Асинхронный TCP-сервер не читает сообщение из сокета boost::asio?

#include <iostream>
#include <boost/bind.hpp>
#include <boost/asio.hpp>

using namespace boost::asio;
using namespace std;

class session
{
public:
	session(io_service& service) : socket(service)
	{
	}

	ip::tcp::socket& get_socket()
	{
		return socket;
	}

	void start()
	{
		socket.async_read_some(
			boost::asio::buffer(buff, message_lenght),
			boost::bind(
				&session::read_handler,
				this,
				boost::asio::placeholders::error,
				boost::asio::placeholders::bytes_transferred
			)
		);
	}

private:
	ip::tcp::socket socket;
	enum { message_lenght = 1024 };
	char buff[message_lenght] = { };

	void read_handler(
		const boost::system::error_code& error,
		std::size_t bytes_transferred
	)
	{
		if (!error)
		{
			async_write(
				socket,
				boost::asio::buffer(buff, message_lenght),
				boost::bind(
					&session::write_handler,
					this,
					boost::asio::placeholders::error,
					boost::asio::placeholders::bytes_transferred
				)
			);
		}
		{
			cout << "read error " << error.message() << endl;
			delete this;
		}
	}

	void write_handler(
		const boost::system::error_code& error,
		std::size_t bytes_transferred
	)
	{
		if (!error)
		{
			socket.async_read_some(
				boost::asio::buffer(buff, message_lenght),
				boost::bind(
					&session::read_handler,
					this,
					boost::asio::placeholders::error,
					boost::asio::placeholders::bytes_transferred
				)
			);
		}
		else
		{
			cout << "read error " << error.message() << endl;
			delete this;
		}
	}
};

class server
{
public:
	server(boost::asio::io_service& service, short port) : service_(),
		acceptor(service, ip::tcp::endpoint(ip::tcp::v4(), port))
	{
		start_accept();
	}
private:
	short port;
	io_service service_;
	ip::tcp::acceptor acceptor;
	
	void start_accept()
	{
		session* new_session = new session(service_);
		acceptor.async_accept(
			new_session->get_socket(),
			boost::bind(
				&server::handle_accept,
				this,
				new_session,
				boost::asio::placeholders::error
			)
		);
	}

	void handle_accept(
		session* new_session,
		const boost::system::error_code& error
	)
	{
		if (!error)
		{
			new_session->start();
		}
		else
		{
			cout << "accept error " << error.message() << endl;
			delete new_session;
		}
		start_accept();
	}
};

int main()
{
	setlocale(LC_ALL, "Rus");
	io_service service;
	server* s = new server(service, 5000);
	service.run();
}