DOCUMENT:Q257621  28-JUL-2001  [vbwin]
TITLE   :FIX: Resources Lost When Loading Modal Form from ActiveX Server
PRODUCT :Microsoft Visual Basic for Windows
PROD/VER:WINDOWS:6.0
OPER/SYS:
KEYWORDS:kbActiveX kbResource kbVBp kbVBp600bug kbGrpDSVB kbDSupport kbVS600sp4fix kbVS600sp5fix

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The information in this article applies to:

 - Microsoft Visual Basic Learning Edition for Windows, version 6.0, on platform(s):
    - the operating system: Microsoft Windows 95 
    - the operating system: Microsoft Windows 98 
 - Microsoft Visual Basic Professional Edition for Windows, version 6.0, on platform(s):
    - the operating system: Microsoft Windows 95 
    - the operating system: Microsoft Windows 98 
 - Microsoft Visual Basic Enterprise Edition for Windows, version 6.0, on platform(s):
    - the operating system: Microsoft Windows 95 
    - the operating system: Microsoft Windows 98 
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SYMPTOMS
========

When a client loads a modal form from an ActiveX EXE server and leaves it up for
an extended period of time, the server may experience a severe resource leak
under Microsoft Windows 95 and Microsoft Windows 98. This behavior happens even
without any user interaction with the application. If you close the modal form
to shut down the server, the resource recovers. The resource loss does not occur
with a non-modal form.

CAUSE
=====

The client application is in a frozen state waiting for the modal form to go
away. During this time the message queue fills up and, therefore, system
resources are lowered.

STATUS
======

Microsoft has confirmed that this is a bug in the Microsoft products that are
listed at the beginning of this article. This bug was corrected in the latest
service pack for Visual Studio 6.0.

For additional information about Visual Studio service packs, click the following
article numbers to view the articles in the Microsoft Knowledge Base:

   Q194022 INFO: Visual Studio 6.0 Service Packs, What, Where, Why

   Q194295 HOWTO: Tell That a Visual Studio Service Pack Is Installed

To download the latest Visual Studio service pack, visit the following Microsoft
Web site:

   http://msdn.microsoft.com/vstudio/downloads/updates.asp

MORE INFORMATION
================

Steps to Reproduce Behavior
---------------------------

1. Create a new ActiveX EXE project and rename it to ModalSvr. Class1 is created
   by default.

2. Paste the following code in Class1:

   Public Sub ShowForm()
       Form1.Show vbModal
   End Sub

3. From the Project menu, add a new form, Form1.

4. Save and compile the project. ModalSvr.exe is made and registered on the
   computer.

5. Create a new Standard EXE project as the client. Form1 is created by default.

6. Add one TextBox and one CommandButton to Form1.

7. Paste the following code to the code window of Form1:

   Dim obj As Object
   Private Sub Command1_Click()
       Set obj = CreateObject("ModalSvr.Class1")
       obj.ShowForm
       Set obj = Nothing
   End Sub

   Private Sub Form_Load()
       Text1.Text = ""
   End Sub

   Private Sub Text1_KeyDown(KeyCode As Integer, Shift As Integer)
       If Not ((KeyCode = vbKeyF4) And (Shift = vbAltMask)) Then
          Command1_Click
       End If
   End Sub

8. On the Start menu, choose Programs, choose Accessories, choose System Tools,
   and then choose Resource Meter. If Resource Meter is not available, on the
   Start menu, choose Control Panel, choose Add/Remove Programs, and then choose
   the Windows Setup tab to add it.

9. Press the F5 key to run the client. Click on the TextBox and press the F4 key
   to launch the server and its modal form.

10. Watch the Resource Meter and note that the System and User resources
   gradually go down. Closing the modal form to shut down the server recovers
   the resources. If you use the KeyUp event or click Command1 to launch the
   modal form, the leak is not as severe.

Additional query words: sp4

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Keywords          : kbActiveX kbResource kbVBp kbVBp600bug kbGrpDSVB kbDSupport kbVS600sp4fix kbVS600sp5fix 
Technology        : kbVBSearch kbAudDeveloper kbZNotKeyword6 kbZNotKeyword2
Version           : WINDOWS:6.0
Issue type        : kbbug
Solution Type     : kbfix

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