1 //
2 // detail/win_iocp_socket_recv_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_WIN_IOCP_SOCKET_RECV_OP_HPP
12 #define BOOST_ASIO_DETAIL_WIN_IOCP_SOCKET_RECV_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 
20 #if defined(BOOST_ASIO_HAS_IOCP)
21 
22 #include <boost/asio/detail/bind_handler.hpp>
23 #include <boost/asio/detail/buffer_sequence_adapter.hpp>
24 #include <boost/asio/detail/fenced_block.hpp>
25 #include <boost/asio/detail/handler_alloc_helpers.hpp>
26 #include <boost/asio/detail/handler_invoke_helpers.hpp>
27 #include <boost/asio/detail/handler_work.hpp>
28 #include <boost/asio/detail/memory.hpp>
29 #include <boost/asio/detail/operation.hpp>
30 #include <boost/asio/detail/socket_ops.hpp>
31 #include <boost/asio/error.hpp>
32 
33 #include <boost/asio/detail/push_options.hpp>
34 
35 namespace boost {
36 namespace asio {
37 namespace detail {
38 
39 template <typename MutableBufferSequence, typename Handler, typename IoExecutor>
40 class win_iocp_socket_recv_op : public operation
41 {
42 public:
43   BOOST_ASIO_DEFINE_HANDLER_PTR(win_iocp_socket_recv_op);
44 
win_iocp_socket_recv_op(socket_ops::state_type state,socket_ops::weak_cancel_token_type cancel_token,const MutableBufferSequence & buffers,Handler & handler,const IoExecutor & io_ex)45   win_iocp_socket_recv_op(socket_ops::state_type state,
46       socket_ops::weak_cancel_token_type cancel_token,
47       const MutableBufferSequence& buffers, Handler& handler,
48       const IoExecutor& io_ex)
49     : operation(&win_iocp_socket_recv_op::do_complete),
50       state_(state),
51       cancel_token_(cancel_token),
52       buffers_(buffers),
53       handler_(BOOST_ASIO_MOVE_CAST(Handler)(handler)),
54       work_(handler_, io_ex)
55   {
56   }
57 
do_complete(void * owner,operation * base,const boost::system::error_code & result_ec,std::size_t bytes_transferred)58   static void do_complete(void* owner, operation* base,
59       const boost::system::error_code& result_ec,
60       std::size_t bytes_transferred)
61   {
62     boost::system::error_code ec(result_ec);
63 
64     // Take ownership of the operation object.
65     win_iocp_socket_recv_op* o(static_cast<win_iocp_socket_recv_op*>(base));
66     ptr p = { boost::asio::detail::addressof(o->handler_), o, o };
67 
68     BOOST_ASIO_HANDLER_COMPLETION((*o));
69 
70     // Take ownership of the operation's outstanding work.
71     handler_work<Handler, IoExecutor> w(
72         BOOST_ASIO_MOVE_CAST2(handler_work<Handler, IoExecutor>)(
73           o->work_));
74 
75 #if defined(BOOST_ASIO_ENABLE_BUFFER_DEBUGGING)
76     // Check whether buffers are still valid.
77     if (owner)
78     {
79       buffer_sequence_adapter<boost::asio::mutable_buffer,
80           MutableBufferSequence>::validate(o->buffers_);
81     }
82 #endif // defined(BOOST_ASIO_ENABLE_BUFFER_DEBUGGING)
83 
84     socket_ops::complete_iocp_recv(o->state_, o->cancel_token_,
85         buffer_sequence_adapter<boost::asio::mutable_buffer,
86           MutableBufferSequence>::all_empty(o->buffers_),
87         ec, bytes_transferred);
88 
89     // Make a copy of the handler so that the memory can be deallocated before
90     // the upcall is made. Even if we're not about to make an upcall, a
91     // sub-object of the handler may be the true owner of the memory associated
92     // with the handler. Consequently, a local copy of the handler is required
93     // to ensure that any owning sub-object remains valid until after we have
94     // deallocated the memory here.
95     detail::binder2<Handler, boost::system::error_code, std::size_t>
96       handler(o->handler_, ec, bytes_transferred);
97     p.h = boost::asio::detail::addressof(handler.handler_);
98     p.reset();
99 
100     // Make the upcall if required.
101     if (owner)
102     {
103       fenced_block b(fenced_block::half);
104       BOOST_ASIO_HANDLER_INVOCATION_BEGIN((handler.arg1_, handler.arg2_));
105       w.complete(handler, handler.handler_);
106       BOOST_ASIO_HANDLER_INVOCATION_END;
107     }
108   }
109 
110 private:
111   socket_ops::state_type state_;
112   socket_ops::weak_cancel_token_type cancel_token_;
113   MutableBufferSequence buffers_;
114   Handler handler_;
115   handler_work<Handler, IoExecutor> work_;
116 };
117 
118 } // namespace detail
119 } // namespace asio
120 } // namespace boost
121 
122 #include <boost/asio/detail/pop_options.hpp>
123 
124 #endif // defined(BOOST_ASIO_HAS_IOCP)
125 
126 #endif // BOOST_ASIO_DETAIL_WIN_IOCP_SOCKET_RECV_OP_HPP
127