using Newtonsoft.Json;
using System;
using System.Net;
using System.Net.Sockets;
using System.Threading.Tasks;

namespace ConsoleApp1
{
    class Program
    {
        class A
        {
            public int X { get; set; }
            public string Y { get; set; }
        }

        static async Task ReceiveLoop(TcpClient client)
        {
            using (client)
            using (var stream = client.GetStream())
            {
                while (true)
                {
                    object obj = await stream.ReadObjectAsync();
                    if (obj == null)
                        break;
                    Console.WriteLine($"server received object: {obj.GetType()} {JsonConvert.SerializeObject(obj)}");
                    await stream.WriteObjectAsync("received success");
                }
                Console.WriteLine("connection closed");
            }
        }

        static async Task Server(IPAddress addr, int port)
        {
            var listener = new TcpListener(addr, port);
            listener.Start();
            while (true)
                ReceiveLoop(await listener.AcceptTcpClientAsync());
        }

        static async Task Client(string addr, int port)
        {
            using (var client = new TcpClient())
            {
                await client.ConnectAsync(addr, port);
                using (var stream = client.GetStream())
                {
                    await stream.WriteObjectAsync(new A() { X = 123, Y = "abc" });
                    var obj = await stream.ReadObjectAsync();
                    Console.WriteLine(obj);
                }
            }
        }

        static void Main(string[] args)
        {
            Task.Run(() => Server(IPAddress.Any, 8888));
            Task.Run(() => Client("127.0.0.1", 8888));
            Task.Run(() => Client("127.0.0.1", 8888));
            Console.ReadLine();
        }
    }
}