Microsoft KB Archive/900822

= FIX: When a .NET Framework based application uses the System.Threading.Timer class, the timer event may not be signaled in the .NET Framework 1.1 SP1 =

Article ID: 900822

Article Last Modified on 12/3/2007

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APPLIES TO


 * Microsoft .NET Framework 1.1 Service Pack 1

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SYMPTOMS
When a managed Microsoft .NET Framework application uses the System.Threading.Timer class in the Microsoft .NET Framework 1.1 Service Pack 1 (SP1), the timer event may not be signaled. Typically, this problem occurs if the computer that is running the application is under a heavy load or if many timer objects are running.



Download information
The following file is available for download from the Microsoft Download Center:

Download the 240388_ENU_i386_zip.exe package or the 240661_ENU_i386_zip.exe package now.

Release Date: 6/18/2007

For more information about how to download Microsoft support files, click the following article number to view the article in the Microsoft Knowledge Base:

119591 How to obtain Microsoft support files from online services

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Hotfix information
A supported software update is now available from Microsoft, but it is only intended to correct the problem that is described in this article. Only apply it to systems that are experiencing this specific problem. This software update may receive additional testing. Therefore, if you are not severely affected by this problem, we recommend that you wait for the next .NET Framework 1.1 service pack that contains this software update.

To resolve this problem immediately, contact Microsoft Product Support Services to obtain the software update. For a complete list of Microsoft Product 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
Microsoft .NET Framework 1.1 SP1

Restart requirement
You do not have to restart the computer after you apply this software update.

Software update replacement information
This software update does not replace any other software updates.

File information
The English version of this software update 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 --  09-Jun-2005  05:46  1.1.4322.2331  2,138,112  Mscorlib.dll 09-Jun-2005 05:48                    10,908  Mscorlib.ldo 09-Jun-2005 05:56  1.1.4322.2331  2,519,040  Mscorsvr.dll 09-Jun-2005 05:57  1.1.4322.2331  2,506,752  Mscorwks.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 Timer classes are implemented as a linked list of timer objects. When the first System.Threading.Timer object is created, the thread pool manager starts a thread to process the linked list. Every timer object is added to the linked list. The thread that process the linked list cycles through the linked list and determines when the timer event is expected to be signaled against the current clock count.

If the timer object has expired, the thread asynchronously queues a callback function before the thread updates the time that the timer event is expected to be signaled. After the thread has processed all timer objects in the linked list, the thread updates the time that the linked list was last processed. Then, the thread calculates the shortest time that the thread should sleep before the thread reprocesses the linked list for the next elapsed timer object.

Sometimes, when the system is under stress or when the linked list includes many timer objects, the processing thread may be pre-empted by a higher priority thread before the whole linked list has been processed. When this behavior occurs, the time that a timer event is next expected to be signaled is calculated to be earlier than the timestamp when the linked list was last processed. Therefore, the time that the timer event is expected to be signaled is in the past and never expires.

Because the time that the timer event is expected to be signaled has already passed, the thread may calculate a negative period to wait before the timer event must be signaled. When the thread has a negative period to wait, the thread enters a sleep state for a long time.



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: kbwinserv2003sp2fix kbfix kbbug kbpubtypekc kbhotfixserver kbqfe KB900822

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