1//
2// detail/reactive_null_buffers_op.hpp
3// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
4//
5// Copyright (c) 2003-2015 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_NULL_BUFFERS_OP_HPP
12#define BOOST_ASIO_DETAIL_REACTIVE_NULL_BUFFERS_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/addressof.hpp>
20#include <boost/asio/detail/fenced_block.hpp>
21#include <boost/asio/detail/handler_alloc_helpers.hpp>
22#include <boost/asio/detail/handler_invoke_helpers.hpp>
23#include <boost/asio/detail/reactor_op.hpp>
24
25#include <boost/asio/detail/push_options.hpp>
26
27namespace boost {
28namespace asio {
29namespace detail {
30
31template <typename Handler>
32class reactive_null_buffers_op : public reactor_op
33{
34public:
35 BOOST_ASIO_DEFINE_HANDLER_PTR(reactive_null_buffers_op);
36
37 reactive_null_buffers_op(Handler& handler)
38 : reactor_op(&reactive_null_buffers_op::do_perform,
39 &reactive_null_buffers_op::do_complete),
40 handler_(BOOST_ASIO_MOVE_CAST(Handler)(handler))
41 {
42 }
43
44 static bool do_perform(reactor_op*)
45 {
46 return true;
47 }
48
49 static void do_complete(io_service_impl* owner, operation* base,
50 const boost::system::error_code& /*ec*/,
51 std::size_t /*bytes_transferred*/)
52 {
53 // Take ownership of the handler object.
54 reactive_null_buffers_op* o(static_cast<reactive_null_buffers_op*>(base));
55 ptr p = { boost::asio::detail::addressof(o->handler_), o, o };
56
57 BOOST_ASIO_HANDLER_COMPLETION((o));
58
59 // Make a copy of the handler so that the memory can be deallocated before
60 // the upcall is made. Even if we're not about to make an upcall, a
61 // sub-object of the handler may be the true owner of the memory associated
62 // with the handler. Consequently, a local copy of the handler is required
63 // to ensure that any owning sub-object remains valid until after we have
64 // deallocated the memory here.
65 detail::binder2<Handler, boost::system::error_code, std::size_t>
66 handler(o->handler_, o->ec_, o->bytes_transferred_);
67 p.h = boost::asio::detail::addressof(handler.handler_);
68 p.reset();
69
70 // Make the upcall if required.
71 if (owner)
72 {
73 fenced_block b(fenced_block::half);
74 BOOST_ASIO_HANDLER_INVOCATION_BEGIN((handler.arg1_, handler.arg2_));
75 boost_asio_handler_invoke_helpers::invoke(handler, handler.handler_);
76 BOOST_ASIO_HANDLER_INVOCATION_END;
77 }
78 }
79
80private:
81 Handler handler_;
82};
83
84} // namespace detail
85} // namespace asio
86} // namespace boost
87
88#include <boost/asio/detail/pop_options.hpp>
89
90#endif // BOOST_ASIO_DETAIL_REACTIVE_NULL_BUFFERS_OP_HPP
91

source code of boost/boost/asio/detail/reactive_null_buffers_op.hpp