求解惑：boost asio io_service.run在不同位置调用产生的不同结果

2013-03-25 03:03:45 399 阅读 AI 写同款 · GEO 优化AI 选题数据监测一键分发 ›
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boost asio 学习总结之 io_service boost 版本 1_45_0io_service 为异步I/O对像提供核心功能.以下是我们常用对象:boost::asio::ip::tcp::socketboost::asio::ip::tcp::acceptorboost::asio::ip::udp::socket这些对象的构造函数里都有一个必须的参数就是io_service&,也就是说每个异步对像都需要1个io_service.但可以共用一个公共的io_servi 阅读详情
A:在main中调用
 

int _tmain(int argc, _TCHAR* argv[])

 {	



	boost::asio::io_service _io_service;

	tcp::endpoint endpoint(tcp::v4(), 6543);

	iohandler srv(_io_service,endpoint);

 	cout << "main thread run iohandle!" << endl;

	srv.run();

	_io_service.run(); //在Main里面调用



 	cout << "main thread returned!" << endl;

 	return 0;

 }


B:在自己的iohandler里调用


void iohandler::run()

{	

	if (_is_run)

		return;

	_is_run = true;

	session_ptr new_session(new session(_io_service,this));

	_acceptor.async_accept(new_session->Socket(),boost::bind(&iohandler::handle_accept, this, new_session,placeholders::error));

	_io_service.run();//不再在MAIN里面调用，在自己的iohandler里调用。



}


A在收到一个客户端消息，向服务器发送回应，客户端断开之后的结果是：
main thread run iohandle!
session::session 386588
session::session 3872d8
03/25/13 14:34:56 session::handle_read_header read 2 bytes
03/25/13 14:34:56 session::handle_read_body read f bytes
xxxxxx23421313
03/25/13 14:34:56 write success with byte_transffered = 22
03/25/13 14:34:56 session::handle_read_error line : 8cerr_code : 2746 err_msg:
远程主机强迫关闭了一个现有的连接。
session::~session 386588

B在收到一个客户端消息，向服务器发送回应，客户端断开之后的结果是：
main thread run iohandle!
session::session 386588
session::session 3872d8
03/25/13 14:50:23 session::handle_read_header read 2 bytes
03/25/13 14:50:23 session::handle_read_body read f bytes
xxxxxx23421313
03/25/13 14:50:23 write success with byte_transffered = 22
03/25/13 14:50:24 session::handle_read_error line : 8cerr_code : 2746 err_msg:
远程主机强迫关闭了一个现有的连接。
session386588没有被释放
(不关闭B再运行一次客户端,一下的信息包括上面那一段)
main thread run iohandle!
session::session 386588
session::session 3872d8
03/25/13 14:50:23 session::handle_read_header read 2 bytes
03/25/13 14:50:23 session::handle_read_body read f bytes
xxxxxx23421313
03/25/13 14:50:23 write success with byte_transffered = 22
03/25/13 14:50:24 session::handle_read_error line : 8cerr_code : 2746 err_msg:
远程主机强迫关闭了一个现有的连接。
session::session 38c028
03/25/13 14:52:38 session::handle_read_header read 2 bytes
03/25/13 14:52:38 session::handle_read_body read f bytes
xxxxxx23421313
03/25/13 14:52:38 write success with byte_transffered = 22
03/25/13 14:52:38 session::handle_read_error line : 8cerr_code : 2746 err_msg:
远程主机强迫关闭了一个现有的连接。
session::~session 3872d8
这次的session被释放了！

直到最后io_service.close()的时候session 386588才会被释放。

求大神解惑这是为什么？？

-----------------------以下是测试代码--------------------------------------------------------

session.h


using namespace boost::asio;

class session : public boost::enable_shared_from_this<session>

{

public:

	session(io_service& svic,iohandler* io);

