static string user_to = "test8";

        static void GetMsgLoop()
        {
            while(true)
            {
                string str = MessengerInterop.GetMessage();
                Console.WriteLine("Message received: " + str);
            }
        }

        static void SendMsgLoop()
        {
            string msg;
            while (true)
            {
                msg = Console.ReadLine();
                byte[] username_bytes = Encoding.UTF8.GetBytes(user_to);
                byte[] msg_bytes = Encoding.UTF8.GetBytes(msg);
                MessengerInterop.SendMessage(username_bytes, msg_bytes);
            }
        }

Thread GetMsgThread = new Thread(GetMsgLoop);
            Thread SendMsgThread = new Thread(SendMsgLoop);


            GetMsgThread.Start();
            SendMsgThread.Start();