udpclient.close doesn't always close the socket??

Question

I'm using the code below, it seem sometime the socket is not released

How did I found that? by using process explorer(from sysinternal), proprieties on the application then going into TCP/IP tab.

I can see the port being used by typing "netstat -a" into a console

My problem is, after a while (like 5 weeks) there is like 40 port used by the application while it should be zero.

Anyone know why it does that?

 public void Connect()
 {
  try {
   // Resolve server address
   IPHostEntry hostadd = Dns.GetHostEntry(TimeServer);
   IPEndPoint EPhost = new IPEndPoint(hostadd.AddressList[0], 123);

   //Connect the time server
   UdpClient TimeSocket = new UdpClient();
   TimeSocket.Connect(EPhost);

   TimeSocket.Send(SNTPData, SNTPData.Length);
   SNTPData = TimeSocket.Receive(ref EPhost);                
            TimeSocket.Close();
            if (!IsResponseValid())
   {
    throw new Exception("Invalid response from " + TimeServer);
   }

  } catch(SocketException e)
    {
   throw new Exception(e.Message);
    }

 }

Answer 1

You're blocking forever on:

SNTPData = TimeSocket.Receive(ref EPhost);

If the socket never receives a packet it will sit there waiting until the process dies.

You'll need to close the socket by calling TimeSocket.Close() on a different thread or by setting a timeout on the receive using SetSocketOption.