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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 - View products that this article applies to.

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.

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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.

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RESOLUTION

Hotfix information

A supported hotfix is 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 software update that contains this hotfix.

If the hotfix is available for download, there is a "Hotfix download available" section at the top of this Knowledge Base article. If this section does not appear, contact Microsoft Customer Service and Support to obtain the hotfix.

Note If additional issues occur or if 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. For a complete list of Microsoft Customer Service and Support telephone numbers or to create a separate service request, visit the following Microsoft Web site:

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

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

Note The "Hotfix download available" form displays the languages for which the hotfix is available. If you do not see your language, it is because a hotfix is not available for that language.

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

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STATUS

Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.

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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:
1. The RPCSS sends a cancel request to the application server by using the NtRequestPort function. This function does not wait for a response.
2. The application server marks the call to the RpcAsyncCancelCa function as cancel pending.
3. The application server fails the call to the RpcAsyncCancelCa function. Then, the application notifies the OLE process that the call is completed.
4. 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.
The application server sends a response to the client .
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.
The application server receives the error and then closes the Local Procedure Call (LPC) port.
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.