using System;

using System.Collections.Generic;

using System.Threading.Tasks;

public class Program

{

        public static void Main()

        {

            Console.WriteLine("Calling GetData with id:{0}", 1);

            var data1 = GetData(1);

            Console.WriteLine("Calling GetData with id:{0}", 2);

            var data2 = GetData(2);

​

            Task.WaitAll(data1, data2);

        }

​

        public static async Task<List<string>> GetData(int id)

        {

            Task<List<string>> task = Task<Task<List<string>>>.Factory.StartNew(async () =>

            {

                System.Runtime.Remoting.Messaging.CallContext.SetData("MS.SqlDependencyCookie", id);

                return await FakeToListAsync();

            }).Unwrap();

​

            return await task;

        }

​

        public static async Task<List<string>> FakeToListAsync()

        {

            int id = (int)System.Runtime.Remoting.Messaging.CallContext.GetData("MS.SqlDependencyCookie");

            Console.WriteLine("Calling FakeToListAsync with id:{0}", id);

            await Task.Delay(1);

            return new List<string>();

        }

}