Microsoft KB Archive/889178

= FIX: You may experience a system freeze when you try to cancel a COM+ method by using the CoCancelCall method while a COM+ object that uses the CoCreateInstanceEx method is instantiated in Windows XP Professional =

Article ID: 889178

Article Last Modified on 8/29/2007

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APPLIES TO


 * Microsoft Windows XP Professional

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SYMPTOMS
Consider the following scenario. In Microsoft Windows XP Professional, a Microsoft COM+ object that uses the CoCreateInstanceEX function is instantiated in a COM+ application. When you try to cancel a COM+ method by using the CoCancelCall function, you may experience system freeze-like symptoms.

Note This problem occurs after you restart the server side of the COM+ application.



CAUSE
This problem occurs because a race condition exists between the following:
 * The end call that goes to the server
 * The server that sends the response

Therefore, a fatal error occurs in the DCOM. This fatal error causes the computer to stop responding.



Hotfix information
A supported hotfix is now available from Microsoft. However, this hotfix is intended to correct only the problem that is described in this article. Apply this hotfix only to systems that are experiencing this specific problem. This hotfix might receive additional testing. Therefore, if you are not severely affected by this problem, we recommend that you wait for the next service pack that contains this hotfix.

To resolve this problem, submit a request to Microsoft Online Customer Services to obtain the hotfix. To submit an online request to obtain the hotfix, visit the following Microsoft Web site:

http://go.microsoft.com/?linkid=6294451

Note If additional issues occur or any troubleshooting is required, you might have to create a separate service request. The usual support costs will apply to additional support questions and issues that do not qualify for this specific hotfix. To create a separate service request, visit the following Microsoft Web site:

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

Prerequisites
Microsoft Windows XP Professional Service Pack 2 (SP2)

Restart requirement
You must 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 24-Mar-2005 21:14  5.1.2600.2621  1,241,088  Ole32.dll 24-Mar-2005 21:11  5.1.2600.2621    555,520  Rpcrt4.dll 24-Mar-2005 21:14  5.1.2600.2621    256,000  Rpcss.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
The following sequence of events occurs between the client and the server:  The COM+ application client connects to the Remote Procedure Call Service (RPCSS) and then sends a request. The RPCSS starts processing the request. The application client calls the RpcAsyncCancelCa function to cancel a COM+ method. The following communication occurs between the COM+ application client and the COM+ application server:  The RPCSS sends a cancel request to the application server by using the NtRequestPort function. This function does not wait for a response. The application server marks the call to the RpcAsyncCancelCa function as cancel pending.</li> The application server fails the call to the RpcAsyncCancelCa function. Then, the application notifies the OLE process that the call is completed.</li> The application client calls the I_RpcReceive and I_RpcFreeBuffer functions. This behavior causes the call to the RpcAsyncCancelCa function to be cleaned up and removed from the client association.</li></ol> </li> The application server sends a response to the client .</li> The client receives the response. Then, it rejects the response with error 1727 (RPC_S_CALL_FAILED_DNE) because it no longer knows about this call to the RpcAsyncCancelCa function.</li> The application server receives the error and then closes the Local Procedure Call (LPC) port.</li> The application client notices that the LPC port is closing, and the client cleans up the association. This step is when the context rundown occurs.</li></ol>

For more information, 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

Keywords: kbrpc kbbug kbfix kbhotfixserver kbqfe KB889178

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