Possibly reason for system overhead? - C / C++ / MFC Discussion Boards

Re: Accesing Platform SDK Help from VS IDE

Norberto Cerezal16-Sep-02 3:23

16-Sep-02 3:23

Yes, I know that option, but it is only meant to include for you the source, headers and lib paths into VS options.

I believe what I want is way more tricky to do Confused | :confused:

something with registry keys.

Thank You anyway!

Re: Accesing Platform SDK Help from VS IDE

Simon.W16-Sep-02 3:30

Simon.W

16-Sep-02 3:30

Check this out:
http://www.codejock.com/developer/article01.htm

I am seeking...
For what?
Why did you ask me for what? I don't know!

Re: Accesing Platform SDK Help from VS IDE

Norberto Cerezal16-Sep-02 3:30

Norberto Cerezal

16-Sep-02 3:30

Yesss

That's what I was looking for!

Thank You!

Re: Accesing Platform SDK Help from VS IDE

axa16-Sep-02 3:42

axa

16-Sep-02 3:42

I don't know if this would work the same way it worked for me.
I alaredy had MSDN library, so after instalig PSDK Ive changed the folowing keys in registry (WinXP):
HKEY_LOCAL_MACHINE\SOFTVARE\Microsoft\HTML Help Collections\Developer Collections\0x0409\0x035eef540
Default: Name
Filename: path to the sdk .col file

Who has used CxImage??How to add these .lib files about jpg format??

NeverGrief16-Sep-02 2:01

NeverGrief

16-Sep-02 2:01

Please send me one.
Thank you very much!
Best regards!
WTF | :WTF:

msn: nevergrief@hotmail.com

C++ lover ,haha

Re: Who has used CxImage??How to add these .lib files about jpg format??

Mustafa Demirhan16-Sep-02 7:25

Mustafa Demirhan

16-Sep-02 7:25

?? You mean linking the lib files?

Mustafa Demirhan
http://www.macroangel.com
Sonork ID 100.9935:zoltrix

<nobr>They say I'm lazy but it takes all my time

Regular MFC dlls

Mangesh Sardesai16-Sep-02 1:21

Mangesh Sardesai

16-Sep-02 1:21

Let me confess that I am a novice VC++ programmer.

I wrote seperate functions in regular MFC dll having following signatures -

1. extern "C" ADODB::_RecordsetPtr declspec(dllexport) GetRs()

2. extern "C" declspec(dllexport) GetRsEx(ADODB::_RecordsetPtr &rs)

Both the functions work as expected when accessed through the exe created in VC++.(i.e I am able to access the recordset)

However when i try accessing them through the VB application the #2 work as expected but the #1 gives memory error.(Probably bcoz of the _RecordsetPtr going out scope
which i have declared inside the function).

Can any one explain the way in which i can return the recordset instead of using parameter by reference(OR using the #1 declaration)?

thanks and regards,

MS

Possibly reason for system overhead?

16-Sep-02 1:15

This program is example from book and I assume I retyped it correctly, but there is a problem which I don't understand its reason.
Program, regardles main thread, creates four other, and when I run the program on WinXP it practically hangs the system, but it runs. CPU usage is 100% and I cannot (or I must wait a long while) do anything else. I cannot move/resize or quit the program, and finally I must kill program directly from Windows Task Manager.
I do not have to much experience on using threads but I assume that (like the book writes, and for example a much more slower machine like 386 or 486) that for systems like mine (AMD TB 1GHz, 256MB RAM...) it is not too much overhead if program creates four other threads, and that it should run smoothly as much as any other program of that form.
VC of course compiled this program with no error or warning in report. I seems that everything is OK in code. But it is not!
So I'm asking for your help to resolve this problem.
Here's the code (again I apologize for text length but I cannot clip the critical part since I don't see which one is it Smile | :)

#include <windows.h> // windows.h
#include <math.h>    // math.h
#include <process.h> // process.h

typedef struct
{
	HWND hwnd;
	int cxClient;
	int cyClient;
	int cyChar;
	BOOL bKill;
}
PARAMS, *PPARAMS;

