incubator-nuttx/libc/time/lib_gettimeofday.c

99 lines
3.4 KiB
C

/****************************************************************************
* libc/time/lib_gettimeofday.c
*
* Copyright (C) 2009, 2015 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 <sys/time.h>
#include <errno.h>
#include <nuttx/clock.h>
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: gettimeofday
*
* Description:
* Get the current time
*
* Conforming to SVr4, 4.3BSD. POSIX.1-2001 describes gettimeofday().
* POSIX.1-2008 marks gettimeofday() as obsolete, recommending the use of
* clock_gettime(2) instead.
*
* NuttX implements gettimeofday() as a thin layer around clock_gettime();
*
* Input Parameters:
* tv - The location to return the current time
* tz - Ignored
*
* Returned value:
* Zero (OK) on success; -1 is returned on failure with the errno variable
* set appropriately.
*
****************************************************************************/
int gettimeofday(FAR struct timeval *tv, FAR struct timezone *tz)
{
struct timespec ts;
int ret;
#ifdef CONFIG_DEBUG
if (!tv)
{
set_errno(EINVAL);
return ERROR;
}
#endif
/* Let clock_gettime do most of the work */
ret = clock_gettime(CLOCK_REALTIME, &ts);
if (ret == OK)
{
/* Convert the struct timespec to a struct timeval */
tv->tv_sec = ts.tv_sec;
tv->tv_usec = ts.tv_nsec / NSEC_PER_USEC;
}
return ret;
}