C / C++ / MFC Discussion Boards

Re: Memory leak detection

ThatsAlok13-Dec-05 22:11

ThatsAlok

13-Dec-05 22:11

the pink jedi wrote:
Memory leak detection

Here what MSDN say about this :-
To detect a memory leak

Create a CMemoryState object and call the Checkpoint member function. This creates the first memory snapshot.
After your program performs its memory allocation and deallocation operations, create another CMemoryState object and call Checkpoint for that object. This gets a second snapshot of memory usage.
Create a third CMemoryState object and call its Difference member function, supplying as arguments the two previous CMemoryState objects. If there is a difference between the two memory states, the Difference function returns a nonzero value. This indicates that some memory blocks have not been deallocated.
This example shows what the code looks like:

// Declare the variables needed
#ifdef _DEBUG
CMemoryState oldMemState, newMemState, diffMemState;
oldMemState.Checkpoint();
#endif

// Do your memory allocations and deallocations.
CString s = "This is a frame variable";
// The next object is a heap object.
CPerson* p = new CPerson( "Smith", "Alan", "581-0215" );

#ifdef _DEBUG
newMemState.Checkpoint();
if( diffMemState.Difference( oldMemState, newMemState ) )
{
TRACE( "Memory leaked!\n" );
}
#endif
Notice that the memory-checking statements are bracketed by #ifdef _DEBUG / #endif blocks so that they are compiled only in Win32 Debug versions of your program.

"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow

cheers,
Alok Gupta
VC Forum Q&A :- I/ IV

How to get size of file ???????

VikramDelhi13-Dec-05 4:01

VikramDelhi

13-Dec-05 4:01

Hi Do anyone know how to get the size of any file in win32 system using APIs. Confused | :confused:

thanks

Re: How to get size of file ???????

Graham Bradshaw13-Dec-05 4:15

Graham Bradshaw

13-Dec-05 4:15

Use _stat64

Re: How to get size of file ???????

Tim Smith13-Dec-05 4:26

Tim Smith

13-Dec-05 4:26

GetFileSize if you want to stick to Win32.

Tim Smith

I'm going to patent thought. I have yet to see any prior art.

Re: How to get size of file ???????

ThatsAlok13-Dec-05 19:39

ThatsAlok

13-Dec-05 19:39

vikramdelhi wrote:
Do anyone know how to get the size of any file in win32 system using APIs.

if you tring to open Big file, try GetFileSizeEx

"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow

cheers,
Alok Gupta
VC Forum Q&A :- I/ IV

Thanks a lot guys

VikramDelhi14-Dec-05 3:39

VikramDelhi

14-Dec-05 3:39

hi
thanks a lot guys.
you all are really nice guys.

Replacing open/save dialogs

Krishnan V13-Dec-05 3:42

Krishnan V

13-Dec-05 3:42

I want to prevent access to windows explorer when the user is using my app. Therefore, I have created a new desktop to run my app on. This way even though he can run explorer, he cannot practically use it. However, if from my app's open/save dialogs the user right-clicks and selects the explore option, he gets a new instance of explorer running on my desktop. Sniff | :^)

My question therefore is how do I prevent this? As far as my app goes, I can think of replacing the standard open/save and browse for folder dialogs with custom made ones. However, my app uses certain third-party resources for which I cannot do the same. Can I then somehow "hook" these dialog boxes, and prevent the user from running explorer.

Any other ideas on achieving my end result are welcome.

Thanks! Smile | :)

Re: Replacing open/save dialogs

David Crow13-Dec-05 3:57

David Crow

13-Dec-05 3:57

Krishnan V wrote:
I want to prevent access to windows explorer when the user is using my app.

Why? What is it that you are ultimately trying to prevent access to?

"Take only what you need and leave the land as you found it." - Native American Proverb

Re: Replacing open/save dialogs

Krishnan V13-Dec-05 18:26

Krishnan V

13-Dec-05 18:26

My application is used in critical applications. Therefore, normal users are not allowed to use anything outside of my app. Not even calculator! To get access to other applications, I might provide a password-protected option to them.

