Hi
Bit of a challenge for me. I need to create a TCP Socket server. Since my understanding is that the built-in network layer in Unity is UDP based, and I need TCP sockets, I need to use the .net Socket Server examples.
So I am using THIS example here.
The only change is that I added ‘using UnityEngine’ and changed all the ‘Console.Writeline’ statements to ‘Debug.Log’.
I also removed the arguments in the Main method entry point.
From Unity in a MonoBehaviour class I simply call
AsynchronousSocketListener.Main() from Start();
The problem seems to be that Unity simply ‘hangs’ when I hit play in the editor. Even though the Server example is Asynchronous could this hanging be because the application execution is blocked’ until a connection is established?
Shouldn’t I be seeing some other error?
Very frustrating is there is essentially NO working TCP socket server code I can find that just works out of the box.
ANY feedback appreciated!
My completed AsynchronousSocketListener .cs file
using System;
using System.Net;
using System.Net.Sockets;
using System.Text;
using System.Threading;
using UnityEngine;
// State object for reading client data asynchronously
public class StateObject
{
// Client socket.
public Socket workSocket = null;
// Size of receive buffer.
public const int BufferSize = 1024;
// Receive buffer.
public byte[] buffer = new byte[BufferSize];
// Received data string.
public StringBuilder sb = new StringBuilder();
}
public class AsynchronousSocketListener
{
// Thread signal.
public static ManualResetEvent allDone = new ManualResetEvent(false);
public AsynchronousSocketListener()
{
}
public static void StartListening()
{
// Data buffer for incoming data.
byte[] bytes = new Byte[1024];
// Establish the local endpoint for the socket.
// The DNS name of the computer
// running the listener is "host.contoso.com".
//IPHostEntry ipHostInfo = Dns.Resolve(Dns.GetHostName());
IPHostEntry ipHostInfo = Dns.GetHostEntry(Dns.GetHostName());
Debug.Log("0 ASSERT ipHostInfo " + ipHostInfo);
//master //IPAddress ipAddress = ipHostInfo.AddressList[0];
IPAddress ipAddress = IPAddress.Loopback;
Debug.Log("1 ASSERT ipAddress " + ipAddress);
IPEndPoint localEndPoint = new IPEndPoint(ipAddress, 8744);
// Create a TCP/IP socket.
Socket listener = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
//alt //Socket listener = new Socket(localEndPoint.AddressFamily, SocketType.Stream, ProtocolType.Tcp);
// Bind the socket to the local endpoint and listen for incoming connections.
try
{
listener.Bind(localEndPoint);
listener.Listen(100);
while (true)
{
// Set the event to nonsignaled state.
allDone.Reset();
// Start an asynchronous socket to listen for connections.
Debug.Log("Waiting for a connection...");
listener.BeginAccept(
new AsyncCallback(AcceptCallback),
listener);
// Wait until a connection is made before continuing.
allDone.WaitOne();
}
}
catch (Exception e)
{
Debug.LogError(e.ToString());
}
Debug.Log("\nPress ENTER to continue...");
// Console.Read();
}
public static void AcceptCallback(IAsyncResult ar)
{
// Signal the main thread to continue.
Debug.Log("++++++++++++++++++++++++++++++++");
Debug.Log(" ");
Debug.Log(" ");
Debug.Log("1 ASSERT AcceptCallback "+ar);
Debug.Log(" ");
Debug.Log(" ");
Debug.Log("++++++++++++++++++++++++++++++++");
allDone.Set();
// Get the socket that handles the client request.
Socket listener = (Socket)ar.AsyncState;
Socket handler = listener.EndAccept(ar);
// Create the state object.
StateObject state = new StateObject();
state.workSocket = handler;
handler.BeginReceive(state.buffer, 0, StateObject.BufferSize, 0,
new AsyncCallback(ReadCallback), state);
}
public static void ReadCallback(IAsyncResult ar)
{
String content = String.Empty;
Debug.Log("2 ASSERT ReadCallback " + ar);
// Retrieve the state object and the handler socket
// from the asynchronous state object.
StateObject state = (StateObject)ar.AsyncState;
Socket handler = state.workSocket;
// Read data from the client socket.
int bytesRead = handler.EndReceive(ar);
Debug.Log("3 ASSERT ReadCallback bytesRead " + bytesRead);
if (bytesRead > 0)
{
// There might be more data, so store the data received so far.
state.sb.Append(Encoding.ASCII.GetString(
state.buffer, 0, bytesRead));
// Check for end-of-file tag. If it is not there, read
// more data.
content = state.sb.ToString();
if (content.IndexOf("TRIGGER") > -1)
{
Debug.LogWarning("4 ASSERT YES TRIGGER!!");
}
if (content.IndexOf("<EOF>") > -1)
{
// All the data has been read from the
// client. Display it on the console.
Debug.Log("4 ASSERT Read {0} bytes from socket. \n Data : {1} " + content.Length+ " and content is "+ content);
// Echo the data back to the client.
// Send(handler, content);
}
else
{
// Not all data received. Get more.
handler.BeginReceive(state.buffer, 0, StateObject.BufferSize, 0,
new AsyncCallback(ReadCallback), state);
}
}
}
private static void Send(Socket handler, String data)
{
// Convert the string data to byte data using ASCII encoding.
byte[] byteData = Encoding.ASCII.GetBytes(data);
// Begin sending the data to the remote device.
handler.BeginSend(byteData, 0, byteData.Length, 0,
new AsyncCallback(SendCallback), handler);
}
private static void SendCallback(IAsyncResult ar)
{
try
{
// Retrieve the socket from the state object.
Socket handler = (Socket)ar.AsyncState;
// Complete sending the data to the remote device.
int bytesSent = handler.EndSend(ar);
string temp = bytesSent.ToString();
Debug.Log("Sent {0} bytes to client."+ temp);
handler.Shutdown(SocketShutdown.Both);
handler.Close();
}
catch (Exception e)
{
Debug.Log(e.ToString());
}
}
//public static int Main(String[] args)
public static int Main()
{
StartListening();
return 0;
}
}