LRESULT APIENTRY WndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam); 

int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, 
						 PSTR szCmdLine, int iCmdShow)
{
	static TCHAR szAppName[] = TEXT("Multi2");
	HWND hwnd;
	MSG msg;
	WNDCLASS wc;

	wc.style				= CS_HREDRAW | CS_VREDRAW;
	wc.lpfnWndProc		= WndProc;
	wc.cbClsExtra		= 0;
	wc.cbWndExtra		= 0;
	wc.hInstance		= hInstance;
	wc.hIcon				= LoadIcon(NULL, IDI_APPLICATION);
	wc.hCursor			= LoadCursor(NULL, IDC_ARROW);
	wc.hbrBackground	= (HBRUSH) GetStockObject(WHITE_BRUSH);
	wc.lpszMenuName	= NULL;
	wc.lpszClassName	= szAppName;

	if (!RegisterClass(&wc))
	{
		MessageBox(NULL, TEXT("This Program Requires Windows NT!"),
					  szAppName, MB_ICONERROR);
		return 0;
	}

	hwnd = CreateWindow(szAppName, TEXT("Multitasking Demo using Threads"),
							  WS_OVERLAPPEDWINDOW,
							  CW_USEDEFAULT, CW_USEDEFAULT,
							  CW_USEDEFAULT, CW_USEDEFAULT,
							  NULL, NULL, hInstance, NULL);

	ShowWindow(hwnd, iCmdShow);
	UpdateWindow(hwnd);

	while (GetMessage(&msg, NULL, 0, 0))
	{
		TranslateMessage(&msg);
		DispatchMessage(&msg);
	}
	return msg.wParam;
}

int CheckBottom(HWND hwnd, int cyClient, int cyChar, int iLine)
{
	if (iLine * cyChar + cyChar > cyClient)
	{
		InvalidateRect(hwnd, NULL, TRUE);
		UpdateWindow(hwnd);
		iLine = 0;
	}
	return iLine;
}

/*----------------------------------------------------
    Window 2: Display increasing sequence of numbers
  ----------------------------------------------------*/
void Thread1(PVOID pvoid)
{
	HDC hdc;
	int iNum = 0, iLine = 0;
	PPARAMS pparams;
	TCHAR szBuffer[16];

	pparams = (PPARAMS) pvoid;

	while (!pparams->bKill)
	{
		if (iNum < 0)
			iNum = 0;

		iLine = CheckBottom(pparams->hwnd, pparams->cyClient, 
								  pparams->cyChar, iLine);

		hdc = GetDC(pparams->hwnd);

		TextOut(hdc, 0, iLine * pparams->cyChar, szBuffer,
				  wsprintf(szBuffer, TEXT("%d"), iNum++));

		ReleaseDC(pparams->hwnd, hdc);
		iLine++;
	}
	_endthread();
}

LRESULT APIENTRY WndProc1(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
	static PARAMS params;

	switch (message)
	{
		case WM_CREATE:
			params.hwnd = hwnd;
			params.cyChar = HIWORD(GetDialogBaseUnits());
			_beginthread(Thread1, 0, ¶ms);	
			return 0;

		case WM_SIZE:
			params.cyClient = HIWORD(lParam);
			return 0;

		case WM_DESTROY:
			params.bKill = TRUE;
			return 0;
	}
	return DefWindowProc(hwnd, message, wParam, lParam);
}

/*---------------------------------------------------------
    Window 2: Display incresing sequence of prime numbers
  ---------------------------------------------------------*/
void Thread2(PVOID pvoid)
{
	HDC hdc;
	int iNum = 1, iLine = 0, i, iSqrt;
	PPARAMS pparams;
	TCHAR szBuffer[16];

	pparams = (PPARAMS) pvoid;

	while (!pparams->bKill)
	{
		do
		{
			if (++iNum < 0)
				iNum = 0;

			iSqrt = (int) sqrt(iNum);
			for (i = 2; i <= iSqrt; i++)
				if (iNum % i == 0)
					break;
			}
			while (i <= iSqrt);

		iLine = CheckBottom(pparams->hwnd, pparams->cyClient,
								  pparams->cyChar, iLine);

		hdc = GetDC(pparams->hwnd);

		TextOut(hdc, 0, iLine * pparams->cyChar, szBuffer,
				  wsprintf(szBuffer, TEXT("%d"), iNum));

		ReleaseDC(pparams->hwnd, hdc);
		iLine++;
	}
	_endthread();
}

LRESULT APIENTRY WndProc2(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
	static PARAMS params;

	switch (message)
	{
		case WM_CREATE:
			params.hwnd = hwnd;
			params.cyChar = HIWORD(GetDialogBaseUnits());
			_beginthread(Thread2, 0, ¶ms);
			return 0;

		case WM_SIZE:
			params.cyClient = HIWORD(lParam);
			return 0;

		case WM_DESTROY:
			params.bKill = TRUE;
			return 0;
	}
	return DefWindowProc(hwnd, message, wParam, lParam);
}

