Help: DotNet Tcp Client Bound

Hi All,

I am using a TCP server to accept connections from n TCP clients (with Socket.Select()). It seems that there is a strange bound on the value of n in Socket.Select. Sad

Steps to reproduce the problem.

1. Bring up a TCP server on port 19999 in a thread. This thread use a socket arraylist as the first parameter for Socket.Select().
2. Bring up client threads one at a time, with 1 second inteval between two client threads. Each thread creates a client and connects to that server. The number of client thread is n.
3. When the number of n reaches 65, I got an exception at Socket.Select(). The message is "Index was outside the bounds of the array".

I tried SetSocketOption with MaxConnections and get an unhandled exception. I also
tried to use different value for socket Listen(int), for example, 100, 255, and 10000. It does not help. Then I played around with the keepalive option. Nothing changes.

Please help me if you have any suggestions! Thanks in advanced!

ps. The test code of client thread, server thread, and main is attached. It is for vs2003 DotNet 1.0. I also tested it with vs2005 DotNet 2.0, the problem is the same.

Tao

using System;
using System.Collections;
using System.ComponentModel;
using System.Diagnostics;
using System.IO;
using System.Net;
using System.Net.Sockets;
using System.Threading;

public class MyTest
{

       public MyTest () {
      }

    static void Main(string [] args)
        {

            Thread s = new Thread(new ThreadStart(MyTest.Server1));
            s.Name="Server";
            s.Start();

            Thread c1 = null;

            for (int i=0; i<100; i++)
            {
                c1 = new Thread(new ThreadStart(MyTest.Client1));
                c1.Name=i.ToString();
                c1.Start();
                Thread.Sleep(1000);
            }

            Console.WriteLine("All threads are up.");
            Thread.Sleep(10000);
            Environment.Exit(-1);
    }

        public static void Server1()
        {
            Socket lisenterSocket = new Socket(AddressFamily.InterNetwork,
                SocketType.Stream, ProtocolType.Tcp);
            lisenterSocket.Bind(new IPEndPoint(IPAddress.Loopback, 19999));
            lisenterSocket.Listen(10000);

            Console.WriteLine("Server1: "+DateTime.Now.ToString("HH-mm-ss.fff")
                +" Tcp server up at "
                +IPv4Address.Loopback.ToString());

            ArrayList allSocketList = new ArrayList();
            ArrayList socketList = new ArrayList();

            allSocketList.Add(lisenterSocket);
            socketList.Add(lisenterSocket);

            while (true)
            {
                Thread.Sleep(100);
                Console.WriteLine("");
                Console.WriteLine("Server1: "+DateTime.Now.ToString("HH-mm-ss.fff")
                    +" select "+socketList.Count+" sockets");

                try
                {
                    Socket.Select(socketList, null, null, 500000000);
                }
                catch (Exception e)
                {
                    Console.WriteLine(e.Message);
                    Environment.Exit(-2);
                }

                Console.WriteLine("Server1: "+DateTime.Now.ToString("HH-mm-ss.fff")
                    +" "+socketList.Count
                    +" sockets got connection requests.");


                for (int j=0; j<socketList.Count; j++)
                {
                    Console.WriteLine("Server1: "+DateTime.Now.ToString("HH-mm-ss.fff")
                        +" get socketList["+(j+1)+" out of "+socketList.Count+"]");
                    Socket activeSocket = ((Socket)socketList[j]);
                    if (activeSocket==lisenterSocket)
                    {
                      //New client connection
                        Socket acceptedSocket = lisenterSocket.Accept();

                        //Back up this socket
                        allSocketList.Add(acceptedSocket);

                        Console.WriteLine("Server1: "+DateTime.Now.ToString("HH-mm-ss.fff")
                            +" allSocketList size = "+allSocketList.Count);
                    }
                    else
                    {
                        byte [] buff = new byte [2000];
                        int size = activeSocket.Receive(buff);

                        MemoryStream ms = new MemoryStream(buff);
                        BinaryReader br = new BinaryReader(ms);
                        int clientIndex = br.ReadInt32();

                        Console.WriteLine("Server1: "+DateTime.Now.ToString("HH-mm-ss.fff")
                            +" received client "+clientIndex+"'s message.");

                    }
                }

                Console.WriteLine("Server1: "+DateTime.Now.ToString("HH-mm-ss.fff")
                    +" reset socketList to size of "+(allSocketList.Count));

                socketList.Clear();
                for (int k=0; k<allSocketList.Count; k++)
                {
                    socketList.Add(allSocketList[k]);
                }

                //If we get 100 clients, quit.
                if (allSocketList.Count == 100)
                {
                    Console.WriteLine("");
                    Console.WriteLine("Got 100 clients. Quit.");
                    Console.WriteLine("");
                    Environment.Exit(-1);
                }

            }

        }

        public static void Client1()
        {
            int name = int.Parse(Thread.CurrentThread.Name);

            Console.WriteLine("Client1: "+name+" "+
                DateTime.Now.ToString("HH-mm-ss.fff")+" connect");

            Socket c = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
            IPEndPoint remoteEndPoint = new IPEndPoint(IPAddress.Loopback, 19999);


            try
            {
            c.Connect(remoteEndPoint);
            }
            catch (Exception e)
            {
                Console.WriteLine(e.Message);
                Environment.Exit(-1);
            }

            Console.WriteLine("Client1: "+name+" "+
                DateTime.Now.ToString("HH-mm-ss.fff")+" connected");

            byte [] buf = new byte [4];
            MemoryStream ms = new MemoryStream(buf);
            BinaryWriter bw = new BinaryWriter(ms);
            bw.Write(name);

            while (true)
            {
                int result = c.Send(buf);
                Console.WriteLine("Client1: "+name+
                    " "+DateTime.Now.ToString("HH-mm-ss.fff")
                    +" sent "+result+" bytes out");

                //Just blocks this client socket until the program quits
                 lock(bw)
                {
                    Monitor.Wait(bw);
                }
            }

        }

}

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