Boost.Asio学习之同步echo服务器实现

冷不防 2022-07-13 13:18 112阅读 0赞

代码见：[http://www.boost.org/doc/libs/1\_61\_0/doc/html/boost\_asio/examples/cpp11\_examples.html][http_www.boost.org_doc_libs_1_61_0_doc_html_boost_asio_examples_cpp11_examples.html]  
或者：[https://github.com/NearXdu/AsioLearn][https_github.com_NearXdu_AsioLearn]

同步echo服务器将阻塞等待连接，并为每一个新的连接创建线程处理IO，也即所谓的`one-thread-per-connection`

#include <cstdlib>
    #include <iostream>
    #include <thread>
    #include <utility>
    #include <boost/asio.hpp>
    
    using namespace boost::asio::ip;
    const int max_length = 1024;
    void session(boost::asio::ip::tcp::socket sock)
    {
        try
        {
        for (;;)
        {
            char data[max_length];
    
            boost::system::error_code error;
            size_t length = sock.read_some(boost::asio::buffer(data), error);//阻塞等待读取消息
            if (error == boost::asio::error::eof)
            break; // Connection closed cleanly by peer.
            else if (error)
            throw boost::system::system_error(error); // Some other error.
    
            boost::asio::write(sock, boost::asio::buffer(data, length));//向网络套接字写消息
        }
        }
        catch (std::exception& e)
        {
        std::cerr << "Exception in thread: " << e.what() << "\n";
        }
    }
    
    
    void server(boost::asio::io_service &io_service, unsigned short port)
    {
        tcp::acceptor a(io_service, tcp::endpoint(tcp::v4(), port));//初始化监听套接字
        for (;;)//循环监听
        {
        tcp::socket sock(io_service);//创建已连接套接子
        a.accept(sock);
        //set detach来接收新的新的连接而不是阻塞join
        std::thread(session, std::move(sock)).detach();//one-thread per connection
        }
    }
    int main()
    {
        try
        {
    #if 0
        if (argc != 2)
        {
            std::cerr << "Usage: blocking_tcp_echo_server <port>\n";
            return 1;
        }
    #endif
    
        boost::asio::io_service io_service;
    
        server(io_service, 1024);
        }
        catch (std::exception& e)
        {
        std::cerr << "Exception: " << e.what() << "\n";
        }
    
        return 0;
    }

[http_www.boost.org_doc_libs_1_61_0_doc_html_boost_asio_examples_cpp11_examples.html]: http://www.boost.org/doc/libs/1_61_0/doc/html/boost_asio/examples/cpp11_examples.html
[https_github.com_NearXdu_AsioLearn]: https://github.com/NearXdu/AsioLearn