ceph/src/boost/libs/asio/example/cpp17/coroutines_ts/echo_server_with_default.cpp

   1 //
   2 // echo_server_with_default.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/co_spawn.hpp>
  12 #include <boost/asio/detached.hpp>
  13 #include <boost/asio/io_context.hpp>
  14 #include <boost/asio/ip/tcp.hpp>
  15 #include <boost/asio/signal_set.hpp>
  16 #include <boost/asio/write.hpp>
  17 #include <cstdio>
  18
  19 using boost::asio::ip::tcp;
  20 using boost::asio::awaitable;
  21 using boost::asio::co_spawn;
  22 using boost::asio::detached;
  23 using boost::asio::use_awaitable_t;
  24 using tcp_acceptor = use_awaitable_t<>::as_default_on_t<tcp::acceptor>;
  25 using tcp_socket = use_awaitable_t<>::as_default_on_t<tcp::socket>;
  26 namespace this_coro = boost::asio::this_coro;
  27
  28 awaitable<void> echo(tcp_socket socket)
  29 {
  30   try
  31   {
  32     char data[1024];
  33     for (;;)
  34     {
  35       std::size_t n = co_await socket.async_read_some(boost::asio::buffer(data));
  36       co_await async_write(socket, boost::asio::buffer(data, n));
  37     }
  38   }
  39   catch (std::exception& e)
  40   {
  41     std::printf("echo Exception: %s\n", e.what());
  42   }
  43 }
  44
  45 awaitable<void> listener()
  46 {
  47   auto executor = co_await this_coro::executor;
  48   tcp_acceptor acceptor(executor, {tcp::v4(), 55555});
  49   for (;;)
  50   {
  51     auto socket = co_await acceptor.async_accept();
  52     co_spawn(executor,
  53         [socket = std::move(socket)]() mutable
  54         {
  55           return echo(std::move(socket));
  56         },
  57         detached);
  58   }
  59 }
  60
  61 int main()
  62 {
  63   try
  64   {
  65     boost::asio::io_context io_context(1);
  66
  67     boost::asio::signal_set signals(io_context, SIGINT, SIGTERM);
  68     signals.async_wait([&](auto, auto){ io_context.stop(); });
  69
  70     co_spawn(io_context, listener, detached);
  71
  72     io_context.run();
  73   }
  74   catch (std::exception& e)
  75   {
  76     std::printf("Exception: %s\n", e.what());
  77   }
  78 }