using System;

using System.Threading;

using System.Threading.Tasks;

​

public class Program

{

    static async Task IdentifyAsync(Task task, int id)

    {

        await task;

​

        var thread = Thread.CurrentThread;

        string name = thread.IsThreadPoolThread

            ? "Thread pool" : thread.Name;

        if (string.IsNullOrEmpty(name))

            name = "#" + thread.ManagedThreadId;

        Console.WriteLine("Continuation #" + id + " on: " + name + ", id: " + Thread.CurrentThread.ManagedThreadId);

    }

​

    public static void Main()

    {

        Thread.CurrentThread.Name = "Main thread";

        Console.WriteLine("Started on: " + Thread.CurrentThread.Name + ", id: " + Thread.CurrentThread.ManagedThreadId);

        var source1 = new TaskCompletionSource<int>();

        IdentifyAsync(source1.Task, 1);

        source1.SetResult(123);

​

        var source2 = new TaskCompletionSource<int>();

        IdentifyAsync(source2.Task, 2);

        source2.SetResultAsync(123);

​

        Console.WriteLine("Press [return]");

        Console.ReadLine();

    }

}

​

public static class TaskExt

{

    static public void SetResultAsync<T>(this TaskCompletionSource<T> tcs, T result)

    {

        FakeSynchronizationContext.Execute(() => tcs.SetResult(result));

    }

​

    // FakeSynchronizationContext

    class FakeSynchronizationContext : SynchronizationContext

    {

        private static readonly ThreadLocal<FakeSynchronizationContext> s_context =

            new ThreadLocal<FakeSynchronizationContext>(() => new FakeSynchronizationContext());

​

        private FakeSynchronizationContext() { }

​

        public static FakeSynchronizationContext Instance { get { return s_context.Value; } }

​

        public static void Execute(Action action)

        {

            var savedContext = SynchronizationContext.Current;

            SynchronizationContext.SetSynchronizationContext(FakeSynchronizationContext.Instance);

            try

            {

                action();

            }

            finally

            {

                SynchronizationContext.SetSynchronizationContext(savedContext);

            }

        }

​

        // SynchronizationContext methods

​

        public override SynchronizationContext CreateCopy()

        {

            return this;

        }

​

        public override void OperationStarted()

        {

            throw new NotImplementedException("OperationStarted");

        }

​

        public override void OperationCompleted()

        {

            throw new NotImplementedException("OperationCompleted");

        }

​

        public override void Post(SendOrPostCallback d, object state)

        {

            throw new NotImplementedException("Post");

        }

​

        public override void Send(SendOrPostCallback d, object state)

        {

            throw new NotImplementedException("Send");

        }

    }

}

​