756319739b
gnulib 9e117ae955a5c6a0406140e62b76c3ef50e3bc2b. * lib/gethrxtime.c, lib/gethrxtime.h, lib/gettime.c, lib/timespec.c, lib/timespec.h, lib/xtime.h, m4/clock_time.m4, m4/gethrxtime.m4, m4/gettime.m4, m4/timespec.m4: New files. * m4/gnulib-cache.m4, m4/gnulib-comp.m4, lib/Makefile.am: Adjust.
68 lines
1.8 KiB
C
68 lines
1.8 KiB
C
/* gethrxtime -- get high resolution real time
|
|
|
|
Copyright (C) 2005-2007, 2009-2012 Free Software Foundation, Inc.
|
|
|
|
This program is free software: you can redistribute it and/or modify
|
|
it under the terms of the GNU General Public License as published by
|
|
the Free Software Foundation; either version 3 of the License, or
|
|
(at your option) any later version.
|
|
|
|
This program is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
GNU General Public License for more details.
|
|
|
|
You should have received a copy of the GNU General Public License
|
|
along with this program. If not, see <http://www.gnu.org/licenses/>. */
|
|
|
|
/* Written by Paul Eggert. */
|
|
|
|
#include <config.h>
|
|
|
|
#include "gethrxtime.h"
|
|
|
|
#include <sys/time.h>
|
|
#include "timespec.h"
|
|
|
|
/* Get the current time, as a count of the number of nanoseconds since
|
|
an arbitrary epoch (e.g., the system boot time). Prefer a
|
|
high-resolution clock that is not subject to resetting or
|
|
drifting. */
|
|
|
|
xtime_t
|
|
gethrxtime (void)
|
|
{
|
|
#if HAVE_NANOUPTIME
|
|
{
|
|
struct timespec ts;
|
|
nanouptime (&ts);
|
|
return xtime_make (ts.tv_sec, ts.tv_nsec);
|
|
}
|
|
#else
|
|
|
|
# if defined CLOCK_MONOTONIC && HAVE_CLOCK_GETTIME
|
|
{
|
|
struct timespec ts;
|
|
if (clock_gettime (CLOCK_MONOTONIC, &ts) == 0)
|
|
return xtime_make (ts.tv_sec, ts.tv_nsec);
|
|
}
|
|
# endif
|
|
|
|
# if HAVE_MICROUPTIME
|
|
{
|
|
struct timeval tv;
|
|
microuptime (&tv);
|
|
return xtime_make (tv.tv_sec, 1000 * tv.tv_usec);
|
|
}
|
|
|
|
# else
|
|
/* No monotonically increasing clocks are available; fall back on a
|
|
clock that might jump backwards, since it's the best we can do. */
|
|
{
|
|
struct timespec ts;
|
|
gettime (&ts);
|
|
return xtime_make (ts.tv_sec, ts.tv_nsec);
|
|
}
|
|
# endif
|
|
#endif
|
|
}
|