FIX: An endless loop in the CEventDispatcher::RemoveEventBuffer function in the Comsvcs.dll file causes the host COM+ application to stop responding on a computer that is running Windows XP SP2

Consider the following scenario. On a computer that is running Microsoft Windows XP Service Pack 2 (SP2), an endless loop occurs in the CEventDispatcher::RemoveEventBuffer function in the Comsvcs.dll file. This endless loop causes the host Microsoft COM+ application to stop responding (hang). This host COM+ application uses all or most of the available CPU cycles. In this scenario, you experience slow performance on the computer because of the increased CPU utilization.

Note Typically, the host COM+ application is a Dllhost.exe process.

This problem occurs under heavy load conditions when the following conditions are true:

• Many events are raised at the same time.
• The component subscribes to multiple COM+ transient events.

This problem occurs because of a code defect in COM Services (Comsvcs.dll).

This problem is fixed in Windows XP Post-Service Pack 2 COM+ 1.0 Hotfix Rollup Package 12. For more information, click the following article number to view the article in the Microsoft Knowledge Base:

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.

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, submit a request to 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: 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

You must have Microsoft Windows XP Service Pack 1 (SP1) or Microsoft Windows XP Service Pack 2 (SP2) installed to apply this hotfix.

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.

Windows XP Service Pack 1, x86

Windows XP Service Pack 2, x86

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