curl/lib/timeval.c

135 строки
3.8 KiB
C

/***************************************************************************
* _ _ ____ _
* Project ___| | | | _ \| |
* / __| | | | |_) | |
* | (__| |_| | _ <| |___
* \___|\___/|_| \_\_____|
*
* Copyright (C) 1998 - 2008, Daniel Stenberg, <daniel@haxx.se>, et al.
*
* This software is licensed as described in the file COPYING, which
* you should have received as part of this distribution. The terms
* are also available at http://curl.haxx.se/docs/copyright.html.
*
* You may opt to use, copy, modify, merge, publish, distribute and/or sell
* copies of the Software, and permit persons to whom the Software is
* furnished to do so, under the terms of the COPYING file.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
***************************************************************************/
#include "timeval.h"
#if defined(WIN32) && !defined(MSDOS)
struct timeval curlx_tvnow(void)
{
/*
** GetTickCount() is available on _all_ Windows versions from W95 up
** to nowadays. Returns milliseconds elapsed since last system boot,
** increases monotonically and wraps once 49.7 days have elapsed.
*/
struct timeval now;
DWORD milliseconds = GetTickCount();
now.tv_sec = milliseconds / 1000;
now.tv_usec = (milliseconds % 1000) * 1000;
return now;
}
#elif defined(HAVE_CLOCK_GETTIME_MONOTONIC)
struct timeval curlx_tvnow(void)
{
/*
** clock_gettime() is granted to be increased monotonically when the
** monotonic clock is queried. Time starting point is unspecified, it
** could be the system start-up time, the Epoch, or something else,
** in any case the time starting point does not change once that the
** system has started up.
*/
struct timeval now;
struct timespec tsnow;
if(0 == clock_gettime(CLOCK_MONOTONIC, &tsnow)) {
now.tv_sec = tsnow.tv_sec;
now.tv_usec = tsnow.tv_nsec / 1000;
}
/*
** Even when the configure process has truly detected monotonic clock
** availability, it might happen that it is not actually available at
** run-time. When this occurs simply fallback to other time source.
*/
#ifdef HAVE_GETTIMEOFDAY
else
(void)gettimeofday(&now, NULL);
#else
else {
now.tv_sec = (long)time(NULL);
now.tv_usec = 0;
}
#endif
return now;
}
#elif defined(HAVE_GETTIMEOFDAY)
struct timeval curlx_tvnow(void)
{
/*
** gettimeofday() is not granted to be increased monotonically, due to
** clock drifting and external source time synchronization it can jump
** forward or backward in time.
*/
struct timeval now;
(void)gettimeofday(&now, NULL);
return now;
}
#else
struct timeval curlx_tvnow(void)
{
/*
** time() returns the value of time in seconds since the Epoch.
*/
struct timeval now;
now.tv_sec = (long)time(NULL);
now.tv_usec = 0;
return now;
}
#endif
/*
* Make sure that the first argument is the more recent time, as otherwise
* we'll get a weird negative time-diff back...
*
* Returns: the time difference in number of milliseconds.
*/
long curlx_tvdiff(struct timeval newer, struct timeval older)
{
return (newer.tv_sec-older.tv_sec)*1000+
(newer.tv_usec-older.tv_usec)/1000;
}
/*
* Same as curlx_tvdiff but with full usec resolution.
*
* Returns: the time difference in seconds with subsecond resolution.
*/
double curlx_tvdiff_secs(struct timeval newer, struct timeval older)
{
if(newer.tv_sec != older.tv_sec)
return (double)(newer.tv_sec-older.tv_sec)+
(double)(newer.tv_usec-older.tv_usec)/1000000.0;
else
return (double)(newer.tv_usec-older.tv_usec)/1000000.0;
}
/* return the number of seconds in the given input timeval struct */
long Curl_tvlong(struct timeval t1)
{
return t1.tv_sec;
}