Question

I am making a chat service for a game,

I am using a TCP listener an client for the account information, some sort of login service. I’m wondering if i can keep the socked the client connected to the server with, to check if he is still online, and keep sending him messages if he has new messages.

I already tried making a list of sockets for the login queue, but it disconnected the previous socket to to server as soon as i accepted a new socket.

byte[] usernameByte = new byte[100];
int usernameRecieved = s.Receive(usernameByte);
//guiController.setText(System.DateTime.Now + " Recieved Login...");

byte[] passByte = new byte[100];
int passRecieved = s.Receive(passByte);
//guiController.setText(System.DateTime.Now + " Recieved Password...");

string username = "";
string password = "";

for (int i = 0; i < usernameRecieved; i++)
     username += (Convert.ToChar(usernameByte[i]));

for (int i = 0; i < passRecieved; i++)
     password += (Convert.ToChar(passByte[i]));

if (DomainController.getInstance().checkAccount(username, password))
{
    ASCIIEncoding asen = new ASCIIEncoding();
    s.Send(asen.GetBytes("true"));
    s.Send(asen.GetBytes("U are succesfully logged in, press enter to continue"));
    guiController.setText(serverName,System.DateTime.Now+"");
    guiController.setText(serverName, "Sent Acknowledgement - Logged in");
}
else
{
    ASCIIEncoding asen = new ASCIIEncoding();
    s.Send(asen.GetBytes("false"));
    s.Send(asen.GetBytes("U are NOT logged in, press enter to continue"));
    guiController.setText(serverName, System.DateTime.Now + "");
    guiController.setText(serverName, "\nSent Acknowledgement - Not logged in");
}

This is the code i currently use to check the account information the user send me. Right after i send this the user dropd the connection and i move on to the next one.

I have tried making 1 list of seperate sockets and processing them one by one, but that failed because the previous socket’s connection dropped, even tho it were 2 different machines that tried to connect.

Does anyone have a sollution / a way to save sockets, that I can use to make the program keep all the connections alive? so i can send a message from user 1 to user 2, and just use the socket they connected with? or do i need to add an id every time they make a connection?

EDIT

The client Code: (this is just a test client)

while (true)
{
TcpClient tcpclnt = new TcpClient();
Console.WriteLine("Connecting.....");
tcpclnt.Connect("xx.xxx.xxx.xx", 26862);
// use the ipaddress as in the server program

while(!(checkResponse(tcpclnt.GetStream())))
{
     Thread.Sleep(1000);
}

Console.WriteLine("Connected");

Console.Write("Enter the string to be transmitted : ");

String str = Console.ReadLine();
if (str == "")
{
    str = " ";
}
                    
Stream stm = tcpclnt.GetStream();

ASCIIEncoding asen = new ASCIIEncoding();
byte[] ba = asen.GetBytes(str);


Console.WriteLine("Transmitting.....");

stm.Write(ba, 0, ba.Length);

Console.Write("Enter the string to be transmitted : ");

String str2 = Console.ReadLine();
if (str2 == "")
{
   str2 = " ";
}

Stream stm2 = tcpclnt.GetStream();

ASCIIEncoding asen2 = new ASCIIEncoding();
byte[] ba2 = asen2.GetBytes(str2);


Console.WriteLine("Transmitting.....");

stm.Write(ba2, 0, ba2.Length);
if (str == "false")
{
    blijvenWerken = false;
}
byte[] bb = new byte[100];
int k = stm.Read(bb, 0, 100);

for (int i = 0; i < k; i++)
Console.Write(Convert.ToChar(bb[i]));

byte[] bb2 = new byte[100];
int k2 = stm.Read(bb2, 0, 100);
Console.Write("\n");
for (int i = 0; i < k2; i++)
Console.Write(Convert.ToChar(bb2[i]));

Console.WriteLine("\n");

tcpclnt.Close();
Thread.Sleep(1000);
}

Server getting the sockets:
This bit of code is on the loginserver, its because i can only accept 1 socket every time to keep the connection alive, that i put queueCount on a maximum of 1.
I want to be able to make a list of Sockets that i accepted to add to a User account.

while (loginServerOn)
{
    if (queueCount < 1)
    {
        if (loginServer.getLoginListener().Pending())
        {
            loginQueue.Add(loginServer.getSocket());
            ASCIIEncoding asen = new ASCIIEncoding();
            Socket s = loginQueue.First();
            try
            {
                s.Send(asen.GetBytes("true"));
                queueCount++;
            }
            catch
            {
                loginQueue.Remove(s);
            }
        }
    }
}

The function that returns the accepted socket.

public Socket getSocket()
{
    return myList.AcceptSocket();
}

EDIT: Essence of the question

I want to add the socked or client recieved to my Account object, so every connection has an Account its linked to, when i want to send a message to a certain account, it should send a message to the socked or client bound to that account, can you help/show me how i can achieve this?

Answer 1

This is still c# and sockets but my approach is different to yours.

I went with the concept of a “connectedCleint” which is similar in purpose to what you’ve called an account.

I have a class called ServerTerminal which is responsible for accepting and top level management of socket connections. In this i’ve got:

 public Dictionary<long, ConnectedClient> DictConnectedClients =
        new Dictionary<long, ConnectedClient>();

So this is my list of connected clients indexed by the sockethandle.

