1 //
2 // detail/reactive_socket_sendto_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_SENDTO_OP_HPP
12 #define BOOST_ASIO_DETAIL_REACTIVE_SOCKET_SENDTO_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 
29 #include <boost/asio/detail/push_options.hpp>
30 
31 namespace boost {
32 namespace asio {
33 namespace detail {
34 
35 template <typename ConstBufferSequence, typename Endpoint>
36 class reactive_socket_sendto_op_base : public reactor_op
37 {
38 public:
reactive_socket_sendto_op_base(const boost::system::error_code & success_ec,socket_type socket,const ConstBufferSequence & buffers,const Endpoint & endpoint,socket_base::message_flags flags,func_type complete_func)39   reactive_socket_sendto_op_base(const boost::system::error_code& success_ec,
40       socket_type socket, const ConstBufferSequence& buffers,
41       const Endpoint& endpoint, socket_base::message_flags flags,
42       func_type complete_func)
43     : reactor_op(success_ec,
44         &reactive_socket_sendto_op_base::do_perform, complete_func),
45       socket_(socket),
46       buffers_(buffers),
47       destination_(endpoint),
48       flags_(flags)
49   {
50   }
51 
do_perform(reactor_op * base)52   static status do_perform(reactor_op* base)
53   {
54     reactive_socket_sendto_op_base* o(
55         static_cast<reactive_socket_sendto_op_base*>(base));
56 
57     typedef buffer_sequence_adapter<boost::asio::const_buffer,
58         ConstBufferSequence> bufs_type;
59 
60     status result;
61     if (bufs_type::is_single_buffer)
62     {
63       result = socket_ops::non_blocking_sendto1(o->socket_,
64           bufs_type::first(o->buffers_).data(),
65           bufs_type::first(o->buffers_).size(), o->flags_,
66           o->destination_.data(), o->destination_.size(),
67           o->ec_, o->bytes_transferred_) ? done : not_done;
68     }
69     else
70     {
71       bufs_type bufs(o->buffers_);
72       result = socket_ops::non_blocking_sendto(o->socket_,
73           bufs.buffers(), bufs.count(), o->flags_,
74           o->destination_.data(), o->destination_.size(),
75           o->ec_, o->bytes_transferred_) ? done : not_done;
76     }
77 
78     BOOST_ASIO_HANDLER_REACTOR_OPERATION((*o, "non_blocking_sendto",
79           o->ec_, o->bytes_transferred_));
80 
81     return result;
82   }
83 
84 private:
85   socket_type socket_;
86   ConstBufferSequence buffers_;
87   Endpoint destination_;
88   socket_base::message_flags flags_;
89 };
90 
91 template <typename ConstBufferSequence, typename Endpoint,
92     typename Handler, typename IoExecutor>
93 class reactive_socket_sendto_op :
94   public reactive_socket_sendto_op_base<ConstBufferSequence, Endpoint>
95 {
96 public:
97   BOOST_ASIO_DEFINE_HANDLER_PTR(reactive_socket_sendto_op);
98 
reactive_socket_sendto_op(const boost::system::error_code & success_ec,socket_type socket,const ConstBufferSequence & buffers,const Endpoint & endpoint,socket_base::message_flags flags,Handler & handler,const IoExecutor & io_ex)99   reactive_socket_sendto_op(const boost::system::error_code& success_ec,
100       socket_type socket, const ConstBufferSequence& buffers,
101       const Endpoint& endpoint, socket_base::message_flags flags,
102       Handler& handler, const IoExecutor& io_ex)
103     : reactive_socket_sendto_op_base<ConstBufferSequence, Endpoint>(
104         success_ec, socket, buffers, endpoint, flags,
105         &reactive_socket_sendto_op::do_complete),
106       handler_(BOOST_ASIO_MOVE_CAST(Handler)(handler)),
107       work_(handler_, io_ex)
108   {
109   }
110 
do_complete(void * owner,operation * base,const boost::system::error_code &,std::size_t)111   static void do_complete(void* owner, operation* base,
112       const boost::system::error_code& /*ec*/,
113       std::size_t /*bytes_transferred*/)
114   {
115     // Take ownership of the handler object.
116     reactive_socket_sendto_op* o(static_cast<reactive_socket_sendto_op*>(base));
117     ptr p = { boost::asio::detail::addressof(o->handler_), o, o };
118 
119     BOOST_ASIO_HANDLER_COMPLETION((*o));
120 
121     // Take ownership of the operation's outstanding work.
122     handler_work<Handler, IoExecutor> w(
123         BOOST_ASIO_MOVE_CAST2(handler_work<Handler, IoExecutor>)(
124           o->work_));
125 
126     // Make a copy of the handler so that the memory can be deallocated before
127     // the upcall is made. Even if we're not about to make an upcall, a
128     // sub-object of the handler may be the true owner of the memory associated
129     // with the handler. Consequently, a local copy of the handler is required
130     // to ensure that any owning sub-object remains valid until after we have
131     // deallocated the memory here.
132     detail::binder2<Handler, boost::system::error_code, std::size_t>
133       handler(o->handler_, o->ec_, o->bytes_transferred_);
134     p.h = boost::asio::detail::addressof(handler.handler_);
135     p.reset();
136 
137     // Make the upcall if required.
138     if (owner)
139     {
140       fenced_block b(fenced_block::half);
141       BOOST_ASIO_HANDLER_INVOCATION_BEGIN((handler.arg1_, handler.arg2_));
142       w.complete(handler, handler.handler_);
143       BOOST_ASIO_HANDLER_INVOCATION_END;
144     }
145   }
146 
147 private:
148   Handler handler_;
149   handler_work<Handler, IoExecutor> work_;
150 };
151 
152 } // namespace detail
153 } // namespace asio
154 } // namespace boost
155 
156 #include <boost/asio/detail/pop_options.hpp>
157 
158 #endif // BOOST_ASIO_DETAIL_REACTIVE_SOCKET_SENDTO_OP_HPP
159