| /* gethrxtime -- get high resolution real time |
| |
| Copyright (C) 2005-2007, 2009-2019 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 <https://www.gnu.org/licenses/>. */ |
| |
| /* Written by Paul Eggert. */ |
| |
| #include <config.h> |
| |
| #define GETHRXTIME_INLINE _GL_EXTERN_INLINE |
| #include "gethrxtime.h" |
| |
| #if ! (HAVE_ARITHMETIC_HRTIME_T && HAVE_DECL_GETHRTIME) |
| |
| #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 |
| } |
| |
| #endif |