C++ Cross-Platform High-Resolution Timer

Question

I'm looking to implement a simple timer mechanism in C++. The code should work in Windows and Linux. The resolution should be as precise as possible (at least millisecond accuracy). This will be used to simply track the passage of time, not to implement any kind of event-driven design. What is the best tool to accomplish this?

Answer 1

The StlSoft open source library provides a quite good timer on both windows and linux platforms. If you want it to implement on your own, just have a look at their sources.

Answer 2

STLSoft have a Performance Library, which includes a set of timer classes, some that work for both UNIX and Windows.

Answer 3

Late to the party here, but I'm working in a legacy codebase that can't be upgraded to c++11 yet. Nobody on our team is very skilled in c++, so adding a library like STL is proving difficult (on top of potential concerns others have raised about deployment issues). I really needed an extremely simple cross platform timer that could live by itself without anything beyond bare-bones standard system libraries. Here's what I found:

http://www.songho.ca/misc/timer/timer.html

Reposting the entire source here just so it doesn't get lost if the site ever dies:

    //////////////////////////////////////////////////////////////////////////////
// Timer.cpp
// =========
// 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 ([e-mail]) - http://www.songho.ca/misc/timer/timer.html
// CREATED: 2003-01-13
// UPDATED: 2017-03-30
//
// Copyright (c) 2003 Song Ho Ahn
//////////////////////////////////////////////////////////////////////////////

#include "Timer.h"
#include <stdlib.h>

///////////////////////////////////////////////////////////////////////////////
// constructor
///////////////////////////////////////////////////////////////////////////////
Timer::Timer()
{
#if defined(WIN32) || defined(_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;
}



///////////////////////////////////////////////////////////////////////////////
// distructor
///////////////////////////////////////////////////////////////////////////////
Timer::~Timer()
{
}



///////////////////////////////////////////////////////////////////////////////
// start timer.
// startCount will be set at this point.
///////////////////////////////////////////////////////////////////////////////
void Timer::start()
{
    stopped = 0; // reset stop flag
#if defined(WIN32) || defined(_WIN32)
    QueryPerformanceCounter(&startCount);
#else
    gettimeofday(&startCount, NULL);
#endif
}



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

#if defined(WIN32) || defined(_WIN32)
    QueryPerformanceCounter(&endCount);
#else
    gettimeofday(&endCount, NULL);
#endif
}



///////////////////////////////////////////////////////////////////////////////
// compute elapsed time in micro-second resolution.
// other getElapsedTime will call this first, then convert to correspond resolution.
///////////////////////////////////////////////////////////////////////////////
double Timer::getElapsedTimeInMicroSec()
{
#if defined(WIN32) || defined(_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;
}



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



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



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

and the header file:

//////////////////////////////////////////////////////////////////////////////
// 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 ([e-mail]) - http://www.songho.ca/misc/timer/timer.html
// CREATED: 2003-01-13
// UPDATED: 2017-03-30
//
// Copyright (c) 2003 Song Ho Ahn
//////////////////////////////////////////////////////////////////////////////

#ifndef TIMER_H_DEF
#define TIMER_H_DEF

#if defined(WIN32) || defined(_WIN32)   // Windows system specific
#include <windows.h>
#else          // Unix based system specific
#include <sys/time.h>
#endif


class Timer
{
public:
    Timer();                                    // default constructor
    ~Timer();                                   // default destructor

    void   start();                             // start timer
    void   stop();                              // stop the timer
    double getElapsedTime();                    // get elapsed time in second
    double getElapsedTimeInSec();               // get elapsed time in second (same as getElapsedTime)
    double getElapsedTimeInMilliSec();          // get elapsed time in milli-second
    double getElapsedTimeInMicroSec();          // get elapsed time in micro-second


protected:


private:
    double startTimeInMicroSec;                 // starting time in micro-second
    double endTimeInMicroSec;                   // ending time in micro-second
    int    stopped;                             // stop flag 
#if defined(WIN32) || defined(_WIN32)
    LARGE_INTEGER frequency;                    // ticks per second
    LARGE_INTEGER startCount;                   //
    LARGE_INTEGER endCount;                     //
#else
    timeval startCount;                         //
    timeval endCount;                           //
#endif
};

#endif // TIMER_H_DEF

Answer 4

The ACE library has portable high resolution timers also.

Doxygen for high res timer:
http://www.dre.vanderbilt.edu/Doxygen/5.7.2/html/ace/a00244.html

Answer 5

Matthew Wilson's STLSoft libraries provide several timer types, with congruent interfaces so you can plug-and-play. Amongst the offerings are timers that are low-cost but low-resolution, and ones that are high-resolution but have high-cost. There are also ones for measuring pre-thread times and for measuring per-process times, as well as all that measure elapsed times.

There's an exhaustive article covering it in Dr. Dobb's from some years ago, although it only covers the Windows ones, those defined in the WinSTL sub-project. STLSoft also provides for UNIX timers in the UNIXSTL sub-project, and you can use the "PlatformSTL" one, which includes the UNIX or Windows one as appropriate, as in:

#include <platformstl/performance/performance_counter.hpp>
#include <iostream>

int main()
{
    platformstl::performance_counter c;

    c.start();
    for(int i = 0; i < 1000000000; ++i);
    c.stop();

    std::cout << "time (s): " << c.get_seconds() << std::endl;
    std::cout << "time (ms): " << c.get_milliseconds() << std::endl;
    std::cout << "time (us): " << c.get_microseconds() << std::endl;
}

HTH

Answer 6

I highly recommend boost::posix_time library for that. It supports timers in various resolutions down to microseconds I believe