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

   1 //
   2 // echo_server.cpp
   3 // ~~~~~~~~~~~~~~~
   4 //
   5 // Copyright (c) 2003-2018 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/experimental/co_spawn.hpp>
  12 #include <boost/asio/experimental/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::experimental::co_spawn;
  21 using boost::asio::experimental::detached;
  22 namespace this_coro = boost::asio::experimental::this_coro;
  23
  24 template <typename T>
  25   using awaitable = boost::asio::experimental::awaitable<
  26     T, boost::asio::io_context::executor_type>;
  27
  28 awaitable<void> echo(tcp::socket socket)
  29 {
  30   auto token = co_await this_coro::token();
  31
  32   try
  33   {
  34     char data[1024];
  35     for (;;)
  36     {
  37       std::size_t n = co_await socket.async_read_some(boost::asio::buffer(data), token);
  38       co_await async_write(socket, boost::asio::buffer(data, n), token);
  39     }
  40   }
  41   catch (std::exception& e)
  42   {
  43     std::printf("echo Exception: %s\n", e.what());
  44   }
  45 }
  46
  47 awaitable<void> listener()
  48 {
  49   auto executor = co_await this_coro::executor();
  50   auto token = co_await this_coro::token();
  51
  52   tcp::acceptor acceptor(executor.context(), {tcp::v4(), 55555});
  53   for (;;)
  54   {
  55     tcp::socket socket = co_await acceptor.async_accept(token);
  56     co_spawn(executor,
  57         [socket = std::move(socket)]() mutable
  58         {
  59           return echo(std::move(socket));
  60         },
  61         detached);
  62   }
  63 }
  64
  65 int main()
  66 {
  67   try
  68   {
  69     boost::asio::io_context io_context(1);
  70
  71     boost::asio::signal_set signals(io_context, SIGINT, SIGTERM);
  72     signals.async_wait([&](auto, auto){ io_context.stop(); });
  73
  74     co_spawn(io_context, listener, detached);
  75
  76     io_context.run();
  77   }
  78   catch (std::exception& e)
  79   {
  80     std::printf("Exception: %s\n", e.what());
  81   }
  82 }