ThreadPriority ThreadPriority ThreadPriority ThreadPriority Enum

定義

Thread のスケジューリング優先順位を指定します。Specifies the scheduling priority of a Thread.

public enum class ThreadPriority
[System.Runtime.InteropServices.ComVisible(true)]
[System.Serializable]
public enum ThreadPriority
type ThreadPriority = 
Public Enum ThreadPriority
継承
ThreadPriorityThreadPriorityThreadPriorityThreadPriority
属性

フィールド

AboveNormal AboveNormal AboveNormal AboveNormal 3

Thread は優先順位が Highest のスレッドから Normal のスレッドの間にスケジュールできます。The Thread can be scheduled after threads with Highest priority and before those with Normal priority.

BelowNormal BelowNormal BelowNormal BelowNormal 1

Thread は優先順位が Normal のスレッドから Lowest のスレッドの間にスケジュールできます。The Thread can be scheduled after threads with Normal priority and before those with Lowest priority.

Highest Highest Highest Highest 4

Thread は、どの優先順位のスレッドの前にでもスケジュールできます。The Thread can be scheduled before threads with any other priority.

Lowest Lowest Lowest Lowest 0

Thread は、ほかのどの優先順位のスレッドの後でもスケジュールできます。The Thread can be scheduled after threads with any other priority.

Normal Normal Normal Normal 2

Thread は優先順位が AboveNormal のスレッドから BelowNormal のスレッドの間にスケジュールできます。The Thread can be scheduled after threads with AboveNormal priority and before those with BelowNormal priority. スレッドの既定の優先順位は Normal です。Threads have Normal priority by default.

次のコード例では、スレッドの優先度の変更の結果を示します。The following code example shows the result of changing the priority of a thread. 3 つのスレッドを作成、BelowNormal に 1 つのスレッドの優先順位が設定されておよび AboveNormal に 1 秒あたりの優先順位を設定します。Three threads are created, the priority of one thread is set to BelowNormal, and the priority of a second is set to AboveNormal. 各スレッド内の変数をインクリメントする、whileループと、設定時間実行されます。Each thread increments a variable in a while loop and runs for a set time.

using System;
using System.Threading;
using Timers = System.Timers;

class Test
{
    static void Main()
    {
        PriorityTest priorityTest = new PriorityTest();

        Thread thread1 = new Thread(priorityTest.ThreadMethod);
        thread1.Name = "ThreadOne";
        Thread thread2 = new Thread(priorityTest.ThreadMethod);
        thread2.Name = "ThreadTwo";
        thread2.Priority = ThreadPriority.BelowNormal;
        Thread thread3 = new Thread(priorityTest.ThreadMethod);
        thread3.Name = "ThreadThree";
        thread3.Priority = ThreadPriority.AboveNormal;

        thread1.Start();
        thread2.Start();
        thread3.Start();
        // Allow counting for 10 seconds.
        Thread.Sleep(10000);
        priorityTest.LoopSwitch = false;
    }
}

class PriorityTest
{
    static bool loopSwitch;
    [ThreadStatic] static long threadCount = 0;

    public PriorityTest()
    {
        loopSwitch = true;
    }

    public bool LoopSwitch
    {
        set{ loopSwitch = value; }
    }

    public void ThreadMethod()
    {
        while(loopSwitch)
        {
            threadCount++;
        }
        Console.WriteLine("{0,-11} with {1,11} priority " +
            "has a count = {2,13}", Thread.CurrentThread.Name, 
            Thread.CurrentThread.Priority.ToString(), 
            threadCount.ToString("N0")); 
    }
}
// The example displays output like the following:
//    ThreadOne   with      Normal priority has a count =   755,897,581
//    ThreadThree with AboveNormal priority has a count =   778,099,094
//    ThreadTwo   with BelowNormal priority has a count =     7,840,984
Imports System.Threading
Imports Timers = System.Timers

Public Module Example
   Dim t As Timers.Timer
   Private priorityTest As New PriorityTest()

    Public Sub Main()
        Dim thread1 As New Thread(AddressOf priorityTest.ThreadMethod)
        thread1.Name = "ThreadOne"
        Dim thread2 As New Thread(AddressOf priorityTest.ThreadMethod)
        thread2.Name = "ThreadTwo"
        thread2.Priority = ThreadPriority.BelowNormal
        Dim thread3 As New Thread(AddressOf priorityTest.ThreadMethod)
        thread3.Name = "ThreadThree"
        thread3.Priority = ThreadPriority.AboveNormal
        thread1.Start()
        thread2.Start()
        thread3.Start()

        ' Allow threads to execute for about 10 seconds.
        t = New Timers.Timer()
        t.AutoReset = False
        t.Interval = 10000
        AddHandler t.Elapsed, AddressOf Elapsed
        t.Start()
    End Sub

    Private Sub Elapsed(sender As Object, e As Timers.ElapsedEventArgs)
       priorityTest.LoopSwitch = False
    End Sub
End Module

Public Class PriorityTest
    Private Shared loopSwitchValue As Boolean
    <ThreadStatic> Shared threadCount As Long

    Sub New()
        loopSwitchValue = True
    End Sub

    WriteOnly Property LoopSwitch As Boolean
        Set
            loopSwitchValue = Value
        End Set
    End Property

    Sub ThreadMethod()
        Do While True
            threadCount += 1
            If Not loopSwitchValue Then Exit Do
        Loop

        Console.WriteLine("{0,-11} with {1,11} priority " &
            "has a count = {2,13}", Thread.CurrentThread.Name,
            Thread.CurrentThread.Priority.ToString(),
            threadCount.ToString("N0")) 
    End Sub
End Class
' The example displays the following output:
'    ThreadOne   with      Normal priority has a count =   755,897,581
'    ThreadThree with AboveNormal priority has a count =   778,099,094
'    ThreadTwo   with BelowNormal priority has a count =     7,840,984

注釈

ThreadPriority スレッドの優先度のすべての値のセットを定義します。ThreadPriority defines the set of all possible values for a thread priority. スレッドの優先順位は、1 つのスレッドと別の相対的な優先順位を指定します。Thread priorities specify the relative priority of one thread versus another.

各スレッドには、割り当てられた優先度。Every thread has an assigned priority. ランタイム内で作成されたスレッドが最初に割り当てられている、Normalランタイム外部で作成されたスレッドは、ランタイムに入るときに、前の優先順位を保持中に、優先順位。Threads created within the runtime are initially assigned the Normal priority, while threads created outside the runtime retain their previous priority when they enter the runtime. 取得し、アクセスすることによって、スレッドの優先順位を設定できますそのPriorityプロパティ。You can get and set the priority of a thread by accessing its Priority property.

スレッドの実行は、優先順位に基づいてスケジュールされます。Threads are scheduled for execution based on their priority. スレッドの実行の順序を決定するために使用するスケジューリング アルゴリズムは、各オペレーティング システムによって異なります。The scheduling algorithm used to determine the order of thread execution varies with each operating system. オペレーティング システムも調整できますスレッドの優先順位に動的にフォア グラウンドとバック グラウンドの間、ユーザー インターフェイスのフォーカスを移動するとします。The operating system can also adjust the thread priority dynamically as the user interface's focus is moved between the foreground and the background.

スレッドの優先順位では、スレッドの状態には影響しませんスレッドの状態である必要がありますRunning前に、オペレーティング システムでスケジュールできます。The priority of a thread does not affect the thread's state; the state of the thread must be Running before the operating system can schedule it.

適用対象

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