proper way to abort a blocked thread

Question

I'm creating a server that a TCP connection. The TCP Connection is run in its own thread for an indefinite amount of time. Is there a good pattern to allow safe shutdown of the TcpListener and Client as well as the thread? Below is what I have so far.

private volatile bool Shudown;

void ThreadStart1()
{
    TcpListener listener = null;
    TcpClient client = null;
    Stream s = null;
    try
    {
        listener = new TcpListener(60000);
        client = listener.AcceptTcpClient();
        Stream s = client.GetStrea();
        while(!Shutdown)  // use shutdown to gracefully shutdown thread.
        {
            try
            {
                string msg = s.ReadLine();  // This blocks the thread so setting shutdown = true will never occur unless a client sends a message.
                DoSomething(msg);
            }
            catch(IOException ex){ } // I would like to avoid using Exceptions for flow control
            catch(Exception ex) { throw; }
        }
    }
    catch(Exception ex)
    {
        LogException(ex);
        throw ex;
    }
    finally
    {
        if(listener != null) listener.Close();
        if(s != null) s.Close();
        if(client != null) client.Close();
    }
}

Answer 1

Set a timeout on the NetworkStream (client.ReadTimeout=...). Once the read operation times out, check to see if the main thread signalled you to stop (by setting a variable or an AutoResetEvent). If it's been signalled to stop, exit gracefully. If not, try reading again until the next timeout.

Setting a 0.5 or 1 second timeout should suffice - you will be able to exit the thread in a timely manner, and yet be very easy on the CPU.