Microsoft KB Archive/926594

= FIX: The ThreadPoolMgr::WorkerThreadStart process may become locked in a loop condition in a .NET Framework 2.0-based application, and CPU utilization may increase to 100 percent =

Article ID: 926594

Article Last Modified on 12/3/2007

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APPLIES TO


 * Microsoft .NET Framework 2.0

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SYMPTOMS
In a Microsoft .NET Framework 2.0-based application, the ThreadPoolMgr::WorkerThreadStart process may become locked in a loop condition. Additionally, CPU utilization may increase to 100 percent.

This problem occurs if the following conditions are true:
 * The NumQueuedWorkRequests variable is set to 0.
 * The application raises the WorkRequestNotification event.



CAUSE
This problem occurs because the following events occur at the same time:
 * The request that is made to the thread pool is added to the queue.
 * The thread removes the request from the queue.

No appropriate lock is available for the variables in the thread. The thread continues to consume 100 percent of the CPU resources until another request is queued.



RESOLUTION
A supported hotfix is now available from Microsoft. However, it is intended to correct only the problem that is described in this article. Apply it only to systems that are experiencing this specific problem. This hotfix may receive additional testing. Therefore, if you are not severely affected by this problem, we recommend that you wait for the next Microsoft .NET Framework 2.0 service pack that contains this hotfix.

To resolve this problem immediately, contact Microsoft Customer Support Services to obtain the hotfix. For a complete list of Microsoft Customer Support Services telephone numbers and information about support costs, visit the following Microsoft Web site:

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

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
You must be running the .NET Framework 2.0 to apply this hotfix.

Restart information
You do not have to restart the computer after you apply this hotfix.

Hotfix 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 item in Control Panel.

For Itanium-based versions


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
For more information about software update terminology, 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: kbfix kbqfe kbprb KB926594

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