1 /* gethrxtime -- get high resolution real time
3 Copyright (C) 2005-2007, 2009-2012 Free Software Foundation, Inc.
5 This program is free software: you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 3 of the License, or
8 (at your option) any later version.
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with this program. If not, see <http://www.gnu.org/licenses/>. */
18 /* Written by Paul Eggert. */
22 #include "gethrxtime.h"
27 /* Get the current time, as a count of the number of nanoseconds since
28 an arbitrary epoch (e.g., the system boot time). Prefer a
29 high-resolution clock that is not subject to resetting or
39 return xtime_make (ts.tv_sec, ts.tv_nsec);
43 # if defined CLOCK_MONOTONIC && HAVE_CLOCK_GETTIME
46 if (clock_gettime (CLOCK_MONOTONIC, &ts) == 0)
47 return xtime_make (ts.tv_sec, ts.tv_nsec);
55 return xtime_make (tv.tv_sec, 1000 * tv.tv_usec);
59 /* No monotonically increasing clocks are available; fall back on a
60 clock that might jump backwards, since it's the best we can do. */
64 return xtime_make (ts.tv_sec, ts.tv_nsec);