libiberty/getruntime.c

   1 /* Return time used so far, in microseconds.
   2    Copyright (C) 1994, 1999 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., 59 Temple Place - Suite 330,
  18 Boston, 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
  76 /*
  77
  78 @deftypefn Replacement long get_run_time (void)
  79
  80 Returns the time used so far, in microseconds.  If possible, this is
  81 the time used by this process, else it is the elapsed time since the
  82 process started.
  83
  84 @end deftypefn
  85
  86 */
  87
  88 long
  89 get_run_time ()
  90 {
  91 #if defined (HAVE_GETRUSAGE) && defined (HAVE_SYS_RESOURCE_H)
  92   struct rusage rusage;
  93
  94   getrusage (0, &rusage);
  95   return (rusage.ru_utime.tv_sec * 1000000 + rusage.ru_utime.tv_usec
  96           + rusage.ru_stime.tv_sec * 1000000 + rusage.ru_stime.tv_usec);
  97 #else /* ! HAVE_GETRUSAGE */
  98 #ifdef HAVE_TIMES
  99   struct tms tms;
 100
 101   times (&tms);
 102   return (tms.tms_utime + tms.tms_stime) * (1000000 / GNU_HZ);
 103 #else /* ! HAVE_TIMES */
 104   /* Fall back on clock and hope it's correctly implemented. */
 105   const long clocks_per_sec = CLOCKS_PER_SEC;
 106   if (clocks_per_sec <= 1000000)
 107     return clock () * (1000000 / clocks_per_sec);
 108   else
 109     return clock () / clocks_per_sec;
 110 #endif  /* HAVE_TIMES */
 111 #endif  /* HAVE_GETRUSAGE */
 112 }