/*--------------------------------------------------------------
	 Window 3: Display incresing sequences of Fibonacci numbers
  --------------------------------------------------------------*/
void Thread3(PVOID pvoid)
{
	HDC hdc;
	int iNum = 0, iNext = 1, iLine = 0, iTemp;
	PPARAMS pparams;
	TCHAR szBuffer[16];

	pparams = (PPARAMS) pvoid;

	while (!pparams->bKill)
	{
		if (iNum < 0)
		{
			iNum = 0;
			iNext = 1;
		}
		iLine = CheckBottom(pparams->hwnd, pparams->cyClient,
								  pparams->cyChar, iLine);

		hdc = GetDC(pparams->hwnd);

		TextOut(hdc, 0, iLine * pparams->cyChar, szBuffer,
				  wsprintf(szBuffer, TEXT("%d"), iNum));

		ReleaseDC(pparams->hwnd, hdc);
		iTemp = iNum;
		iNum = iNext;
		iNext += iTemp;
		iLine++;
	}
	_endthread();
}

LRESULT APIENTRY WndProc3(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
	static PARAMS params;

	switch (message)
	{
		case WM_CREATE:
			params.hwnd = hwnd;
			params.cyChar = HIWORD(GetDialogBaseUnits());
			_beginthread(Thread3, 0, ¶ms);
			return 0;		

		case WM_SIZE:
			params.cyClient = HIWORD(lParam);
			return 0;

		case WM_DESTROY:
			params.bKill = TRUE;
			return 0;
	}
	return DefWindowProc(hwnd, message, wParam, lParam);
}

/*---------------------------------------------
	 Window 4: Display circles of random radii
  ---------------------------------------------*/
void Thread4(PVOID pvoid)
{
	HDC hdc;
	int iDiameter;
	PPARAMS pparams;

	pparams = (PPARAMS) pvoid;

	while (!pparams->bKill)
	{
		InvalidateRect(pparams->hwnd, NULL, TRUE);
		UpdateWindow(pparams->hwnd);

		iDiameter = rand() % (max (1, 
										min(pparams->cxClient, pparams->cyClient)));

		hdc = GetDC(pparams->hwnd);

		Ellipse(hdc, (pparams->cxClient - iDiameter) / 2,
						 (pparams->cyClient - iDiameter) / 2,
						 (pparams->cxClient + iDiameter) / 2,
						 (pparams->cyClient + iDiameter) / 2);

		ReleaseDC(pparams->hwnd, hdc);
	}
	_endthread();
}

LRESULT APIENTRY WndProc4(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
	static PARAMS params;

	switch (message)
	{
		case WM_CREATE:
			params.hwnd = hwnd;
			params.cyChar = HIWORD(GetDialogBaseUnits());
			_beginthread(Thread4, 0, ¶ms);
			return 0;	

		case WM_SIZE:
			params.cxClient = LOWORD(lParam);
			params.cyClient = HIWORD(lParam);
			return 0;

		case WM_DESTROY:
			params.bKill = TRUE;
			return 0;
	}
	return DefWindowProc(hwnd, message, wParam, lParam);
}

/*---------------------------------------
	 Main window to create child windows
  ---------------------------------------*/
LRESULT APIENTRY WndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
	static HWND hwndChild[4];
	static TCHAR* szChildClass[] = { TEXT("Child1"), TEXT("Child2"),
												TEXT("Child3"), TEXT("Child4") };
	static WNDPROC ChildProc[] = { WndProc1, WndProc2, WndProc3, WndProc4 };
	HINSTANCE hInstance;
	int i, cxClient, cyClient;
	WNDCLASS wc;

	switch (message)
	{
		case WM_CREATE:
			hInstance = (HINSTANCE) GetWindowLong(hwnd, GWL_HINSTANCE);

			wc.style				= CS_HREDRAW | CS_VREDRAW;
			wc.cbClsExtra		= 0;
			wc.cbWndExtra		= 0;
			wc.hInstance		= hInstance;
			wc.hIcon				= NULL;
			wc.hCursor			= LoadCursor(NULL, IDC_ARROW);
			wc.hbrBackground	= (HBRUSH) GetStockObject(WHITE_BRUSH);
			wc.lpszMenuName	= NULL;

			for (i = 0; i < 4; i++)
			{
				wc.lpfnWndProc	= ChildProc[i];
				wc.lpszClassName = szChildClass[i];

