How to measure the time taken to run a certain process?

[newix]

Nice code, Matthew! But I have a remark (or two). This is your program:

#define	MAX_64BIT_SIGNED_NO	9223372036854775807
#define	MIN_64BIT_SIGNED_NO	-9223372036854775808

LARGE_INTEGER Abs64( LARGE_INTEGER Value )
{
	if(	Value.QuadPart < 0 )
	{
		if(	Value.QuadPart == MIN_64BIT_SIGNED_NO )	Value.QuadPart++;
		Value.QuadPart *= -1;
	}

	return Value;
}
unsigned int TimeTaken(	BOOL Start )
{
	static LARGE_INTEGER Frequency;
	static LARGE_INTEGER StartTime;
	static LARGE_INTEGER StopTime;
	double dTimeTaken;
	LARGE_INTEGER Temp;

	if(	Start )
	{
		QueryPerformanceFrequency( &Frequency );
		QueryPerformanceCounter( &StartTime	);
		return 0; 
	}
	else
	{
		QueryPerformanceCounter( &StopTime ); 
		if(	StopTime.QuadPart <	StartTime.QuadPart ) //	Timer wrapped around
		{
*->			dTimeTaken = (double)MAX_64BIT_SIGNED_NO - StartTime.QuadPart;
			Temp.QuadPart =	MIN_64BIT_SIGNED_NO	- StopTime.QuadPart;
			Temp = Abs64( Temp );
*->			dTimeTaken = (double)Temp.QuadPart;
		}
		else
		{
			dTimeTaken = (double)(StopTime.QuadPart	- StartTime.QuadPart);
		}

		dTimeTaken = (dTimeTaken / (double)Frequency.QuadPart) * 1000.0;
		return (unsigned int)dTimeTaken;
	}
}

In the first marked line, dTimeTaken gets a value, but in the next marked line dTimeTaken gets a new value without using the first. So, is the first marked line really necessary?

I've read also an article from Microsoft about this function: Read this before using this function.

But, as I've said: I like your code and I'm already using it. Thx.