Thread.AllocateDataSlot Methode

Definition

Reserviert einen unbenannten Datenslot für alle Threads. Eine höhere Leistung erzielen Sie, wenn Sie stattdessen Felder verwenden, die mit dem ThreadStaticAttribute-Attribut markiert sind.

public:
 static LocalDataStoreSlot ^ AllocateDataSlot();
public static LocalDataStoreSlot AllocateDataSlot ();
static member AllocateDataSlot : unit -> LocalDataStoreSlot
Public Shared Function AllocateDataSlot () As LocalDataStoreSlot

Gibt zurück

LocalDataStoreSlot

Der reservierte benannte Datenslot für alle Threads.

Beispiele

Dieser Abschnitt enthält zwei Codebeispiele. Im ersten Beispiel wird gezeigt, wie ein mit dem -Attribut markiertes Feld verwendet wird, ThreadStaticAttribute um threadspezifische Informationen zu enthalten. Im zweiten Beispiel wird gezeigt, wie ein Datenslot verwendet wird, um dasselbe zu tun.

Erstes Beispiel

Im folgenden Beispiel wird gezeigt, wie ein mit markiertes Feld verwendet ThreadStaticAttribute wird, um threadspezifische Informationen zu enthalten. Diese Technik bietet eine bessere Leistung als die im zweiten Beispiel gezeigte Technik.

using namespace System;
using namespace System::Threading;

ref class ThreadData
{
private:
   [ThreadStatic]
   static int threadSpecificData;

public:
   static void ThreadStaticDemo()
   {
      // Store the managed thread id for each thread in the static
      // variable.
      threadSpecificData = Thread::CurrentThread->ManagedThreadId;
      
      // Allow other threads time to execute the same code, to show
      // that the static data is unique to each thread.
      Thread::Sleep( 1000 );

      // Display the static data.
      Console::WriteLine( "Data for managed thread {0}: {1}", 
         Thread::CurrentThread->ManagedThreadId, threadSpecificData );
   }
};

int main()
{
   for ( int i = 0; i < 3; i++ )
   {
      Thread^ newThread = 
          gcnew Thread( gcnew ThreadStart( ThreadData::ThreadStaticDemo )); 
      newThread->Start();
   }
}

/* This code example produces output similar to the following:

Data for managed thread 4: 4
Data for managed thread 5: 5
Data for managed thread 3: 3
 */
using System;
using System.Threading;

class Test
{
    static void Main()
    {
        for(int i = 0; i < 3; i++)
        {
            Thread newThread = new Thread(ThreadData.ThreadStaticDemo);
            newThread.Start();
        }
    }
}

class ThreadData
{
    [ThreadStatic]
    static int threadSpecificData;

    public static void ThreadStaticDemo()
    {
        // Store the managed thread id for each thread in the static
        // variable.
        threadSpecificData = Thread.CurrentThread.ManagedThreadId;
      
        // Allow other threads time to execute the same code, to show
        // that the static data is unique to each thread.
        Thread.Sleep( 1000 );

        // Display the static data.
        Console.WriteLine( "Data for managed thread {0}: {1}", 
            Thread.CurrentThread.ManagedThreadId, threadSpecificData );
    }
}

/* This code example produces output similar to the following:

Data for managed thread 4: 4
Data for managed thread 5: 5
Data for managed thread 3: 3
 */
Imports System.Threading

Class Test

    <MTAThread> _
    Shared Sub Main()

        For i As Integer = 1 To 3
            Dim newThread As New Thread(AddressOf ThreadData.ThreadStaticDemo)
            newThread.Start()
        Next i

    End Sub

End Class

Class ThreadData

    <ThreadStatic> _
    Shared threadSpecificData As Integer

    Shared Sub ThreadStaticDemo()

        ' Store the managed thread id for each thread in the static
        ' variable.
        threadSpecificData = Thread.CurrentThread.ManagedThreadId
      
        ' Allow other threads time to execute the same code, to show
        ' that the static data is unique to each thread.
        Thread.Sleep( 1000 )

        ' Display the static data.
        Console.WriteLine( "Data for managed thread {0}: {1}", _
            Thread.CurrentThread.ManagedThreadId, threadSpecificData )

    End Sub

End Class

' This code example produces output similar to the following:
'
'Data for managed thread 4: 4
'Data for managed thread 5: 5
'Data for managed thread 3: 3

Zweites Beispiel

Das folgende Codebeispiel veranschaulicht die Verwendung eines Datenslots zum Speichern threadspezifischer Informationen.

using namespace System;
using namespace System::Threading;
ref class Slot
{
private:
   static Random^ randomGenerator;
   static LocalDataStoreSlot^ localSlot;
   static Slot()
   {
      randomGenerator = gcnew Random;
      localSlot = Thread::AllocateDataSlot();
   }


public:
   static void SlotTest()
   {
      
      // Set different data in each thread's data slot.
      Thread::SetData( localSlot, randomGenerator->Next( 1, 200 ) );
      
