ThreadStaticAttribute クラス

定義

静的フィールドの値がスレッドごとに一意であることを示します。Indicates that the value of a static field is unique for each thread.

public ref class ThreadStaticAttribute : Attribute
[System.AttributeUsage(System.AttributeTargets.Field, Inherited=false)]
public class ThreadStaticAttribute : Attribute
[System.AttributeUsage(System.AttributeTargets.Field, Inherited=false)]
[System.Serializable]
public class ThreadStaticAttribute : Attribute
[System.AttributeUsage(System.AttributeTargets.Field, Inherited=false)]
[System.Serializable]
[System.Runtime.InteropServices.ComVisible(true)]
public class ThreadStaticAttribute : Attribute
[<System.AttributeUsage(System.AttributeTargets.Field, Inherited=false)>]
type ThreadStaticAttribute = class
    inherit Attribute
[<System.AttributeUsage(System.AttributeTargets.Field, Inherited=false)>]
[<System.Serializable>]
type ThreadStaticAttribute = class
    inherit Attribute
[<System.AttributeUsage(System.AttributeTargets.Field, Inherited=false)>]
[<System.Serializable>]
[<System.Runtime.InteropServices.ComVisible(true)>]
type ThreadStaticAttribute = class
    inherit Attribute
Public Class ThreadStaticAttribute
Inherits Attribute
継承
ThreadStaticAttribute
属性

次の例では、乱数ジェネレーターをインスタンス化し、メインスレッドに加えて10個のスレッドを作成した後、各スレッドで200万の乱数を生成します。The following example instantiates a random number generator, creates ten threads in addition to the main thread, and then generates two million random numbers in each thread. 属性を使用して ThreadStaticAttribute 、合計と、スレッドあたりの乱数の数を計算します。It uses the ThreadStaticAttribute attribute to calculate the sum and the count of random numbers per thread. また、スレッドごとの追加のフィールドとという2つのフィールドを定義して、 previous abnormal 乱数ジェネレーターの破損を検出できるようにします。It also defines two additional per-thread fields, previous and abnormal, that allows it to detect corruption of the random number generator.

using System;
using System.Threading;

public class Example
{
   [ThreadStatic] static double previous = 0.0;
   [ThreadStatic] static double sum = 0.0;
   [ThreadStatic] static int calls = 0;
   [ThreadStatic] static bool abnormal;
   static int totalNumbers = 0;
   static CountdownEvent countdown;
   private static Object lockObj;
   Random rand;
   
   public Example()
   { 
      rand = new Random();
      lockObj = new Object();
      countdown = new CountdownEvent(1);
   } 

   public static void Main()
   {
      Example ex = new Example();
      Thread.CurrentThread.Name = "Main";
      ex.Execute();
      countdown.Wait();
      Console.WriteLine("{0:N0} random numbers were generated.", totalNumbers);
   }

   private void Execute()
   {   
      for (int threads = 1; threads <= 10; threads++)
      {
         Thread newThread = new Thread(new ThreadStart(this.GetRandomNumbers));
         countdown.AddCount();
         newThread.Name = threads.ToString();
         newThread.Start();
      }
      this.GetRandomNumbers();
   }

   private void GetRandomNumbers()
   {
      double result = 0.0;

      for (int ctr = 0; ctr < 2000000; ctr++)
      {
         lock (lockObj) {
            result = rand.NextDouble();
            calls++;
            Interlocked.Increment(ref totalNumbers);
            // We should never get the same random number twice.
            if (result == previous) {
               abnormal = true;
               break;
            }
            else {
               previous = result;
               sum += result;
            }   
         }
      }
      // get last result
      if (abnormal)
         Console.WriteLine("Result is {0} in {1}", previous, Thread.CurrentThread.Name);
       
      Console.WriteLine("Thread {0} finished random number generation.", Thread.CurrentThread.Name);
      Console.WriteLine("Sum = {0:N4}, Mean = {1:N4}, n = {2:N0}\n", sum, sum/calls, calls);        
      countdown.Signal();
   }
}
// The example displays output similar to the following:
//    Thread 1 finished random number generation.
//    Sum = 1,000,556.7483, Mean = 0.5003, n = 2,000,000
//    
//    Thread 6 finished random number generation.
//    Sum = 999,704.3865, Mean = 0.4999, n = 2,000,000
//    
//    Thread 2 finished random number generation.
//    Sum = 999,680.8904, Mean = 0.4998, n = 2,000,000
//    
//    Thread 10 finished random number generation.
//    Sum = 999,437.5132, Mean = 0.4997, n = 2,000,000
//    
//    Thread 8 finished random number generation.
//    Sum = 1,000,663.7789, Mean = 0.5003, n = 2,000,000
//    
//    Thread 4 finished random number generation.
//    Sum = 999,379.5978, Mean = 0.4997, n = 2,000,000
//    
//    Thread 5 finished random number generation.
//    Sum = 1,000,011.0605, Mean = 0.5000, n = 2,000,000
//    
//    Thread 9 finished random number generation.
//    Sum = 1,000,637.4556, Mean = 0.5003, n = 2,000,000
//    
//    Thread Main finished random number generation.
//    Sum = 1,000,676.2381, Mean = 0.5003, n = 2,000,000
//    
//    Thread 3 finished random number generation.
//    Sum = 999,951.1025, Mean = 0.5000, n = 2,000,000
//    
//    Thread 7 finished random number generation.
//    Sum = 1,000,844.5217, Mean = 0.5004, n = 2,000,000
//    
//    22,000,000 random numbers were generated.
Imports System.Threading

