getruntime.c revision 33965 
1/* Return time used so far, in microseconds.
2   Copyright (C) 1994 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 "ansidecl.h"
21#include "libiberty.h"
22
23/* There are several ways to get elapsed execution time; unfortunately no
24   single way is available for all host systems, nor are there reliable
25   ways to find out which way is correct for a given host. */
26
27#include <time.h>
28
29/* These should go away when libiberty uses autoconf. */
30
31#if defined(__sun__) && !defined(__svr4__)
32#define HAVE_GETRUSAGE
33#endif
34
35#ifdef HAVE_SYSCONF
36#define HAVE_TIMES
37#endif
38
39#ifdef HAVE_GETRUSAGE
40#include <sys/time.h>
41#include <sys/resource.h>
42#endif
43
44#ifdef HAVE_TIMES
45#ifndef NO_SYS_PARAM_H
46#include <sys/param.h>
47#endif
48#include <sys/times.h>
49#endif
50
51/* This is a fallback; if wrong, it will likely make obviously wrong
52   results. */
53
54#ifndef CLOCKS_PER_SEC
55#define CLOCKS_PER_SEC 1
56#endif
57
58long
59get_run_time ()
60{
61#ifdef HAVE_GETRUSAGE
62  struct rusage rusage;
63
64  getrusage (0, &rusage);
65  return (rusage.ru_utime.tv_sec * 1000000 + rusage.ru_utime.tv_usec
66	  + rusage.ru_stime.tv_sec * 1000000 + rusage.ru_stime.tv_usec);
67#else /* ! HAVE_GETRUSAGE */
68#ifdef HAVE_TIMES
69  struct tms tms;
70
71  times (&tms);
72  return (tms.tms_utime + tms.tms_stime) * (1000000 / HZ);
73#else /* ! HAVE_TIMES */
74  /* Fall back on clock and hope it's correctly implemented. */
75  const long clocks_per_sec = CLOCKS_PER_SEC;
76  if (clocks_per_sec <= 1000000)
77    return clock () * (1000000 / clocks_per_sec);
78  else
79    return clock () / clocks_per_sec;
80#endif  /* HAVE_TIMES */
81#endif  /* HAVE_GETRUSAGE */
82}
83