1 //
2 // detail/reactive_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_REACTIVE_SOCKET_RECVMSG_OP_HPP
12 #define BOOST_ASIO_DETAIL_REACTIVE_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 #include <boost/asio/detail/bind_handler.hpp>
20 #include <boost/asio/detail/buffer_sequence_adapter.hpp>
21 #include <boost/asio/detail/fenced_block.hpp>
22 #include <boost/asio/detail/handler_alloc_helpers.hpp>
23 #include <boost/asio/detail/handler_invoke_helpers.hpp>
24 #include <boost/asio/detail/handler_work.hpp>
25 #include <boost/asio/detail/memory.hpp>
26 #include <boost/asio/detail/reactor_op.hpp>
27 #include <boost/asio/detail/socket_ops.hpp>
28 #include <boost/asio/socket_base.hpp>
29 
30 #include <boost/asio/detail/push_options.hpp>
31 
32 namespace boost {
33 namespace asio {
34 namespace detail {
35 
36 template <typename MutableBufferSequence>
37 class reactive_socket_recvmsg_op_base : public reactor_op
38 {
39 public:
reactive_socket_recvmsg_op_base(const boost::system::error_code & success_ec,socket_type socket,const MutableBufferSequence & buffers,socket_base::message_flags in_flags,socket_base::message_flags & out_flags,func_type complete_func)40   reactive_socket_recvmsg_op_base(const boost::system::error_code& success_ec,
41       socket_type socket, const MutableBufferSequence& buffers,
42       socket_base::message_flags in_flags,
43       socket_base::message_flags& out_flags, func_type complete_func)
44     : reactor_op(success_ec,
45         &reactive_socket_recvmsg_op_base::do_perform, complete_func),
46       socket_(socket),
47       buffers_(buffers),
48       in_flags_(in_flags),
49       out_flags_(out_flags)
50   {
51   }
52 
do_perform(reactor_op * base)53   static status do_perform(reactor_op* base)
54   {
55     reactive_socket_recvmsg_op_base* o(
56         static_cast<reactive_socket_recvmsg_op_base*>(base));
57 
58     buffer_sequence_adapter<boost::asio::mutable_buffer,
59         MutableBufferSequence> bufs(o->buffers_);
60 
61     status result = socket_ops::non_blocking_recvmsg(o->socket_,
62         bufs.buffers(), bufs.count(),
63         o->in_flags_, o->out_flags_,
64         o->ec_, o->bytes_transferred_) ? done : not_done;
65 
66     BOOST_ASIO_HANDLER_REACTOR_OPERATION((*o, "non_blocking_recvmsg",
67           o->ec_, o->bytes_transferred_));
68 
69     return result;
70   }
71 
72 private:
73   socket_type socket_;
74   MutableBufferSequence buffers_;
75   socket_base::message_flags in_flags_;
76   socket_base::message_flags& out_flags_;
77 };
78 
79 template <typename MutableBufferSequence, typename Handler, typename IoExecutor>
80 class reactive_socket_recvmsg_op :
81   public reactive_socket_recvmsg_op_base<MutableBufferSequence>
82 {
83 public:
84   BOOST_ASIO_DEFINE_HANDLER_PTR(reactive_socket_recvmsg_op);
85 
reactive_socket_recvmsg_op(const boost::system::error_code & success_ec,socket_type socket,const MutableBufferSequence & buffers,socket_base::message_flags in_flags,socket_base::message_flags & out_flags,Handler & handler,const IoExecutor & io_ex)86   reactive_socket_recvmsg_op(const boost::system::error_code& success_ec,
87       socket_type socket, const MutableBufferSequence& buffers,
88       socket_base::message_flags in_flags,
89       socket_base::message_flags& out_flags, Handler& handler,
90       const IoExecutor& io_ex)
91     : reactive_socket_recvmsg_op_base<MutableBufferSequence>(
92         success_ec, socket, buffers, in_flags, out_flags,
93         &reactive_socket_recvmsg_op::do_complete),
94       handler_(BOOST_ASIO_MOVE_CAST(Handler)(handler)),
95       work_(handler_, io_ex)
96   {
97   }
98 
do_complete(void * owner,operation * base,const boost::system::error_code &,std::size_t)99   static void do_complete(void* owner, operation* base,
100       const boost::system::error_code& /*ec*/,
101       std::size_t /*bytes_transferred*/)
102   {
103     // Take ownership of the handler object.
104     reactive_socket_recvmsg_op* o(
105         static_cast<reactive_socket_recvmsg_op*>(base));
106     ptr p = { boost::asio::detail::addressof(o->handler_), o, o };
107 
108     BOOST_ASIO_HANDLER_COMPLETION((*o));
109 
110     // Take ownership of the operation's outstanding work.
111     handler_work<Handler, IoExecutor> w(
112         BOOST_ASIO_MOVE_CAST2(handler_work<Handler, IoExecutor>)(
113           o->work_));
114 
115     // Make a copy of the handler so that the memory can be deallocated before
116     // the upcall is made. Even if we're not about to make an upcall, a
117     // sub-object of the handler may be the true owner of the memory associated
118     // with the handler. Consequently, a local copy of the handler is required
119     // to ensure that any owning sub-object remains valid until after we have
120     // deallocated the memory here.
121     detail::binder2<Handler, boost::system::error_code, std::size_t>
122       handler(o->handler_, o->ec_, o->bytes_transferred_);
123     p.h = boost::asio::detail::addressof(handler.handler_);
124     p.reset();
125 
126     // Make the upcall if required.
127     if (owner)
128     {
129       fenced_block b(fenced_block::half);
130       BOOST_ASIO_HANDLER_INVOCATION_BEGIN((handler.arg1_, handler.arg2_));
131       w.complete(handler, handler.handler_);
132       BOOST_ASIO_HANDLER_INVOCATION_END;
133     }
134   }
135 
136 private:
137   Handler handler_;
138   handler_work<Handler, IoExecutor> work_;
139 };
140 
141 } // namespace detail
142 } // namespace asio
143 } // namespace boost
144 
145 #include <boost/asio/detail/pop_options.hpp>
146 
147 #endif // BOOST_ASIO_DETAIL_REACTIVE_SOCKET_RECVMSG_OP_HPP
148