1 //
2 // detail/reactive_socket_accept_op.hpp
3 // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
4 //
5 // Copyright (c) 2003-2021 Christopher M. Kohlhoff (chris at kohlhoff dot com)
6 //
7 // Distributed under the Boost Software License, Version 1.0. (See accompanying
8 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
9 //
10 
11 #ifndef BOOST_ASIO_DETAIL_REACTIVE_SOCKET_ACCEPT_OP_HPP
12 #define BOOST_ASIO_DETAIL_REACTIVE_SOCKET_ACCEPT_OP_HPP
13 
14 #if defined(_MSC_VER) && (_MSC_VER >= 1200)
15 # pragma once
16 #endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
17 
18 #include <boost/asio/detail/config.hpp>
19 #include <boost/asio/detail/bind_handler.hpp>
20 #include <boost/asio/detail/fenced_block.hpp>
21 #include <boost/asio/detail/handler_alloc_helpers.hpp>
22 #include <boost/asio/detail/handler_invoke_helpers.hpp>
23 #include <boost/asio/detail/handler_work.hpp>
24 #include <boost/asio/detail/memory.hpp>
25 #include <boost/asio/detail/reactor_op.hpp>
26 #include <boost/asio/detail/socket_holder.hpp>
27 #include <boost/asio/detail/socket_ops.hpp>
28 
29 #include <boost/asio/detail/push_options.hpp>
30 
31 namespace boost {
32 namespace asio {
33 namespace detail {
34 
35 template <typename Socket, typename Protocol>
36 class reactive_socket_accept_op_base : public reactor_op
37 {
38 public:
reactive_socket_accept_op_base(const boost::system::error_code & success_ec,socket_type socket,socket_ops::state_type state,Socket & peer,const Protocol & protocol,typename Protocol::endpoint * peer_endpoint,func_type complete_func)39   reactive_socket_accept_op_base(const boost::system::error_code& success_ec,
40       socket_type socket, socket_ops::state_type state, Socket& peer,
41       const Protocol& protocol, typename Protocol::endpoint* peer_endpoint,
42       func_type complete_func)
43     : reactor_op(success_ec,
44         &reactive_socket_accept_op_base::do_perform, complete_func),
45       socket_(socket),
46       state_(state),
47       peer_(peer),
48       protocol_(protocol),
49       peer_endpoint_(peer_endpoint),
50       addrlen_(peer_endpoint ? peer_endpoint->capacity() : 0)
51   {
52   }
53 
do_perform(reactor_op * base)54   static status do_perform(reactor_op* base)
55   {
56     reactive_socket_accept_op_base* o(
57         static_cast<reactive_socket_accept_op_base*>(base));
58 
59     socket_type new_socket = invalid_socket;
60     status result = socket_ops::non_blocking_accept(o->socket_,
61         o->state_, o->peer_endpoint_ ? o->peer_endpoint_->data() : 0,
62         o->peer_endpoint_ ? &o->addrlen_ : 0, o->ec_, new_socket)
63     ? done : not_done;
64     o->new_socket_.reset(new_socket);
65 
66     BOOST_ASIO_HANDLER_REACTOR_OPERATION((*o, "non_blocking_accept", o->ec_));
67 
68     return result;
69   }
70 
do_assign()71   void do_assign()
72   {
73     if (new_socket_.get() != invalid_socket)
74     {
75       if (peer_endpoint_)
76         peer_endpoint_->resize(addrlen_);
77       peer_.assign(protocol_, new_socket_.get(), ec_);
78       if (!ec_)
79         new_socket_.release();
80     }
81   }
82 
83 private:
84   socket_type socket_;
85   socket_ops::state_type state_;
86   socket_holder new_socket_;
87   Socket& peer_;
88   Protocol protocol_;
89   typename Protocol::endpoint* peer_endpoint_;
90   std::size_t addrlen_;
91 };
92 
93 template <typename Socket, typename Protocol,
94     typename Handler, typename IoExecutor>
95 class reactive_socket_accept_op :
96   public reactive_socket_accept_op_base<Socket, Protocol>
97 {
98 public:
99   BOOST_ASIO_DEFINE_HANDLER_PTR(reactive_socket_accept_op);
100 
reactive_socket_accept_op(const boost::system::error_code & success_ec,socket_type socket,socket_ops::state_type state,Socket & peer,const Protocol & protocol,typename Protocol::endpoint * peer_endpoint,Handler & handler,const IoExecutor & io_ex)101   reactive_socket_accept_op(const boost::system::error_code& success_ec,
102       socket_type socket, socket_ops::state_type state, Socket& peer,
103       const Protocol& protocol, typename Protocol::endpoint* peer_endpoint,
104       Handler& handler, const IoExecutor& io_ex)
105     : reactive_socket_accept_op_base<Socket, Protocol>(
106         success_ec, socket, state, peer, protocol, peer_endpoint,
107         &reactive_socket_accept_op::do_complete),
108       handler_(BOOST_ASIO_MOVE_CAST(Handler)(handler)),
109       work_(handler_, io_ex)
110   {
111   }
112 
do_complete(void * owner,operation * base,const boost::system::error_code &,std::size_t)113   static void do_complete(void* owner, operation* base,
114       const boost::system::error_code& /*ec*/,
115       std::size_t /*bytes_transferred*/)
116   {
117     // Take ownership of the handler object.
118     reactive_socket_accept_op* o(static_cast<reactive_socket_accept_op*>(base));
119     ptr p = { boost::asio::detail::addressof(o->handler_), o, o };
120 
121     // On success, assign new connection to peer socket object.
