getruntime.c revision 77298 
1/* Return time used so far, in microseconds.
2   Copyright (C) 1994, 1999 Free Software Foundation, Inc.
3
4This file is part of the libiberty library.
5Libiberty is free software; you can redistribute it and/or
6modify it under the terms of the GNU Library General Public
7License as published by the Free Software Foundation; either
8version 2 of the License, or (at your option) any later version.
9
10Libiberty is distributed in the hope that it will be useful,
11but WITHOUT ANY WARRANTY; without even the implied warranty of
12MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13Library General Public License for more details.
14
15You should have received a copy of the GNU Library General Public
16License along with libiberty; see the file COPYING.LIB.  If
17not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
18Boston, MA 02111-1307, USA.  */
19
20#include "config.h"
21
22#include "ansidecl.h"
23#include "libiberty.h"
24
25/* There are several ways to get elapsed execution time; unfortunately no
26   single way is available for all host systems, nor are there reliable
27   ways to find out which way is correct for a given host. */
28
29#ifdef TIME_WITH_SYS_TIME
30# include <sys/time.h>
31# include <time.h>
32#else
33# if HAVE_SYS_TIME_H
34#  include <sys/time.h>
35# else
36#  ifdef HAVE_TIME_H
37#   include <time.h>
38#  endif
39# endif
40#endif
41
42#if defined (HAVE_GETRUSAGE) && defined (HAVE_SYS_RESOURCE_H)
43#include <sys/resource.h>
44#endif
45
46#ifdef HAVE_TIMES
47#ifdef HAVE_SYS_PARAM_H
48#include <sys/param.h>
49#endif
50#include <sys/times.h>
51#endif
52
53#ifdef HAVE_UNISTD_H
54#include <unistd.h>
55#endif
56
57/* This is a fallback; if wrong, it will likely make obviously wrong
58   results. */
59
60#ifndef CLOCKS_PER_SEC
61#define CLOCKS_PER_SEC 1
62#endif
63
64#ifdef _SC_CLK_TCK
65#define GNU_HZ  sysconf(_SC_CLK_TCK)
66#else
67#ifdef HZ
68#define GNU_HZ  HZ
69#else
70#ifdef CLOCKS_PER_SEC
71#define GNU_HZ  CLOCKS_PER_SEC
72#endif
73#endif
74#endif
75
76long
77get_run_time ()
78{
79#if defined (HAVE_GETRUSAGE) && defined (HAVE_SYS_RESOURCE_H)
80  struct rusage rusage;
81
82  getrusage (0, &rusage);
83  return (rusage.ru_utime.tv_sec * 1000000 + rusage.ru_utime.tv_usec
84	  + rusage.ru_stime.tv_sec * 1000000 + rusage.ru_stime.tv_usec);
85#else /* ! HAVE_GETRUSAGE */
86#ifdef HAVE_TIMES
87  struct tms tms;
88
89  times (&tms);
90  return (tms.tms_utime + tms.tms_stime) * (1000000 / GNU_HZ);
91#else /* ! HAVE_TIMES */
92  /* Fall back on clock and hope it's correctly implemented. */
93  const long clocks_per_sec = CLOCKS_PER_SEC;
94  if (clocks_per_sec <= 1000000)
95    return clock () * (1000000 / clocks_per_sec);
96  else
97    return clock () / clocks_per_sec;
98#endif  /* HAVE_TIMES */
99#endif  /* HAVE_GETRUSAGE */
100}
101