				RegisterClass(&wc);

				hwndChild[i] = CreateWindow(szChildClass[i], NULL, 
													 WS_CHILDWINDOW | WS_BORDER | WS_VISIBLE,
													 0, 0, 0, 0,
													 hwnd, (HMENU) i, hInstance, NULL);
			}
			return 0;

		case WM_SIZE:
			cxClient = LOWORD(lParam);
			cyClient = HIWORD(lParam);

			for (i = 0; i < 4; i++)
				MoveWindow(hwndChild[i], (i % 2) * cxClient / 2,
												 (i > 1) * cyClient / 2,
							  cxClient / 2, cyClient / 2, TRUE);
			return 0;

		case WM_CHAR:
			if (wParam == '\x1B')
				DestroyWindow(hwnd);
			return 0;

		case WM_DESTROY:
			PostQuitMessage(0);
			return 0;
	}
	return DefWindowProc(hwnd, message, wParam, lParam);
}

Thanks.

Re: Possibly reason for system overhead?

Michael Dunn16-Sep-02 3:37

Michael Dunn

16-Sep-02 3:37

Look at your thread functions. They are immediately going into loops and doing all sorts of drawing, without ever sleeping. That's why the CPU is being hogged. You should only do drawing in response to a WM_PAINT message.

(Also, use <pre> instead of <code> to make your code more readable on the forum.)

--Mike--
Just released - RightClick-Encrypt v1.4 - Adds fast & easy file encryption to Explorer
My really out-of-date homepage
Sonork-100.19012 Acid_Helm

Re: Possibly reason for system overhead?

axa16-Sep-02 3:46

axa

16-Sep-02 3:46

Michael Dunn wrote:
Look at your thread functions. They are immediately going into loops and doing all sorts of drawing, without ever sleeping. That's why the CPU is being hogged. You should only do drawing in response to a WM_PAINT message.

Yea, I know but that's the example from Petzold's "Programming Windows" and the code is the same, but he didn't said anything about overheding the system, in fact he wrote that users are in able to move or resize window.

(Sorry, for my bad english Smile | :)

)

Developing a password filter

abhinarulkar16-Sep-02 1:07

abhinarulkar

16-Sep-02 1:07

Hi All,
I need to develop a password filter, which would enforce minimum password length and other composition rules for the passwords.How do I develop such a password filter.
Can anyone help please?
Thanks,
Abhishek.

Learning is a never ending process of Life.

Re: Developing a password filter

Roger Stewart16-Sep-02 13:46

Roger Stewart

16-Sep-02 13:46

You could start by writing a custom Data Validation (DDV) routine to enforce the minimum length, and then your other rules. Take a look at TN026: DDX and DDV Routines[^]

Roger Stewart
"I Owe, I Owe, it's off to work I go..."

pardon my french

Zizilamoroso16-Sep-02 0:45

Zizilamoroso

16-Sep-02 0:45

Is it possible to configure the visual studio 6 interface so, that language doesn't matter?

I always get language errors when I want to re-open the resource after transferring the project to another machine. After the error, the resource doesn't load anymore. It says something about french language, but I've never ever installed something regarding a french language, and both win98 are english versions.

Can somebody help me out here?

error msg: Code page 1252 is required to support a french language resource in this file ...

There are absolutely NO french resources in my project, but after compiling the resource, and opening it with a text editor, the resource is filled with loads of french bullshit I've never asked for. So, it's visual studio that adds this by itself. How can I change this???

[VISUAL STUDIO 6.0] [MFC] [WIN98/2]

Re: pardon my french

Bill Wilson16-Sep-02 7:01

Bill Wilson

16-Sep-02 7:01

Open up the project .dsp (or maybe .dsw) You should find a line that sets the language. Something like:

<blanguage=french>

Just delete it. I had this problem with some code from China several years ago. Unfortunately, I don't remember the details.

vm_scroll

suresh_sathya15-Sep-02 23:44

suresh_sathya

15-Sep-02 23:44

Hi,
I place listbox in a small window.The listbox is a child of the window,but
when i move the vscroll bar of the listbox,the wm_vscroll message is not
getting generaterated.

How to convert POSITION to int?

John Wong15-Sep-02 23:37

John Wong

15-Sep-02 23:37

The CListBox uses int to index and displays segment of the CList,
while CList using the POSITION to index.
How to calculate int index to get correct POSITION?
Confused | :confused:

Re: How to convert POSITION to int?

Anonymous15-Sep-02 23:56

Anonymous

15-Sep-02 23:56

theList.GetAt ( theList.FindIndex ( intValue ) ) ;

Re: How to convert POSITION to int?

