c++如何使用Boost.Asio进行异步网络编程_c++异步IO框架Boost.Asio使用教程

#include <boost/asio.hpp>
#include <iostream>
#include <array>

using boost::asio::ip::tcp;

int main() {
    try {
        boost::asio::io_context io_context;

        tcp::resolver resolver(io_context);
        tcp::resolver::results_type endpoints = resolver.resolve("127.0.0.1", "8080");

        tcp::socket socket(io_context);
        boost::asio::async_connect(socket, endpoints,
            [&](const boost::system::error_code& error, const tcp::endpoint&) {
                if (!error) {
                    std::cout << "Connected to server\n";

                    // 发起异步读取
                    std::array<char, 128> buf;
                    socket.async_read_some(boost::asio::buffer(buf),
                        [&](const boost::system::error_code& read_error, size_t bytes_transferred) {
                            if (!read_error) {
                                std::cout.write(buf.data(), bytes_transferred);
                                std::cout << "\n";
                            } else {
                                std::cerr << "Read error: " << read_error.message() << "\n";
                            }
                        });
                } else {
                    std::cerr << "Connect failed: " << error.message() << "\n";
                }
            });

        io_context.run();  // 启动事件循环
    }
    catch (std::exception& e) {
        std::cerr << "Exception: " << e.what() << "\n";
    }

    return 0;
}

class session : public std::enable_shared_from_this<session> {
public:
    session(tcp::socket socket) : socket_(std::move(socket)) {}

    void start() {
        do_read();
    }

private:
    void do_read() {
        auto self(shared_from_this());
        socket_.async_read_some(boost::asio::buffer(data_),
            [this, self](const boost::system::error_code& error, size_t length) {
                if (!error) {
                    do_write(length);
                }
            });
    }

    void do_write(size_t length) {
        auto self(shared_from_this());
        boost::asio::async_write(socket_, boost::asio::buffer(data_, length),
            [this, self](const boost::system::error_code& error, size_t /*length*/) {
                if (!error) {
                    do_read();  // 继续读取
                }
            });
    }

    tcp::socket socket_;
    std::array<char, 1024> data_;
};

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() {
        acceptor_.async_accept(
            [this](const boost::system::error_code& error, tcp::socket socket) {
                if (!error) {
                    std::make_shared<session>(std::move(socket))->start();
                }
                do_accept();  // 接受下一个连接
            });
    }

    tcp::acceptor acceptor_;
};

g++ -std=c++17 client.cpp -o client -lboost_system

find_package(Boost REQUIRED COMPONENTS system)
target_link_libraries(your_target Boost::system)