Microsoft KB Archive/818539

= FIX: A deadlock occurs when you repeatedly load and then unload the Dbnetlib DLL =

Article ID: 818539

Article Last Modified on 4/7/2006

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APPLIES TO


 * Microsoft Data Access Components 2.7 Service Pack 1a
 * Microsoft Data Access Components 2.6 Service Pack 2

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SYMPTOMS
When you repeatedly load and then unload the Dbnetlib.dllI file in an application, a deadlock may occur.



CAUSE
The DllMain function of the Dbnetlib DLL calls the WSAStartup function. If you pass DLL_PROCESS_ATTACH or DLL_PROCESS_DETACH as the dwReason parameter to the DllMain function, threads may deadlock. Thread deadlocking causes the behavior that is mentioned in the &quot;Symptoms&quot; section.

Note You may notice similar behavior if the DllMain function of any DLL calls the WSACleanup function after you pass DLL_PROCESS_ATTACH or DLL_PROCESS_DETACH as the dwReason parameter to the DllMain function.



RESOLUTION
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.The English version of this hotfix has the file attributes (or later) 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.

Microsoft Data Access Components (MDAC) 2.6
 Date              Time      Version              Size            File name - 16-Apr-2003    05:08     2000.80.742.0    86,588        Dbnetlib.dll

Microsoft Data Access Components (MDAC) 2.7
 Date             Time       Version                  Size          File name 26-Jun-2003   09:09      2000.81.9031.49     61,440      Dbnetlib.dll



STATUS
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the &quot;Applies to&quot; section. This problem was corrected in MDAC 2.8.

