How do you benchmark code?

[AlwaysLearning]

I wrote my own time system to help me benchmark code. (below)

But I'm not sure it is the best system. Have a better one? Please share.

timeGetTime()
returns system time since windows started in milliseconds.

//.h
#ifndef _TIME_H_
#define _TIME_H_

#pragma comment (lib,"Winmm.lib")

#define WIN32_LEAN_AND_MEAN
#include <windows.h>
#include <mmsystem.h>

class cTime
{
public:
	static cTime*	Instance();
	static void		Destroy();

	void	operator()();
	UINT64	GetDTime(){return mDTime;}

private:
	cTime();
	~cTime();

	static cTime *mInstance;
	UINT64 mLastGameTime;
	UINT64 mDTime;
};

#endif 

//.cpp
#include "Time.hpp"

cTime *cTime::mInstance	=	0;

cTime *cTime::Instance()
{
	if(mInstance)
		return mInstance;
	return mInstance = new cTime;
}

void cTime::Destroy()
{
	if(mInstance)
		delete mInstance;
}

cTime::cTime():
mDTime(0)
{
	mLastGameTime = (UINT64)timeGetTime();
}

cTime::~cTime(){}

void cTime::operator()()
{
	UINT64 ticks = (UINT64)timeGetTime();

	mDTime = ticks - mLastGameTime;

	mLastGameTime = ticks;
}

Example usage

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

void main()
{
	cTime &TimeRef = *cTime::Instance();

	TimeRef();
	// ... code to benchmark here ... //
	TimeRef();

	cout<<"Benchmark: "<<TimeRef.GetDTime();
}

[Zaita]

I use a profiling tool. There are some open source ones, but I use a commercial tool called "AQTime". It allows me to profile performance and memory usage etc of my code.

[jmc]

I let the compiler create the assembly code, insert a loop in the assembly code. At the start of the program I use clock() for the number of clock ticks since the program start and at the end of the program I return (startvalue-clock())/CLOCKS_PER_SECOND.

[AlwaysLearning]

Zaita:
are there any open source ones you recommend?

[Zaita]

http://sourceforge.net/projects/shinyprofiler

[exception]

I usually use gprof (with the kprof frontend) and valgrind (callgrind actually) with the kcachegrind frontend. Those are for Linux and BSD, though (all Free & Open Source Software).