/* Copyright (C) 1991, 1992, 1996, 1999 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 <time.h> #include <unistd.h> #include <sys/times.h> /* Return the time used by the program so far (user time + system time). */ clock_t clock (void) { struct tms buf; long clk_tck = CLK_TCK; /* We don't check for errors here. The only error the kernel returns is EFAULT if the value cannot be written to the struct we pass a pointer to. Otherwise the kernel returns an `unsigned long' value which is the number of jiffies since system start. But this number can be negative (when read as `long') when the system is up for some time. Ignoring errors should therefore have no negative impacts but solve the problem. */ times (&buf); 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); }