C++ 对已删除对象调用了deadline\u计时器回调
在流动的代码中,即使我从boost::enable_shared_this继承了net类,当net被删除时,OnTimer仍然会再次被无效对象调用。如何解决这个问题?提前谢谢C++ 对已删除对象调用了deadline\u计时器回调,c++,boost-asio,C++,Boost Asio,在流动的代码中,即使我从boost::enable_shared_this继承了net类,当net被删除时,OnTimer仍然会再次被无效对象调用。如何解决这个问题?提前谢谢 boost::shared_ptr<boost::asio::io_service> service = boost::make_shared<boost::asio::io_service>(); class net:public boost::enable_shared_from_this&l
boost::shared_ptr<boost::asio::io_service> service =
boost::make_shared<boost::asio::io_service>();
class net:public boost::enable_shared_from_this<net>
{
public:
net(boost::shared_ptr<boost::asio::io_service>& service);
void StartTimer();
void OnTimer(const boost::system::error_code& e);
~net();
private:
boost::asio::deadline_timer timer_;
int a;
};
net::net(boost::shared_ptr<boost::asio::io_service>& service)
:timer_(*service, boost::posix_time::milliseconds(1000))
{
}
net::~net()
{
timer_.cancel();
}
void net::StartTimer()
{
timer_.async_wait(boost::bind(&net::OnTimer,
shared_from_this(), boost::asio::placeholders::error));
}
void net::OnTimer(const boost::system::error_code& e)
{
a = 10;
timer_.async_wait(boost::bind(&net::OnTimer,
shared_from_this(), boost::asio::placeholders::error));
}
unsigned int WINAPI ThreadMain(void* arg)
{
boost::shared_ptr<net> ptr(new net(service));
ptr->StartTimer();
Sleep(5000);
boost::shared_ptr<net> invalid_ptr;
ptr = invalid_ptr;
return 0;
}
int _tmain(int argc, _TCHAR* argv[])
{
boost::shared_ptr<boost::asio::io_service::work> io_service_work =
boost::make_shared<boost::asio::io_service::work>(*service);
boost::system::error_code ec;
HANDLE hThread = (HANDLE)_beginthreadex(NULL, 0, ThreadMain, NULL, 0, NULL);
if (hThread == NULL)
{
return -1;
}
boost::shared_ptr<boost::thread> thread_ =
boost::make_shared<boost::thread>(boost::bind(&boost::asio::io_service::run, service.get(), ec));
// in order to make sure OnTimer can be called at least once
Sleep(2000);
boost::shared_ptr<boost::asio::io_service::work> invalid_ptr;
io_service_work = invalid_ptr;
thread_->join();
WaitForSingleObject(hThread, INFINITE);
CloseHandle(hThread);
return 0;
}
boost::共享ptr服务=
boost::使_共享();
类net:public boost::从\u中启用\u共享\u
{
公众:
net(boost::共享存储和服务);
void StartTimer();
void OnTimer(const boost::system::error\u code&e);
~net();
私人:
boost::asio::截止时间\u计时器\uu;
INTA;
};
net::net(boost::共享存储和服务)
:timer_uu(*服务,boost::posix_时间::毫秒(1000))
{
}
net::~net()
{
计时器u0.cancel();
}
void net::StartTimer()
{
计时器异步等待(boost::bind(&net::OnTimer,
共享_from_this(),boost::asio::placeholders::error));
}
void net::OnTimer(const boost::system::error\u code&e)
{
a=10;
计时器异步等待(boost::bind(&net::OnTimer,
共享_from_this(),boost::asio::placeholders::error));
}
无符号int-WINAPI-ThreadMain(void*arg)
{
boost::shared_ptr ptr(新网络(服务));
ptr->StartTimer();
睡眠(5000);
boost::共享\u ptr无效\u ptr;
ptr=无效的ptr;
返回0;
}
int _tmain(int argc,_TCHAR*argv[]
{
boost::共享\u ptr io\u服务\u工作=
boost::使_共享(*服务);
boost::system::error_code ec;
HANDLE hThread=(HANDLE)u beginthreadex(NULL,0,ThreadMain,NULL,0,NULL);
if(hThread==NULL)
{
返回-1;
}
boost::共享线程
boost::make_shared(boost::bind(&boost::asio::io_service::run,service.get(),ec));
//为了确保至少可以调用OnTimer一次
睡眠(2000年);
boost::共享\u ptr无效\u ptr;
io\服务\工作=无效\ ptr;
线程->连接();
WaitForSingleObject(hThread,无限);
CloseHandle(hThread);
返回0;
}
您正在使用boost::asio::placeholders::error设置对OnTimer的回调,但忽略其错误代码。您应该真正获取并使用此错误代码,否则您将访问已删除的net
实例的成员(变量a
和计时器
):
@伊戈尔。这正是他案例中出现的错误代码。
void net::OnTimer(const boost::system::error_code& e)
{
if( e == boost::asio::error::operation_aborted ) return; //Do nothing if timer is cancelled
if( e ) return; //Do nothing in case of error
a = 10;
timer_.async_wait(boost::bind(&net::OnTimer,
shared_from_this, boost::asio::placeholders::error));
}