C / C++ / MFC

Re: TCP header checksum calculation

30-Aug-02 1:02

I can't help you.
But which Packet driver do you use, i have a similar project, but not with TCP.

Marco

AIDS30-Aug-02 1:40

AIDS

30-Aug-02 1:40

I do not use any Packet driver.
I have captured the packet using Windows 2000 Network Monitor.
And I need to calculate checksums in my driver, which is NDIS intermediate driver.

Re: TCP header checksum calculation

Stephen C. Steel30-Aug-02 12:30

Stephen C. Steel

30-Aug-02 12:30

It may not be the problem, but you should be suspicous of any cross platform code using bitfields to pick out bits like this. The C standard does not define whether bitfields are allocated starting from the most or least significant bits of the variable. Different compilers may interpret this code differently!

<br />
UCHAR HeaderLength :4; // Header length in 32-bit words<br />

Some compilers will use the high nibble, others the lower nibble. Its much safer to use masks and shifts:

Either

HeaderLength = (uchar_var & 0xF0) >> 4

or

HeaderLength = (uchar_var & 0x0F)

as appropriate.

Stephen C. Steel
Kerr Vayne Systems Ltd.

Problems with CArray Updated

Koep30-Aug-02 0:50

30-Aug-02 0:50

Hi,

i believe that i have a problem to create a instance of the following object.

Declaration :
CArray <CEndPointGroup*,CEndPointGroup*> m_arEndPointGroups;

Add Pointer :
CEndPointGroup* _pEndPointGroup = NULL;
_pEndPointGroup = new CEndPointGroup(_groupname);
m_arEndPointGroups.Add(_pEndPointGroup);

At the last line i get an error. It seems that the arEndPointGroups-object is wrong allocated. What do i wrong ?

Marco

Tomasz Sowinski30-Aug-02 0:56

30-Aug-02 0:56

What kind of error it is? Compiler error? Assert at runtime? Hardware error?

Tomasz Sowinski -- http://www.shooltz.com

Free your mind and your ass will follow.

Koep30-Aug-02 1:00

30-Aug-02 1:00

It's an assert error at runtime. Pointer Access Error !

i've tried only to make an array of CEndPointsGroup-Pointer. Frown | :(

Marco

Tomasz Sowinski30-Aug-02 1:12

30-Aug-02 1:12

Have a look at call stack. Where (file/line) is ASSERT located?

Tomasz Sowinski -- http://www.shooltz.com

Free your mind and your ass will follow.

jhwurmbach30-Aug-02 3:20

jhwurmbach

30-Aug-02 3:20

Do you have looked at CPtrArray? Maybe that helps.

BTW CArray is deprecated, nonstandard and broken. You are better off using a
std::vector<CEndPointGroup*>
or even a
std::vector<boost::shared_ptr<CEndPointGroup>>

Just remember to never use std::auto_ptr in a std:: container.

Tomasz Sowinski30-Aug-02 3:21

30-Aug-02 3:21

jhwurmbach wrote:
BTW CArray is deprecated, nonstandard and broken

Nonstandard, yes. But I'd appreciate if you'd explain 'broken' and 'deprecated' part.

Tomasz Sowinski -- http://www.shooltz.com

Free your mind and your ass will follow.

jhwurmbach30-Aug-02 3:48

jhwurmbach

30-Aug-02 3:48

Broken:
http://www.codeproject.com/cpp/ocarray.asp[^]
or
http://www.codeproject.com/cpp/carray_pitfall.asp[^]
The use of 'pitfall' is the same as MS using 'issue': Politically correct term for 'ERROR'
Meaning: CArray and references don't work.

Deprecated:
CArray is what MS had to come up with when the STL was not working, but they needed the functionality for MFC. Since the time the standard was released, there is no need to use these old nostandard CArray.

Problems with CArray

Koep30-Aug-02 0:48

30-Aug-02 0:48

Hi,

i believe that i have a problem to create a instance of the following object.

Declaration :
CArray <cendpointgroup*,cendpointgroup*> m_arEndPointGroups;

Add Pointer :
CEndPointGroup* _pEndPointGroup = NULL;
_pEndPointGroup = new CEndPointGroup(_groupname);
m_arEndPointGroups.Add(_pEndPointGroup);

At the last line i get an error. It seems that the arEndPointGroups-object is wrong allocated. What do i wrong ?

