Resource Leak in Toolbar ??????

[Chris Boss]

I have found a quirk with the Common control - Toolbar.

I have a program where I create a Toolbar on a Window, then later destroy the Toolbar, and then create a Toolbar again (it is a Visual Designer for Designing Dialogs).

If I use my own Bitmap for the Toolbar and after I destroy the Toolbar, I delete the Bitmap and then recreate the Toolbar again from scratch, I have no problem.

My problem is when I create a Toolbar using the "builtin" Bitmaps in the Common Control DLL. There are 4 builtin Bitmaps, available in the Common control DLL, for use with the Toolbar. If you use the correct constant, instead of a Bitmap handle, when creating the Toolbar, it will automatically use one of the Builtin Bitmaps.

When I use a Builtin Bitmap and then create, destroy, create , destroy the Toolbar over and over again, I get a very bad Resource leak. Even if you use one Toolbar in a program (where it remains until app terminates) and then run the program many times (run it, quit it, run it, quit it), the same Resource Leak occurs.

Has anyone every experienced a problem with a Resource Leak, when using the Toolbar control with the Builtin Bitmaps ????

[Lance Edmonds]

Did you try using MemCheck? It often suggests possible remedies for resource leaks. Also, did you search MSDN or MSKB for relevant information?


-------------
Lance
PowerBASIC Support
( mailto:[email protected][email protected]</A> )

[Chris Boss]

I did some testing.

I tried using the PBNote sample that comes with PB 5.0 and it displays the same behavior. So I gutted the PBNote program and left only the window and Toolbar to create the following "Test" program and it also displays the same behavior of a memory leak.

This is how you will see the Resource leak:

(1) Compile the program below:
(2) Create an Icon on your Desktop to run the program
(3) Run the "Resource Meter" (On the Start menu under "Accessories"/"System Tools"/"Resource Meter" )
(4) Move the Resource Meter to Bottom Right corner of desktop out of the way
(5)Now run the test by Running the Test program (below) over and over again. Simple run it, then click the X (close) icon and quit and run it again.

The Resource leak will NOT show up until you have run the program 30 times.
At this point it will progressively leak more and more resources. When you get to 70 times, you will start to get to a point where resources will drop low enough to cause problems for the system (below 80%)

Now, you may say, "big deal" since nobody is going to run your program 70 times at one sitting, but the problem appears to grow exponentially with the more programs running simultaneously with Toolbars that use the BuiltIn Bitmaps. If you were to create a Test program with multiple windows, with a Toolbar on each window, then you will begin to see Resource problems as soon after running your program 10 times.

The reason, I found this problem is that in my "Visual Designer" for EZGUI (for PB DLL) it is possible to create and destroy a window many times while developing Dialogs. Since I make the BuiltIn Bitmaps for Toolbars available, the problem showed up.

My code has been tested on Win 95 only. I do not know if Win 98/NT/2000 has the same problem.

' ** Eliminate unnecessary macros
%NOANIMATE    = 1
%NODRAGLIST   = 1
%NOHEADER     = 1
%NOIMAGELIST  = 1
%NOLISTVIEW   = 1
%NOTABCONTROL = 1
%NOTRACKBAR   = 1
%NOTREEVIEW   = 1
%NOUPDOWN     = 1

'------------------------------------------------------------------------------

$COMPILE EXE

$INCLUDE "WIN32API.INC"
$INCLUDE "COMMCTRL.INC"

'------------------------------------------------------------------------------

'------------------------------------------------------------------------------

GLOBAL hInst      AS LONG
GLOBAL hToolbar   AS LONG
GLOBAL hWndMain   AS LONG

'------------------------------------------------------------------------------

FUNCTION WinMain (BYVAL hInstance     AS LONG, _
                  BYVAL hPrevInstance AS LONG, _
                  lpCmdLine           AS ASCIIZ PTR, _
                  BYVAL iCmdShow      AS LONG) AS LONG

  LOCAL Msg         AS tagMsg
  LOCAL wndclass    AS WndClassEx
  LOCAL szClassName AS ASCIIZ * 80
  LOCAL hWnd        AS LONG
  LOCAL hMenu       AS LONG
  LOCAL hAccel      AS LONG
  LOCAL hRichEd     AS LONG
  LOCAL vi          AS OSVERSIONINFO

  hInst                  = hInstance


' ** Register Main Window Class
  szClassName            = "TBUG32"
  wndclass.cbSize        = SIZEOF(WndClass)
  wndclass.style         = %CS_HREDRAW OR %CS_VREDRAW
  wndclass.lpfnWndProc   = CODEPTR( WndProc )
  wndclass.cbClsExtra    = 0
  wndclass.cbWndExtra    = 0
  wndclass.hInstance     = hInstance
  wndclass.hIcon         = %NULL
  wndclass.hCursor       = LoadCursor( %NULL, BYVAL %IDC_ARROW )
  wndclass.hbrBackground = %COLOR_APPWORKSPACE + 1
  wndclass.lpszMenuName  = %NULL
  wndclass.lpszClassName = VARPTR( szClassName )
  wndclass.hIconSm       = LoadIcon( hInstance, BYVAL %IDI_APPLICATION )
  RegisterClassEx wndclass


