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 long
  77 get_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 }