John Wong16-Sep-02 0:23

John Wong

16-Sep-02 0:23

Thank!

How to display icon under this situation?

Joecodepro15-Sep-02 23:21

Joecodepro

15-Sep-02 23:21

I have use the sdk to create and show a skined window , and it runs well . But the only problem is since I create the window using the WS_POPUP style( is this the reason ?) , there isn't any icon being shown when the application has been minimized ( I have set an icon in the window class ), what I need is that when I minimized my skined-window , an specified icon should be shown on its left side , the bar on the taskbar( you know , most of the window do like this. )
How can I do this ?

Re: How to display icon under this situation?

Mike Nordell15-Sep-02 23:48

Mike Nordell

15-Sep-02 23:48

Look up WS_EX_TOOLWINDOW vs. WS_EX_APPWINDOW. Use the latter to get a tab ("button") in the taskbar.

Re: How to display icon under this situation?

Anonymous16-Sep-02 23:14

Anonymous

16-Sep-02 23:14

I have found the key , just add the WM_SYSMENU to the window style , then let the window draw the icon for you .

Error control

Raphael Kindt15-Sep-02 21:59

Raphael Kindt

15-Sep-02 21:59

Hello world...
Anybody have a good idea to control the errors in a program?
I often return an error ID from a function...
I've already use Exception but I found that not very usefull...
I've tried with a specific thread which uses a loop. Like this:

volatile int error = 0;  // global
CEvent g_eventStart;  // global

UINT CatchErrorThread(LPVOID pParam)
{
   CWnd* MyDlg = CWnd::FromHandle((HWND)pParam);
   do {
      ::WaitForSingleObject(g_eventStart, INFINITE);
      g_eventStart.ResetEvent();
      switch(error) {
      case 0:
         break;
      case 1:
         MyDlg->MessageBox("error message 1", "catch error", MB_ICONERROR | MB_OK);
         break;
      case 2:
         MyDlg->MessageBox("error message 2", "catch error", MB_ICONERROR | MB_OK);
         break;
      default:
         MyDlg->MessageBox("unknown message", "catch error", MB_ICONERROR | MB_OK);
         break;
      }
   } while(error != 0);
   return 0;
}

There is not another solution to make pass the errors???
Anybody have another solution???

Thanks in advance...

Hello World!!! Smile | :)

from Raphaël

Re: Error control

Bill Wilson16-Sep-02 5:48

Bill Wilson

16-Sep-02 5:48

Pretty hard to tell what this code is supposed to accomplish. Is the variable error assigned somewhere? It appears to be undefined in your code. Maybe you need something like

int error = g_eventStart.ResetEvent();

although that is just a guess. The code you presented would, of course, not even compile, unless error is some kind of global, set by the ResetEvent method?

<small>
You wrote:

I've already use Exception but I found that not very usefull...
I've tried with a specific thread which uses a loop. Like this:


</small>

This makes it sound like you are trying to use a thread in a loop to perform the same function as exception handling. Sorry, but that makes absolutely no sense. Handling errors is one topic, but I fail to see what a separate thread has to do with anything.

I think you should try harder with exceptions.

Re: Error control

Raphael Kindt16-Sep-02 6:42

Raphael Kindt

16-Sep-02 6:42

My aim is to catch an error ID and display a message error corresponding to this ID. I try to find any methods who can help me...

My code before work correctly...
the variable error is global.
When a error occure (for example a NULL handle is an error), I do this :

if(!MyHandle) {
   error = ERR_001; // with #define ERR_001 1
   g_eventStart.SetEvent();  // I display the error message with this ID
}

The advantage is that I can do that in my program anywhere.

But, yes, I'm a not an expert with Exception...
Thus this thread with his loop is doing the same thing as Exception!
I didn't know that!

What methods use you to catch error?

thanks

Hello World!!! Smile | :)

from Raphaël

Re: Error control

Bill Wilson16-Sep-02 6:54

Bill Wilson

16-Sep-02 6:54

You could do something like this...

in the calling program

   try {
      int x = SomeProcedure();
...

   }
   catch (CMyException *e)
   {
     // Do something with the error return
        LogError(e->nMyErrorNum....

     delete e;
   }



int SomeProcedure()
{
   n = new CMyClass();
   if (!n)  {
       CMyException* pErr = new CMyException(TRUE);
       pErr->errNum = ERRORNUMBERIWANTTOUSE;
       throw pErr;
   }
...


Define class CMyException

class CMyException : public CException {
   int nMyErrorNum;

...




 

Hope this helps

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