libc/unistd/time.c

/*	$OpenBSD: time.c,v 1.5 2005/08/08 08:05:34 espie Exp $ */
/*
 * Copyright (c) 1983, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <time.h>

time_t
time(time_t *t)
{
	struct timeval tt;

	if (gettimeofday(&tt, (struct timezone *)0) < 0)
		return (-1);
	if (t)
		*t = (time_t)tt.tv_sec;
	return (tt.tv_sec);
}


clock_t
clock(void)
{
	struct timespec  tm;
	static int       clock_inited;
	static clock_t   clock_start;
	clock_t          now;

	clock_gettime( CLOCK_MONOTONIC, &tm);
	now = tm.tv_sec * CLOCKS_PER_SEC + (tm.tv_nsec * (CLOCKS_PER_SEC/1e9));

	if (!clock_inited) {
		clock_start  = now;
		clock_inited = 1;
	}
	return  now - clock_start;
}