ProcessThread.IdealProcessor Property

Definition

Namespace:

System.Diagnostics

Assembly:

System.Diagnostics.Process.dll

Source:

ProcessThread.Unix.cs

Sets the preferred processor for this thread to run on.

public:
 property int IdealProcessor {  void set(int value); };

public int IdealProcessor { set; }

member this.IdealProcessor : int

Public Property IdealProcessor As Integer

Property Value

Int32

The preferred processor for the thread, used when the system schedules threads, to determine which processor to run the thread on.

Exceptions

Win32Exception

The system could not set the thread to start on the specified processor.

NotSupportedException

The process is on a remote computer.

Examples

The following example demonstrates how to set the IdealProcessor property for an instance of Notepad to the first processor.

using System;
using System.Diagnostics;

namespace ProcessThreadIdealProcessor
{
    class Program
    {
        static void Main(string[] args)
        {
            // Make sure there is an instance of notepad running.
            Process[] notepads = Process.GetProcessesByName("notepad");
            if (notepads.Length == 0)
                Process.Start("notepad");
            ProcessThreadCollection threads;
            //Process[] notepads;
            // Retrieve the Notepad processes.
            notepads = Process.GetProcessesByName("Notepad");
            // Get the ProcessThread collection for the first instance
            threads = notepads[0].Threads;
            // Set the properties on the first ProcessThread in the collection
            threads[0].IdealProcessor = 0;
            threads[0].ProcessorAffinity = (IntPtr)1;
        }
    }
}

Imports System.Diagnostics



Class Program
    
    Shared Sub Main(ByVal args() As String) 
        ' Make sure there is an instance of notepad running.
        Dim notepads As Process() = Process.GetProcessesByName("notepad")
        If notepads.Length = 0 Then
            Process.Start("notepad")
        End If
        Dim threads As ProcessThreadCollection
        'Process[] notepads;
        ' Retrieve the Notepad processes.
        notepads = Process.GetProcessesByName("Notepad")
        ' Get the ProcessThread collection for the first instance
        threads = notepads(0).Threads
        ' Set the properties on the first ProcessThread in the collection
        threads(0).IdealProcessor = 0
        threads(0).ProcessorAffinity = CType(1, IntPtr)
    End Sub
End Class

Remarks

The IdealProcessor value is zero-based. In other words, to set the thread affinity for the first processor, set the property to zero.

The system schedules threads on their preferred processors whenever possible.

A process thread can migrate from processor to processor, with each migration reloading the processor cache. Specifying a processor for a thread can improve performance under heavy system loads by reducing the number of times the processor cache is reloaded.