/Src/Dependencies/Boost/boost/asio/detail/reactive_null_buffers_op.hpp

 1//
 2// detail/reactive_null_buffers_op.hpp
 3// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 4//
 5// Copyright (c) 2003-2011 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/utility/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      boost::system::error_code /*ec*/, std::size_t /*bytes_transferred*/)
51  {
52    // Take ownership of the handler object.
53    reactive_null_buffers_op* o(static_cast<reactive_null_buffers_op*>(base));
54    ptr p = { boost::addressof(o->handler_), o, o };
55
56    BOOST_ASIO_HANDLER_COMPLETION((o));
57
58    // Make a copy of the handler so that the memory can be deallocated before
59    // the upcall is made. Even if we're not about to make an upcall, a
60    // sub-object of the handler may be the true owner of the memory associated
61    // with the handler. Consequently, a local copy of the handler is required
62    // to ensure that any owning sub-object remains valid until after we have
63    // deallocated the memory here.
64    detail::binder2<Handler, boost::system::error_code, std::size_t>
65      handler(o->handler_, o->ec_, o->bytes_transferred_);
66    p.h = boost::addressof(handler.handler_);
67    p.reset();
68
69    // Make the upcall if required.
70    if (owner)
71    {
72      boost::asio::detail::fenced_block b;
73      BOOST_ASIO_HANDLER_INVOCATION_BEGIN((handler.arg1_, handler.arg2_));
74      boost_asio_handler_invoke_helpers::invoke(handler, handler.handler_);
75      BOOST_ASIO_HANDLER_INVOCATION_END;
76    }
77  }
78
79private:
80  Handler handler_;
81};
82
83} // namespace detail
84} // namespace asio
85} // namespace boost
86
87#include <boost/asio/detail/pop_options.hpp>
88
89#endif // BOOST_ASIO_DETAIL_REACTIVE_NULL_BUFFERS_OP_HPP