[anitdragon13]

hello, i currently learning socket programming. it seem easy, but i see a problem... while creating a DOS server program i can start a while loop but it stays true intill i exit the program example..

            while (true)
            {
                //do stuff
            }

            clientSocket.Close();
            serverSocket.Stop();
            Console.WriteLine("server now exiting.");
            Console.ReadLine();

my problem is .close & .stop nevers happens. is there a way to refracted this? like on exit do this? -Thanks

[janne_panne]

Hi

Because closing a console application from the close cross doesn't fire any regular events because it's killing the application with quite brutal methods, you'll have to do something different.

I created this small sample to mimic your problem. The way I handled exiting is to hook up to Kernel32.Dll's SetConsoleCtrlHandler which fires events when your console application closes.

In my test app I have a class called server which writes to a file. In Main() I hook to the event and in the event I call stop method of the Server which flushes the stream to the text file. If the stop isn't called, it won't flush to the file and the file remains empty.
I replaced the while(true) loop with while(isRunning) and in Stop() I set isRunning to false.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Collections.ObjectModel;

namespace ConsoleApplication1
{
    class Program
    {
        [System.Runtime.InteropServices.DllImport("Kernel32")]
        private static extern bool SetConsoleCtrlHandler(EventHandler handler, bool add);

        private delegate bool EventHandler(CtrlType sig);
        static EventHandler _handler;

        enum CtrlType
        {
            CTRL_C_EVENT = 0,
            CTRL_BREAK_EVENT = 1,
            CTRL_CLOSE_EVENT = 2,
            CTRL_LOGOFF_EVENT = 5,
            CTRL_SHUTDOWN_EVENT = 6
        }

        private static Server server;

        static void Main(string[] args)
        {
            _handler = new EventHandler(Handler);
            SetConsoleCtrlHandler(_handler, true);
            server = new Server();
            server.Start();
        }

        private static bool Handler(CtrlType sig)
        {
            bool b = false;
            switch (sig) {
                case CtrlType.CTRL_C_EVENT:
                case CtrlType.CTRL_LOGOFF_EVENT:
                case CtrlType.CTRL_SHUTDOWN_EVENT:
                case CtrlType.CTRL_CLOSE_EVENT:
                    SetConsoleCtrlHandler(_handler, false);
                    server.Stop();
                    b = true;
                    break;
                default:
                    break;
            }
            return b;
        }

    }

    class Server
    {
        public Server()
        {

        }

        ~Server()
        {
            Stop();
        }

        System.IO.StreamWriter stream;

        public void Start()
        {
            stream = new System.IO.StreamWriter(@"D:\temp\server.txt", false);
            stream.WriteLine("Start");
            isRunning = true;
            Run();
        }

        private bool isRunning = false;

        private void Run()
        {
            while (isRunning) {
                System.Threading.Thread.Sleep(500);
                stream.WriteLine("running...");
            }
        }

        public void Stop()
        {
            stream.WriteLine("Stop");
            stream.Flush();
            stream.Close();
            isRunning = false;
        }
    }
}

[Snowl]

You can also do it without importing any dlls:

First, put in your using section:

using System.Windows.Forms;

Then in your main code, make a function:

static void OnProcessExit (object sender, EventArgs e)
{
    Console.WriteLine("Shutting down Process");
    //DO STUFF HERE
    Application.Exit();
}

Then in your inital code, at the top, put this line of code:

AppDomain.CurrentDomain.ProcessExit += new EventHandler (OnProcessExit);

Be aware that this method has around 10 seconds of execution before your process will be considered "frozen"

This post has been edited by Atli: 04 February 2012 - 03:45 PM
Reason for edit:: Changed [quote] tags to [code] tags.

[Curtis Rutland]

I can't confirm this. I've tested it, and the ProcessExit handler is never called. Are you sure this will work with a Console Application?

[Snowl]

Yes, this is with a console application. Here is the code (besides the server code):

using System.Runtime.InteropServices;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Classic6;
using System.Windows.Forms;

namespace Classic6Server
{
    class Program
    {
        static ClassicServer server;
        private static Server server2 = new Server();
		
        static void Main()
        {
	AppDomain.CurrentDomain.ProcessExit += new EventHandler (OnProcessExit);
            server = server2.NewServer();

            string url = server.ServerUrl.ToString();
            bool hasSet = false;

            while (true)
            {
                if (!String.IsNullOrEmpty(url) && !hasSet)
                {
                    Clipboard.SetText(server.ServerUrl.ToString());
                    hasSet = true;
                }
                string input = "";
                while (input != "quit" && input != "q")
                {
                    input = Console.ReadLine();
                    ParseInput(input);
                }
            }
        }

        static bool ParseInput(string input)
        {
            //unimportant stuff
            return false;
        }
		
	static void OnProcessExit (object sender, EventArgs e)
    	{
        	Server.server.Log("Shutting down Server");
			Server.server.Exit(false);
			Application.Exit();
    	}
    }
}

[anitdragon13]

thank you very much, this helped me a lot. rep++