ThreadStaticAttribute Clase

Definición

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

Herencia

Object

Attribute

ThreadStaticAttribute

Atributos

AttributeUsageAttribute SerializableAttribute ComVisibleAttribute

Ejemplos

En el código de ejemplo siguiente se muestra cómo usar ThreadStaticAttribute para asegurarse de que un campo estático es único para cada subproceso. En el código, cada subproceso asigna un identificador de solicitud diferente al campo estático del subproceso y, a continuación, simula el procesamiento de solicitudes en varias llamadas de método.

using System;
using System.Threading;

class Program
{
    [ThreadStatic]
    private static string? _requestId;

    static void Main()
    {
        Thread thread1 = new(ProcessRequest);
        Thread thread2 = new(ProcessRequest);

        thread1.Start("REQ-001");
        thread2.Start("REQ-002");

        thread1.Join();
        thread2.Join();

        Console.WriteLine("Main thread execution completed.");
    }

    static void ProcessRequest(object? requestId)
    {
        // Assign the request ID to the thread-static field.
        _requestId = requestId as string;

        // Simulate request processing across multiple method calls.
        PerformDatabaseOperation();
        PerformLogging();
    }

    static void PerformDatabaseOperation()
    {
        Console.WriteLine($"Thread {Environment.CurrentManagedThreadId}: Processing DB operation for request {_requestId}");
    }

    static void PerformLogging()
    {
        Console.WriteLine($"Thread {Environment.CurrentManagedThreadId}: Logging request {_requestId}");
    }
}

open System
open System.Threading

type ThreadLocal() =
    [<ThreadStatic; DefaultValue>]
    static val mutable private requestId: string option

    static member PerformLogging() =
        Console.WriteLine($"Thread {Environment.CurrentManagedThreadId}: Logging request {ThreadLocal.requestId.Value}")

    static member PerformDatabaseOperation() =
        Console.WriteLine($"Thread {Environment.CurrentManagedThreadId}: Processing DB operation for request {ThreadLocal.requestId.Value}")

    static member ProcessRequest(reqId: obj) =
        ThreadLocal.requestId <- Some(reqId :?> string)
        ThreadLocal.PerformDatabaseOperation()
        ThreadLocal.PerformLogging()

[<EntryPoint>]
let main _ =
    let thread1 = Thread(ThreadStart(fun () -> ThreadLocal.ProcessRequest("REQ-001")))
    let thread2 = Thread(ThreadStart(fun () -> ThreadLocal.ProcessRequest("REQ-002")))

    thread1.Start()
    thread2.Start()
    thread1.Join()
    thread2.Join()

    Console.WriteLine("Main thread execution completed.")
    0

Imports System
Imports System.Threading

Module Program

    <ThreadStatic>
    Private _requestId As String

    Sub Main()
        Dim thread1 As New Thread(AddressOf ProcessRequest)
        Dim thread2 As New Thread(AddressOf ProcessRequest)

        thread1.Start("REQ-001")
        thread2.Start("REQ-002")

        thread1.Join()
        thread2.Join()

        Console.WriteLine("Main thread execution completed.")
    End Sub

    Sub ProcessRequest(ByVal requestId As Object)
        ' Assign the request ID to the thread-static field
        _requestId = requestId.ToString()

        ' Simulate request processing across multiple method calls
        PerformDatabaseOperation()
        PerformLogging()
    End Sub

    Sub PerformDatabaseOperation()
        Console.WriteLine($"Thread {Environment.CurrentManagedThreadId}: Processing DB operation for request {_requestId}")
    End Sub

    Sub PerformLogging()
        Console.WriteLine($"Thread {Environment.CurrentManagedThreadId}: Logging request {_requestId}")
    End Sub

End Module

Comentarios

Un static campo marcado con ThreadStaticAttribute no se comparte entre subprocesos. Cada subproceso en ejecución tiene una instancia independiente del campo y establece y obtiene valores para ese campo de forma independiente. Si se accede al campo en un subproceso diferente, contendrá un valor diferente.

Además de aplicar el atributo ThreadStaticAttribute a un campo, también debe definirlo como static (en C# o F#) o Shared (en Visual Basic).

Use este atributo tal como está y no derive de él.

Para obtener más información sobre el uso de atributos, vea Atributos.

Consulte también

• Attribute
• Thread
• AsyncLocal<T>
• extensión de metadatos mediante atributos
• Subprocesamiento administrado