ceph/src/boost/libs/asio/example/cpp03/spawn/echo_server.cpp

   1 //
   2 // echo_server.cpp
   3 // ~~~~~~~~~~~~~~~
   4 //
   5 // Copyright (c) 2003-2019 Christopher M. Kohlhoff (chris at kohlhoff dot com)
   6 //
   7 // Distributed under the Boost Software License, Version 1.0. (See accompanying
   8 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   9 //
  10
  11 #include <boost/asio/io_context.hpp>
  12 #include <boost/asio/ip/tcp.hpp>
  13 #include <boost/asio/spawn.hpp>
  14 #include <boost/asio/steady_timer.hpp>
  15 #include <boost/asio/write.hpp>
  16 #include <boost/bind.hpp>
  17 #include <boost/shared_ptr.hpp>
  18 #include <boost/enable_shared_from_this.hpp>
  19 #include <iostream>
  20
  21 using boost::asio::ip::tcp;
  22
  23 class session : public boost::enable_shared_from_this<session>
  24 {
  25 public:
  26   explicit session(boost::asio::io_context& io_context)
  27     : strand_(boost::asio::make_strand(io_context)),
  28       socket_(io_context),
  29       timer_(io_context)
  30   {
  31   }
  32
  33   tcp::socket& socket()
  34   {
  35     return socket_;
  36   }
  37
  38   void go()
  39   {
  40     boost::asio::spawn(strand_,
  41         boost::bind(&session::echo,
  42           shared_from_this(), _1));
  43     boost::asio::spawn(strand_,
  44         boost::bind(&session::timeout,
  45           shared_from_this(), _1));
  46   }
  47
  48 private:
  49   void echo(boost::asio::yield_context yield)
  50   {
  51     try
  52     {
  53       char data[128];
  54       for (;;)
  55       {
  56         timer_.expires_after(boost::asio::chrono::seconds(10));
  57         std::size_t n = socket_.async_read_some(boost::asio::buffer(data), yield);
  58         boost::asio::async_write(socket_, boost::asio::buffer(data, n), yield);
  59       }
  60     }
  61     catch (std::exception& e)
  62     {
  63       socket_.close();
  64       timer_.cancel();
  65     }
  66   }
  67
  68   void timeout(boost::asio::yield_context yield)
  69   {
  70     while (socket_.is_open())
  71     {
  72       boost::system::error_code ignored_ec;
  73       timer_.async_wait(yield[ignored_ec]);
  74       if (timer_.expiry() <= boost::asio::steady_timer::clock_type::now())
  75         socket_.close();
  76     }
  77   }
  78
  79   boost::asio::strand<boost::asio::io_context::executor_type> strand_;
  80   tcp::socket socket_;
  81   boost::asio::steady_timer timer_;
  82 };
  83
  84 void do_accept(boost::asio::io_context& io_context,
  85     unsigned short port, boost::asio::yield_context yield)
  86 {
  87   tcp::acceptor acceptor(io_context, tcp::endpoint(tcp::v4(), port));
  88
  89   for (;;)
  90   {
  91     boost::system::error_code ec;
  92     boost::shared_ptr<session> new_session(new session(io_context));
  93     acceptor.async_accept(new_session->socket(), yield[ec]);
  94     if (!ec) new_session->go();
  95   }
  96 }
  97
  98 int main(int argc, char* argv[])
  99 {
 100   try
 101   {
 102     if (argc != 2)
 103     {
 104       std::cerr << "Usage: echo_server <port>\n";
 105       return 1;
 106     }
 107
 108     boost::asio::io_context io_context;
 109
 110     boost::asio::spawn(io_context,
 111         boost::bind(do_accept,
 112           boost::ref(io_context), atoi(argv[1]), _1));
 113
 114     io_context.run();
 115   }
 116   catch (std::exception& e)
 117   {
 118     std::cerr << "Exception: " << e.what() << "\n";
 119   }
 120
 121   return 0;
 122 }