  ' Create a window using the registered class
  hWndMain = CreateWindow("TBUG32", _                  ' window class name
                          "Test Toolbar Bug", _                  ' window caption
                          %WS_OVERLAPPEDWINDOW, _      ' window style
                          %CW_USEDEFAULT, _            ' initial x position
                          %CW_USEDEFAULT, _            ' initial y position
                          %CW_USEDEFAULT, _            ' initial x size
                          %CW_USEDEFAULT, _            ' initial y size
                          %NULL, _                     ' parent window handle
                          %NULL, _                     ' window menu handle
                          hInstance, _                 ' program instance handle
                          BYVAL %NULL)                 ' creation parameters

  ShowWindow hWndMain, iCmdShow
  UpdateWindow hWndMain

' ** Message handler loop
  WHILE ISTRUE(GetMessage(Msg, BYVAL %NULL, 0, 0))
        TranslateMessage Msg
        DispatchMessage Msg
  WEND

  FUNCTION = msg.wParam

END FUNCTION  ' WinMain

'------------------------------------------------------------------------------

FUNCTION WndProc (BYVAL hWnd AS LONG, BYVAL wMsg AS LONG, _
                  BYVAL wParam AS LONG, BYVAL lParam AS LONG) AS LONG

  LOCAL dwProc      AS DWORD
  LOCAL tbab        AS TBADDBITMAP
  LOCAL lpToolTip   AS TOOLTIPTEXT PTR
  LOCAL cc          AS CLIENTCREATESTRUCT
  LOCAL hMdi        AS LONG
  LOCAL Style       AS LONG
  LOCAL f           AS STRING
  LOCAL Buffer      AS STRING
  LOCAL Path        AS STRING
  LOCAL RetVal      AS LONG
  LOCAL hFile       AS LONG

  STATIC tRect      AS RECT
  STATIC zText      AS ASCIIZ * 255
  STATIC ToolHeight AS LONG
  STATIC StatHeight AS LONG

  STATIC hEdit      AS LONG

  SELECT CASE wMsg

    CASE %WM_CREATE

      DIM tbb(0 to 6) AS STATIC TBBUTTON

      ' Initialize the common controls
      InitCommonControls

      ' Fill the TBBUTTON array with button information
      tbb(0).iBitmap   = %STD_FILENEW
      tbb(0).idCommand = 1000
      tbb(0).fsState   = %TBSTATE_ENABLED
      tbb(0).fsStyle   = %TBSTYLE_BUTTON
      tbb(0).dwData    = 0
      tbb(0).iString   = 0

      tbb(1).iBitmap   = %STD_FILEOPEN
      tbb(1).idCommand = 1010
      tbb(1).fsState   = %TBSTATE_ENABLED
      tbb(1).fsStyle   = %TBSTYLE_BUTTON
      tbb(1).dwData    = 0
      tbb(1).iString   = 0

      tbb(2).iBitmap   = %STD_FILESAVE
      tbb(2).idCommand = 1020
      tbb(2).fsState   = %TBSTATE_ENABLED
      tbb(2).fsStyle   = %TBSTYLE_BUTTON
      tbb(2).dwData    = 0
      tbb(2).iString   = 0

      tbb(3).iBitmap   = 0
      tbb(3).idCommand = 0
      tbb(3).fsState   = %TBSTATE_ENABLED
      tbb(3).fsStyle   = %TBSTYLE_SEP
      tbb(3).dwData    = 0
      tbb(3).iString   = 0

      tbb(4).iBitmap   = %STD_CUT
      tbb(4).idCommand = 1030
      tbb(4).fsState   = %TBSTATE_ENABLED
      tbb(4).fsStyle   = %TBSTYLE_BUTTON
      tbb(4).dwData    = 0
      tbb(4).iString   = 0

      tbb(5).iBitmap   = %STD_COPY
      tbb(5).idCommand = 1040
      tbb(5).fsState   = %TBSTATE_ENABLED
      tbb(5).fsStyle   = %TBSTYLE_BUTTON
      tbb(5).dwData    = 0
      tbb(5).iString   = 0

      tbb(6).iBitmap   = %STD_PASTE
      tbb(6).idCommand = 1050
      tbb(6).fsState   = %TBSTATE_ENABLED
      tbb(6).fsStyle   = %TBSTYLE_BUTTON
      tbb(6).dwData    = 0
      tbb(6).iString   = 0


      ' Create the toolbar window
      hToolbar = CreateToolbarEx(hWnd, %WS_CHILD, _
                                 900, 12, %HINST_COMMCTRL, %IDB_STD_LARGE_COLOR, _
                                 tbb(0), 7, 0, 0, 100, 30, LEN(TBBUTTON))
      ' Display the toolbar
      SendMessage hToolbar, %TB_AUTOSIZE, 0, 0
      ShowWindow hToolbar, %SW_SHOW

      EXIT FUNCTION

    CASE %WM_SIZE
      IF wParam <> %SIZE_MINIMIZED THEN
        SendMessage hToolbar, wMsg, wParam, lParam
       END IF
      EXIT FUNCTION

    CASE %WM_DESTROY
      PostQuitMessage 0
      FUNCTION = 0
      EXIT FUNCTION

  END SELECT

  FUNCTION = DefWindowProc(hWnd, wMsg, wParam, lParam)

END FUNCTION