simgear/misc/stopwatch.hxx

   1 /***************************************************************************
   2  * stopwatch.hxx        Timer class, for use in benchmarking
   3  *
   4  * Based on blitz/Timer.h
   5  *
   6  * $Id$
   7  *
   8  * Copyright (C) 1997,1998 Todd Veldhuizen <tveldhui@seurat.uwaterloo.ca>
   9  *
  10  * This program is free software; you can redistribute it and/or
  11  * modify it under the terms of the GNU General Public License
  12  * as published by the Free Software Foundation; either version 2
  13  * of the License, or (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * Suggestions:          blitz-suggest@cybervision.com
  21  * Bugs:                 blitz-bugs@cybervision.com
  22  *
  23  * For more information, please see the Blitz++ Home Page:
  24  *    http://seurat.uwaterloo.ca/blitz/
  25  *
  26  */
  27
  28 // This class is not portable to non System V platforms.
  29 // It will need to be rewritten for Windows, NT, Mac.
  30 // NEEDS_WORK
  31
  32 #ifndef _STOPWATCH_HXX
  33 #define _STOPWATCH_HXX
  34
  35 #ifndef __cplusplus
  36 # error This library requires C++
  37 #endif
  38
  39 #ifdef HAVE_CONFIG_H
  40 #  include <config.h>
  41 #endif
  42
  43 #if defined(__linux__) && ! defined(HAVE_GETRUSAGE)
  44 #  define HAVE_GETRUSAGE
  45 #endif
  46
  47 #if defined( WIN32 ) && defined( HAVE_GETRUSAGE )
  48 #  undef HAVE_GETRUSAGE
  49 #endif // WIN32
  50
  51 #if defined( HAVE_GETRUSAGE )
  52 #  if defined( __FreeBSD__ )
  53 #    include <sys/types.h>
  54 #  endif
  55 #  include <sys/time.h>
  56 #  include <sys/resource.h>
  57 #  include <unistd.h>
  58 #elif defined( WIN32 )
  59 #  include <windows.h>
  60 #else
  61 #  include <time.h>
  62 #endif
  63
  64 class StopWatch {
  65
  66 public:
  67     StopWatch()
  68     {
  69 //         state_ = uninitialized;
  70     }
  71
  72     void start()
  73     {
  74 //         state_ = running;
  75         t1_ = systemTime();
  76     }
  77
  78     void stop()
  79     {
  80         t2_ = systemTime();
  81 //      BZPRECONDITION(state_ == running);
  82 //      state_ = stopped;
  83     }
  84
  85     double elapsedSeconds()
  86     {
  87 //         BZPRECONDITION(state_ == stopped);
  88         return t2_ - t1_;
  89     }
  90
  91 private:
  92     StopWatch(StopWatch&) { }
  93     void operator=(StopWatch&) { }
  94
  95     double systemTime()
  96     {
  97 #if defined( HAVE_GETRUSAGE )
  98         getrusage(RUSAGE_SELF, &resourceUsage_);
  99         double seconds = resourceUsage_.ru_utime.tv_sec
 100             + resourceUsage_.ru_stime.tv_sec;
 101         double micros  = resourceUsage_.ru_utime.tv_usec
 102             + resourceUsage_.ru_stime.tv_usec;
 103         return seconds + micros/1.0e6;
 104 #elif defined( WIN32 )
 105         return double(GetTickCount()) * double(1e-3);
 106 #else
 107         return clock() / (double) CLOCKS_PER_SEC;
 108 #endif
 109     }
 110
 111 //     enum { uninitialized, running, stopped } state_;
 112
 113 #if defined( HAVE_GETRUSAGE )
 114     struct rusage resourceUsage_;
 115 #endif
 116
 117     double t1_, t2_;
 118 };
 119
 120 #endif // _STOPWATCH_HXX
 121