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

本例示范了我們如何將已經(jīng)實現(xiàn)的兩種異步服務器整合為一個服務器應用程序。

The main() function

int main()
{
  try
  {
    boost::asio::io_service io_service;

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

 我們首先創(chuàng)建一個用于接收TCP客戶端連接的服務器對象。

   tcp_server server1(io_service);

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

我們也需要一個用于接收UDP客戶端請求的服務器對象。

udp_server server2(io_service);

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

這樣我們就已經(jīng)創(chuàng)建了兩個需要完成很多工作的服務器，而這些工作都由boost::asio::io_service對象完成。

   io_service.run();
  }
  catch (std::exception& e)
  {
    std::cerr << e.what() << std::endl;
  }

  return 0;
}

The tcp_connection and tcp_server classes

TCP連接和TCP服務器類

The following two classes are taken from Daytime.3 .

下面的兩個類實例來自例子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_service& io_service)
  {
    return pointer(new tcp_connection(io_service));
  }

  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_service& io_service)
    : socket_(io_service)
  {
  }

  void handle_write()
  {
  }

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

class tcp_server
{
public:
  tcp_server(boost::asio::io_service& io_service)
    : acceptor_(io_service, tcp::endpoint(tcp::v4(), 13))
  {
    start_accept();
  }

private:
  void start_accept()
  {
    tcp_connection::pointer new_connection =
      tcp_connection::create(acceptor_.io_service());

    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

UDP服務器類

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

同樣，下面的這個類實例也是來自以前的示例程序。

class udp_server
{
public:
  udp_server(boost::asio::io_service& io_service)
    : socket_(io_service, 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

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