1 /* Return time used so far, in microseconds.
2    Copyright (C) 1994, 1999, 2002 Free Software Foundation, Inc.
3 
4 This file is part of the libiberty library.
5 Libiberty is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Library General Public
7 License as published by the Free Software Foundation; either
8 version 2 of the License, or (at your option) any later version.
9 
10 Libiberty is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13 Library General Public License for more details.
14 
15 You should have received a copy of the GNU Library General Public
16 License along with libiberty; see the file COPYING.LIB.  If
17 not, write to the Free Software Foundation, Inc., 51 Franklin Street - Fifth Floor,
18 Boston, MA 02110-1301, USA.  */
19 
20 #include "config.h"
21 
22 #include "ansidecl.h"
23 #include "libiberty.h"
24 
25 /* On some systems (such as WindISS), you must include <sys/types.h>
26    to get the definition of "time_t" before you include <time.h>.  */
27 #include <sys/types.h>
28 
29 /* There are several ways to get elapsed execution time; unfortunately no
30    single way is available for all host systems, nor are there reliable
31    ways to find out which way is correct for a given host. */
32 
33 #ifdef TIME_WITH_SYS_TIME
34 # include <sys/time.h>
35 # include <time.h>
36 #else
37 # if HAVE_SYS_TIME_H
38 #  include <sys/time.h>
39 # else
40 #  ifdef HAVE_TIME_H
41 #   include <time.h>
42 #  endif
43 # endif
44 #endif
45 
46 #if defined (HAVE_GETRUSAGE) && defined (HAVE_SYS_RESOURCE_H)
47 #include <sys/resource.h>
48 #endif
49 
50 #ifdef HAVE_TIMES
51 #ifdef HAVE_SYS_PARAM_H
52 #include <sys/param.h>
53 #endif
54 #include <sys/times.h>
55 #endif
56 
57 #ifdef HAVE_UNISTD_H
58 #include <unistd.h>
59 #endif
60 
61 /* This is a fallback; if wrong, it will likely make obviously wrong
62    results. */
63 
64 #ifndef CLOCKS_PER_SEC
65 #define CLOCKS_PER_SEC 1
66 #endif
67 
68 #ifndef RUSAGE_SELF
69 #define RUSAGE_SELF 0
70 #endif
71 
72 #ifdef _SC_CLK_TCK
73 #define GNU_HZ  sysconf(_SC_CLK_TCK)
74 #else
75 #ifdef HZ
76 #define GNU_HZ  HZ
77 #else
78 #ifdef CLOCKS_PER_SEC
79 #define GNU_HZ  CLOCKS_PER_SEC
80 #endif
81 #endif
82 #endif
83 
84 /*
85 
86 @deftypefn Replacement long get_run_time (void)
87 
88 Returns the time used so far, in microseconds.  If possible, this is
89 the time used by this process, else it is the elapsed time since the
90 process started.
91 
92 @end deftypefn
93 
94 */
95 
96 long
97 get_run_time (void)
98 {
99 #if defined (HAVE_GETRUSAGE) && defined (HAVE_SYS_RESOURCE_H)
100   struct rusage rusage;
101 
102   getrusage (RUSAGE_SELF, &rusage);
103   return (rusage.ru_utime.tv_sec * 1000000 + rusage.ru_utime.tv_usec
104 	  + rusage.ru_stime.tv_sec * 1000000 + rusage.ru_stime.tv_usec);
105 #else /* ! HAVE_GETRUSAGE */
106 #ifdef HAVE_TIMES
107   struct tms tms;
108 
109   times (&tms);
110   return (tms.tms_utime + tms.tms_stime) * (1000000 / GNU_HZ);
111 #else /* ! HAVE_TIMES */
112   /* Fall back on clock and hope it's correctly implemented. */
113   const long clocks_per_sec = CLOCKS_PER_SEC;
114   if (clocks_per_sec <= 1000000)
115     return clock () * (1000000 / clocks_per_sec);
116   else
117     return clock () / clocks_per_sec;
118 #endif  /* HAVE_TIMES */
119 #endif  /* HAVE_GETRUSAGE */
120 }
121