我是 boost::asio 的初学者，所以请帮助我。
我需要编写单线程 TCP 服务器。服务器应接受客户端连接并不断从客户端套接字读取输入数据。服务器应定期向客户端发送数据。所以我有一些问题 - 所有例子都描述了我们总是有循环的情况
- async_receive()
- on_receive() -> async_write()
- on_write() -> 转到 1 :)
所以我的决定是使用计时器来检查要发送到套接字的数据。
我编写了测试服务器并且有非常奇怪的行为 - 如果客户端连接，做某事并一个接一个断开连接一段时间 delta ，它就可以工作。但是，如果所有客户端同时断开连接，我会遇到计时器处理程序尝试使用已销毁对象的成员类（锁定关键部分）的情况。
我无法描述为什么！请帮忙 ！
[此视频展示了它是如何复制的] ( http://www.youtube.com/watch?v=NMWkD7rqf7Y&feature=youtu.be "1080p" )
谢谢 ！
#include <boost/none.hpp>
#include <boost/bind.hpp>
#include <boost/asio.hpp>
#include <boost/shared_ptr.hpp>
#include <boost/enable_shared_from_this.hpp>
#include <iostream>
using namespace boost::asio;
using namespace boost::posix_time;
class CIncommingConnection ;
typedef boost::shared_ptr<CIncommingConnection> CIncommingConnectionPtr;
struct IIncomingServer
{
virtual void OnData(CIncommingConnectionPtr pConn, const char *pData, size_t bytes) = 0;
virtual void OnConnected(CIncommingConnectionPtr pConn) = 0;
virtual void OnDisconnected(const boost::system::error_code& err, CIncommingConnectionPtr pConn) = 0;
};
class CAutoLock
{
public:
CAutoLock(CRITICAL_SECTION &cs) :
m_cs(cs)
{
::EnterCriticalSection(&m_cs);
}
~CAutoLock()
{
::LeaveCriticalSection(&m_cs);
}
private:
CRITICAL_SECTION &m_cs;
};
class CIncommingConnection : public boost::enable_shared_from_this<CIncommingConnection>
,boost::noncopyable
{
public:
CIncommingConnection(const std::string sPeerName, boost::asio::io_service &service, IIncomingServer *pServer) :
m_service(service)
,sock_(service)
,m_sPeerName(sPeerName)
,m_pServer(pServer)
,m_timer(service)
{
::InitializeCriticalSection(&m_cs);
std::cout << "CIncommingConnection()" << std::endl ;
}
~CIncommingConnection()
{
std::cout << "CIncommingConnection()~" << std::endl ;
::DeleteCriticalSection(&m_cs);
}
ip::tcp::socket & sock()
{
return sock_;
}
void start()
{
m_pServer->OnConnected(shared_from_this());
do_read();
wait_for_outgoingdata();
}
private:
void stop()
{
sock_.close();
m_timer.cancel();
}
void do_read()
{
sock_.async_receive(buffer(read_buffer_), boost::bind(&CIncommingConnection::handler_read, this, _1, _2) );
}
void do_error(const boost::system::error_code& error)
{
CIncommingConnectionPtr pConn = shared_from_this();
stop() ;
m_pServer->OnDisconnected(error, pConn);
}
void handler_read(const boost::system::error_code& error, std::size_t bytes)
{
if (error)
{
do_error(error);
return ;
}
CIncommingConnectionPtr pConn = shared_from_this() ;
m_pServer->OnData(pConn, read_buffer_, bytes);
do_read();
}
void wait_for_outgoingdata()
{
m_timer.expires_from_now( boost::posix_time::millisec( 100 ) );
m_timer.async_wait( boost::bind( &CIncommingConnection::on_output_queue_timer, this, _1 ) );
}
void on_output_queue_timer(const boost::system::error_code& error)
{
if (error == boost::asio::error::operation_aborted)
{
return ;
}
CAutoLock oLock(m_cs);
if (!m_sOutBuf.empty())
sock_.async_send(buffer(m_sOutBuf), boost::bind(&CIncommingConnection::handler_write, this, _1, _2) );
else
wait_for_outgoingdata();
