glibc/sysdeps/unix/sysv/linux/clock.c

40 lines
1.4 KiB
C

/* Copyright (C) 1991, 1992, 1996 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.
The GNU C Library 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
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If not,
write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
#include <sys/times.h>
#include <time.h>
#include <unistd.h>
/* Return the time used by the program so far (user time + system time). */
clock_t
clock (void)
{
struct tms buf;
long clk_tck = __sysconf (_SC_CLK_TCK);
if (__times (&buf) < 0)
return (clock_t) -1;
return
(clk_tck <= CLOCKS_PER_SEC)
? ((unsigned long) buf.tms_utime + buf.tms_stime) * (CLOCKS_PER_SEC
/ clk_tck)
: ((unsigned long) buf.tms_utime + buf.tms_stime) / (clk_tck
/ CLOCKS_PER_SEC);
}