Access Synchronization in VC++

zinc_z13-Dec-05 2:35

zinc_z

13-Dec-05 2:35

Hi ,

I m having problem updating my temporary Access databse , I get messages from socket every 1 sec , and I have to update Access tables . My application is a multithreaded , so there are times when multiple threads are trying to reand/ write same table.

Now my problem is I have tried to open Access table through CRecordset class , and when I debug it locally it run fine in multithread environment , like same table is opened by thread 1 and thread 2 is reading it , thread 3 is updating it etc.

But when I go live , I get errors like :
"Could not update; currently locked by user 'admin' on machine 'XXX"

how to catch this bug ? n how to fix it ?

plz can any body help ? If I use MS SQL SERVER can it resolve problem ?

Thx,
Zinc

HELLO

Re: Access Synchronization in VC++

kakan13-Dec-05 3:30

kakan

13-Dec-05 3:30

Hello

One way is to use a Mutex (and keep Access).
You could create a special function (or class) that handles all reads from, and writes to, the Access DB.
In that function (or class), use a Mutex.

Or, if reads are allowed at all times, just block the writes with a Mutex.

Kakan

Re: Access Synchronization in VC++

Sheng Jiang 蒋晟13-Dec-05 9:57

Sheng Jiang 蒋晟

13-Dec-05 9:57

Let SQL Server or MSDE(http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnacc2k2/html/odc_msdeintro.asp[^]) do the job for you.

My blogs:

http://blog.joycode.com/jiangsheng
http://blog.csdn.net/jiangsheng
http://bloglines.com/public/jiangsheng

Command what is yours
Conquer what is not
---Kane

Exporting a function from an .exe??

Gunn31713-Dec-05 2:34

Gunn317

13-Dec-05 2:34

Just as in that you can call LoadLibrary() on a DLL and then use GetProcAddress() to call a function within that DLL, is it possible to export a function from an exe? I know you can call LoadLibrary() and pass it an .exe and it will return a valid handle...

My end result is that I'd like to load an executable by another program (NOT run it) and determine what specific version it is...without using a version info resource within it. If I could set a function to export to return the version, that would be *perfect*.

Any other suggestions on getting at my end result would be appreciated.

Thanks,

Re: Exporting a function from an .exe??

David Crow13-Dec-05 3:58

David Crow

13-Dec-05 3:58

Gunn317 wrote:
...is it possible to export a function from an exe?

Not that I am aware of.

"Take only what you need and leave the land as you found it." - Native American Proverb

Re: Exporting a function from an .exe??

Gunn31713-Dec-05 4:35

Gunn317

13-Dec-05 4:35

It IS possible! In searching the internet, I came across this article:

http://www.codeguru.com/Cpp/W-P/dll/article.php/c3649/

In trying to solve this problem yesterday, I had created a Win32 DLL using the VS.NET wizard with one function I was exporting. So, I just copy/pasted the code into a new header file which I included in one of my .exe source files, then linked. That was it and it worked.

I was able to call LoadLibrary() on the exe, then GetProcAddress() for the function. Here's the complete .h needed (VERSION_EXPORTS was defined in the project properties):

<br />
#ifdef VERSION_EXPORTS<br />
#define VERSION_API __declspec(dllexport)<br />
#else<br />
#define VERSION_API __declspec(dllimport)<br />
#endif<br />
<br />
VERSION_API int fnVersion(void)<br />
{<br />
return 6030;<br />
}<br />

Re: Exporting a function from an .exe??

toxcct13-Dec-05 5:22

toxcct

13-Dec-05 5:22

but you are using some dll methods to came across this : dllexport and dllimport
i never seen an application (.exe) defining some symbols that are to be exported... !!
this is done in dll generally.

TOXCCT >>> GEII power
[toxcct][VisualCalc 2.20][VisualCalc 3.0]

Re: Exporting a function from an .exe??

