CAUSE
This access violation occurs because of a race condition between threads in the Mqoa.dll file. When this problem occurs, the running program thread calls the
MSMQQueue.EnableNotification method. The message is peeked immediately and is dispatched to the MSMQEvent event handler. Because the MSMQEvent event handler is in a multithreaded apartment (MTA), the call is dispatched to a worker thread. This worker thread will execute the event handler code and may take some time to complete.
The race condition starts when the program thread exits and runs its destructor. Because the MSMQEvent event handler is an apartment thread, the release event is dispatched to the MSMQEvent event handler, and the
MSMQEvent object is released from memory. In the meantime, the event handler worker thread still tries to finish processing the event message. When the worker thread tries to reference the
MSMQEvent object, an access violation occurs because the
MSMQEvent object has been released from memory.
For additional information about race conditions, click the following article number to view the article in the Microsoft Knowledge Base:
317723
INFO: What Are Race Conditions and Deadlocks?
For additional information about multithreaded apartments (MTA), click the following article number to view the article in the Microsoft Knowledge Base:
150777
INFO: Descriptions and Workings of OLE Threading Models
RESOLUTION
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:
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 must restart your 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) 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
--------------------------------------------------------------
21-Oct-2003 14:03 5.0.0.778 281,360 Mq1repl.dll
20-Sep-2003 17:23 5.0.0.778 14,096 Mq1sync.exe
02-Oct-2003 19:21 5.0.0.785 76,016 Mqac.sys
21-Oct-2003 14:03 5.0.0.783 217,360 Mqads.dll
20-Sep-2003 17:23 5.0.0.761 25,360 Mqbkup.exe
21-Oct-2003 14:03 5.0.0.785 76,560 Mqdscli.dll
21-Oct-2003 14:03 5.0.0.773 42,256 Mqdssrv.dll
20-Sep-2003 17:23 5.0.0.759 98,064 Mqmig.exe
21-Oct-2003 14:03 5.0.0.759 265,488 Mqmigrat.dll
21-Oct-2003 14:03 5.0.0.787 222,480 Mqoa.dll
21-Oct-2003 14:03 5.0.0.784 10,000 Mqperf.dll
21-Oct-2003 14:03 5.0.0.786 433,936 Mqqm.dll
21-Oct-2003 14:03 5.0.0.778 102,672 Mqrt.dll
21-Oct-2003 14:03 5.0.0.776 70,928 Mqsec.dll
21-Oct-2003 14:03 5.0.0.783 400,656 Mqsnap.dll
21-Oct-2003 14:03 5.0.0.762 23,824 Mqupgrd.dll
21-Oct-2003 14:03 5.0.0.782 110,864 Mqutil.dll
21-Oct-2003 14:03 5.0.0.748 64,784 Msmq.cpl
09-Oct-2003 00:18 5.4.1.0 6,656 Spmsg.dll
09-Oct-2003 00:19 5.4.1.0 140,800 Spuninst.exe
09-Oct-2003 00:19 5.4.1.0 22,016 Spcustom.dll