Public Class Example
   <ThreadStatic> Shared previous As Double = 0.0
   <ThreadStatic> Shared sum As Double = 0.0
   <ThreadStatic> Shared calls As Integer = 0
   <ThreadStatic> Shared abnormal As Boolean
   Shared totalNumbers As Integer = 0
   Shared countdown As CountdownEvent
   Private Shared lockObj As Object
   Dim rand As Random

   Public Sub New()
      rand = New Random()
      lockObj = New Object()
      countdown = New CountdownEvent(1)
   End Sub

   Public Shared Sub Main()
      Dim ex As New Example()
      Thread.CurrentThread.Name = "Main"
      ex.Execute()
      countdown.Wait()
      Console.WriteLine("{0:N0} random numbers were generated.", totalNumbers)
   End Sub

   Private Sub Execute()
      For threads As Integer = 1 To 10
         Dim newThread As New Thread(New ThreadStart(AddressOf GetRandomNumbers))
         countdown.AddCount()
         newThread.Name = threads.ToString()
         newThread.Start()
      Next
      Me.GetRandomNumbers()
   End Sub

   Private Sub GetRandomNumbers()
      Dim result As Double = 0.0
      
       
      For ctr As Integer = 1 To 2000000
         SyncLock lockObj
            result = rand.NextDouble()
            calls += 1
            Interlocked.Increment(totalNumbers)
            ' We should never get the same random number twice.
            If result = previous Then
               abnormal = True
               Exit For
            Else
               previous = result
               sum += result
            End If   
         End SyncLock
      Next
      ' Get last result.
      If abnormal Then
         Console.WriteLine("Result is {0} in {1}", previous, Thread.CurrentThread.Name)
      End If       
      
      Console.WriteLine("Thread {0} finished random number generation.", Thread.CurrentThread.Name)
      Console.WriteLine("Sum = {0:N4}, Mean = {1:N4}, n = {2:N0}", sum, sum/calls, calls)
      Console.WriteLine()        
      countdown.Signal()
   End Sub
End Class
' The example displays output similar to the following:
'    Thread 1 finished random number generation.
'    Sum = 1,000,556.7483, Mean = 0.5003, n = 2,000,000
'    
'    Thread 6 finished random number generation.
'    Sum = 999,704.3865, Mean = 0.4999, n = 2,000,000
'    
'    Thread 2 finished random number generation.
'    Sum = 999,680.8904, Mean = 0.4998, n = 2,000,000
'    
'    Thread 10 finished random number generation.
'    Sum = 999,437.5132, Mean = 0.4997, n = 2,000,000
'    
'    Thread 8 finished random number generation.
'    Sum = 1,000,663.7789, Mean = 0.5003, n = 2,000,000
'    
'    Thread 4 finished random number generation.
'    Sum = 999,379.5978, Mean = 0.4997, n = 2,000,000
'    
'    Thread 5 finished random number generation.
'    Sum = 1,000,011.0605, Mean = 0.5000, n = 2,000,000
'    
'    Thread 9 finished random number generation.
'    Sum = 1,000,637.4556, Mean = 0.5003, n = 2,000,000
'    
'    Thread Main finished random number generation.
'    Sum = 1,000,676.2381, Mean = 0.5003, n = 2,000,000
'    
'    Thread 3 finished random number generation.
'    Sum = 999,951.1025, Mean = 0.5000, n = 2,000,000
'    
'    Thread 7 finished random number generation.
'    Sum = 1,000,844.5217, Mean = 0.5004, n = 2,000,000
'    
'    22,000,000 random numbers were generated.

この例では、 lock C# のステートメントと Visual Basic のコンストラクトを使用して、 SyncLock 乱数ジェネレーターへのアクセスを同期します。The example uses the lock statement in C# and the SyncLock construct in Visual Basic to synchronize access to the random number generator. これにより、乱数ジェネレーターが破損するのを防ぐことができます。通常は、後続のすべての呼び出しで値0が返されます。This prevents corruption of the random number generator, which typically results in its returning a value of zero for all subsequent calls.

