ThreadPool.SetMaxThreads Method (System.Threading)

.NET Framework Class Library

ThreadPool..::.SetMaxThreads Method

Sets the number of requests to the thread pool that can be active concurrently. All requests above that number remain queued until thread pool threads become available.

Namespace: System.Threading
Assembly: mscorlib (in mscorlib.dll)

Syntax

Visual Basic (Declaration)

<SecurityPermissionAttribute(SecurityAction.Demand, ControlThread := True)> _
Public Shared Function SetMaxThreads ( _
    workerThreads As Integer, _
    completionPortThreads As Integer _
) As Boolean

Visual Basic (Usage)

Dim workerThreads As Integer
Dim completionPortThreads As Integer
Dim returnValue As Boolean

returnValue = ThreadPool.SetMaxThreads(workerThreads, _
    completionPortThreads)

[SecurityPermissionAttribute(SecurityAction.Demand, ControlThread = true)]
public static bool SetMaxThreads(
    int workerThreads,
    int completionPortThreads
)

Visual C++

[SecurityPermissionAttribute(SecurityAction::Demand, ControlThread = true)]
public:
static bool SetMaxThreads(
    int workerThreads, 
    int completionPortThreads
)

JScript

public static function SetMaxThreads(
    workerThreads : int, 
    completionPortThreads : int
) : boolean

Parameters

workerThreads: Type: System..::.Int32
The maximum number of worker threads in the thread pool.

completionPortThreads: Type: System..::.Int32
The maximum number of asynchronous I/O threads in the thread pool.

Return Value

Type: System..::.Boolean
true if the change is successful; otherwise, false.

Remarks

You cannot set the number of worker threads or the number of I/O completion threads to a number smaller than the number of processors in the computer.

If the common language runtime is hosted, for example by Internet Information Services (IIS) or SQL Server, the host can limit or prevent changes to the thread pool size.

Use caution when changing the maximum number of threads in the thread pool. While your code might benefit, the changes might have an adverse effect on code libraries you use.

Setting the thread pool size too large can cause performance problems. If too many threads are executing at the same time, the task switching overhead becomes a significant factor.

Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows CE Platform Note: The maximum value that can be set is 256.

.NET Framework Security

SecurityPermission
for the ability to control threads. Permission value: SecurityPermissionFlag..::.ControlThread

Platforms

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98, Windows CE, Windows Mobile for Smartphone, Windows Mobile for Pocket PC, Xbox 360, Zune

The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

Version Information

.NET Framework

Supported in: 3.5, 3.0, 2.0

.NET Compact Framework

Supported in: 3.5, 2.0

XNA Framework

Supported in: 3.0, 2.0, 1.0

Reference

ThreadPool Class

ThreadPool Members

System.Threading Namespace