doc/html/boost_asio/example/cpp17/coroutines_ts/range_based_for.cpp
//
// range_based_for.cpp
// ~~~~~~~~~~~~~~~~~~~
//
// Copyright (c) 2003-2019 Christopher M. Kohlhoff (chris at kohlhoff dot com)
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//
#include <boost/asio/co_spawn.hpp>
#include <boost/asio/detached.hpp>
#include <boost/asio/io_context.hpp>
#include <boost/asio/ip/tcp.hpp>
#include <boost/asio/signal_set.hpp>
#include <boost/asio/write.hpp>
#include <cstdio>
using boost::asio::ip::tcp;
using boost::asio::awaitable;
using boost::asio::co_spawn;
using boost::asio::detached;
using boost::asio::use_awaitable;
class connection_iter
{
friend class connections;
tcp::acceptor* acceptor_ = nullptr;
tcp::socket socket_;
connection_iter(tcp::acceptor& a, tcp::socket s)
: acceptor_(&a), socket_(std::move(s)) {}
public:
tcp::socket operator*()
{
return std::move(socket_);
}
awaitable<void> operator++()
{
socket_ = co_await acceptor_->async_accept(use_awaitable);
}
bool operator==(const connection_iter&) const noexcept
{
return false;
}
bool operator!=(const connection_iter&) const noexcept
{
return true;
}
};
class connections
{
tcp::acceptor& acceptor_;
public:
explicit connections(tcp::acceptor& a) : acceptor_(a) {}
awaitable<connection_iter> begin()
{
tcp::socket s = co_await acceptor_.async_accept(use_awaitable);
co_return connection_iter(acceptor_, std::move(s));
}
connection_iter end()
{
return connection_iter(acceptor_,
tcp::socket(acceptor_.get_executor()));
}
};
awaitable<void> listener(tcp::acceptor acceptor)
{
for co_await (tcp::socket s : connections(acceptor))
{
co_await boost::asio::async_write(s, boost::asio::buffer("hello\r\n", 7), use_awaitable);
}
}
int main()
{
try
{
boost::asio::io_context io_context(1);
boost::asio::signal_set signals(io_context, SIGINT, SIGTERM);
signals.async_wait([&](auto, auto){ io_context.stop(); });
tcp::acceptor acceptor(io_context, {tcp::v4(), 55555});
co_spawn(io_context,
[acceptor = std::move(acceptor)]() mutable
{
return listener(std::move(acceptor));
},
detached);
io_context.run();
}
catch (std::exception& e)
{
std::printf("Exception: %s\n", e.what());
}
}