Microsoft KB Archive/899282

= FIX: You may experience a deadlock condition when you host DLLs that are created in Visual Basic 6.0 in a multithreaded environment =

Article ID: 899282

Article Last Modified on 10/18/2005

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APPLIES TO


 * Microsoft Visual Basic 6.0 Professional Edition

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SYMPTOMS
When you host dynamic link libraries (DLLs) that are created in Microsoft Visual Basic 6.0 in a multithreaded environment, you may experience a deadlock condition.

Note A multithreaded environment may be a Microsoft COM+ application or a Web application that is running in Microsoft Internet Information Services (IIS).



CAUSE
This problem occurs when one thread tries to load the Msvbvm60.dll file as a resource DLL at the same time that another thread is responding to the WM_WININICHANGE event message.

Typically, this problem is an uncommon scenario because of the following:
 * When a Visual Basic 6.0 DLL has loaded the Msvbvm60.dll file as a resource DLL, the Visual Basic 6.0 DLL stores the required data and does not have to reload the Msvbvm60.dll file.
 * Most Visual Basic 6.0 components that are hosted in a multithreaded environment do not use the Printer object or any user interface (UI) objects that require the Msvbvm60.dll file.
 * Typically, the WM_WININICHANGE event message is only sent to a process as a broadcast message when a Microsoft Windows setting has changed. Under ordinary server operations, the WM_WININICHANGE event message is rarely sent.



Hotfix information
A supported hotfix is now available from Microsoft, but it is only intended to correct the problem that this article describes. Apply it only to systems that are experiencing this specific problem.

To resolve this problem, contact Microsoft Product Support Services to obtain the hotfix. For a complete list of Microsoft Product Support Services telephone numbers and information about support costs, visit the following Microsoft Web site:

http://support.microsoft.com/contactus/?ws=support

Note In special cases, charges that are ordinarily incurred for support calls may be canceled if a Microsoft Support Professional determines that a specific update will resolve your problem. The usual support costs will apply to additional support questions and issues that do not qualify for the specific update in question.

Prerequisites
No prerequisites are required.

Restart requirement
You do not have to restart the computer after you apply this hotfix.

Hotfix replacement information
This hotfix does not replace any other hotfixes.

File information
The English version of this hotfix has the file attributes (or later file attributes) that are listed in the following table. The dates and times for these files are listed in Coordinated Universal Time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time tool in Control Panel.   Date         Time   Version    Size       File name --  18-Jun-2005  23:51  6.0.97.89  1,386,496  Msvbvm60.dll



STATUS
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the &quot;Applies to&quot; section.



MORE INFORMATION
For more information about the terminology that Microsoft uses when Microsoft corrects software after it is released, click the following article number to view the article in the Microsoft Knowledge Base:

824684 Description of the standard terminology that is used to describe Microsoft software updates

Additional query words: VB6 VSUQFE

Keywords: kbinfo kbtshoot kbthread kbcomservices kbprb KB899282

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