Thread.SetData(LocalDataStoreSlot, Object) Metodo

public:
 static void SetData(LocalDataStoreSlot ^ slot, System::Object ^ data);

public static void SetData(LocalDataStoreSlot slot, object data);

static member SetData : LocalDataStoreSlot * obj -> unit

Public Shared Sub SetData (slot As LocalDataStoreSlot, data As Object)

Parametri

Esempio

Questa sezione contiene due esempi di codice. Il primo esempio mostra come usare un campo contrassegnato con l'attributo ThreadStaticAttribute per contenere informazioni specifiche del thread. Il secondo esempio mostra come usare uno slot di dati per eseguire la stessa operazione.

Primo esempio

Nell'esempio seguente viene illustrato come usare un campo contrassegnato con ThreadStaticAttribute per contenere informazioni specifiche del thread. Questa tecnica offre prestazioni migliori rispetto alla tecnica illustrata nel secondo esempio.

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
 */

open System
open System.Threading

type ThreadData() =
    // Create a static variable to hold the data for each thread.
    [<ThreadStatic; DefaultValue>]
    static val mutable private threadSpecificData : int

    static member ThreadStaticDemo() =
        // Store the managed thread id for each thread in the static
        // variable.
        ThreadData.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.
        printfn $"Data for managed thread {Thread.CurrentThread.ManagedThreadId}: {ThreadData.threadSpecificData}" 

for i = 0 to 2 do 
    let newThread = Thread 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

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

Secondo esempio

Nell'esempio seguente viene illustrato come usare uno slot di dati denominato per archiviare informazioni specifiche del thread.

using System;
using System.Threading;

class Test
{
    public static void Main()
    {
        Thread[] newThreads = new Thread[4];
        int i;
        for (i = 0; i < newThreads.Length; i++)
        {
            newThreads[i] =
                new Thread(new ThreadStart(Slot.SlotTest));
            newThreads[i].Start();
        }
        Thread.Sleep(2000);
        for (i = 0; i < newThreads.Length; i++)
        {
            newThreads[i].Join();
            Console.WriteLine("Thread_{0} finished.",
                newThreads[i].ManagedThreadId);
        }
    }
}

class Slot
{
    private static Random randomGenerator = new Random();

    public static void SlotTest()
    {
        // Set random data in each thread's data slot.
        int slotData = randomGenerator.Next(1, 200);
        int threadId = Thread.CurrentThread.ManagedThreadId;

        Thread.SetData(
            Thread.GetNamedDataSlot("Random"),
            slotData);

        // Show what was saved in the thread's data slot.
        Console.WriteLine("Data stored in thread_{0}'s data slot: {1,3}",
            threadId, slotData);

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

        int newSlotData =
            (int)Thread.GetData(Thread.GetNamedDataSlot("Random"));

        if (newSlotData == slotData)
        {
            Console.WriteLine("Data in thread_{0}'s data slot is still: {1,3}",
                threadId, newSlotData);
        }
        else
        {
            Console.WriteLine("Data in thread_{0}'s data slot changed to: {1,3}",
                threadId, newSlotData);
        }
    }
}

open System
open System.Threading

module Slot =
    let private randomGenerator = Random()

    let slotTest () =
        // Set random data in each thread's data slot.
        let slotData = randomGenerator.Next(1, 200)
        let threadId = Thread.CurrentThread.ManagedThreadId

        Thread.SetData(Thread.GetNamedDataSlot "Random", slotData)

        // Show what was saved in the thread's data slot.
        printfn $"Data stored in thread_{threadId}'s data slot: {slotData, 3}"

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

        let newSlotData = Thread.GetData(Thread.GetNamedDataSlot "Random") :?> int

        if newSlotData = slotData then
            printfn $"Data in thread_{threadId}'s data slot is still: {newSlotData, 3}"
        else
            printfn $"Data in thread_{threadId}'s data slot changed to: {newSlotData, 3}"

let newThreads =
    [| for _ = 0 to 3 do
           let thread = Thread Slot.slotTest
           thread.Start()
           thread |]

Thread.Sleep 2000

for tread in newThreads do
    tread.Join()
    printfn $"Thread_{tread.ManagedThreadId} finished."

Imports System.Threading

Class Test
    Public Shared Sub Main()
        Dim newThreads(3) As Thread
        Dim i As Integer
        For i = 0 To newThreads.Length - 1
            newThreads(i) = _
                New Thread(New ThreadStart(AddressOf Slot.SlotTest))
            newThreads(i).Start()
        Next i
        Thread.Sleep(2000)
        For i = 0 To newThreads.Length - 1
            newThreads(i).Join()
            Console.WriteLine("Thread_{0} finished.", _
                newThreads(i).ManagedThreadId)
        Next i
    End Sub
End Class

Class Slot
    Private Shared randomGenerator As New Random()

    Public Shared Sub SlotTest()
        ' Set random data in each thread's data slot.
        Dim slotData As Integer = randomGenerator.Next(1, 200)
        Dim threadId As Integer = Thread.CurrentThread.ManagedThreadId

        Thread.SetData(
            Thread.GetNamedDataSlot("Random"),
            slotData)

        ' Show what was saved in the thread's data slot.
        Console.WriteLine("Data stored in thread_{0}'s data slot: {1,3}",
            threadId, slotData)

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

        Dim newSlotData As Integer = _
            CType(Thread.GetData(Thread.GetNamedDataSlot("Random")), Integer)

        If newSlotData = slotData Then
            Console.WriteLine("Data in thread_{0}'s data slot is still: {1,3}",
                threadId, newSlotData)
        Else
            Console.WriteLine("Data in thread_{0}'s data slot changed to: {1,3}",
                threadId, newSlotData)
        End If
    End Sub
End Class

Commenti

I thread usano un meccanismo di memoria dell'archivio locale per archiviare dati specifici del thread. Common Language Runtime alloca una matrice di archivi dati multi-slot a ogni processo al momento della creazione. Il thread può allocare uno slot di dati nell'archivio dati, archiviare e recuperare un valore di dati nello slot e liberare lo slot per il riutilizzo al termine della procedura di thread e l'oggetto Thread è stato recuperato da Garbage Collection. Gli slot di dati sono univoci per ogni thread. Nessun altro thread (nemmeno un thread figlio) può ottenere tali dati.

Vedi anche

• GetData(LocalDataStoreSlot)
• Thread e threading
• Memoria Locale del Thread: Thread-Relative Campi Statici e Slots di Dati