122     if (owner)
123       o->do_assign();
124 
125     BOOST_ASIO_HANDLER_COMPLETION((*o));
126 
127     // Take ownership of the operation's outstanding work.
128     handler_work<Handler, IoExecutor> w(
129         BOOST_ASIO_MOVE_CAST2(handler_work<Handler, IoExecutor>)(
130           o->work_));
131 
132     // Make a copy of the handler so that the memory can be deallocated before
133     // the upcall is made. Even if we're not about to make an upcall, a
134     // sub-object of the handler may be the true owner of the memory associated
135     // with the handler. Consequently, a local copy of the handler is required
136     // to ensure that any owning sub-object remains valid until after we have
137     // deallocated the memory here.
138     detail::binder1<Handler, boost::system::error_code>
139       handler(o->handler_, o->ec_);
140     p.h = boost::asio::detail::addressof(handler.handler_);
141     p.reset();
142 
143     // Make the upcall if required.
144     if (owner)
145     {
146       fenced_block b(fenced_block::half);
147       BOOST_ASIO_HANDLER_INVOCATION_BEGIN((handler.arg1_));
148       w.complete(handler, handler.handler_);
149       BOOST_ASIO_HANDLER_INVOCATION_END;
150     }
151   }
152 
153 private:
154   Handler handler_;
155   handler_work<Handler, IoExecutor> work_;
156 };
157 
158 #if defined(BOOST_ASIO_HAS_MOVE)
159 
160 template <typename Protocol, typename PeerIoExecutor,
161     typename Handler, typename IoExecutor>
162 class reactive_socket_move_accept_op :
163   private Protocol::socket::template rebind_executor<PeerIoExecutor>::other,
164   public reactive_socket_accept_op_base<
165     typename Protocol::socket::template rebind_executor<PeerIoExecutor>::other,
166     Protocol>
167 {
168 public:
169   BOOST_ASIO_DEFINE_HANDLER_PTR(reactive_socket_move_accept_op);
170 
reactive_socket_move_accept_op(const boost::system::error_code & success_ec,const PeerIoExecutor & peer_io_ex,socket_type socket,socket_ops::state_type state,const Protocol & protocol,typename Protocol::endpoint * peer_endpoint,Handler & handler,const IoExecutor & io_ex)171   reactive_socket_move_accept_op(const boost::system::error_code& success_ec,
172       const PeerIoExecutor& peer_io_ex, socket_type socket,
173       socket_ops::state_type state, const Protocol& protocol,
174       typename Protocol::endpoint* peer_endpoint, Handler& handler,
175       const IoExecutor& io_ex)
176     : peer_socket_type(peer_io_ex),
177       reactive_socket_accept_op_base<peer_socket_type, Protocol>(
178         success_ec, socket, state, *this, protocol, peer_endpoint,
179         &reactive_socket_move_accept_op::do_complete),
180       handler_(BOOST_ASIO_MOVE_CAST(Handler)(handler)),
181       work_(handler_, io_ex)
182   {
183   }
184 
do_complete(void * owner,operation * base,const boost::system::error_code &,std::size_t)185   static void do_complete(void* owner, operation* base,
186       const boost::system::error_code& /*ec*/,
187       std::size_t /*bytes_transferred*/)
188   {
189     // Take ownership of the handler object.
190     reactive_socket_move_accept_op* o(
191         static_cast<reactive_socket_move_accept_op*>(base));
192     ptr p = { boost::asio::detail::addressof(o->handler_), o, o };
193 
194     // On success, assign new connection to peer socket object.
195     if (owner)
196       o->do_assign();
197 
198     BOOST_ASIO_HANDLER_COMPLETION((*o));
199 
200     // Take ownership of the operation's outstanding work.
201     handler_work<Handler, IoExecutor> w(
202         BOOST_ASIO_MOVE_CAST2(handler_work<Handler, IoExecutor>)(
203           o->work_));
204 
205     // Make a copy of the handler so that the memory can be deallocated before
206     // the upcall is made. Even if we're not about to make an upcall, a
207     // sub-object of the handler may be the true owner of the memory associated
208     // with the handler. Consequently, a local copy of the handler is required
209     // to ensure that any owning sub-object remains valid until after we have
210     // deallocated the memory here.
211     detail::move_binder2<Handler,
212       boost::system::error_code, peer_socket_type>
213         handler(0, BOOST_ASIO_MOVE_CAST(Handler)(o->handler_), o->ec_,
214           BOOST_ASIO_MOVE_CAST(peer_socket_type)(*o));
215     p.h = boost::asio::detail::addressof(handler.handler_);
216     p.reset();
217 
218     // Make the upcall if required.
219     if (owner)
220     {
221       fenced_block b(fenced_block::half);
222       BOOST_ASIO_HANDLER_INVOCATION_BEGIN((handler.arg1_, "..."));
223       w.complete(handler, handler.handler_);
224       BOOST_ASIO_HANDLER_INVOCATION_END;
225     }
226   }
227 
228 private:
229   typedef typename Protocol::socket::template
230     rebind_executor<PeerIoExecutor>::other peer_socket_type;
231 
232   Handler handler_;
233   handler_work<Handler, IoExecutor> work_;
234 };
235 
236 #endif // defined(BOOST_ASIO_HAS_MOVE)
237 
238 } // namespace detail
239 } // namespace asio
240 } // namespace boost
241 
242 #include <boost/asio/detail/pop_options.hpp>
243 
244 #endif // BOOST_ASIO_DETAIL_REACTIVE_SOCKET_ACCEPT_OP_HPP
245