timing performance of code

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ronny - 27 Feb 2005 15:33 GMT

Hi

I am looking to time the performance of my code, I am currently using the
system time "DateTime::Now" however I am finding the results are not very
accurate.

I have been told that I can use the system diagnostics to use a performance
counter. However I have not been able to get any code that relates to
C++.net (managed).

Can anyone help me get started?

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Carl Daniel [VC++ MVP] - 27 Feb 2005 15:42 GMT

> Hi
>
[quoted text clipped - 7 lines]
>
> Can anyone help me get started?

You can just use the native
QueryPerformanceCounter/QueryPerformanceFrequency Win32 functions from
managed C++. If you'd rather not #include <windows.h>, you could just
declare them:

#pragma unmanaged

extern "C"
{
int __stdcall QueryPerformanceCounter(__int64* p);
int __stdcall QueryPerformanceFrequency(__int64* p);
}

#pragma managed

To use them, call QueryPerformanceCounter at the start and end of your code
block. Call QueryPerformanceFrequency once to determine the resolution of
the counts.

__int64 start;
__int64 end;

::QueryPerformanceCounter(&start);

//
// Your code to be measured here
//

::QueryPerformanceCounter(&end);

__int64 freq;

::QueryPerformanceFrequency(&freq);

double elapsedSeconds = double(end-start)/freq;

HTH

-cd

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ronny - 27 Feb 2005 17:35 GMT

Thanks for your reply Carl. I have tried to add the code you suggested but I
get the following errors

...Include\WinBase.h(9839): error C2733: second C linkage of overloaded
function 'QueryPerformanceCounter' not allowed
...Include\WinBase.h(9846): error C2733: second C linkage of overloaded
function 'QueryPerformanceFrequency' not allowed
...WinBase.h(9844) : see declaration of 'QueryPerformanceFrequency'

I'm not sure if I have added the code to the correct place. My "Form1.h"
looks like this.

***********************************************
#pragma unmanaged
extern "C"
{
int __stdcall QueryPerformanceCounter(__int64* p);
int __stdcall QueryPerformanceFrequency(__int64* p);
}

#pragma managed
#include <stdio.h>
using namespace System;
using namespace System::ComponentModel;
using namespace System::Collections;
using namespace System::Windows::Forms;
using namespace System::Data;
......
**********************************************

Ronny

>> Hi
>>
[quoted text clipped - 42 lines]
>
> -cd

Reply to this Message

Carl Daniel [VC++ MVP] - 27 Feb 2005 17:46 GMT

> Thanks for your reply Carl. I have tried to add the code you
> suggested but I get the following errors
[quoted text clipped - 4 lines]
> overloaded function 'QueryPerformanceFrequency' not allowed
> ...WinBase.h(9844) : see declaration of 'QueryPerformanceFrequency'

Just get rid of the re-definition of the functions - you've obviously
already included <windows.h>.

-cd

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Carl Daniel [VC++ MVP] - 27 Feb 2005 18:47 GMT

>> Thanks for your reply Carl. I have tried to add the code you
>> suggested but I get the following errors
[quoted text clipped - 7 lines]
> Just get rid of the re-definition of the functions - you've obviously
> already included <windows.h>.

... and you'll have to use LARGE_INTEGER (look it up) instead of __int64.

-cd

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ronny - 28 Feb 2005 11:16 GMT

Ok, i've got it working fine now. Thanks for your help.

>>> Thanks for your reply Carl. I have tried to add the code you
>>> suggested but I get the following errors
[quoted text clipped - 11 lines]
>
> -cd

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Ioannis Vranos - 28 Feb 2005 14:13 GMT

> Ok, i've got it working fine now. Thanks for your help.

Perhaps you are looking for a .NET profiler? Here is a free one:

http://www.microsoft.com/downloads/details.aspx?FamilyId=86CE6052-D7F4-4AEB-9B7A
-94635BEEBDDA&displaylang=en

It displays time-costs and everything.

And two videos about how to use it:

http://www.microsoft.com/downloads/details.aspx?FamilyId=CD5AA57C-9CD1-45AB-AA4B
-8DC586D30938&displaylang=en

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Ioannis Vranos

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timing performance of code

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