incubator-nuttx/sched/clock/clock_getres.c

87 lines
3.0 KiB
C

/****************************************************************************
* sched/clock/clock_getres.c
*
* Copyright (C) 2007, 2009 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 <stdint.h>
#include <time.h>
#include <errno.h>
#include <debug.h>
#include "clock/clock.h"
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: clock_getres
*
* Description:
* Clock Functions based on POSIX APIs
*
****************************************************************************/
int clock_getres(clockid_t clock_id, struct timespec *res)
{
int ret = OK;
sinfo("clock_id=%d\n", clock_id);
/* Only CLOCK_REALTIME is supported */
if (clock_id != CLOCK_REALTIME)
{
serr("Returning ERROR\n");
set_errno(EINVAL);
ret = ERROR;
}
else
{
/* Form the timspec using clock resolution in nanoseconds */
res->tv_sec = 0;
res->tv_nsec = NSEC_PER_TICK;
sinfo("Returning res=(%d,%d)\n", (int)res->tv_sec, (int)res->tv_nsec);
}
return ret;
}