tests/glean/timer.h

   1 // BEGIN_COPYRIGHT -*- glean -*-
   2 //
   3 // Copyright (C) 1999-2000  Allen Akin   All Rights Reserved.
   4 //
   5 // Permission is hereby granted, free of charge, to any person
   6 // obtaining a copy of this software and associated documentation
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   9 // copy, modify, merge, publish, distribute, sublicense, and/or
  10 // sell copies of the Software, and to permit persons to whom the
  11 // Software is furnished to do so, subject to the following
  12 // conditions:
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  14 // The above copyright notice and this permission notice shall be
  15 // included in all copies or substantial portions of the
  16 // Software.
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  27 // END_COPYRIGHT
  28
  29 // timer.h:  Simple benchmark timing utilities based on the previous timer.h
  30 // Modified from timer.h by Rickard E. (Rik) Faith <faith@valinux.com>
  31
  32 // Timer objects provide a framework for measuring the rate at which an
  33 // operation can be performed.
  34
  35 #ifndef __timer_h__
  36 #define __timer_h__
  37
  38 namespace GLEAN {
  39
  40 class Timer {
  41         double overhead;        // Overhead (in seconds) of initial op,
  42                                 // final op, and timer access.
  43
  44         int    calibrated;      // Has calibrate been called?
  45
  46         double chooseRunTime(); // Select a runtime that will reduce random
  47                                 // timing error to an acceptable level.
  48
  49 public:
  50         virtual void   premeasure() {}; // called in measure(), before time()
  51         virtual void   postmeasure() {}; // called in measure(), after time()
  52         virtual void   preop()  {}; // before op, in each loop in time()
  53         virtual void   op()     {}; // in each loop in time()
  54         virtual void   postop() {}; // after op, in each loop in time()
  55         virtual double compute(double t) {
  56                 // modify measure()'s result -- e.g., by computing a rate
  57                 return t;
  58         }
  59
  60         void         calibrate();
  61         double       time();
  62         double       getClock();    // Get wall-clock time, in seconds
  63         double       waitForTick(); // Wait for next clock tick; return time
  64         void         measure(int count,
  65                              double* low, double* avg, double* high);
  66
  67         Timer() { overhead = 0.0; calibrated = false; }
  68         virtual ~Timer() { /* just silence warning */ }
  69
  70 }; // class Timer
  71
  72 } // namespace GLEAN
  73
  74 #endif // __timer_h__