I want to std::move(my_asio_socket)
to the instance of some class. What if I do the same for an instance of some other class?
My purpose is to read_async
in one class instance (let's say class A
), and to execute write_async
in the other (let's say class B
). Because of some functionality implementations, I should do it this way.
Any suggestion would be nice.
UPDATED
it's not working properly as i expected.
The VS2015(vc14 compiler) shows me a kind of exception while debugging:
Microsoft C++ exception: boost::exception_detail::clone_impl<boost::exception_detail::error_info_injector<boost::system::system_error> > at memory location 0x02D8E3BC.
And after i hit continue
in VS it show me that:
Run-Time Check Failure #0 - The value of ESP was not properly saved across a function call. This is usually a result of calling a function declared with one calling convention with a function pointer declared with a different calling convention.
As i said, i'm trying to boost::move
(or std::move
) the socket to other class instance. Here is a snippet of code of what i'm doing:
boost::shared_ptr<connection> new_connection_;//it's a field in my class,
//that's why i should reset it later
new_connection_.reset(new connection(std::move(socket_), io_service_));
new_connection_->start();
Now here is my connection
ctor:
connection::connection(boost::asio::ip::tcp::socket sock, boost::asio::io_service& io_ptr)
: socket_(boost::move(sock)),
io_ptr_(io_ptr),
remote_ep(socket_.remote_endpoint()),
//request_handler_(new request_handler(boost::move(socket_))),
work(new boost::asio::io_service::work(io_ptr))
{
boost::shared_ptr<request_handler> req_ptr(new request_handler(boost::move(socket_)));
request_handler_.swap(req_ptr);
}
As you can see, i've tried initializing in the commented line, but it shows me the same result.
Here is the ctor for request_handler
:
request_handler::request_handler(boost::asio::ip::tcp::socket sock):
socket_(boost::move(sock)){ }
And here is my method connection::start
where the problem detects:
void connection::start()
{
boost::asio::ip::tcp::socket::keep_alive kl(true);
boost::asio::ip::tcp::socket::enable_connection_aborted eca(true);
// here it breaks, when trying to set an option
socket_.set_option(eca);
socket_.set_option(kl);
socket_.async_read_some(boost::asio::buffer(buffer_),
boost::bind(&connection::handle_read, shared_from_this(),
boost::asio::placeholders::error,
boost::asio::placeholders::bytes_transferred));
}
This problem appears only when i use to move socket
into the new instance of request_handler
. If i'm not - then all goes okey. I can't understand what reason it could be, but seems like my socket_
(i declare it everywhere without any &
or *
) field from connection
class is lost or kind of. But the debugger isn't showing me smthing like null, so i don't know what is it.
In general it is not guaranteed:
Move assignment operators typically "steal" the resources held by the argument (e.g. pointers to dynamically-allocated objects, file descriptors, TCP sockets, I/O streams, running threads, etc.), rather than make copies of them, and leave the argument in some valid but otherwise indeterminate state. For example, move-assigning from a std::string or from a std::vector may result in the argument being left empty. However, this behaviour should not be relied upon.
But according to the documentation for tcp::socket
it is left in the same state:
Following the move, the moved-from object is in the same state as if constructed using the basic_stream_socket(io_service&) constructor.