asio(12), asynchronous tcp, udp server

Official website tutorial: https://think-async.com/Asio/asio-1.26.0/doc/asio/tutorial/tutdaytime7.html

asio asynchronous tcp, udp server

int main()
{<!-- -->
  try
  {<!-- -->
    asio::io_context io_context;

We will first create a server object to accept TCP client connections.

 tcp_server server1(io_context);

We also need a server object to accept UDP client requests.

 udp_server server2(io_context);

We’ve created two io_context objects that do a lot of work.

 io_context. run();
  }
  catch (std::exception & e)
  {<!-- -->
    std::cerr << e.what() << std::endl;
  }

  return 0;
}

tcp_connection and tcp_server classes

class tcp_connection
  : public boost::enable_shared_from_this<tcp_connection>
{<!-- -->
public:
  typedef boost::shared_ptr<tcp_connection> pointer;

  static pointer create(asio::io_context & io_context)
  {<!-- -->
    return pointer(new tcp_connection(io_context));
  }

  tcp::socket & socket()
  {<!-- -->
    return socket_;
  }

  void start()
  {<!-- -->
    message_ = make_daytime_string();

    asio::async_write(socket_, asio::buffer(message_),
        boost::bind( &tcp_connection::handle_write, shared_from_this()));
  }

private:
  tcp_connection(asio::io_context & io_context)
    : socket_(io_context)
  {<!-- -->
  }

  void handle_write()
  {<!-- -->
  }

  tcp::socket socket_;
  std::string message_;
};

class tcp_server
{<!-- -->
public:
  tcp_server(asio::io_context & io_context)
    : io_context_(io_context),
      acceptor_(io_context, tcp::endpoint(tcp::v4(), 13))
  {<!-- -->
    start_accept();
  }

private:
  void start_accept()
  {<!-- -->
    tcp_connection::pointer new_connection =
      tcp_connection::create(io_context_);

    acceptor_.async_accept(new_connection->socket(),
        boost::bind( &tcp_server::handle_accept, this, new_connection,
          asio::placeholders::error));
  }

  void handle_accept(tcp_connection::pointer new_connection,
      const asio::error_code & amp; error)
  {<!-- -->
    if (!error)
    {<!-- -->
      new_connection->start();
    }

    start_accept();
  }

  asio::io_context & io_context_;
  tcp::acceptor acceptor_;
};

udp_server class

class udp_server
{<!-- -->
public:
  udp_server(asio::io_context & io_context)
    : socket_(io_context, udp::endpoint(udp::v4(), 13))
  {<!-- -->
    start_receive();
  }

private:
  void start_receive()
  {<!-- -->
    socket_.async_receive_from(
        asio::buffer(recv_buffer_), remote_endpoint_,
        boost::bind( & amp;udp_server::handle_receive, this,
          asio::placeholders::error));
  }

  void handle_receive(const asio::error_code & error)
  {<!-- -->
    if (!error)
    {<!-- -->
      boost::shared_ptr<std::string> message(
          new std::string(make_daytime_string()));

      socket_.async_send_to(asio::buffer(*message), remote_endpoint_,
          boost::bind( &udp_server::handle_send, this, message));

      start_receive();
    }
  }

  void handle_send(boost::shared_ptr<std::string> /*message*/)
  {<!-- -->
  }

  udp::socket socket_;
  udp::endpoint remote_endpoint_;
  boost::array<char, 1> recv_buffer_;
};

#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 

using asio::ip::tcp;
using asio::ip::udp;

std::string make_daytime_string()
{
  using namespace std; // For time_t, time and ctime;
  time_t now = time(0);
  return ctime( &now);
}

class tcp_connection
  : public boost::enable_shared_from_this<tcp_connection>
{<!-- -->
public:
  typedef boost::shared_ptr<tcp_connection> pointer;

  static pointer create(asio::io_context & io_context)
  {<!-- -->
    return pointer(new tcp_connection(io_context));
  }

  tcp::socket & socket()
  {<!-- -->
    return socket_;
  }

  void start()
  {<!-- -->
    message_ = make_daytime_string();

    asio::async_write(socket_, asio::buffer(message_),
        boost::bind( &tcp_connection::handle_write, shared_from_this()));
  }

private:
  tcp_connection(asio::io_context & io_context)
    : socket_(io_context)
  {<!-- -->
  }

  void handle_write()
  {<!-- -->
  }

  tcp::socket socket_;
  std::string message_;
};

class tcp_server
{<!-- -->
public:
  tcp_server(asio::io_context & io_context)
    : io_context_(io_context),
      acceptor_(io_context, tcp::endpoint(tcp::v4(), 13))
  {<!-- -->
    start_accept();
  }

private:
  void start_accept()
  {<!-- -->
    tcp_connection::pointer new_connection =
      tcp_connection::create(io_context_);

    acceptor_.async_accept(new_connection->socket(),
        boost::bind( &tcp_server::handle_accept, this, new_connection,
          asio::placeholders::error));
  }

  void handle_accept(tcp_connection::pointer new_connection,
      const asio::error_code & amp; error)
  {<!-- -->
    if (!error)
    {<!-- -->
      new_connection->start();
    }

    start_accept();
  }

  asio::io_context & io_context_;
  tcp::acceptor acceptor_;
};

class udp_server
{<!-- -->
public:
  udp_server(asio::io_context & io_context)
    : socket_(io_context, udp::endpoint(udp::v4(), 13))
  {<!-- -->
    start_receive();
  }

private:
  void start_receive()
  {<!-- -->
    socket_.async_receive_from(
        asio::buffer(recv_buffer_), remote_endpoint_,
        boost::bind( & amp;udp_server::handle_receive, this,
          asio::placeholders::error));
  }

  void handle_receive(const asio::error_code & error)
  {<!-- -->
    if (!error)
    {<!-- -->
      boost::shared_ptr<std::string> message(
          new std::string(make_daytime_string()));

      socket_.async_send_to(asio::buffer(*message), remote_endpoint_,
          boost::bind( &udp_server::handle_send, this, message));

      start_receive();
    }
  }

  void handle_send(boost::shared_ptr<std::string> /*message*/)
  {<!-- -->
  }

  udp::socket socket_;
  udp::endpoint remote_endpoint_;
  boost::array<char, 1> recv_buffer_;
};

int main()
{<!-- -->
  try
  {<!-- -->
    asio::io_context io_context;
    tcp_server server1(io_context);
    udp_server server2(io_context);
    io_context. run();
  }
  catch (std::exception & e)
  {<!-- -->
    std::cerr << e.what() << std::endl;
  }

  return 0;
}