To accept connections i’ve got a routine:

public void StartListen(int port)
    {
        socketClosed = false;
        IPEndPoint ipLocal = new IPEndPoint(IPAddress.Any, port);

        listenSocket = new Socket(AddressFamily.InterNetwork,
            SocketType.Stream, ProtocolType.Tcp);

        //bind to local IP Address...
        //if ip address is allready being used write to log
        try
        {
            listenSocket.Bind(ipLocal);
        }
        catch (Exception excpt)
        {
            // Deal with this.. write your own log code here ?
            socketClosed = true;

            return;
        }
        //start listening...

        listenSocket.Listen(100); // Max 100 connections for my app

        // create the call back for any client connections...
        listenSocket.BeginAccept(new AsyncCallback(OnClientConnection), null);

    }

So when a client connects it then fires off:

private void OnClientConnection(IAsyncResult asyn)
    {
        if (socketClosed)
        {
            return;
        }

        try
        {
            Socket clientSocket = listenSocket.EndAccept(asyn);

            ConnectedClient connectedClient = new ConnectedClient(clientSocket, this, _ServerTerminalReceiveMode);

            //connectedClient.MessageReceived += OnMessageReceived;
            connectedClient.Disconnected += OnDisconnection;
            connectedClient.dbMessageReceived += OndbMessageReceived;

            connectedClient.ccSocketFaulted += ccSocketFaulted;

            connectedClient.StartListening();

            long key = clientSocket.Handle.ToInt64();
            if (DictConnectedClients.ContainsKey(connectedClient.SocketHandleInt64))
            {
                // Already here - use your own error reporting..
            }

            lock (DictConnectedClients)
            {
                DictConnectedClients[key] = connectedClient;
            }

            // create the call back for any client connections...
            listenSocket.BeginAccept(new AsyncCallback(OnClientConnection), null);

        }
        catch (ObjectDisposedException excpt)
        {
            // Your own code here..
        }
        catch (Exception excpt)
        {
            // Your own code here...
        }

    }

The crucial part of this for you is:

            // create the call back for any client connections...
            listenSocket.BeginAccept(new AsyncCallback(OnClientConnection), null);

This sets up the serverterminal to receive new connections.

Edit:
Cut down version of my connectedclient:

public class ConnectedClient
{
    private Socket mySocket;
    private SocketIO mySocketIO;

    private long _mySocketHandleInt64 = 0;


    // These events are pass through; ConnectedClient offers them but really
    // they are from SocketIO

    public event TCPTerminal_ConnectDel Connected
    {
        add
        {
            mySocketIO.Connected += value;
        }
        remove
        {
            mySocketIO.Connected -= value;
        }
    }

    public event TCPTerminal_DisconnectDel Disconnected
    {
        add
        {
            mySocketIO.Disconnected += value;
        }
        remove
        {
            mySocketIO.Disconnected -= value;
        }
    }

    // Own Events

    public event TCPTerminal_TxMessagePublished TxMessageReceived;

    public delegate void SocketFaulted(ConnectedClient cc);
    public event SocketFaulted ccSocketFaulted;

    private void OnTxMessageReceived(Socket socket, TxMessage myTxMessage)
    {
     // process your message
    }



    private void OnMessageSent(int MessageNumber, int MessageType)
    {
    // successful send, do what you want..
    }





    public ConnectedClient(Socket clientSocket, ServerTerminal ParentST)
    {
        Init(clientSocket, ParentST, ReceiveMode.Handler);
    }

    public ConnectedClient(Socket clientSocket, ServerTerminal ParentST, ReceiveMode RecMode)
    {
        Init(clientSocket, ParentST, RecMode);
    }

    private void Init(Socket clientSocket, ServerTerminal ParentST, ReceiveMode RecMode)
    {
        ParentServerTerminal = ParentST;
        _myReceiveMode = RecMode;

        _FirstConnected = DateTime.Now;
        mySocket = clientSocket;
        _mySocketHandleInt64 = mySocket.Handle.ToInt64();
        mySocketIO = new SocketIO(clientSocket, RecMode);

        // Register for events
        mySocketIO.TxMessageReceived += OnTxMessageReceived;
        mySocketIO.MessageSent += OnMessageSent;
        mySocketIO.dbMessageReceived += OndbMessageReceived;

    }


    public void StartListening()
    {
        mySocketIO.StartReceiving();
    }

    public void Close()
    {
        if (mySocketIO != null)
        {
            mySocketIO.Close();
            mySocketIO = null;
        }

        try
        {
            mySocket.Close();
        }
        catch
        {
            // We're closing.. don't worry about it
        }
    }

    public void SendMessage(int MessageNumber, int MessageType, string Message)
    {
        if (mySocket != null && mySocketIO != null)
        {
            try
            {
                mySocketIO.SendMessage(MessageNumber, MessageType, Message);
            }
            catch
            {
                // mySocketIO disposed inbetween check and call
            }
        }
        else
        {
            // Raise socket faulted event
            if (ccSocketFaulted != null)
                ccSocketFaulted(this);
        }
    }


}

}

Some useful links:

This is where I started:
http://vadmyst.blogspot.com.au/2008/01/how-to-transfer-fixed-sized-data-with.html

http://vadmyst.blogspot.com.au/2008/03/part-2-how-to-transfer-fixed-sized-data.html

And..

C# Sockets and Multithreading

Cause a connected socket to accept new messages right after .BeginReceive?

http://nitoprograms.blogspot.com.au/2009/04/tcpip-net-sockets-faq.html

http://www.codeproject.com/Articles/83102/C-SocketAsyncEventArgs-High-Performance-Socket-Cod

I can’t post my entire solution just now; there is a flaw in my server code I need to debug; plus there are parts which my employer may not want published. But i based my code on what Vadym had for variable length messages.