Marco

Re: Problems with CArray

mishgun30-Aug-02 1:35

mishgun

30-Aug-02 1:35

Maybe error in declaration of m_arEndPointsGroup?
CArray is class template
try CArray<cendpointgroup*, cendpointgroup*=""> m_arEndPointsGroup

nobody is perfect

Re: Problems with CArray

Koep30-Aug-02 1:43

30-Aug-02 1:43

Have u ever worked with CArray ?

Marco

CPrintDialog problem

Wouter Dhondt29-Aug-02 23:58

Wouter Dhondt

29-Aug-02 23:58

I'm losing all my hair on this one.

In my app, I create a CPrintDialog like this:

CPrintDialog dlg(FALSE);<br />
dlg.DoModal();

which is very basic stuff. Running this, the dialog appears. When I select the printer properties, the app closes itself without a message! So I created a new app with the MFC wizard. In this app, I've put the same code. And guess what: no problems at all. The printer properties are shown without a problem.

To make things worse, I only have this problem in NT SP6. No problem in W2K. Haven't tested this on other windows versions...

In debugging, I get an assertion.
Pressing retry on the assertion:
call stack:

AfxWndProc(HWND__ * 0x0012e870, unsigned int 1240072, unsigned int 1239180, long 1239124) line 365 + 25 bytes<br />
AfxWndProcBase(HWND__ * 0x0012e870, unsigned int 1240072, unsigned int 1239180, long 1239124) line 220 + 21 bytes

function:

/////////////////////////////////////////////////////////////////////////////<br />
// The WndProc for all CWnd's and derived classes<br />
<br />
LRESULT CALLBACK<br />
AfxWndProc(HWND hWnd, UINT nMsg, WPARAM wParam, LPARAM lParam)<br />
{<br />
	// special message which identifies the window as using AfxWndProc<br />
	if (nMsg == WM_QUERYAFXWNDPROC)<br />
		return 1;<br />
<br />
	// all other messages route through message map<br />
	CWnd* pWnd = CWnd::FromHandlePermanent(hWnd);<br />
	ASSERT(pWnd != NULL); // ASSERT FAIL HERE	ASSERT(pWnd->m_hWnd == hWnd);<br />
	return AfxCallWndProc(pWnd, hWnd, nMsg, wParam, lParam);<br />
}

Any ideas? I'm thinking of some conflicting resources...

New and improved: kwakkelflap.com

Recompiler Engine

Joel Holdsworth29-Aug-02 23:55

Joel Holdsworth

29-Aug-02 23:55

Hi Everyone,
I'm currently embarking on the most exciting, but complex project I've ever attempted. The program is an advanced parametric image generator. In the last version of the program I had a wonderful engine in place, but in the end it got rather tripped by its own complexity, and the overhead involved. So now in this second generation of the program I want to implement a dynamic recompilation engine.

Atm my plugins spit out a whole load of C++ code into a buffer which is then saved, and I'm using the MSVC compiler to compile the code into a dll, which I can then call to perform my image making work. The problem is that any possible speed increases are kind of lost in the time taken to build the dll, and in the wasted cycles from C++'s inherant slowness problems. Also the microsoft license specifically states that bundling their compiler with your product is illegal - I'm not so worried about this because its only a homebrew thing. (Btw I'm only using C++ because I need to comunicate with my C++ objects, I would prefer C in this case of coarse). But the whole system is a little messy.

I would prefer a lighter language such, but it must capable of interfacing with a MSC++ DLL, be reasonably easy to learn, compiling quickly, produce reasonably quick code, and preferably be open source (so I can mod it so that it spits out function ptrs rather than files). I know this is a tall order, and I'm asking if any of you know at all. Am I going about it the right way? would you suggest that I make my own scripting language which cuts and pastes blocks of asembler together? Maybe if anyone has experience in this type of thing...

Any help is much appreciated...

With time we live, with money we spend!
Joel Holdsworth.

Re: Recompiler Engine

Tomasz Sowinski30-Aug-02 0:03

30-Aug-02 0:03

Joel Holdsworth wrote:
in the wasted cycles from C++'s inherant slowness problems

Jig | [Dance]

LOL

Are you programming in assembler or just entering binary codes? Smile | :)

You can consider GCC - I think that C++ objects could be made compatible, as long as you don't use multiple inheritance.

Tomasz Sowinski -- http://www.shooltz.com

Free your mind and your ass will follow.

Re: Recompiler Engine

Joel Holdsworth30-Aug-02 0:26

Joel Holdsworth

30-Aug-02 0:26

Isn't GCC only for UNIX? Or is there some way of getting it run well with windows? Does it work with XP?

With time we live, with money we spend!
Joel Holdsworth.

Re: Recompiler Engine

Tomasz Sowinski30-Aug-02 0:37