1 //
2 // detail/win_iocp_socket_recvmsg_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_RECVMSG_OP_HPP
12 #define BOOST_ASIO_DETAIL_WIN_IOCP_SOCKET_RECVMSG_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 #include <boost/asio/socket_base.hpp>
33 
34 #include <boost/asio/detail/push_options.hpp>
35 
36 namespace boost {
37 namespace asio {
38 namespace detail {
39 
40 template <typename MutableBufferSequence, typename Handler, typename IoExecutor>
41 class win_iocp_socket_recvmsg_op : public operation
42 {
43 public:
44   BOOST_ASIO_DEFINE_HANDLER_PTR(win_iocp_socket_recvmsg_op);
45 
win_iocp_socket_recvmsg_op(socket_ops::weak_cancel_token_type cancel_token,const MutableBufferSequence & buffers,socket_base::message_flags & out_flags,Handler & handler,const IoExecutor & io_ex)46   win_iocp_socket_recvmsg_op(
47       socket_ops::weak_cancel_token_type cancel_token,
48       const MutableBufferSequence& buffers,
49       socket_base::message_flags& out_flags,
50       Handler& handler, const IoExecutor& io_ex)
51     : operation(&win_iocp_socket_recvmsg_op::do_complete),
52       cancel_token_(cancel_token),
53       buffers_(buffers),
54       out_flags_(out_flags),
55       handler_(BOOST_ASIO_MOVE_CAST(Handler)(handler)),
56       work_(handler_, io_ex)
57   {
58   }
59 
do_complete(void * owner,operation * base,const boost::system::error_code & result_ec,std::size_t bytes_transferred)60   static void do_complete(void* owner, operation* base,
61       const boost::system::error_code& result_ec,
62       std::size_t bytes_transferred)
63   {
64     boost::system::error_code ec(result_ec);
65 
66     // Take ownership of the operation object.
67     win_iocp_socket_recvmsg_op* o(
68         static_cast<win_iocp_socket_recvmsg_op*>(base));
69     ptr p = { boost::asio::detail::addressof(o->handler_), o, o };
70 
71     BOOST_ASIO_HANDLER_COMPLETION((*o));
72 
73     // Take ownership of the operation's outstanding work.
74     handler_work<Handler, IoExecutor> w(
75         BOOST_ASIO_MOVE_CAST2(handler_work<Handler, IoExecutor>)(
76           o->work_));
77 
78 #if defined(BOOST_ASIO_ENABLE_BUFFER_DEBUGGING)
79     // Check whether buffers are still valid.
80     if (owner)
81     {
82       buffer_sequence_adapter<boost::asio::mutable_buffer,
83           MutableBufferSequence>::validate(o->buffers_);
84     }
85 #endif // defined(BOOST_ASIO_ENABLE_BUFFER_DEBUGGING)
86 
87     socket_ops::complete_iocp_recvmsg(o->cancel_token_, ec);
88     o->out_flags_ = 0;
89 
90     // Make a copy of the handler so that the memory can be deallocated before
91     // the upcall is made. Even if we're not about to make an upcall, a
92     // sub-object of the handler may be the true owner of the memory associated
93     // with the handler. Consequently, a local copy of the handler is required
94     // to ensure that any owning sub-object remains valid until after we have
95     // deallocated the memory here.
96     detail::binder2<Handler, boost::system::error_code, std::size_t>
97       handler(o->handler_, ec, bytes_transferred);
98     p.h = boost::asio::detail::addressof(handler.handler_);
99     p.reset();
100 
101     // Make the upcall if required.
102     if (owner)
103     {
104       fenced_block b(fenced_block::half);
105       BOOST_ASIO_HANDLER_INVOCATION_BEGIN((handler.arg1_, handler.arg2_));
106       w.complete(handler, handler.handler_);
107       BOOST_ASIO_HANDLER_INVOCATION_END;
108     }
109   }
110 
111 private:
112   socket_ops::weak_cancel_token_type cancel_token_;
113   MutableBufferSequence buffers_;
114   socket_base::message_flags& out_flags_;
115   Handler handler_;
116   handler_work<Handler, IoExecutor> work_;
117 };
118 
119 } // namespace detail
120 } // namespace asio
121 } // namespace boost
122 
123 #include <boost/asio/detail/pop_options.hpp>
124 
125 #endif // defined(BOOST_ASIO_HAS_IOCP)
126 
127 #endif // BOOST_ASIO_DETAIL_WIN_IOCP_SOCKET_RECVMSG_OP_HPP
128