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Q152947: XCON: Err Msg: Suspected Deadlock

Article: Q152947
Product(s): Microsoft Exchange
Version(s): winnt:4.0
Operating System(s): 
Keyword(s): kbusage
Last Modified: 30-MAR-1999

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The information in this article applies to:

- Microsoft Exchange Server, version 4.0 
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SYMPTOMS
========

The Microsoft Exchange Message Transfer Agent (MTA) is still alive but it fails
to handle any additional incoming or outgoing messages via the Microsoft
Exchange X.400 TCP/IP Connector. Several 9405 Event IDs appear in the Windows NT
Event Log:

  Error: suspected deadlock BASE KERNEL 29 (16) and MAIN BASE 1 (16)

CAUSE
=====

The OPVRECON semaphore and the Kernel Control Block (CB) KPSEMID semaphore are
acquired in a different order by two threads, causing a deadlock. This occurs
when a message for an previously freed CB is sent into Platform, due to a close
race condition, while the root thread is trying to acquire the same CB for a new
connection.

STATUS
======

Microsoft has confirmed this to be a problem in Microsoft Exchange Server
version 4.0. This problem was corrected in the latest Microsoft Exchange Service
Pack. For information on obtaining the Service Pack, query on the following word
in the Microsoft Knowledge Base (without the spaces):

  S E R V P A C K

Additional query words:

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Keywords          : kbusage 
Technology        : kbExchangeSearch kbExchange400 kbZNotKeyword2
Version           : winnt:4.0

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