using System;

using System.Collections.Generic;

using System.Threading.Tasks;

using System.Threading;

​

class Concurrent

{

    static public Concurrent<T> Create<T>(T item) where T : class

    {

        return new Concurrent<T>(item);

    }

}

​

class Concurrent<T> where T : class

{

    protected readonly T _item;

    protected object _lockObject = new object();

    public Concurrent(T item)

    {

        _item = item;

    }

    public void Execute(Action<T> action)

    {

        //lock(_lockObject)

        {

            action(_item);

        }

    }

}

public class Program

{

    public static void Main()

    {

        var dict = Concurrent.Create(new Dictionary<string,string>());

        try

        {

            Parallel.Invoke

            ( 

                () => dict.Execute

                ( 

                    d => 

                    {

                        d.Add("Key1","ThreadA");

                        Thread.Sleep(500);

                        d.Add("Key2","ThreadA");

                        Thread.Sleep(500);

                        d.Add("Key3","ThreadA");

                    }

                ),

                () => dict.Execute

                ( 

                    d => 

                    {

                        d.Add("Key1","ThreadB");

                        Thread.Sleep(500);

                        d.Add("Key2","ThreadB");

                        Thread.Sleep(500);

                        d.Add("Key3","ThreadB");

                    }

                )

            );

        }

        catch

        {

        }

        dict.Execute

        ( 

            d =>

            {

                foreach (var entry in d)

                    Console.WriteLine("{0}={1}", entry.Key, entry.Value);

            }

        );

    }

}