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//
// async_tcp_echo_server.cpp
// ~~~~~~~~~~~~~~~~~~~~~~~~~
//
// Copyright (c) 2003-2020 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 <cstdlib>
#include <iostream>
#include <memory>
#include <utility>
#include <boost/asio.hpp>
using boost::asio::ip::tcp;
// Define a helper macro to invoke BOOST_ASIO_HANDLER_LOCATION with the current
// file name, line number, and function name. For the function name, you might
// also consider using __PRETTY_FUNCTION__, BOOST_CURRENT_FUNCTION, or a hand-
// crafted name. For C++20 or later, you may also use std::source_location.
#define HANDLER_LOCATION \
BOOST_ASIO_HANDLER_LOCATION((__FILE__, __LINE__, __func__))
class session
: public std::enable_shared_from_this<session>
{
public:
session(tcp::socket socket)
: socket_(std::move(socket))
{
}
void start()
{
HANDLER_LOCATION;
do_read();
}
private:
void do_read()
{
HANDLER_LOCATION;
auto self(shared_from_this());
socket_.async_read_some(boost::asio::buffer(data_, max_length),
[this, self](boost::system::error_code ec, std::size_t length)
{
HANDLER_LOCATION;
if (!ec)
{
do_write(length);
}
});
}
void do_write(std::size_t length)
{
HANDLER_LOCATION;
auto self(shared_from_this());
boost::asio::async_write(socket_, boost::asio::buffer(data_, length),
[this, self](boost::system::error_code ec, std::size_t /*length*/)
{
HANDLER_LOCATION;
if (!ec)
{
do_read();
}
});
}
tcp::socket socket_;
enum { max_length = 1024 };
char data_[max_length];
};
class server
{
public:
server(boost::asio::io_context& io_context, short port)
: acceptor_(io_context, tcp::endpoint(tcp::v4(), port))
{
do_accept();
}
private:
void do_accept()
{
HANDLER_LOCATION;
acceptor_.async_accept(
[this](boost::system::error_code ec, tcp::socket socket)
{
HANDLER_LOCATION;
if (!ec)
{
std::make_shared<session>(std::move(socket))->start();
}
do_accept();
});
}
tcp::acceptor acceptor_;
};
int main(int argc, char* argv[])
{
try
{
if (argc != 2)
{
std::cerr << "Usage: async_tcp_echo_server <port>\n";
return 1;
}
boost::asio::io_context io_context;
server s(io_context, std::atoi(argv[1]));
io_context.run();
}
catch (std::exception& e)
{
std::cerr << "Exception: " << e.what() << "\n";
}
return 0;
}
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