timer.h

Go to the documentation of this file.

// from: http://snipplr.com/view/40650/timer-class-for-both-unixlinuxmac-and-windows-system/

// How to Use ////

//#include <iostream>
//#include "timer.h"
//using namespace std;

//int main()
//{
//    Timer timer;
// 
//    // start timer
//    timer.start();
// 
//    // do something
//    ...
// 
//    // stop timer
//    timer.stop();
// 
//    // print the elapsed time in millisec
//    cout << timer.getElapsedTimeInMilliSec() << " ms.\n";
// 
//    return 0;
//}


// Timer.h
// =======
// High Resolution Timer.
// This timer is able to measure the elapsed time with 1 micro-second accuracy
// in both Windows, Linux and Unix system 
//
//  AUTHOR: Song Ho Ahn (song.ahn@gmail.com)
// CREATED: 2003-01-13
// UPDATED: 2006-01-13
//
// Copyright (c) 2003 Song Ho Ahn

#ifndef TIMER_H_DEF
#define TIMER_H_DEF

#ifndef __LINUX__   // Windows system specific
#include <windows.h>
#else          // Unix based system specific
#include <sys/time.h>
#endif

#include <stdlib.h>

class Timer
{
public:
        // default constructor
        Timer()
        {
#ifdef WIN32
                QueryPerformanceFrequency(&frequency);
                startCount.QuadPart = 0;
                endCount.QuadPart = 0;
#else
                startCount.tv_sec = startCount.tv_usec = 0;
                endCount.tv_sec = endCount.tv_usec = 0;
#endif

                stopped = 0;
                startTimeInMicroSec = 0;
                endTimeInMicroSec = 0;
        }

        // default destructor
        ~Timer()
        {
        }

        // start timer.
        // startCount will be set at this point.
        void start()
        {
                stopped = 0; // reset stop flag
#ifdef WIN32
                QueryPerformanceCounter(&startCount);
#else
                gettimeofday(&startCount, NULL);
#endif
        }

        // stop the timer.
        // endCount will be set at this point.
        void stop()
        {
                stopped = 1; // set timer stopped flag

#ifdef WIN32
                QueryPerformanceCounter(&endCount);
#else
                gettimeofday(&endCount, NULL);
#endif
        }

        // same as getElapsedTimeInSec()
        double getElapsedTime()
        {
                return this->getElapsedTimeInSec();
        }

        // divide elapsedTimeInMicroSec by 1000000
        double getElapsedTimeInSec()
        {
                return this->getElapsedTimeInMicroSec() * 0.000001;
        }

        // divide elapsedTimeInMicroSec by 1000
        double getElapsedTimeInMilliSec()
        {
                return this->getElapsedTimeInMicroSec() * 0.001;
        }

        // compute elapsed time in micro-second resolution.
        // other getElapsedTime will call this first, then convert to correspond resolution.
        double getElapsedTimeInMicroSec()
        {
#ifdef WIN32
                if(!stopped)
                QueryPerformanceCounter(&endCount);

                startTimeInMicroSec = startCount.QuadPart * (1000000.0 / frequency.QuadPart);
                endTimeInMicroSec = endCount.QuadPart * (1000000.0 / frequency.QuadPart);
#else
                if (!stopped)
                        gettimeofday(&endCount, NULL);

                startTimeInMicroSec = (startCount.tv_sec * 1000000.0) + startCount.tv_usec;
                endTimeInMicroSec = (endCount.tv_sec * 1000000.0) + endCount.tv_usec;
#endif

                return endTimeInMicroSec - startTimeInMicroSec;
        }

protected:

private:
        double startTimeInMicroSec; // starting time in micro-second
        double endTimeInMicroSec; // ending time in micro-second
        int stopped; // stop flag
#ifdef WIN32
        LARGE_INTEGER frequency; // ticks per second
        LARGE_INTEGER startCount; //
        LARGE_INTEGER endCount; //
#else
        timeval startCount; //
        timeval endCount; //
#endif
};

#endif // TIMER_H_DEF