}
void handler_write(const boost::system::error_code& error, std::size_t bytes)
{
if (error)
return ;
if (bytes)
{
m_sOutBuf = m_sOutBuf.substr(bytes, m_sOutBuf.length()-bytes);
}
wait_for_outgoingdata();
}
private:
ip::tcp::socket sock_;
enum { max_msg = 1024 };
char read_buffer_[max_msg];
char write_buffer_[max_msg];
boost::asio::io_service &m_service ;
std::string m_sPeerName ;
std::string m_sOutBuf;
CRITICAL_SECTION m_cs ;
IIncomingServer *m_pServer;
boost::asio::deadline_timer m_timer;
};
class CIncomingServer : public boost::enable_shared_from_this<CIncomingServer>
, public IIncomingServer
, boost::noncopyable
{
public:
CIncomingServer(boost::asio::io_service &service,
unsigned int port,
bool bAllowManyConnections,
const std::string sPeerName) :
m_acceptor (service, ip::tcp::endpoint(ip::tcp::v4(), port), false)
,m_sPeerName(sPeerName)
,m_port(port)
,m_service(service)
,m_timer(service)
,m_bAllowManyConnections(bAllowManyConnections)
{
}
~CIncomingServer()
{
}
void run()
{
CIncommingConnectionPtr pConn (new CIncommingConnection(m_sPeerName, m_service, this));
m_clients.push_back( pConn );
m_acceptor.async_accept(pConn->sock(), boost::bind(&CIncomingServer::handle_accept, this, _1));
m_timer.expires_from_now( boost::posix_time::millisec( 500 ) );
m_timer.async_wait( boost::bind( &CIncomingServer::on_timer, this ) );
}
private:
void handle_accept(const boost::system::error_code & err)
{
m_clients.back()->start();
CIncommingConnectionPtr pConnNew (new CIncommingConnection(m_sPeerName, m_service, this));
m_clients.push_back( pConnNew );
m_acceptor.async_accept(pConnNew->sock(), boost::bind(&CIncomingServer::handle_accept, this, _1));
}
//IIncomingServer
virtual void OnData(CIncommingConnectionPtr pConn, const char *pData, size_t bytes)
{
std::cout << "Data received" << std::endl ;
}
virtual void OnConnected(CIncommingConnectionPtr pConn)
{
std::cout << "Client connected" << std::endl ;
}
virtual void OnDisconnected(const boost::system::error_code& err, CIncommingConnectionPtr pConn)
{
std::cout << "Client disconnected" << std::endl ;
auto it = std::find(m_clients.begin(), m_clients.end(), pConn) ;
if (it != m_clients.end())
{
m_clients.erase(it);
}
}
void on_timer()
{
//if (NeedTerminate())
//{
// m_service.stop();
// return ;
//}
m_timer.expires_from_now( boost::posix_time::millisec( 500 ) );
m_timer.async_wait( boost::bind( &CIncomingServer::on_timer, this ) );
}
private:
ip::tcp::acceptor m_acceptor ;
std::vector<CIncommingConnectionPtr> m_clients;
std::string m_sPeerName ;
unsigned int m_port ;
boost::asio::io_service &m_service ;
boost::asio::deadline_timer m_timer;
bool m_bAllowManyConnections;
};
int _tmain(int argc, _TCHAR* argv[])
{
boost::asio::io_service service ;
boost::shared_ptr<CIncomingServer> pServer;
try
{
pServer.reset( new CIncomingServer(service, 8000, false, "BS Server"));
pServer->run();
}
catch (const boost::system::system_error &err)
{
std::cout << "Error : " << err.what() << std::endl ;
return 0 ;
}
service.run();
return 0 ;
}