nuttx/libs/libc/unistd/lib_times.c
Xiang Xiao af1dceb3e3 libc: Implement times function
https://pubs.opengroup.org/onlinepubs/009604599/functions/times.html

Signed-off-by: Xiang Xiao <xiaoxiang@xiaomi.com>
Change-Id: If2cccfedd532a77f86035d16d36d94ae38d8f09c
2021-07-21 13:11:54 -03:00

62 lines
2.3 KiB
C

/****************************************************************************
* libs/libc/unistd/lib_times.c
*
* 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 <errno.h>
#include <string.h>
#include <sys/times.h>
#include <time.h>
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: times
*
* Description:
* The times() function shall fill the tms structure pointed to by buffer
* with time-accounting information.
*
* Returned Value:
* Upon successful completion, times() shall return the elapsed real time,
* in clock ticks, since an arbitrary point in the past (for example,
* system start-up time). This point does not change from one invocation
* of times() within the process to another. The return value may overflow
* the possible range of type clock_t. If times() fails, (clock_t)-1 shall
* be returned and errno set to indicate the error.
*
****************************************************************************/
clock_t times(FAR struct tms *buffer)
{
if (buffer == NULL)
{
set_errno(EINVAL);
return -1;
}
memset(buffer, 0, sizeof(*buffer));
return clock();
}