	~session(void);

public:

	bool	Send(unsigned char* pMsg,unsigned short wSize);

	void	OnRecv( unsigned char *pMsg, unsigned short wSize );

	void	Start();

	void	handle_read_header(const boost::system::error_code& error,std::size_t bytes_transferred);

	void	handle_read_body(const boost::system::error_code& error,std::size_t bytes_transferred);

	void	handle_write_msg(const boost::system::error_code& error,std::size_t bytes_transferred);

	void	CloseSession();

	ip::tcp::socket& Socket() { return _socket; }



private:

	void	handle_read_error(const boost::system::error_code& error);

private:

	net_packet _packet_for_recv;

	net_packet_queue _packets_for_send;



	ip::tcp::socket _socket;

	iohandler* _io;

	boost::recursive_mutex* _mutex_for_write_buffer;



	SESSION_FLAGS bool _is_started;

	SESSION_FLAGS bool _is_closed;

	SESSION_FLAGS bool _is_in_writing;

	SESSION_FLAGS bool _is_notify_disconnect;

	

};


session.cpp


session::session(io_service& svic,iohandler* io)

:_socket(svic),

_is_in_writing(false),

_mutex_for_write_buffer(new boost::recursive_mutex),

_is_closed(false),

_is_started(false),

_io(io),

_is_notify_disconnect(false)

{

	std::cout << __FUNCTION__ << " "  << std::hex<< (int)this << std::endl;

}



session::~session(void)

{

	std::cout << __FUNCTION__ << " " << std::hex <<(int)this  << std::endl;

	if (_mutex_for_write_buffer)

	{

		delete _mutex_for_write_buffer;

		_mutex_for_write_buffer = NULL;

	}

}



void session::Start()

{

	if (_is_started){

		std::cerr << etr::timestamp << "session already start!" << std::endl;

		return;

	}

	_is_started = true;

	boost::asio::async_read(_socket,

		boost::asio::buffer(_packet_for_recv.data(),2),

		boost::bind(&session::handle_read_header, shared_from_this(), placeholders::error,placeholders::bytes_transferred));

}



void session::handle_read_header(const boost::system::error_code& error,std::size_t bytes_transferred)

{

	if (!error)

	{

		std::cout << "\t" << etr::timestamp << __FUNCTION__ <<" read " << bytes_transferred << " bytes" << std::endl;

		unsigned short len = _packet_for_recv.decode_header();

		_packet_for_recv.body_length(len);

		boost::asio::async_read(_socket,

								boost::asio::buffer(_packet_for_recv.body(),_packet_for_recv.body_length()),

								boost::bind(&session::handle_read_body, shared_from_this(),placeholders::error,placeholders::bytes_transferred));

	}

	else

	{

		handle_read_error(error);

	}

}



void session::CloseSession()

{

	if (_is_closed)

		return;

	_is_closed = true;

	std::cout << etr::timestamp << "close session " << std::hex << (int)this << std::endl;

	//cause we need recv to detective socket closed message;

	_socket.shutdown(boost::asio::ip::tcp::socket::shutdown_send);

	_socket.close();

	return;

}



void session::handle_read_body( const boost::system::error_code& error ,std::size_t bytes_transferred )

{

	if (!error)

	{

		std::cout << "\t" << etr::timestamp << __FUNCTION__ <<" read " << bytes_transferred << " bytes" << std::endl;

		std::cout << _packet_for_recv.body() << std::endl;

		

		char szText[32] = "hello wolrd!";

		Send((unsigned char*)szText,sizeof(szText));



		boost::asio::async_read(_socket,

								boost::asio::buffer(_packet_for_recv.data(),2),

								boost::bind(&session::handle_read_header, shared_from_this(), placeholders::error,placeholders::bytes_transferred));

	}else{

		handle_read_error(error);

	}

}



bool session::Send( unsigned char* pMsg,unsigned short wSize )

{

	net_packet np;

	np.encode_header(wSize);

	np.body_length(0);

	np.body((char*)pMsg,wSize);

	

	{

		boost::recursive_mutex::scoped_lock  lock(*_mutex_for_write_buffer);

		_is_in_writing = !_packets_for_send.empty();

		_packets_for_send.push_back(np);	



	}		

	if (!_is_in_writing)

