/// <summary>
/// If necessary, connect the remote <c>RemoteSocket</c> socket
/// to the given host and port
/// </summary>
/// <param name="hostname">Remote host name</param>
/// <param name="port">Remote port</param>
/// <remarks>
/// If RemoteSocket is already connected to the right host and port,
/// the socket is reused as is.
/// </remarks>
protected void Connect(string hostname, int port)
{
Debug.Assert(!String.IsNullOrEmpty(hostname));
Debug.Assert(port > 0);
if (DestinationHostName != null &&
DestinationHostName.Equals(hostname) &&
DestinationPort == port &&
(RemoteSocket != null && !RemoteSocket.IsSocketDead()))
{
// Nothing to do, just reuse the socket
return;
}
if (RemoteSocket != null)
{
// We have a socket connected to the wrong host (or port)
RemoteSocket.CloseSocket();
RemoteSocket = null;
}
IPAddress[] ips = Dns.GetHostAddresses(hostname);
Socket socket = null;
Exception e = null;
foreach (var ip in ips)
{
try {
socket = new Socket(ip.AddressFamily, SocketType.Stream, ProtocolType.Tcp);
socket.Connect(ip, port);
break;
}
catch (Exception ee) {
if (ip.Equals(IPAddress.IPv6Loopback))
{
// Do not log that
continue;
}
if (e == null)
{
e = ee;
}
if (socket != null)
{
socket.Close();
socket = null;
}
}
}
if (socket == null)
{
throw e;
}
// Checked up, and good to go
RemoteSocket = new SocketState(socket);
DestinationHostName = hostname;
DestinationPort = port;
}
/// <summary>
/// Close broken sockets
/// </summary>
/// <remarks>
/// This function is called regularly to clean up the list of
/// connected sockets.
/// </remarks>
private void CheckSockets(object eventState)
{
try {
lock (ConnectedSockets) {
foreach (var kv in ConnectedSockets)
{
try {
Guid id = kv.Key;
SocketState state = kv.Value;
if (state == null || state.IsSocketDead())
{
ConnectedSockets.Remove(id);
}
}
catch (Exception e) {}
}
}
}
catch {}
}
/// <summary>
/// Callback method for accepting new connections
/// </summary>
private void AcceptCallback(IAsyncResult ar)
{
if (listeningThread.ManagedThreadId == Thread.CurrentThread.ManagedThreadId)
{
new Thread(() => AcceptCallback(ar)).Start();
return;
}
if (IsShuttingDown)
{
return;
}
// Get the socket that handles the client request
var listener = (Socket)ar.AsyncState;
Socket handler = listener.EndAccept(ar);
// Signal the main thread to continue
listenThreadSwitch.Set();
// Create the state object
var state = new SocketState(handler);
state.guid = Guid.NewGuid();
lock (ConnectedSockets) {
ConnectedSockets[state.guid] = state;
}
QTransfer transfer = null;
try {
transfer = new QTransfer(state);
transfer.OnReceiveRequest = OnReceiveRequest;
transfer.OnReceiveResponse = OnReceiveResponse;
}
catch (Exception e) {
Console.WriteLine(e.Message);
}
if (transfer == null)
{
CloseSocket(state);
return;
}
// No need for asynchronous I/O from now on
try {
while (transfer.LogicLoop())
{
if (IsShuttingDown || state.IsSocketDead())
{
break;
}
}
}
catch (SocketException) {
/* ignore */
}
catch (IoBroken) {
/* ignore */
}
catch (Exception e) {
Console.WriteLine(e.Message);
Console.WriteLine("Closing socket on error");
}
CloseSocket(state);
}
/// <summary>
/// Callback method for accepting new connections
/// </summary>
private void AcceptCallback(IAsyncResult ar)
{
if (listeningThread.ManagedThreadId == Thread.CurrentThread.ManagedThreadId) {
new Thread(() => AcceptCallback(ar)).Start();
return;
}
if (IsShuttingDown) {
return;
}
// Get the socket that handles the client request
var listener = (Socket)ar.AsyncState;
Socket handler = listener.EndAccept(ar);
// Signal the main thread to continue
listenThreadSwitch.Set();
// Create the state object
var state = new SocketState(handler);
state.guid = Guid.NewGuid();
lock (ConnectedSockets) {
ConnectedSockets[state.guid] = state;
}
QTransfer transfer = null;
try {
transfer = new QTransfer(state);
transfer.OnReceiveRequest = OnReceiveRequest;
transfer.OnReceiveResponse = OnReceiveResponse;
}
catch (Exception e) {
Console.WriteLine(e.Message);
}
if (transfer == null) {
CloseSocket(state);
return;
}
// No need for asynchronous I/O from now on
try {
while (transfer.LogicLoop()) {
if (IsShuttingDown || state.IsSocketDead()) {
break;
}
}
}
catch (SocketException) {
/* ignore */
}
catch (IoBroken) {
/* ignore */
}
catch (Exception e) {
Console.WriteLine(e.Message);
Console.WriteLine("Closing socket on error");
}
CloseSocket(state);
}
