// main method
// call this method to start the server
public void StartListening()
{
m_MarineExchangeDB = new MarineExchangeEntities();
IPHostEntry ipHostInfo = new IPHostEntry();
ipHostInfo.AddressList = new IPAddress[] { _serverIP };
IPAddress ipAddress = ipHostInfo.AddressList[0];
IPEndPoint localEndPoint = new IPEndPoint(ipAddress, _serverPortNumber);
// Create a TCP/IP socket.
Socket listener = new Socket(AddressFamily.InterNetwork,
SocketType.Stream, ProtocolType.Tcp);
// client threads
List<Thread> listOfThreads = new List<Thread>();
_clients = new List<AsynchronousClient>();
// connect to feeds configured in database
SetupFeeds();
if (_feeds.Count() > 0)
{
Thread transferBufferThread = new Thread(() => CheckFeedBuffer());
transferBufferThread.Start();
// start the listener socket
try
{
listener.Bind(localEndPoint);
listener.Listen(100);
// will continue to run as long as the thread which is transferring
while (transferBufferThread.IsAlive && _feeds.Count > 0)
{
// reset _addDone - will be set again in BeginAccept
_allDone.Reset();
Socket newSocket = null;
EntireConnection newConnection;
try
{
newConnection = (EntireConnection)listener.BeginAccept(new AsyncCallback(ServerAcceptCallback), new EntireConnection { serverSocket = listener, clientSocket = newSocket }).AsyncState;
}
catch (Exception ex)
{
m_MarineExchangeDB.LogError(ex.Message,
ex.StackTrace,
"AsynchronousSocketListener.StartListening",
ex.InnerException.ToString(),
ex.TargetSite.ToString(),
DateTime.Now,
null,
null,
null);
newConnection = null;
}
// wait till accept is complete
_allDone.WaitOne();
if (newConnection != null)
{
try
{
// create new client - client has own thread which starts processing
AsynchronousClient newClient = new AsynchronousClient(newConnection.clientSocket);
_clients.Add(newClient);
}
catch (Exception ex)
{
m_MarineExchangeDB.LogError(ex.Message,
ex.StackTrace,
"AsynchronousSocketListener.StartListening",
ex.InnerException.ToString(),
ex.TargetSite.ToString(),
DateTime.Now,
null,
null,
null);
}
}
}
}
catch (Exception ex)
{
m_MarineExchangeDB.LogError(ex.Message,
ex.StackTrace,
"AsynchronousSocketListener.StartListening",
ex.InnerException.ToString(),
ex.TargetSite.ToString(),
DateTime.Now,
null,
null,
null);
}
}
}
// this method accepts a client socket and begins sending data to that client
private static void ServerSend(AsynchronousClient client)
{
Socket handler = client.ClientSocket;
byte[] data = null;
lock (feed.sb)
{
data = Encoding.ASCII.GetBytes(feed.sb.ToString());
feed.sb.Clear();
}
if (data != null)
handler.BeginSend(data, 0, data.Length, 0, new AsyncCallback(ServerSendCallback), client);
}
// used to accept a new client connection
// this method should be called as part of the creation of a new thread
private static void ServerAcceptCallback(IAsyncResult ar)
{
// signal the main thread to continue (move this to after the EndAccept?)
lock (_allDone)
{
_allDone.Set();
}
// retrieve the listener socket
Socket listener = (Socket)ar.AsyncState;
// retrieve the new socket created for this connect
Socket clientSocket = listener.EndAccept(ar);
// use the created socket as the basis for the new client (new AsynchronousClient)
AsynchronousClient newClient = new AsynchronousClient();
newClient.ClientSocket = clientSocket;
newClient.sendDone.Reset();
// call client's method to BeginReceive
clientSocket.BeginReceive(newClient.buffer, 0, 1024, 0, new AsyncCallback(ServerReceiveCallback), newClient);
newClient.sendDone.WaitOne();
// once the client has identified itself, begin sending data
while (newClient.ClientSocket.Connected)
{
ServerSend(newClient);
}
}
// this method accepts a client socket and begins sending data to that client
private void ServerSend(AsynchronousClient client)
{
Socket handler = client.ClientSocket;
byte[] data = null;
lock (LocalBuffer)
{
data = Encoding.ASCII.GetBytes(LocalBuffer);
LocalBuffer = string.Empty;
}
if (data != null)
{
try
{
handler.BeginSend(data, 0, data.Length, 0, new AsyncCallback(ServerSendCallback), client);
}
catch (Exception ex)
{
// response to any socket errors is to close the connection
handler.Close();
m_MarineExchangeDB.LogError(ex.Message,
ex.StackTrace,
"AsynchronousClient.Start",
ex.InnerException.ToString(),
ex.TargetSite.ToString(),
DateTime.Now,
null,
ClientID,
DeviceID);
m_MarineExchangeDB.LogCloseConnection(AccessIP, ClientID, DeviceID);
}
}
}