      // Write the data from each thread's data slot.
      Console::WriteLine( "Data in thread_{0}'s data slot: {1,3}", AppDomain::GetCurrentThreadId().ToString(), Thread::GetData( localSlot )->ToString() );
      
      // Allow other threads time to execute SetData to show
      // that a thread's data slot is unique to the thread.
      Thread::Sleep( 1000 );
      Console::WriteLine( "Data in thread_{0}'s data slot: {1,3}", AppDomain::GetCurrentThreadId().ToString(), Thread::GetData( localSlot )->ToString() );
   }

};

int main()
{
   array<Thread^>^newThreads = gcnew array<Thread^>(4);
   for ( int i = 0; i < newThreads->Length; i++ )
   {
      newThreads[ i ] = gcnew Thread( gcnew ThreadStart( &Slot::SlotTest ) );
      newThreads[ i ]->Start();

   }
}
using System;
using System.Threading;

class Test
{
    static void Main()
    {
        Thread[] newThreads = new Thread[4];
        for(int i = 0; i < newThreads.Length; i++)
        {
            newThreads[i] = new Thread(
                new ThreadStart(Slot.SlotTest));
            newThreads[i].Start();
        }
    }
}

class Slot
{
    static Random randomGenerator;
    static LocalDataStoreSlot localSlot;

    static Slot()
    {
        randomGenerator = new Random();
        localSlot = Thread.AllocateDataSlot();
    }

    public static void SlotTest()
    {
        // Set different data in each thread's data slot.
        Thread.SetData(localSlot, randomGenerator.Next(1, 200));

        // Write the data from each thread's data slot.
        Console.WriteLine("Data in thread_{0}'s data slot: {1,3}", 
            AppDomain.GetCurrentThreadId().ToString(),
            Thread.GetData(localSlot).ToString());

        // Allow other threads time to execute SetData to show
        // that a thread's data slot is unique to the thread.
        Thread.Sleep(1000);

        Console.WriteLine("Data in thread_{0}'s data slot: {1,3}", 
            AppDomain.GetCurrentThreadId().ToString(),
            Thread.GetData(localSlot).ToString());
    }
}
Imports System.Threading

Class Test

    <MTAThread> _
    Shared Sub Main()
        Dim newThreads(3) As Thread
        For i As Integer = 0 To newThreads.Length - 1
            newThreads(i) = New Thread(AddressOf Slot.SlotTest)
            newThreads(i).Start()
        Next i
    End Sub

End Class

Public Class Slot

    Shared randomGenerator As Random
    Shared localSlot As LocalDataStoreSlot

    Shared Sub New()
        randomGenerator = new Random()
        localSlot = Thread.AllocateDataSlot()
    End Sub

    Shared Sub SlotTest()

        ' Set different data in each thread's data slot.
        Thread.SetData(localSlot, randomGenerator.Next(1, 200))

        ' Write the data from each thread's data slot.
        Console.WriteLine("Data in thread_{0}'s data slot: {1,3}", _
            AppDomain.GetCurrentThreadId().ToString(), _
            Thread.GetData(localSlot).ToString())

        ' Allow other threads time to execute SetData to show
        ' that a thread's data slot is unique to the thread.
        Thread.Sleep(1000)

        ' Write the data from each thread's data slot.
        Console.WriteLine("Data in thread_{0}'s data slot: {1,3}", _
            AppDomain.GetCurrentThreadId().ToString(), _
            Thread.GetData(localSlot).ToString())
    End Sub

End Class

Hinweise

Wichtig

Das .NET Framework bietet zwei Mechanismen für die Verwendung des threadbasierten lokalen Speichers (TLS): thread relative statische Felder (d. h. Felder, die mit dem -Attribut gekennzeichnet ThreadStaticAttribute sind) und Datenslots. Thread relative statische Felder bieten eine wesentlich bessere Leistung als Datenslots und ermöglichen die Typüberprüfung zur Kompilierzeit. Weitere Informationen zur Verwendung von TLS finden Sie unter Thread Local Storage: Thread-Relative Static Fields and Data Slots.

Der Slot wird allen Threads zugeordnet.

Threads verwenden einen lokalen Speicherspeichermechanismus, um threadspezifische Daten zu speichern. Die Common Language Runtime ordnet jedem Prozess beim Erstellen ein Datenspeicherarray mit mehreren Slots zu. Der Thread kann einen Datenslot im Datenspeicher zuordnen, einen Datenwert im Slot speichern und abrufen und den Slot für die Wiederverwendung nach Ablauf des Threads frei geben. Datenslots sind pro Thread eindeutig. Kein anderer Thread (nicht einmal ein untergeordneter Thread) kann diese Daten erhalten.

Gilt für

Siehe auch