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Q312218: BUG: Deadlock in Multithreaded Process Using Declare Statements

Article: Q312218
Product(s): Microsoft Visual Basic for Windows
Version(s): 6.0
Operating System(s): 
Keyword(s): 
Last Modified: 16-APR-2002

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The information in this article applies to:

- Microsoft Visual Basic Enterprise Edition for Windows, version 6.0 
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SYMPTOMS
========

If a multithreaded process hosts in-process Visual Basic ActiveX components
(.dll or .ocx files), the multithreaded process may experience a deadlock or may
stop responding (hang).

Examples of multithreaded processes include:

- Microsoft COM+ (Dllhost.exe)
- Microsoft Internet Information Server (Inetinfo.exe)
- Microsoft Transaction Server (Mtx.exe)

CAUSE
=====

There are many causes for a deadlock in a multithreaded process. One possible
cause is the use of Visual Basic 6.0 ActiveX components with Declare statements
for application programming interfaces (APIs).

RESOLUTION
==========

To work around this problem, remove the Declare statements in the ActiveX .dll
or .ocx projects, and use a type library to declare those APIs instead. For
additional information about how to create and use a type library, click the
article number below to view the article in the Microsoft Knowledge Base:

  Q189133 HOWTO: Make C DLL More Accessible to VB with a Type Library



STATUS
======

Microsoft has confirmed this to be a bug in the Microsoft products listed at the
beginning of this article.


Additional query words: in-proc hang DLL OCX IIS MTS multi-threaded

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Keywords          :  
Technology        : kbVBSearch kbAudDeveloper kbZNotKeyword6 kbZNotKeyword2 kbVB600Search kbVB600
Version           : :6.0
Issue type        : kbbug
Solution Type     : kbnofix

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