SocketServer from PPP book by Robet C. Martin

gistfile1.cs

using System.Collections;
using System.Net;
using System.Net.Sockets;
using System.Threading;
public interface SocketService
{
    void Serve(Socket s);
}

public class SocketServer
{
    private TcpListener serverSocket = null;
    private Thread serverThread = null;
    private bool running = false;
    private SocketService itsService = null;
    private ArrayList threads = new ArrayList();

    public SocketServer(int port, SocketService service)
    {
        itsService = service;
        IPAddress addr = IPAddress.Parse("127.0.0.1");
        serverSocket = new TcpListener(addr, port);
        serverThread = new Thread(new ThreadStart(Server));
        serverThread.Start();
    }

    public void Close()
    {
        running = false;
        serverThread.Interrupt();
        serverSocket.Stop();
        serverThread.Join();
        WaitForServiceThreads();
    }

    private void Server()
    {
        serverSocket.Start();
        running = true;
        while (running)
        {
            Socket s = serverSocket.AcceptSocket();
            StartServiceThread(s);
        }
    }

    private void StartServiceThread(Socket s)
    {
        Thread serviceThread =
            new Thread(new ServiceRunner(s, this).ThreadStart());
        lock (threads)
        {
            threads.Add(serviceThread);
        }
        serviceThread.Start();
    }

    private void WaitForServiceThreads()
    {
        while (threads.Count > 0)
        {
            Thread t;
            lock (threads)
            {
                t = (Thread)threads[0];
            }
            t.Join();
        }
    }

    internal class ServiceRunner
    {
        private Socket itsSocket;
        private SocketServer itsServer;

        public ServiceRunner(Socket s, SocketServer server)
        {
            itsSocket = s;
            itsServer = server;
        }

        public void Run()
        {
            itsServer.itsService.Serve(itsSocket);
            lock (itsServer.threads)
            {
                itsServer.threads.Remove(Thread.CurrentThread);
            }
            itsSocket.Close();
        }

        public ThreadStart ThreadStart()
        {
            return new ThreadStart(Run);
        }
    }
}