BUG: Object References Might Not Be Released Properly (190067)
The information in this article applies to:
- Microsoft Visual Basic Learning Edition for Windows 6.0
- Microsoft Visual Basic Professional Edition for Windows 6.0
- Microsoft Visual Basic Enterprise Edition for Windows 6.0
This article was previously published under Q190067 SYMPTOMS
If a function call to an object returns a Variant and the Variant is not
assigned to a local variable, Visual Basic might not dereference the object
correctly. As a result, a new thread is created in the object's process
space each time the function is called.
RESOLUTION
Assign the function's return value to a local variable, regardless of
whether or not it is needed.
Example
The class clsMyObject has a function called MyVariantFunction that returns
a Variant:
Public Function MyVariantFunction() As Variant
If the return result of the function is not needed, calling the function
without assigning the return value might cause new threads to be created:
Public Sub TestFunction()
clsMyObject.MyVariantFunction
End Sub
To avoid the unnecessary creation of threads, assign the function's return
value to a local variable, regardless of whether or not it is needed:
Public Sub TestFunction()
Dim vReturnValue As Variant
' Although this will not be used, it guarantees proper dereferencing.
vReturnValue = clsMyObject.MyVariantFunction
End Sub
STATUS
Microsoft has confirmed this to be a bug in the Microsoft products listed
at the beginning of this article. We are researching this bug and will post
new information here in the Microsoft Knowledge Base as it becomes
available.
MORE INFORMATION
This type of behavior usually occurs when returning variant arrays that
contain user-defined types.
| Modification Type: | Major | Last Reviewed: | 5/12/2003 |
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| Keywords: | kbBug kbpending KB190067 |
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