//------------------------------------------------------------------------------

// <copyright file="DisposableAction.cs" company="Microsoft">

// Copyright (c) Microsoft Corporation. All rights reserved.

// </copyright>

//------------------------------------------------------------------------------

namespace System.Web.Util {

using System;

using System.Threading;

// Helper class for wrapping a continuation inside an IDisposable.

// This class is thread-safe.

internal sealed class DisposableAction : IDisposable {

public static readonly DisposableAction Empty = new DisposableAction(null);

private Action _disposeAction;

public DisposableAction(Action disposeAction) {

_disposeAction = disposeAction;

}

public void Dispose() {

// Interlocked allows the continuation to be executed only once

Action continuation = Interlocked.Exchange(ref _disposeAction, null);

if (continuation != null) {

continuation();

}

}

}

}