timer.h

Go to the documentation of this file.

#ifndef _timer_h
#define _timer_h

#include <sys/resource.h>
#include <iostream>
#include <iomanip>

using namespace std;

class Timer {

 public:
  Timer() : state_(uninitialized), t1_(0), t2_(0) {;}  
  Timer(double floating_ops1 ) : floating_ops(floating_ops1) {}
  ~Timer() {;}

  void start()
    { 
      state_ = running;
      t1_ = systemTime();
    }

  void stop()
    {
      t2_ = systemTime();
      state_ = stopped;
    }

  double elapsedSeconds()
    {
      return t2_ - t1_;
    }

  double sec()
    {
      return t2_ - t1_;
    }

  void report( char const* what ) const
    {
      double t = t2_ - t1_;
      std::cout << "Time for "
                                << what
                                << " = "
                                << setw(8)
                                << t
                                << " seconds [ "
                                << setw(6)
                                << floating_ops/t/1000000 
                                << " Mflops]"
                                << std::endl;
    }
 private:
  Timer(Timer&) { }
  void operator=(Timer&) { }

  double systemTime()
    {
      getrusage(RUSAGE_SELF, &resourceUsage_);
      double seconds = resourceUsage_.ru_utime.tv_sec 
                + resourceUsage_.ru_stime.tv_sec;
      double micros  = resourceUsage_.ru_utime.tv_usec 
                + resourceUsage_.ru_stime.tv_usec;
      return seconds + micros/1.0e6;
    }

  enum { uninitialized, running, stopped } state_;

  double floating_ops;

  struct rusage resourceUsage_;

  double t1_, t2_;
};


#endif