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//
// async_udp_echo_server.cpp
// ~~~~~~~~~~~~~~~~~~~~~~~~~
//
// Copyright (c) 2003-2017 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 <boost/bind.hpp>
#include <boost/asio.hpp>
using boost::asio::ip::udp;
class server
{
public:
server(boost::asio::io_context& io_context, short port)
: socket_(io_context, udp::endpoint(udp::v4(), port))
{
socket_.async_receive_from(
boost::asio::buffer(data_, max_length), sender_endpoint_,
boost::bind(&server::handle_receive_from, this,
boost::asio::placeholders::error,
boost::asio::placeholders::bytes_transferred));
}
void handle_receive_from(const boost::system::error_code& error,
size_t bytes_recvd)
{
if (!error && bytes_recvd > 0)
{
socket_.async_send_to(
boost::asio::buffer(data_, bytes_recvd), sender_endpoint_,
boost::bind(&server::handle_send_to, this,
boost::asio::placeholders::error,
boost::asio::placeholders::bytes_transferred));
}
else
{
socket_.async_receive_from(
boost::asio::buffer(data_, max_length), sender_endpoint_,
boost::bind(&server::handle_receive_from, this,
boost::asio::placeholders::error,
boost::asio::placeholders::bytes_transferred));
}
}
void handle_send_to(const boost::system::error_code& /*error*/,
size_t /*bytes_sent*/)
{
socket_.async_receive_from(
boost::asio::buffer(data_, max_length), sender_endpoint_,
boost::bind(&server::handle_receive_from, this,
boost::asio::placeholders::error,
boost::asio::placeholders::bytes_transferred));
}
private:
udp::socket socket_;
udp::endpoint sender_endpoint_;
enum { max_length = 1024 };
char data_[max_length];
};
int main(int argc, char* argv[])
{
try
{
if (argc != 2)
{
std::cerr << "Usage: async_udp_echo_server <port>\n";
return 1;
}
boost::asio::io_context io_context;
using namespace std; // For atoi.
server s(io_context, atoi(argv[1]));
io_context.run();
}
catch (std::exception& e)
{
std::cerr << "Exception: " << e.what() << "\n";
}
return 0;
}
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