	{

		boost::asio::async_write(_socket,

								boost::asio::buffer(_packets_for_send.front().data(),_packets_for_send.front().length()),

								boost::bind(&session::handle_write_msg, shared_from_this(), placeholders::error,placeholders::bytes_transferred));

	}



	

	return true;

}



void session::handle_write_msg( const boost::system::error_code& error,std::size_t bytes_transferred)

{

	if (!error)

	{

		std::cout << "\t" << etr::timestamp << "write success with byte_transffered = " << bytes_transferred << std::endl;

		{

			boost::recursive_mutex::scoped_lock  lock(*_mutex_for_write_buffer);

			_packets_for_send.pop_front();

		}



		if (!_packets_for_send.empty())

		{

			std::cout << "\t" << etr::timestamp << "try to post " << _packets_for_send.front().length() << " bytes" << std::endl;

			boost::asio::async_write(_socket,

				boost::asio::buffer(_packets_for_send.front().data(),_packets_for_send.front().length()),

				boost::bind(&session::handle_write_msg,shared_from_this(),placeholders::error,placeholders::bytes_transferred));

		}

	}else{

		std::cerr << etr::timestamp << "error in func :" << __FUNCTION__ << ".Line " << __LINE__ << "with err_code = " << error << std::endl;

		CloseSession();

	}

}



void session::handle_read_error( const boost::system::error_code& error )

{

	std::cout << etr::timestamp << __FUNCTION__ << " line : " << __LINE__ << "err_code : " << error.value() << " err_msg: " << error.message() << std::endl;

	if (!_is_closed) //尚未调用_is_closed

	{

		_is_closed = true;

		_socket.shutdown(boost::asio::ip::tcp::socket::shutdown_both);

		_socket.close();

	}



	if (!_is_notify_disconnect)

	{

		_is_notify_disconnect = true;

		_io->rm_session(shared_from_this());

	}

}

iohandler.h


#pragma once

class iohandler :

	public boost::noncopyable

{

public:

	iohandler(boost::asio::io_service& srv,const tcp::endpoint& endpoint);

	~iohandler(void);



	void run();



	void rm_session(session_ptr session);



	void stop();

private:

	unsigned short _port;

	void handle_accept(session_ptr session,const boost::system::error_code& error);

	bool _is_run;

	io_service& _io_service;

	tcp::acceptor _acceptor;

	set<session_ptr> _active_session;

};

iohanlder.cpp


iohandler::iohandler(boost::asio::io_service& srv,const tcp::endpoint& endpoint )

:_is_run(false),

_io_service(srv),

_acceptor(_io_service,endpoint)

{	

}



iohandler::~iohandler(void)

{

	cout << etr::timestamp << __FUNCTION__ << std::endl;

}



void iohandler::run()

{	

	if (_is_run)

		return;

	_is_run = true;

	session_ptr new_session(new session(_io_service,this));

	_acceptor.async_accept(new_session->Socket(),boost::bind(&iohandler::handle_accept, this, new_session,placeholders::error));

	_io_service.run();



}



void iohandler::handle_accept(session_ptr ses,const boost::system::error_code& error)

{

	if (!error)

	{

		_active_session.insert(ses);

		ses->Start();



		session_ptr new_session(new session(_io_service,this));

		_acceptor.async_accept(new_session->Socket(),boost::bind(&iohandler::handle_accept, this, new_session,placeholders::error));

	}else{

		std::cerr << etr::timestamp << "handle_accept error :"  << GetLastError()<< error.message() << "\n"

			<< "in file:" << __FILE__ << "in line: " << __LINE__ << std::endl;		

	}

}



void iohandler::rm_session( session_ptr ses )

{

	_active_session.erase(ses);

}
...全文
boost::asio::io_service与socket（C++） boost::asio::io_serviceio_service类为下面的异步对象提供核心的I/O操作函数，主要用途还是用于socket编程 boost::asio::ip::tcp::socket boost::asio::ip::tcp::acceptor boost::asio::ip::udp::socket boost::asio::deadline_timer io_servie 实现 阅读详情

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