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 #include <time.h>
  30
  31 #if defined (HAVE_GETRUSAGE) && defined (HAVE_SYS_RESOURCE_H)
  32 #include <sys/time.h>
  33 #include <sys/resource.h>
  34 #endif
  35
  36 #ifdef HAVE_TIMES
  37 #ifdef HAVE_SYS_PARAM_H
  38 #include <sys/param.h>
  39 #endif
  40 #include <sys/times.h>
  41 #endif
  42
  43 /* This is a fallback; if wrong, it will likely make obviously wrong
  44    results. */
  45
  46 #ifndef CLOCKS_PER_SEC
  47 #define CLOCKS_PER_SEC 1
  48 #endif
  49
  50 #if defined (HAVE_TIMES) && ! defined (HZ)
  51 #define HZ CLOCKS_PER_SEC
  52 #endif
  53
  54 long
  55 get_run_time ()
  56 {
  57 #if defined (HAVE_GETRUSAGE) && defined (HAVE_SYS_RESOURCE_H)
  58   struct rusage rusage;
  59
  60   getrusage (0, &rusage);
  61   return (rusage.ru_utime.tv_sec * 1000000 + rusage.ru_utime.tv_usec
  62           + rusage.ru_stime.tv_sec * 1000000 + rusage.ru_stime.tv_usec);
  63 #else /* ! HAVE_GETRUSAGE */
  64 #ifdef HAVE_TIMES
  65   struct tms tms;
  66
  67   times (&tms);
  68   return (tms.tms_utime + tms.tms_stime) * (1000000 / HZ);
  69 #else /* ! HAVE_TIMES */
  70   /* Fall back on clock and hope it's correctly implemented. */
  71   const long clocks_per_sec = CLOCKS_PER_SEC;
  72   if (clocks_per_sec <= 1000000)
  73     return clock () * (1000000 / clocks_per_sec);
  74   else
  75     return clock () / clocks_per_sec;
  76 #endif  /* HAVE_TIMES */
  77 #endif  /* HAVE_GETRUSAGE */
  78 }