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Q239919: Handle Leak in SnaBase When SNA API DLL Is Loaded/Unloaded

Article: Q239919
Product(s): Microsoft SNA Server
Version(s): WINDOWS:3.0,3.0 SP1,3.0 SP2,3.0 SP3,3.0 SP4,4.0,4.0 SP1,4.0 SP2
Operating System(s): 
Keyword(s): kbsna400sp3fix kbsna300sp1 kbsna300sp2 kbsna300sp3 kbsna300sp4 sna4 kbsna400sp1 kbsna40
Last Modified: 08-MAY-2002

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The information in this article applies to:

- Microsoft SNA Server, versions 3.0, 3.0 SP1, 3.0 SP2, 3.0 SP3, 3.0 SP4, 4.0, 4.0 SP1, 4.0 SP2 
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SYMPTOMS
========

An SNA Server application may experience a memory and handle leak if the
application repeatedly calls LoadLibrary and FreeLibrary on the SNA API DLL
interface that its using. These API interfaces include RUI (Winrui32.dll), SLI
(Winsli32.dll), APPC (Wappc32.dll) and CPIC (Wcpic32.dll). In addition to the
application resource leaks, this behavior will also cause the SnaBase process
handle count to increase over time, as viewed by Windows NT Performance Monitor.
This behavior was found by an application which repeatedly loaded and unloaded
the RUI interface (Winrui32.dll).

CAUSE
=====

When the SNA API DLL is dynamically loaded and unloaded, resource leaks occurred
in the underlying Snadmod.dll, which is statically linked to the SNA API DLLs.

RESOLUTION
==========

To resolve this problem, obtain the latest service pack for SNA Server version
4.0. For additional information, please see the following article in the
Microsoft Knowledge Base:

  Q215838 How to Obtain the Latest SNA Server Version 4.0 Service Pack


WORKAROUND
==========

This problem can be avoided if the application loads the SNA API DLL only once
when starting, and unloads it when exiting.

STATUS
======

Microsoft has confirmed this to be a problem in Microsoft SNA Server versions
3.0, 3.0 SP1, 3.0 SP2, 3.0 SP3, 3.0 SP4, 4.0, 4.0 SP1, 4.0 SP2. This problem was
first corrected in SNA Server version 4.0 Service Pack 3.

Additional query words:

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Keywords          : kbsna400sp3fix kbsna300sp1 kbsna300sp2 kbsna300sp3 kbsna300sp4 sna4 kbsna400sp1 kbsna400sp2 
Technology        : kbAudDeveloper kbSNAServSearch kbSNAServ300 kbSNAServ400 kbSNAServ300SP3 kbSNAServ300SP1 kbSNAServ400SP1 kbSNAServ400SP2 kbSNAServ300SP2 kbSNAServ300SP4
Version           : WINDOWS:3.0,3.0 SP1,3.0 SP2,3.0 SP3,3.0 SP4,4.0,4.0 SP1,4.0 SP2
Issue type        : kbbug
Solution Type     : kbfix

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