FIX: After you use the ThreadPool.SetMinThreads method in the Microsoft .NET Framework 3.5, threads maintained by the thread pool do not work as expected

SYMPTOMS
You use the ThreadPool.SetMinThreads method in the Microsoft .NET Framework 3.5 to increase the minimum number of the idle asynchronous I/O threads that are maintained by the thread pool. However, these idle asynchronous I/O threads do not work as expected.

For example, consider the following scenario:
  • You run the ThreadPool.SetMinThreads method to increase the minimum number of the idle asynchronous I/O threads that are maintained by the thread pool.
  • You run a service that depends on multiple I/O threads for throughput.
In this scenario, instead of using idle asynchronous I/O threads from the thread pool, common language runtime (CLR) still tries to create more threads. Therefore, the service does not perform as you want.
RESOLUTION

Hotfix information

A supported hotfix is now available from Microsoft. However, it is intended to correct only the problem that this article describes. Apply it only to systems that are experiencing this specific problem.

To resolve this problem, 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 website: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 have the Microsoft .NET Framework 3.5 Service Pack 1 (SP1) 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 item in Control Panel.
x86-based versions of Windows Server 2000, Windows Server 2003 and Windows XP
File nameFile versionFile sizeDateTimePlatform
Mscordacwks.dll2.0.50727.4417989,01602-Nov-200911:38x86
Mscorlib.dll2.0.50727.44174,550,65602-Nov-200911:38x86
Mscorwks.dll2.0.50727.44175,818,68802-Nov-200911:38x86
Sos.dll2.0.50727.4417388,92002-Nov-200911:38x86

x64-based versions of Windows Server 2000, Windows Server 2003 and Windows XP
File nameFile versionFile sizeDateTimePlatform
Mscordacwks.dll2.0.50727.44171,758,55201-Nov-200923:44x64
Mscorlib.dll2.0.50727.44174,567,04001-Nov-200923:38x64
Mscorwks.dll2.0.50727.441710,061,13601-Nov-200923:42x64
Sos.dll2.0.50727.4417485,19201-Nov-200923:40x64

Itanium-based versions of Windows Server 2000, Windows Server 2003 and Windows XP
File nameFile versionFile sizeDateTimePlatform
Mscordacwks.dll2.0.50727.44173,085,12802-Nov-200909:44IA-64
Mscorlib.dll2.0.50727.44174,009,98402-Nov-200909:42IA-64
Mscorwks.dll2.0.50727.441720,173,12002-Nov-200909:38IA-64
Sos.dll2.0.50727.4417872,76002-Nov-200909:41IA-64

x86-based versions of Windows Vista SP2 and Windows Server 2008 SP2
File nameFile versionFile sizeDateTime
Mscorlib.dll2.0.50727.44194,550,65606-Nov-200907:54
Mscordacwks.dll2.0.50727.4419989,01606-Nov-200907:54
Mscorwks.dll2.0.50727.44195,818,70406-Nov-200907:54

x64-based versions of Windows Vista SP2 and Windows Server 2008 SP2
File nameFile versionFile sizeDateTime
Mscorlib.dll2.0.50727.44194,567,04006-Nov-200907:53
Mscordacwks.dll2.0.50727.44191,758,55206-Nov-200907:53
Mscorwks.dll2.0.50727.441910,061,13606-Nov-200907:53

Itanium-based versions of Windows Server 2008 SP2
File nameFile versionFile sizeDateTime
Mscorlib.dll2.0.50727.44194,567,04006-Nov-200907:53
Mscordacwks.dll2.0.50727.44191,758,55206-Nov-200907:53
Mscorwks.dll2.0.50727.441910,061,13606-Nov-200907:53

x86-based versions of Windows 7
File nameFile versionFile sizeDateTime
Mscorlib.dll2.0.50727.44194,550,65606-Nov-200907:53
Mscordacwks.dll2.0.50727.4419995,67206-Nov-200907:53
Mscorwks.dll2.0.50727.44195,817,15206-Nov-200907:53
Sos.dll2.0.50727.4417388,93606-Nov-200907:53

x64-based versions of Windows 7 and of Windows Server 2008 R2
File nameFile versionFile sizeDateTime
Mscorlib.dll2.0.50727.49364,567,04007-Nov-200900:02
Mscordacwks.dll2.0.50727.49361,757,51207-Nov-200900:02
Mscorwks.dll2.0.50727.493610,057,53607-Nov-200900:02
Sos.dll2.0.50727.4936485,17607-Nov-200900:02

Itanium-based versions of Windows Server 2008 R2
File nameFile versionFile sizeDateTime
Mscorlib.dll2.0.50727.49364,009,98407-Nov-200900:03
Mscordacwks.dll2.0.50727.49363,086,16807-Nov-200900:03
Mscorwks.dll2.0.50727.493620,165,96807-Nov-200900:03
Sos.dll2.0.50727.4936872,76007-Nov-200900:03
STATUS
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
REFERENCES
For more information about the ThreadPool.SetMinThreads method, visit the following Microsoft Web site:



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
Properties

Article ID: 976898 - Last Review: 09/08/2010 05:58:00 - Revision: 2.0

  • Microsoft .NET Framework 3.5
  • Microsoft .NET Framework 3.5 Service Pack 1
  • kbexpertiseadvanced kbfix kbsurveynew kbqfe KB976898
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