Gunn31713-Dec-05 5:36

Gunn317

13-Dec-05 5:36

I sure am...I'm sure in most cases this may not be appropriate or needed. But it fits my case perfectly. And since LoadLibrary() and GetProcAddress() both work with .exe's, there's no reason why it can't be done.

Thanks,

Problem with regions

emadns13-Dec-05 2:03

emadns

13-Dec-05 2:03

Hi,
I have a problem when creating win32 regions and drawing into them. The edges of the shapes drawing inside the region are distored or cut-off. For example:

CDC* pdc = GetDC();
CRgn rgn;
rgn.CreateEllipticRgn(10,10,50,50);
pdc->SelectClipRgn(&rgn, RGN_COPY);
pdc->Ellipse(10, 10, 50, 50);
pdc->SelectClipRgn(NULL, RGN_COPY);
ReleaseDC(pdc);

Although the coordinates of the region are the same of the ellipse coordinates, it still does not draw the ellipse perfectly. The edges are distorted. Is there a way I can calculate the perfect region. I also do not want to use paths as they don't work properly in win98. What could be the solution.

Thanks

Re: Problem with regions

Blake Miller13-Dec-05 9:47

Blake Miller

13-Dec-05 9:47

Are you acconting for the pen width of the border of the object?
In that case, your region needs to be slightly larger than the actual object boundaries, since most programs leave the pen drawing code to drawn ON the object's edge rather than within it.
Since I don't see any code explicitly setting your pen, it could be any guess what it is at the time this code executes. Are you seeing distortion when the pen width is more than 1? I would not expect it too much with this code when the pen width is 1, except maybe at the outer edge of the ellipse.

No shirt, no shoes, no brains, no service.

Re: Problem with regions

emadns13-Dec-05 16:12

emadns

13-Dec-05 16:12

Thanks for your reply. I am not selecting any pen into the device, so I assume that the default is a 1 pixel black pen. I tried making the region larger by one pixel, but the result shows the ellipse. However, there are extra little blank spaces around the ellipse. I also tried to make the pen PS_INSIDEFRAME but with the same result.

Message Queue Implementation how to create queue

selva198013-Dec-05 1:56

selva1980

13-Dec-05 1:56

hai

selvaraj@kappsoft.com

i have downloaded the message Queue implementation.
i need to create a private queue... In my local meachine(CLIENT)
what i have to give in the fields of

ServerMSMQ
Path Queue
Label Queue
Message Lable

I gave serverMSMQ empty pathQueue :"private$","private",".\<comp.name>\private$\test",.....
it shows the error "error to create private queue"
when i click create private Queue(note: i can create directly i.e message Queue in computer management

if possible give me the docment or help file

waiting for your suggestion
selvaraj
selvaraj@kappsoft.com

How to do programmatical digest authentication against active directory?

redclover13-Dec-05 1:52

redclover

13-Dec-05 1:52

Does anyone know about how to do programmatical digest authentication against microsoft active directory? Confused | :confused:

I'd really appriciate if someone helps me.

Osama Askari
programmer.askari@gmail.com

Defining global variables

abhinarulkar13-Dec-05 1:35

abhinarulkar

13-Dec-05 1:35

Hello,
I had some doubt regarding definition of global variables. If I have to define two global variables with the same name in two cpp files then is it somehow possible to do so..?
However I am aware of providing a definition in one file and declaring in other for usage(using extern keyword).

Example:
int i;
should be "defined" in CPP1.cpp and CPP2.cpp belonging to the same project.

Regards,
Abhishek.

Learning is a never ending process of Life.

Re: Defining global variables

Alex Orovetskiy13-Dec-05 1:42

Alex Orovetskiy

13-Dec-05 1:42

Global variables are only visible in 1 cpp

--------------------------------
Human stupidity is infinite.

Re: Defining global variables

JonEngle13-Dec-05 1:46

JonEngle

13-Dec-05 1:46

in cpp1.h ->

extern int i;

in cpp1.cpp ->

int i;

Then include cpp1.h where ever you need to use i

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