c-使用Boost :: asio触发写入
作者:互联网
我有一些要制作TCP客户端的软件.我不知道这是否是最好的体系结构,但是在我的软件中,我产生了一个将用于网络I / O的线程.如果有更好的架构,我将不胜感激一些建议和建议.
这两个线程都引用了boost :: asio :: io_service对象和一个封装套接字对象的Session对象. sesson对象大致如下:
class Session
{
public:
Session(
boost::asio::io_service & io_service,
std::string const & ip_address,
std::string const & port)
: io_service_(io_service),
resolver_(io_service),
socket_(io_service),
ip_address_(ip_address),
port_(port),
{}
virtual void start();
virtual ~Session();
virtual void stop();
void write(std::string const & msg);
void handle_resolve(
const boost::system::error_code & error,
boost::asio::ip::tcp::resolver::iterator endpoint_itr);
void handle_connect(
const boost::system::error_code & error,
boost::asio::ip::tcp::resolver::iterator endpoint_itr);
void handle_close();
void handle_write(const boost::system::error_code & error);
private:
boost::asio::io_service & io_service_;
boost::asio::ip::tcp::resolver resolver_;
boost::asio::ip::tcp::socket socket_;
std::string ip_address_;
std::string port_;
};
在I / O线程运行循环中,将调用连接到服务器的会话对象的start()方法. (顺便说一句,有效).然后,线程位于一个循环中,该循环在I / O服务对象[io_service_.run()]上调用run()方法以触发事件.
主线程要发送数据时,将调用会话的write()方法,会话对象将调用boost :: async_write并写入要写入的数据,然后调用作为会话对象成员的回调方法(handle_write).
当我有I / O线程连接到服务器时,我无法触发handle_write方法.我已经验证主线程正在调用会话对象并在套接字上执行async_write().只是永远不会触发回调.我也没有在服务器端或tcpdump的网络上看到任何数据.
知道我的问题可能在哪里吗?有没有更好的方法来组织架构?最重要的是,我不想阻塞执行I / O的主线程.
这是从主线程产生io线程的代码(对空格表示歉意):
boost::asio::io_service io_service;
boost::shared_ptr<Session> session_ptr;
boost::thread io_thread;
....
session_ptr.reset(
new Session::Session(
io_service,
std::string("127.0.0.1"),
std::string("17001")));
// spawn new thread for the network I/O endpoint
io_thread = boost::thread(
boost::bind(
&Session::start,
session_ptr_.get()));
start()方法的代码如下:
void Session::start()
{
typedef boost::asio::ip::tcp tcp;
tcp::resolver::query query(
tcp::v4(),
ip_address_,
port_);
resolver_.async_resolve(
query,
boost::bind(
&Session::handle_resolve,
this,
boost::asio::placeholders::error,
boost::asio::placeholders::iterator));
while(1){ // improve this later
io_service_.run();
}
}
解析程序的回调:
void Session::handle_resolve(
const boost::system::error_code & error,
boost::asio::ip::tcp::resolver::iterator endpoint_itr)
{
if (!error)
{
boost::asio::ip::tcp::endpoint endpoint = *endpoint_itr;
socket_.async_connect(
endpoint,
boost::bind(
&Session::handle_connect,
this,
boost::asio::placeholders::error,
++endpoint_itr));
}
else
{
std::cerr << "Failed to resolve\n";
std::cerr << "Error: " << error.message() << std::endl;
}
}
连接的回调:
void Session::handle_connect(
const boost::system::error_code & error,
boost::asio::ip::tcp::resolver::iterator endpoint_itr)
{
typedef boost::asio::ip::tcp tcp;
if (!error)
{
std::cerr << "Connected to the server!\n";
}
else if (endpoint_itr != tcp::resolver::iterator())
{
socket_.close();
socket_.async_connect(
*endpoint_itr,
boost::bind(
&Session::handle_connect,
this,
boost::asio::placeholders::error,
++endpoint_itr));
}
else
{
std::cerr << "Failed to connect\n";
}
}
主线程可以调用的write()方法发送帖子以异步方式发送.
void Session::write(
std::string const & msg)
{
std::cout << "Write: " << msg << std::endl;
boost::asio::async_write(
socket_,
boost::asio::buffer(
msg.c_str(),
msg.length()),
boost::bind(
&Session::handle_write,
this,
boost::asio::placeholders::error));
}
最后,写完成回调:
void Session::handle_write(
const boost::system::error_code & error)
{
if (error)
{
std::cout << "Write complete with errors !!!\n";
}
else
{
std::cout << "Write complete with no errors\n";
}
}
解决方法:
看起来您的io服务将在连接后耗尽,然后您只需再次调用io_service :: run即可?看起来好像在while循环中调用了run,但是我看不到任何地方可以重置的调用.您需要先调用io :: service :: reset,然后再在同一io_service上运行.
从结构上讲,最好将work添加到io_service,然后您无需在循环中调用它,并且一旦调用io_service :: stop将退出运行.
标签:asynchronous,boost,boost-asio,c 来源: https://codeday.me/bug/20191023/1913312.html