Memory problem...?

I've been trying to figure out this what's wrong with my program with little success, so I'm going to post what I've been experiencing to see if anyone can figure it out. Basically, when my program hit's a cetain amount of memory usage (aproximately 9-10 mb), the whole thing goes completly screwy. First of all, on the control I wrote which is the program's primary memory guzzler, whenever it tries to redraw itself it causes various parts of the screen to turn grey. Even parts it shouldn't be able to draw over like the start menu. On top of that, I keep getting error messages when using API funtions (just the ones that handle drawing) under circumstances where they worked perfect before the problem was triggered. But despite all this, the VC++ debugger reports absolutely nothing unusual. If anybody has had a similar problem while programming a windows app I'd like to know about it because I have absolutely no clue what's going on.

It looks like you're leaking GDI handles.

Maybe... I'll post my draw routine so you can take a look at it

Code:

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LRESULT DasmViewer_OnPaint(DASMVIEWERINFO * dvp, WPARAM wParam, LPARAM lParam)
{

        HDC          hdc;
        HDC                        hdcTemp;
        HBITMAP      hbmNew;
        HBITMAP      hbmOld;
        PAINTSTRUCT  ps;
        HANDLE      hOldFont;
        RECT        rect;
        RECT        titleBarRect;
        RECT        selectedRect;
        UINT        offsetMod = 0;
        char *      string;
        int                        iRow;
        int          iCol;
        int          i;

        //Get a device context for this window
        if(wParam)
                hdc = (HDC)wParam;
        else
                hdc = BeginPaint(dvp->hWnd, &ps);               

        //Work out where to draw
        GetClientRect(dvp->hWnd, &rect);

        //Set up to draw to a temporary bitmap
        hdcTemp = CreateCompatibleDC(hdc);

        hbmNew = CreateCompatibleBitmap(hdc, rect.right - rect.left, rect.bottom - rect.top);

        hbmOld = SelectObject(hdcTemp, hbmNew);

        //Set the font
        hOldFont = SelectObject(hdcTemp, dvp->hFont);

        //Paint the background black
        FillRect(hdcTemp, &rect, CreateSolidBrush(dvp->bgColor));

        SetTextColor(hdcTemp, dvp->fgColor);

        SetBkMode(hdcTemp, TRANSPARENT);

        for(iCol = 0; iCol < dvp->collumns; iCol++)
        {
                DrawString(hdcTemp, rect, dvp->colTitles[iCol], dvp->colPstns[iCol], dvp->rowTopPad, NULL, -1);
        }

        dvp->tempOffset = dvp->offset;

        if(dvp->tempFileInfo.hFile)
        {

                dvp->rowOffset[0] = dvp->offset;

                //Calculate the offset for each row
                for(iRow = 1; iRow <= dvp->rows; iRow++)  //Also Calculates one row ahead in order to set rowCurrentBytes
                        dvp->rowOffset[iRow] = dvp->rowOffset[iRow - 1] + dvp->fixedOpcodeBytes;

                for(iRow = 0; iRow < dvp->rows && (dvp->tempOffset  < dvp->tempFileInfo.fileSizeLow || (!dvp->tempFileInfo.fileSizeLow && !iRow)); iRow++)
                {
                        dvp->rowCurrentBytes = dvp->rowOffset[iRow + 1] - dvp->rowOffset[iRow];

                        for(iCol = 0; iCol < dvp->collumns; iCol++)
                        {
                                if(dvp->colPstns[iCol] > -1)
                                {
                                        string = dvp->colTextFuncs[iCol](dvp);                                       

                                        //Update charWidthArrays and charWidthArraysTotals as neccessary
                                        if(dvp->colLongestLength[iCol] < (dvp->colCurrentLength[iCol] = (int) strlen(string)))
                                        {
                                                for(i = dvp->colLongestLength[iCol]; i < dvp->colCurrentLength[iCol]; i++)
                                                        dvp->charWidthArrays[iCol][i] = dvp->charWidth;

                                                if(dvp->colDrawGroups[iCol])
                                                {
                                                                for(i = dvp->colLongestLength[iCol] + (dvp->colLongestLength[iCol] % dvp->colDrawGroups[iCol]) + (dvp->colDrawGroups[iCol] - 1); i <= dvp->colCurrentLength[iCol]; i += dvp->colDrawGroups[iCol])
                                                                        dvp->charWidthArrays[iCol][i] +=dvp->colGroupSpace[iCol];
                                                }

                                                if(dvp->colLongestLength[iCol] == 0)
                                                                dvp->charWidthTotals[iCol][0] = dvp->charWidthArrays[iCol][0];

                                                for(i = dvp->colLongestLength[iCol] + !dvp->colLongestLength[iCol]; i < dvp->colCurrentLength[iCol]; i++)
                                                                dvp->charWidthTotals[iCol][i] = dvp->charWidthArrays[iCol][i] + dvp->charWidthTotals[iCol][i - 1];

                                                dvp->colLongestLength[iCol] = dvp->colCurrentLength[iCol];

                                        }

                                        //Paint the highlighting
                                        if(iCol == dvp->colEditable)
                                                if(dvp->selectedAreaBeginIndex > dvp->tempOffset * dvp->colCharsPerByte[iCol] && dvp->selectedAreaEndIndex <= (dvp->tempOffset * dvp->colCharsPerByte[iCol]) + dvp->colCurrentLength[iCol])
                                                {
                                                        selectedRect.top    = dvp->rowHeightTotals[iRow] + dvp->rowTopPad + 1;
                                                        selectedRect.bottom = dvp->rowHeightTotals[iRow] + dvp->rowHeight + dvp->rowTopPad;
                                                        selectedRect.left  = dvp->colPstns[iCol];
                                                        selectedRect.right  = dvp->colPstns[iCol] + dvp->charWidthTotals[iCol][dvp->colCurrentLength[iCol] - 1] - dvp->colGroupSpace[iCol] * !(dvp->colCurrentLength[iCol] % dvp->colDrawGroups[iCol]) + 3;
                                                       
