1 //
2 // detail/reactive_socket_send_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_SEND_OP_HPP
12 #define BOOST_ASIO_DETAIL_REACTIVE_SOCKET_SEND_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>
36 class reactive_socket_send_op_base : public reactor_op
37 {
38 public:
reactive_socket_send_op_base(const boost::system::error_code & success_ec,socket_type socket,socket_ops::state_type state,const ConstBufferSequence & buffers,socket_base::message_flags flags,func_type complete_func)39   reactive_socket_send_op_base(const boost::system::error_code& success_ec,
40       socket_type socket, socket_ops::state_type state,
41       const ConstBufferSequence& buffers,
42       socket_base::message_flags flags, func_type complete_func)
43     : reactor_op(success_ec,
44         &reactive_socket_send_op_base::do_perform, complete_func),
45       socket_(socket),
46       state_(state),
47       buffers_(buffers),
48       flags_(flags)
49   {
50   }
51 
do_perform(reactor_op * base)52   static status do_perform(reactor_op* base)
53   {
54     reactive_socket_send_op_base* o(
55         static_cast<reactive_socket_send_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_send1(o->socket_,
64           bufs_type::first(o->buffers_).data(),
65           bufs_type::first(o->buffers_).size(), o->flags_,
66           o->ec_, o->bytes_transferred_) ? done : not_done;
67 
68       if (result == done)
69         if ((o->state_ & socket_ops::stream_oriented) != 0)
70           if (o->bytes_transferred_ < bufs_type::first(o->buffers_).size())
71             result = done_and_exhausted;
72     }
73     else
74     {
75       bufs_type bufs(o->buffers_);
76       result = socket_ops::non_blocking_send(o->socket_,
77             bufs.buffers(), bufs.count(), o->flags_,
78             o->ec_, o->bytes_transferred_) ? done : not_done;
79 
80       if (result == done)
81         if ((o->state_ & socket_ops::stream_oriented) != 0)
82           if (o->bytes_transferred_ < bufs.total_size())
83             result = done_and_exhausted;
84     }
85 
86     BOOST_ASIO_HANDLER_REACTOR_OPERATION((*o, "non_blocking_send",
87           o->ec_, o->bytes_transferred_));
88 
89     return result;
90   }
91 
92 private:
93   socket_type socket_;
94   socket_ops::state_type state_;
95   ConstBufferSequence buffers_;
96   socket_base::message_flags flags_;
97 };
98 
99 template <typename ConstBufferSequence, typename Handler, typename IoExecutor>
100 class reactive_socket_send_op :
101   public reactive_socket_send_op_base<ConstBufferSequence>
102 {
103 public:
104   BOOST_ASIO_DEFINE_HANDLER_PTR(reactive_socket_send_op);
105 
reactive_socket_send_op(const boost::system::error_code & success_ec,socket_type socket,socket_ops::state_type state,const ConstBufferSequence & buffers,socket_base::message_flags flags,Handler & handler,const IoExecutor & io_ex)106   reactive_socket_send_op(const boost::system::error_code& success_ec,
107       socket_type socket, socket_ops::state_type state,
108       const ConstBufferSequence& buffers, socket_base::message_flags flags,
109       Handler& handler, const IoExecutor& io_ex)
110     : reactive_socket_send_op_base<ConstBufferSequence>(success_ec, socket,
111         state, buffers, flags, &reactive_socket_send_op::do_complete),
112       handler_(BOOST_ASIO_MOVE_CAST(Handler)(handler)),
113       work_(handler_, io_ex)
114   {
115   }
116 
do_complete(void * owner,operation * base,const boost::system::error_code &,std::size_t)117   static void do_complete(void* owner, operation* base,
118       const boost::system::error_code& /*ec*/,
119       std::size_t /*bytes_transferred*/)
120   {
121     // Take ownership of the handler object.
122     reactive_socket_send_op* o(static_cast<reactive_socket_send_op*>(base));
123     ptr p = { boost::asio::detail::addressof(o->handler_), o, o };
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::binder2<Handler, boost::system::error_code, std::size_t>
139       handler(o->handler_, o->ec_, o->bytes_transferred_);
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_, handler.arg2_));
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 } // namespace detail
159 } // namespace asio
160 } // namespace boost
161 
162 #include <boost/asio/detail/pop_options.hpp>
163 
164 #endif // BOOST_ASIO_DETAIL_REACTIVE_SOCKET_SEND_OP_HPP
165