private void AcceptClient(IAsyncResult ar)
{
TcpClient newClient;
try
{
// a new connection has been accepted
newClient = _listener.EndAcceptTcpClient(ar);
Debug.WriteLine("Listener established TCP connection with " + ((IPEndPoint)newClient.Client.RemoteEndPoint).Address.ToString());
}
catch (ObjectDisposedException)
{
// occurs if we close the TCP listener while waiting for data
return;
}
catch (IOException ex)
{
Debug.WriteLine("Caught [" + ex.GetType().ToString() + "]\n\n" + ex.StackTrace);
return;
}
catch (SocketException ex)
{
Debug.WriteLine("Caught [" + ex.GetType().ToString() + "]\n\n" + ex.StackTrace);
return;
}
// keep listening for more connections
_listenerAsyncResult = _listener.BeginAcceptTcpClient(AcceptClient, new object());
NetworkStream ns = newClient.GetStream();
IPAddress addr = ((IPEndPoint)newClient.Client.RemoteEndPoint).Address;
TcpPeerConnection conn = new TcpPeerConnection(newClient, ns, addr);
// add connection to the peer list
if (_peerConns.ContainsKey(addr))
{
try
{
_peerConns[addr].stream.Close();
_peerConns[addr].client.Close();
}
catch (Exception e)
{
// eat exception - exceptions likely when closing a dead connection that's been reopened
Debug.WriteLine("Exception while closing connection assumed to be dead");
Debug.WriteLine(e);
}
_peerConns[addr] = conn;
}
else
{
_peerConns.Add(addr, conn);
}
// asynchronously read data from the connection. When data arrives, ReceiveData() will be called
// todo this can throw an exception
ns.BeginRead(conn.buffer, 0, conn.buffer.Length, ReceiveData, conn);
}
private void ConnectedToPeer(IAsyncResult ar)
{
TcpPeerConnection conn = (TcpPeerConnection)ar.AsyncState;
IPAddress addr = conn.remoteAddress;
// check if connection was successful
if (!conn.client.Connected)
{
Debug.WriteLine("Failed to connect to " + addr.ToString());
return;
}
conn.stream = conn.client.GetStream();
// see if we already have a connection to this peer -- if so, close it
if (_peerConns.ContainsKey(addr))
{
TcpPeerConnection oldConn = _peerConns[addr];
try
{
oldConn.stream.Close();
oldConn.client.Close();
}
catch (Exception ex)
{
Debug.WriteLine("Caught " + ex.ToString() + " while closing old connection");
}
finally
{
_peerConns.Remove(addr);
}
}
// store the peer in our peers list
_peerConns.Add(addr, conn);
Debug.WriteLine("Established connection to " + addr.ToString());
// see if the peer has any data to send us
conn.stream.BeginRead(conn.buffer, 0, conn.buffer.Length, ReceiveData, conn);
// send any queued messages to the peer
Queue <Message> q = _sendQueue[addr];
Message sendThis = q.Dequeue();
if (sendThis != null)
{
SendMessage(sendThis, addr);
}
}
private void DataSent(IAsyncResult ar)
{
TcpPeerConnection conn = (TcpPeerConnection)ar.AsyncState;
try
{
conn.stream.EndWrite(ar);
}
catch (SocketException ex)
{
Debug.Write("Caught SocketException in DataSent");
Debug.Write(ex);
try
{
conn.stream.Close();
conn.client.Close();
}
catch (Exception)
{
// have to eat it
}
}
catch (IOException ex)
{
Debug.Write("Caught IOException in DataSent");
Debug.Write(ex);
try
{
conn.stream.Close();
conn.client.Close();
}
catch (Exception)
{
// have to eat it
}
}
catch (ObjectDisposedException ex)
{
// occurs if we close the TCP connection while trying to send data
Debug.Write("Caught ObjectDisposedException in DataSent");
Debug.Write(ex);
return;
}
}
public void SendMessage(Message msg, IPAddress addr)
{
// see if we have an existing connection to this peer
TcpPeerConnection conn;
if (_peerConns.ContainsKey(addr))
{
// convert message to bytes and send it
conn = _peerConns[addr];
try
{
byte[] msgBytes = Encoding.ASCII.GetBytes(msg.Serialize());
conn.stream.BeginWrite(msgBytes, 0, msgBytes.Length, DataSent, conn);
return;
}
catch (SocketException ex)
{
Debug.Write("Caught SocketException in SendMessage");
Debug.Write(ex);
try
{
conn.stream.Close();
conn.client.Close();
}
catch (Exception)
{
// have to eat it
}
// fall through queue the message instead
}
catch (IOException ex)
{
Debug.Write("Caught IOException in SendMessage");
Debug.Write(ex);
try
{
conn.stream.Close();
conn.client.Close();
}
catch (Exception)
{
// have to eat it
}
// fall through queue the message instead
}
catch (ObjectDisposedException ex)
{
// occurs if we close the TCP connection while trying to send data
Debug.Write("Caught ObjectDisposedException in SendMessage");
Debug.Write(ex);
return;
}
}
// either we didn't have an active connection, or we tried to send on our active connection and failed,
// so add the message to the queue
if (!_sendQueue.ContainsKey(addr))
{
_sendQueue.Add(addr, new Queue <Message>());
}
_sendQueue[addr].Enqueue(msg);
// connect to the peer
conn = new TcpPeerConnection(null, null, addr);
TcpClient client = new TcpClient();
conn.client = client;
client.BeginConnect(addr, Port, ConnectedToPeer, conn);
// ConnectedToPeer() will send the message once we're connected
}
