Boost C++ Libraries

...one of the most highly regarded and expertly designed C++ library projects in the world. Herb Sutter and Andrei Alexandrescu, C++ Coding Standards

This is the documentation for an old version of Boost. Click here to view this page for the latest version.
PrevUpHomeNext

Daytime.7 - A combined TCP/UDP asynchronous server

This tutorial program shows how to combine the two asynchronous servers that we have just written, into a single server application.

The main() function

We will begin by creating a server object to accept a TCP client connection.

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

We have created two lots of work for the boost::asio::io_service object to do.

The tcp_connection and tcp_server classes

The following two classes are taken from Daytime.3 .

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

  static pointer create(boost::asio::io_context& io_context)
  {
    return pointer(new tcp_connection(io_context));
  }

  tcp::socket& socket()
  {
    return socket_;
  }

  void start()
  {
    message_ = make_daytime_string();

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

private:
  tcp_connection(boost::asio::io_context& io_context)
    : socket_(io_context)
  {
  }

  void handle_write()
  {
  }

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

class tcp_server
{
public:
  tcp_server(boost::asio::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(acceptor_.get_executor().context());

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

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

    start_accept();
  }

  tcp::acceptor acceptor_;
};
The udp_server class

Similarly, this next class is taken from the previous tutorial step .

class udp_server
{
public:
  udp_server(boost::asio::io_context& io_context)
    : socket_(io_context, udp::endpoint(udp::v4(), 13))
  {
    start_receive();
  }

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

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

      socket_.async_send_to(boost::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_;
};

See the full source listing

Return to the tutorial index

Previous: Daytime.6 - An asynchronous UDP daytime server


PrevUpHomeNext