c# - How to set up TcpListener to always listen and accept multiple connections?

Question

This is my Server App:

public static void Main()
{
    try
    {
        IPAddress ipAddress = IPAddress.Parse("127.0.0.1");

        Console.WriteLine("Starting TCP listener...");

        TcpListener listener = new TcpListener(ipAddress, 500);

        listener.Start();

        while (true)
        {
            Console.WriteLine("Server is listening on " + listener.LocalEndpoint);

            Console.WriteLine("Waiting for a connection...");

            Socket client = listener.AcceptSocket();

            Console.WriteLine("Connection accepted.");

            Console.WriteLine("Reading data...");

            byte[] data = new byte[100];
            int size = client.Receive(data);
            Console.WriteLine("Recieved data: ");
            for (int i = 0; i < size; i++)
                Console.Write(Convert.ToChar(data[i]));

            Console.WriteLine();

            client.Close();
        }

        listener.Stop();
    }
    catch (Exception e)
    {
        Console.WriteLine("Error: " + e.StackTrace);
        Console.ReadLine();
    }
}

As you can see , it always listens while working , but I would like to specify that I want the app be able to listen and to have multiple connections support in the same time.

How could I modify this to constantly listen while also accepting the multiple connections?

Answer 1

1. The socket on which you want to listen for incoming connections is commonly referred to as the listening socket.

2. When the listening socket acknowledges an incoming connection, a socket that commonly referred to as a child socket is created that effectively represents the remote endpoint.

3. In order to handle multiple client connections simultaneously, you will need to spawn a new thread for each child socket on which the server will receive and handle data.
   Doing so will allow for the listening socket to accept and handle multiple connections as the thread on which you are listening will no longer be blocking or waiting while you wait for the incoming data.

while (true)
{
   Socket client = listener.AcceptSocket();
   Console.WriteLine("Connection accepted.");
    
   var childSocketThread = new Thread(() =>
   {
       byte[] data = new byte[100];
       int size = client.Receive(data);
       Console.WriteLine("Recieved data: ");
       
       for (int i = 0; i < size; i++)
       {
           Console.Write(Convert.ToChar(data[i]));
       }

       Console.WriteLine();
    
       client.Close();
    });

    childSocketThread.Start();
}