62 lines
1.6 KiB
C
62 lines
1.6 KiB
C
/* Copyright (C) 1999, 2000 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Library General Public License as
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published by the Free Software Foundation; either version 2 of the
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License, or (at your option) any later version.
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The GNU C Library 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 GNU
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Library General Public License for more details.
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You should have received a copy of the GNU Library General Public
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License along with the GNU C Library; see the file COPYING.LIB. If not,
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write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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Boston, MA 02111-1307, USA. */
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#include <errno.h>
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#include <unistd.h>
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#include <sys/time.h>
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#ifndef EXTRA_CLOCK_CASES
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# define EXTRA_CLOCK_CASES
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#endif
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/* Get resolution of clock. */
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int
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clock_getres (clockid_t clock_id, struct timespec *res)
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{
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int retval = -1;
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switch (clock_id)
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{
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case CLOCK_REALTIME:
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{
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long int clk_tck = sysconf (_SC_CLK_TCK);
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if (__builtin_expect (clk_tck != -1, 1))
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{
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/* This implementation assumes that the realtime clock has a
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resolution higher than 1 second. This is the case for any
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reasonable implementation. */
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res->tv_sec = 0;
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res->tv_nsec = 1000000000 / clk_tck;
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retval = 0;
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}
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}
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break;
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EXTRA_CLOCK_CASES
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default:
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__set_errno (EINVAL);
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break;
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}
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return retval;
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}
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