public void Connect()
{
if (!MsgCenter.Running)
{
if (Log.IsVerbose)
{
Log.Verbose(ErrorCode.ProxyClient_MsgCtrNotRunning, "Ignoring connection attempt to gateway {0} because the proxy message center is not running", Address);
}
return;
}
// Yes, we take the lock around a Sleep. The point is to ensure that no more than one thread can try this at a time.
// There's still a minor problem as written -- if the sending thread and receiving thread both get here, the first one
// will try to reconnect. eventually do so, and then the other will try to reconnect even though it doesn't have to...
// Hopefully the initial "if" statement will prevent that.
lock (Lockable)
{
if (!IsLive)
{
if (Log.IsVerbose)
{
Log.Verbose(ErrorCode.ProxyClient_DeadGateway, "Ignoring connection attempt to gateway {0} because this gateway connection is already marked as non live", Address);
}
return; // if the connection is already marked as dead, don't try to reconnect. It has been doomed.
}
for (var i = 0; i < ProxiedMessageCenter.CONNECT_RETRY_COUNT; i++)
{
try
{
if (Socket != null)
{
if (Socket.Connected)
{
return;
}
MarkAsDisconnected(Socket); // clean up the socket before reconnecting.
}
if (lastConnect != new DateTime())
{
// We already tried at least once in the past to connect to this GW.
// If we are no longer connected to this GW and it is no longer in the list returned
// from the GatewayProvider, consider directly this connection dead.
if (!MsgCenter.GatewayManager.GetLiveGateways().Contains(Address))
{
break;
}
// Wait at least ProxiedMessageCenter.MINIMUM_INTERCONNECT_DELAY before reconnection tries
var millisecondsSinceLastAttempt = DateTime.UtcNow - lastConnect;
if (millisecondsSinceLastAttempt < ProxiedMessageCenter.MINIMUM_INTERCONNECT_DELAY)
{
var wait = ProxiedMessageCenter.MINIMUM_INTERCONNECT_DELAY - millisecondsSinceLastAttempt;
if (Log.IsVerbose)
{
Log.Verbose(ErrorCode.ProxyClient_PauseBeforeRetry, "Pausing for {0} before trying to connect to gateway {1} on trial {2}", wait, Address, i);
}
Thread.Sleep(wait);
}
}
lastConnect = DateTime.UtcNow;
Socket = new Socket(Silo.Endpoint.AddressFamily, SocketType.Stream, ProtocolType.Tcp);
SocketManager.Connect(Socket, Silo.Endpoint, MsgCenter.MessagingConfiguration.OpenConnectionTimeout);
NetworkingStatisticsGroup.OnOpenedGatewayDuplexSocket();
MsgCenter.OnGatewayConnectionOpen();
SocketManager.WriteConnectionPreamble(Socket, MsgCenter.ClientId); // Identifies this client
Log.Info(ErrorCode.ProxyClient_Connected, "Connected to gateway at address {0} on trial {1}.", Address, i);
return;
}
catch (Exception ex)
{
Log.Warn(ErrorCode.ProxyClient_CannotConnect, $"Unable to connect to gateway at address {Address} on trial {i} (Exception: {ex.Message})");
MarkAsDisconnected(Socket);
}
}
// Failed too many times -- give up
MarkAsDead();
}
}