在后台线程上执行异步套接字

Question

I have been having playing with implementing some socket code to see if it fits my needs and so use the sample code @spender kindly added to this question .

If I run this on the main thread it works as expected but when I invoke it on a background thread it never gets awoken from its sleep when a client attempts to connect, my thread spawn is as below:

_Thread = new Thread(new ThreadStart(StartListening));
_Thread.Name = "ThreadForSocket";
_Thread.IsBackground = true;
_Thread.Start();


private void StartListening()
{
    new AsyncSocketListener().StartListening(InitializeEndPoint());
}

public class AsyncSocketListener : IDisposable
{
    public void StartListening(IPEndPoint endPoint)
    {
        try
        {
            var socket = new Socket(endPoint.Address.AddressFamily, SocketType.Stream, ProtocolType.Tcp);
            socket.Bind(endPoint);
            socket.Listen(10);

            while (true)
            {
                string info = string.Format("{0} Waiting for a connection...", DateTime.Now.ToString("HH:mm.ss"));
                Controller.StatusSignal.Reset();

                Console.WriteLine(info);
                Debug.WriteLine(info);

                socket.BeginAccept(new     AsyncCallback(SocketListener.AcceptCallback), socket);

                Controller.StatusSignal.WaitOne();
            }
        }
        catch (Exception e)
        {
            Console.WriteLine(e.ToString());
        }

        Console.WriteLine("Closing the listener...");
    }

The thread is still present in the Threads Window and is in the expected state so I'm at a loss as to why it refuses to wake up on client connection.

Should that be possible? I read the socket msdn page and it appears to suggest it should be OK for a background thread.

Answer 1

(After too much hair-pulling and a process of elimination)

The code is fine, (Windows) Firewall had blocked the binary using the background thread (without notifying, despite its settings) but had allowed the non-threaded version thru, hence why I originally thought it was a code issue.

So, yes, the async pattern shown above is perfectly fine running on a background thread as shown, and of course its quite a nice way of using it as you are simply sleeping the bg thread and your main (eg. UI) thread can operate normally.