Multiple client TCP stream reader

Question

My server code is currently reading String data over a TCP connection form 2 different client computers. To do this I am duplicating the StreamReader functions for the two separate clients. How can I simplify my code into just one method without having to duplicate for every client? (I want to do 4 clients in the future, duplicating a part of the code 4 times is very tedious and clumsy).

public class AsynchIOServer
{
    static TcpListener tcpListener = new TcpListener(15);
    static TcpListener tcpListener2 = new TcpListener(10);


    static void Listeners()
    {
        using (Socket socketForClient = tcpListener.AcceptSocket())
        {
            if (socketForClient.Connected)
            {
                Console.WriteLine("Client:" + socketForClient.RemoteEndPoint + " now connected to server.");
                using (NetworkStream networkStream = new NetworkStream(socketForClient))
                //using (NetworkStream networkStream2 = new NetworkStream(socketForClient))
                using (System.IO.StreamWriter streamWriter = new System.IO.StreamWriter(networkStream))
                using (System.IO.StreamReader streamReader = new System.IO.StreamReader(networkStream))
                //using (System.IO.StreamReader streamReader2 = new System.IO.StreamReader(networkStream2))
                {
                    try
                    {
                        while (true)
                        {
                            string theString = streamReader.ReadLine();
                            if (string.IsNullOrEmpty(theString) == false)
                            {
                                Console.WriteLine("Kinect1:" + theString);
                            }
                        }
                    }
                    catch (Exception ex)
                    {
                        Console.WriteLine("Error: " + ex.Message);
                    }
                }
            }
        }
        Console.WriteLine("Press any key to exit from server program");
        Console.ReadKey();
    }
//---------------------------------------------------------------------------
    static void Listeners2()
    {
        using (Socket socketForClient2 = tcpListener2.AcceptSocket())
        {
            if (socketForClient2.Connected)
            {
                Console.WriteLine("Client:" + socketForClient2.RemoteEndPoint + " now connected to server.");
                //using (NetworkStream networkStream = new NetworkStream(socketForClient))
                using (NetworkStream networkStream2 = new NetworkStream(socketForClient2))
                using (System.IO.StreamWriter streamWriter = new System.IO.StreamWriter(networkStream2))
                //using (System.IO.StreamReader streamReader = new System.IO.StreamReader(networkStream))
                using (System.IO.StreamReader streamReader2 = new System.IO.StreamReader(networkStream2))
                {
                    try
                    {
                        while (true)
                        {
                            string theString2 = streamReader2.ReadLine();
                            if (string.IsNullOrEmpty(theString2) == false)
                            {
                                Console.WriteLine("Kinect2:" + theString2);
                            }
                        }
                    }
                    catch (Exception ex)
                    {
                        Console.WriteLine("Error: " + ex.Message);
                    }
                }
            }
        }
        Console.WriteLine("Press any key to exit from server program");
        Console.ReadKey();
    }

    public static void Main()
    {
        tcpListener.Start();
        tcpListener2.Start();
        Console.WriteLine("************This is Server program************");
        Console.WriteLine("How many clients are going to connect to this server?:");
        int numberOfClientsYouNeedToConnect =int.Parse( Console.ReadLine());
        for (int i = 0; i < numberOfClientsYouNeedToConnect; i++)
        {
            Thread newThread = new Thread(new ThreadStart(Listeners));
            newThread.Start();
        }

        for (int i = 0; i < numberOfClientsYouNeedToConnect; i++)
        {
            Thread newThread2 = new Thread(new ThreadStart(Listeners2));
            newThread2.Start();
        }
    }
}

Answer 1

You can use a ParameterizedThreadStart instead of TheadStart and then provide each TcpListener instance as parameter to each new Thread:

  TcpListener[] listeners =
  {
    new TcpListener(15),
    new TcpListener(10)
  };

  foreach (TcpListener listener in listeners)
  {
    listener.Start();
    for (int i = 0; i < numberOfClientsYouNeedToConnect; i++)
    {
      Thread newThread = new Thread(new ParameterizedThreadStart(Listeners));
      newThread.Start(listener);
    }
  }

You'll then have to change the signature of the Listeners-function:

static void Listeners(object state)
{
  TcpListener listener = state as TcpListener;
  using (Socket socketForClient = listener.AcceptSocket())
  {
     ...

EDIT:

If you want to provide more information to the thread function, you can create a class, that holds any information beside the TcpListener object:

  public class ListenerInfo
  {
    public ListenerInfo(TcpListener listener, string name, int index)
    {
      Listener = listener;
      Name = name;
      Index = index;
    }

    public TcpListener Listener { get; }
    public string Name { get; }
    public int Index { get; }
  }

You can then create the threads like this:

  var infos = new []
  {
    new { Listener = new TcpListener(15), Name = "Listener 15" },
    new { Listener = new TcpListener(10), Name = "Listener 10" }
  };

  foreach (var info in infos)
  {
    for (int i = 0; i < numberOfClientsYouNeedToConnect; i++)
    {
      Thread newThread = new Thread(new ParameterizedThreadStart(AsynchIOServer.Listeners));
      newThread.Start(new ListenerInfo(info.Listener, info.Name, i));
    }
  }

And modify the thread-function to handle the new object:

public static void Listeners(object state)
{
  ListenerInfo listenerInfo = state as ListenerInfo;
  using (Socket socketForClient = listenerInfo.Listener.AcceptSocket())
  {
    if (socketForClient.Connected)
    {
      Console.WriteLine("Client:" + socketForClient.RemoteEndPoint + " now connected to server.");
      using (NetworkStream networkStream = new NetworkStream(socketForClient))
      //using (NetworkStream networkStream2 = new NetworkStream(socketForClient))
      using (System.IO.StreamWriter streamWriter = new System.IO.StreamWriter(networkStream))
      using (System.IO.StreamReader streamReader = new System.IO.StreamReader(networkStream))
      //using (System.IO.StreamReader streamReader2 = new System.IO.StreamReader(networkStream2))
      {
        try
        {
          while (true)
          {
            string theString = streamReader.ReadLine();
            if (string.IsNullOrEmpty(theString) == false)
            {
              Console.WriteLine($"Connection {listenerInfo.Name} {listenerInfo.Index}: {theString}");
            }
          }
        }
        catch (Exception ex)
        {
          Console.WriteLine("Error: " + ex.Message);
        }
      }
    }
  }
  Console.WriteLine("Press any key to exit from server program");
  Console.ReadKey();
}

---

What is your break/stop-condition for the while (true)-loop in the Listener()-method?