TCP/IP

Hello, all!
I am trying to make a TCP/IP connection in unity(unity as a server), but when I run my application, it seems there is something in the code that keeps unity from starting
My code is:

Code (CSharp):

1. using UnityEngine;
2. using System.Collections;
3. using System;
4. using System.Collections.Generic;
5. using System.Linq;
6. using System.Text;
7. using System.Threading.Tasks;
8.  
9. using System.Net;
10. using System.Net.Sockets;
11. public class test: MonoBehaviour {
12. void Start()
13. {
14.    
15.             TcpListener listen = new TcpListener(IPAddress.Any, 1234);
16.             Console.WriteLine("listening ...");
17.             listen.Start();
18.             TcpClient client = listen.AcceptTcpClient();
19.             NetworkStream stream = client.GetStream();
20.             while (true)
21.             {
22.              
23.                 Console.WriteLine("connected");
24.                
25.  
26.                 byte[] buffer = new byte[720];
27.                 int data = stream.Read(buffer, 0, 720);
28.             }
29. }
30. }

I have tried this code as a standalone C# project and it works fine
Anyone have an idea of what is happening?

 

Unity's MonoBehaviour-based scripting system is single-threaded and runs on the main thread. When Unity loads a scene for the first time it will call every Start() function on every script attached to every game object, and it won't move onto the next task until they're finished.

An infinite loop in your Start() function means it will never move on.

Code (csharp):

1. while (true)

https://docs.unity3d.com/Manual/ExecutionOrder.html

Show us the code you wrote for the standalone project.

 

Hello!
I tried the codes in this link as two standalone project in Visual Studio at first https://www.c-sharpcorner.com/artic..._DoMXGG68WQ7SQ7NhyRmqimaAwDMYatp8yr8H9msC-qOw, which works fine
While attempting to run it, here is what I face:
And I am forced to close it from task manager

 

Right. That's precisely how the editor will behave when an infinite loop is entered. Because just like Unity it is running on the main thread.

Right. It's working fine because it has code that checks for a condition and once it is met breaks out of the loop. You need to add a similar section to the script you posted earlier starting after line 27.

Code (csharp):

1. if (data.IndexOf("<EOF>") > -1)
2. {
3.     break;
4. }

 

Ok, what if I do not know the data incoming. I mean that the example I am following in this link is just for checking the protocol works fine in Unity. My incoming data would be a stream of bytes. Should I manage that by checking if the length is completed or not?

 

I have very limited experience with networking. My first thought would be to have the code for handling reading and writing across the stream in its own thread and use queues to pass the data between the main thread and the network thread.

This question would be better answered by someone experienced in networking like @JoeStrout.

 

This is exactly right. The only way to service a socket properly is to do it in its own thread.

 

Okay, I am trying to figure how to use threading in my unity application, and these two codes that work fine as standalone C# applications

Code (CSharp):

1. using System;
2. using System.IO;
3. using System.Net;
4. using System.Net.Sockets;
5.  
6. public class EchoClient {
7.   public static void Main(){
8.    try {
9.     TcpClient client = new TcpClient("192.168.1.4", 9000);
10.     StreamReader reader = new StreamReader(client.GetStream());
11.     StreamWriter writer = new StreamWriter(client.GetStream());
12.     String s = String.Empty;
13.     while(!s.Equals("Exit")){
14.      Console.Write("Enter a string to send to the server: ");
15.      s = Console.ReadLine();
16.      Console.WriteLine();
17.      writer.WriteLine(s);
18.      writer.Flush();
19.      String server_string = reader.ReadLine();
20.      Console.WriteLine(server_string);
21.     }
22.     reader.Close();
23.     writer.Close();
24.     client.Close();
25.     } catch(Exception e){
26.       Console.WriteLine(e);
27.     }
28.  
29.   Console.ReadLine();
30.   }
31. }

Code (CSharp):

1. using System;
2. using System.IO;
3. using System.Net;
4. using System.Net.Sockets;
5. using System.Threading;
6.  
7. public class MultiThreadedEchoServer {
8.  
9.     private static void ProcessClientRequests(object argument){
10.         TcpClient client = (TcpClient)argument;
11.         try {
12.             StreamReader reader = new StreamReader(client.GetStream());
13.             StreamWriter writer = new StreamWriter(client.GetStream());
14.             string s = String.Empty;
15.             while(!(s = reader.ReadLine()).Equals("Exit") || (s == null)){
16.                 Console.WriteLine("From client -> " + s);
17.                 writer.WriteLine("From server -> " + s);
18.                 writer.Flush();
19.             }
20.             reader.Close();
21.             writer.Close();
22.             client.Close();
23.             Console.WriteLine("Closing client connection!");
24.         } catch(IOException){
25.                 Console.WriteLine("Problem with client communication. Exiting thread.");
26.         } finally{
27.                 if(client != null){
28.                     client.Close();
29.                 }
30.         }  
31.     }
32.  
33.     public static void Main(){
34.         TcpListener listener = null;
35.         try {
36.             listener = new TcpListener(IPAddress.Parse("192.168.1.4"), 9000);
37.             listener.Start();
38.             Console.WriteLine("MultiThreadedEchoServer started...");
39.             while(true){
40.                 Console.WriteLine("Waiting for incoming client connections...");
41.                 TcpClient client = listener.AcceptTcpClient();
42.                 Console.WriteLine("Accepted new client connection...");
43.                 Thread t = new Thread(ProcessClientRequests);
44.                 t.Start(client);
45.             }
46.         } catch(Exception e){
47.                 Console.WriteLine(e);
48.         } finally{
49.                 if(listener != null){
50.                     listener.Stop();
51.                 }
52.         }
53.         Console.ReadLine();
54.   }
55. }

And the same thing happens to unity...