Minimalist C# Actors

Actor.cs

// Inspired by https://gist.github.com/2557678
// and http://dspace.mit.edu/bitstream/handle/1721.1/6935/AITR-633.pdf
using System;
using System.Collections.Concurrent;
using System.Collections.Generic;
using System.Threading.Tasks.Dataflow;
using Message = System.Object;
namespace Actors
{
    public interface Behavior { Behavior OnArrival(Message message); }
    public class Actor
    {
        private volatile Behavior behavior;
        private readonly ActionBlock<Message> arrivals;

        public Actor(Behavior initialBehavior)
        {
            this.behavior = initialBehavior;
            this.arrivals = new ActionBlock<Message>(message => { this.behavior = this.behavior.OnArrival(message); });
        }

        public void Send(Message message)
        {
            this.arrivals.SendAsync(message);
        }
    }
}

You'll have to unsafely publish the reference to the newly allocated Actor and have the thread that picks it up send it a message.