Knowledge Base

FIX: GetSetting Function Is Leaking Handles

Article ID: 171842

Article Last Modified on 12/10/2003

APPLIES TO

Microsoft Visual Basic 5.0 Control Creation Edition
Microsoft Visual Basic 5.0 Learning Edition
Microsoft Visual Basic 5.0 Professional Edition
Microsoft Visual Basic 5.0 Enterprise Edition

This article was previously published under Q171842

SYMPTOMS

The GetSetting function leaks one handle per use of the function.

CAUSE

The GetSetting function was not calling RegClose on the key that it was opening. This caused the key to be left open each time the function was called.

RESOLUTION

Install Visual Studio 97 Service Pack 2 (SP2) or use the registry API functions from the article in the REFERENCES section below.

This problem does not occur on Windows 2000.

STATUS

Microsoft has confirmed this to be a bug in the Microsoft products listed at the beginning of this article. This bug has been fixed in Visual Studio 97 Service Pack 2.

For more information on the Visual Studio 97 Service Pack 2, please see the following article in the Microsoft Knowledge Base:

170365 : INFO: Visual Studio 97 Service Packs - What, Where, and Why

For a list of the Visual Basic 5.0 bugs that were fixed in the Visual Studio 97 Service Pack 2, please see the following article in the Microsoft Knowledge Base:

171554 : INFO: Visual Basic 5.0 Fixes in Visual Studio 97 Service Pack 2

MORE INFORMATION

Steps to Reproduce Behavior

Create a Standard EXE project and add a CommandButton (Command1) to the default form (Form1).

Put the following code in Command1's click event:

      Private Sub Command1_Click()
          Dim LoopCount As Integer

          Call SaveSetting("MyApp", "Options", "TestValue", "Hello")
          For LoopCount = 1 To 100
              Call GetSetting("MyApp", "Options", "TestValue")
          Next LoopCount
      End Sub

Under Windows NT, start the Windows NT Task Manager, select the Processes tab, click on menu View | Select Columns and turn on the handle count column. (Under Windows 95, Windows 98, and Windows Me, a third-party utility would be required to monitor the handle count for a process.)
Run the application and click the Command1 button. Note that the handle count in the Task manager increase by 100 for every button click.

The expected result is that the handle should be released or should be re-used on subsequent calls.

REFERENCES

For more information on the Registry API functions, please see the following article in the Microsoft Knowledge Base:

145679 : HOWTO: Use the Registry API to Save and Retrieve Setting

Keywords: kbbug kbfix kbregistry kbvbp500fix KB171842

Microsoft KB Archive/171842

Contents