| // |
| // async_udp_echo_server.cpp |
| // ~~~~~~~~~~~~~~~~~~~~~~~~~ |
| // |
| // Copyright (c) 2003-2021 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 "asio.hpp" |
| |
| using asio::ip::udp; |
| |
| class server |
| { |
| public: |
| server(asio::io_context& io_context, short port) |
| : socket_(io_context, udp::endpoint(udp::v4(), port)) |
| { |
| do_receive(); |
| } |
| |
| void do_receive() |
| { |
| socket_.async_receive_from( |
| asio::buffer(data_, max_length), sender_endpoint_, |
| [this](std::error_code ec, std::size_t bytes_recvd) |
| { |
| if (!ec && bytes_recvd > 0) |
| { |
| do_send(bytes_recvd); |
| } |
| else |
| { |
| do_receive(); |
| } |
| }); |
| } |
| |
| void do_send(std::size_t length) |
| { |
| socket_.async_send_to( |
| asio::buffer(data_, length), sender_endpoint_, |
| [this](std::error_code /*ec*/, std::size_t /*bytes_sent*/) |
| { |
| do_receive(); |
| }); |
| } |
| |
| 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; |
| } |
| |
| 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; |
| } |