /* CONFIG_DISABLE_POSIX_TIMERS */