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81 lines
2.0 KiB
C
81 lines
2.0 KiB
C
/* gethrxtime -- get high resolution real time
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Copyright (C) 2005 Free Software Foundation, Inc.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2, or (at your option)
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any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software Foundation,
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Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
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/* Written by Paul Eggert. */
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#ifdef HAVE_CONFIG_H
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# include <config.h>
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#endif
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#include "gethrxtime.h"
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#include <sys/types.h>
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#if TIME_WITH_SYS_TIME
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# include <sys/time.h>
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# include <time.h>
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#else
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# if HAVE_SYS_TIME_H
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# include <sys/time.h>
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# else
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# include <time.h>
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# endif
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#endif
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/* Get the time of a high-resolution clock, preferably one that is not
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subject to resetting or drifting. */
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xtime_t
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gethrxtime (void)
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{
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#if HAVE_NANOUPTIME
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{
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struct timespec ts;
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nanouptime (&ts);
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return xtime_make (ts.tv_sec, ts.tv_nsec);
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}
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#else
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# if defined CLOCK_MONOTONIC && HAVE_CLOCK_GETTIME
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{
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struct timespec ts;
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if (clock_gettime (CLOCK_MONOTONIC, &ts) == 0)
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return xtime_make (ts.tv_sec, ts.tv_nsec);
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}
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# endif
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#if HAVE_MICROUPTIME
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{
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struct timeval tv;
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microuptime (&tv);
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return xtime_make (tv.tv_sec, 1000 * tv.tv_usec);
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}
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/* No monotonically increasing clocks are available; fall back on a
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clock that might jump backwards, since it's the best we can do. */
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# elif HAVE_GETTIMEOFDAY && XTIME_PRECISION != 1
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{
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struct timeval tv;
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gettimeofday (&tv, NULL);
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return xtime_make (tv.tv_sec, 1000 * tv.tv_usec);
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}
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# else
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return xtime_make (time (NULL), 0);
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# endif
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#endif
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}
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