また、この例では、クラスを使用して、 CountdownEvent 呼び出しの合計数を表示する前に、各スレッドが乱数の生成を完了したことを確認します。The example also uses the CountdownEvent class to ensure that each thread has finished generating random numbers before it displays the total number of calls. それ以外の場合、メインスレッドが生成する追加スレッドの前に実行が完了すると、メソッド呼び出しの合計数に対して不正確な値が表示されます。Otherwise, if the main thread completes execution before the additional threads that it spawns, it displays an inaccurate value for the total number of method calls.

注釈

staticでマークされたフィールド ThreadStaticAttribute は、スレッド間で共有されません。A static field marked with ThreadStaticAttribute is not shared between threads. 実行中の各スレッドには、フィールドの個別のインスタンスがあり、そのフィールドの値を個別に設定して取得します。Each executing thread has a separate instance of the field, and independently sets and gets values for that field. フィールドに別のスレッドでアクセスした場合は、別の値が格納されます。If the field is accessed on a different thread, it will contain a different value.

フィールドに属性を適用するだけで ThreadStaticAttribute なく、フィールド static (C# の場合) またはフィールド Shared (Visual Basic) としても定義する必要があることに注意してください。Note that in addition to applying the ThreadStaticAttribute attribute to a field, you must also define it as a static field (in C#) or a Shared field (in Visual Basic).

注意

でマークされたフィールドに初期値を指定しないでください。この初期化は、 ThreadStaticAttribute クラスコンストラクターが実行されるときに1回だけ行われるため、1つのスレッドにしか影響しません。Do not specify initial values for fields marked with ThreadStaticAttribute, because such initialization occurs only once, when the class constructor executes, and therefore affects only one thread. 初期値を指定しない場合は、値の型である場合、または参照型である場合は、既定値に初期化されているフィールドに依存できます nullIf you do not specify an initial value, you can rely on the field being initialized to its default value if it is a value type, or to null if it is a reference type.

この属性はそのように使用し、派生させません。Use this attribute as it is, and do not derive from it.

属性の使用方法の詳細については、「 属性」を参照してください。For more information about using attributes, see Attributes.

コンストラクター

ThreadStaticAttribute()

ThreadStaticAttribute クラスの新しいインスタンスを初期化します。Initializes a new instance of the ThreadStaticAttribute class.

プロパティ

TypeId

派生クラスで実装されると、この Attribute の一意の識別子を取得します。When implemented in a derived class, gets a unique identifier for this Attribute.

(継承元 Attribute)

メソッド

Equals(Object)

このインスタンスが、指定されたオブジェクトと等価であるかどうかを示す値を返します。Returns a value that indicates whether this instance is equal to a specified object.

(継承元 Attribute)
GetHashCode()

このインスタンスのハッシュ コードを返します。Returns the hash code for this instance.

(継承元 Attribute)
GetType()

現在のインスタンスの Type を取得します。Gets the Type of the current instance.

(継承元 Object)
IsDefaultAttribute()

派生クラスでオーバーライドされるとき、このインスタンスの値が派生クラスの既定値であるかどうかを示します。When overridden in a derived class, indicates whether the value of this instance is the default value for the derived class.

(継承元 Attribute)
Match(Object)

派生クラス内でオーバーライドされたときに、指定したオブジェクトとこのインスタンスが等しいかどうかを示す値を返します。When overridden in a derived class, returns a value that indicates whether this instance equals a specified object.

(継承元 Attribute)
MemberwiseClone()

現在の Object の簡易コピーを作成します。Creates a shallow copy of the current Object.

(継承元 Object)
ToString()

現在のオブジェクトを表す文字列を返します。Returns a string that represents the current object.

(継承元 Object)

明示的なインターフェイスの実装

_Attribute.GetIDsOfNames(Guid, IntPtr, UInt32, UInt32, IntPtr)

一連の名前を対応する一連のディスパッチ識別子に割り当てます。Maps a set of names to a corresponding set of dispatch identifiers.

(継承元 Attribute)
_Attribute.GetTypeInfo(UInt32, UInt32, IntPtr)

オブジェクトの型情報を取得します。この情報はインターフェイスの型情報の取得に使用できます。Retrieves the type information for an object, which can be used to get the type information for an interface.

(継承元 Attribute)
_Attribute.GetTypeInfoCount(UInt32)

オブジェクトが提供する型情報インターフェイスの数 (0 または 1) を取得します。Retrieves the number of type information interfaces that an object provides (either 0 or 1).

(継承元 Attribute)
_Attribute.Invoke(UInt32, Guid, UInt32, Int16, IntPtr, IntPtr, IntPtr, IntPtr)

オブジェクトによって公開されたプロパティおよびメソッドへのアクセスを提供します。Provides access to properties and methods exposed by an object.

(継承元 Attribute)

適用対象

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