                                                        if(dvp->selectedAreaBeginIndex - 1 > dvp->rowOffset[iRow] * dvp->colCharsPerByte[iCol])
                                                                selectedRect.left += dvp->charWidthTotals[iCol][dvp->selectedAreaBeginIndex - dvp->rowOffset[iRow] * dvp->colCharsPerByte[iCol] - 2];

                                                        if(dvp->selectedAreaEndIndex < dvp->rowOffset[iRow + 1] * dvp->colCharsPerByte[iCol])
                                                                selectedRect.right -= dvp->charWidthTotals[iCol][dvp->rowOffset[iRow + 1] * dvp->colCharsPerByte[iCol] - dvp->selectedAreaEndIndex - 1];

                                                        FillRect(hdcTemp, &selectedRect, CreateSolidBrush(dvp->slBgColor));
                                                }

                                        //Draw the text
                                        DrawString(hdcTemp, rect, string, dvp->colPstns[iCol], (dvp->rowHeight * (iRow + 1)) + dvp->rowTopPad + (dvp->barWidth * 2), dvp->charWidthArrays[iCol], -1);

                                        free((void *) string);
                                }
                        }

                        dvp->tempOffset += dvp->rowCurrentBytes;
                }
        }
        SetBkColor(hdcTemp, dvp->bgColor);

        //Paint a bar under the title row
        titleBarRect = rect;

        titleBarRect.top = dvp->rowHeight + dvp->rowTopPad;
        titleBarRect.bottom = dvp->rowHeight + dvp->rowTopPad + dvp->barWidth;

        FillRect(hdcTemp, &titleBarRect, CreateSolidBrush(dvp->fgColor));

        //Update the control's display
        BitBlt(hdc, rect.left, rect.top, rect.right - rect.left, rect.bottom - rect.top, hdcTemp, 0, 0, SRCCOPY);

        //Release paint objects
        SelectObject(hdcTemp, hbmOld);

        DeleteObject(hbmNew);
        DeleteDC(hdcTemp);
        DeleteDC(hdc);

        EndPaint(dvp->hWnd, &ps);

        return FALSE;

}

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1. Code:

   ---

   DeleteDC(hdc);

   ---

   We should not delete a DC obtained from BeginPaint, nor the hdc passed in the wParam of WM_ERASEBKGND. You can blame the documentation(or lack thereof) on this one.
2. Code:

   ---

   hOldFont = SelectObject(hdcTemp, dvp->hFont);

   ---

   There is no matching call to select hOldFont back in.
3. Code:

   ---

           //Paint the background black
        FillRect(hdcTemp, &rect, CreateSolidBrush(dvp->bgColor));

   ---

   The return value of CreateSolidBrush() is leaking.
4. Code:

   ---

           FillRect(hdcTemp, &selectedRect, CreateSolidBrush(dvp->slBgColor));

   ---

   The return value of CreateSolidBrush() is leaking.
5. Code:

   ---

           FillRect(hdcTemp, &titleBarRect, CreateSolidBrush(dvp->fgColor));

   ---

   The return value of CreateSolidBrush() is leaking.

That's some pretty advanced code you have there! Just out of curiosity, what OS are you running? The idea of modern (ie. 2000, XP) OSs is that leaks in one application shouldn't overly effect the rest of the system. If you're running one of those OSs, it would suggest that they haven't quite reached that point yet.

Quote:

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Originally Posted by anonytmouse

1. Code:

   ---

   DeleteDC(hdc);

   ---

   We should not delete a DC obtained from BeginPaint, nor the hdc passed in the wParam of WM_ERASEBKGND. You can blame the documentation(or lack thereof) on this one.
2. Code:

   ---

   hOldFont = SelectObject(hdcTemp, dvp->hFont);

   ---

   There is no matching call to select hOldFont back in.
3. Code:

   ---

           //Paint the background black
        FillRect(hdcTemp, &rect, CreateSolidBrush(dvp->bgColor));

   ---

   The return value of CreateSolidBrush() is leaking.
4. Code:

   ---

           FillRect(hdcTemp, &selectedRect, CreateSolidBrush(dvp->slBgColor));

   ---

   The return value of CreateSolidBrush() is leaking.
5. Code:

   ---

           FillRect(hdcTemp, &titleBarRect, CreateSolidBrush(dvp->fgColor));

   ---

   The return value of CreateSolidBrush() is leaking.

That's some pretty advanced code you have there!

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Thanks, but I think I may be coding above my head here since I've been having a lot of trouble debugging it...

Quote:

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Originally Posted by anonytmouse

Just out of curiosity, what OS are you running? The idea of modern (ie. 2000, XP) OSs is that leaks in one application shouldn't overly effect the rest of the system. If you're running one of those OSs, it would suggest that they haven't quite reached that point yet.

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Yea, I'm running XP. And after running that code I think I'm going to have to restart my comp to get my right click menues to look right again :p. BTW, CreateSolidBrush is another example of inadequite documentation because nowhere does it say that you have to free the handle you create with it (well ok, except in the example code which I didn't bother to read till just now.)