1 //
2 // detail/win_iocp_overlapped_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_WIN_IOCP_OVERLAPPED_OP_HPP
12 #define BOOST_ASIO_DETAIL_WIN_IOCP_OVERLAPPED_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 
20 #if defined(BOOST_ASIO_HAS_IOCP)
21 
22 #include <boost/asio/detail/bind_handler.hpp>
23 #include <boost/asio/detail/fenced_block.hpp>
24 #include <boost/asio/detail/handler_alloc_helpers.hpp>
25 #include <boost/asio/detail/handler_invoke_helpers.hpp>
26 #include <boost/asio/detail/handler_work.hpp>
27 #include <boost/asio/detail/memory.hpp>
28 #include <boost/asio/detail/operation.hpp>
29 #include <boost/asio/error.hpp>
30 
31 #include <boost/asio/detail/push_options.hpp>
32 
33 namespace boost {
34 namespace asio {
35 namespace detail {
36 
37 template <typename Handler, typename IoExecutor>
38 class win_iocp_overlapped_op : public operation
39 {
40 public:
41   BOOST_ASIO_DEFINE_HANDLER_PTR(win_iocp_overlapped_op);
42 
win_iocp_overlapped_op(Handler & handler,const IoExecutor & io_ex)43   win_iocp_overlapped_op(Handler& handler, const IoExecutor& io_ex)
44     : operation(&win_iocp_overlapped_op::do_complete),
45       handler_(BOOST_ASIO_MOVE_CAST(Handler)(handler)),
46       work_(handler_, io_ex)
47   {
48   }
49 
do_complete(void * owner,operation * base,const boost::system::error_code & ec,std::size_t bytes_transferred)50   static void do_complete(void* owner, operation* base,
51       const boost::system::error_code& ec, std::size_t bytes_transferred)
52   {
53     // Take ownership of the operation object.
54     win_iocp_overlapped_op* o(static_cast<win_iocp_overlapped_op*>(base));
55     ptr p = { boost::asio::detail::addressof(o->handler_), o, o };
56 
57     BOOST_ASIO_HANDLER_COMPLETION((*o));
58 
59     // Take ownership of the operation's outstanding work.
60     handler_work<Handler, IoExecutor> w(
61         BOOST_ASIO_MOVE_CAST2(handler_work<Handler, IoExecutor>)(
62           o->work_));
63 
64     // Make a copy of the handler so that the memory can be deallocated before
65     // the upcall is made. Even if we're not about to make an upcall, a
66     // sub-object of the handler may be the true owner of the memory associated
67     // with the handler. Consequently, a local copy of the handler is required
68     // to ensure that any owning sub-object remains valid until after we have
69     // deallocated the memory here.
70     detail::binder2<Handler, boost::system::error_code, std::size_t>
71       handler(o->handler_, ec, bytes_transferred);
72     p.h = boost::asio::detail::addressof(handler.handler_);
73     p.reset();
74 
75     // Make the upcall if required.
76     if (owner)
77     {
78       fenced_block b(fenced_block::half);
79       BOOST_ASIO_HANDLER_INVOCATION_BEGIN((handler.arg1_, handler.arg2_));
80       w.complete(handler, handler.handler_);
81       BOOST_ASIO_HANDLER_INVOCATION_END;
82     }
83   }
84 
85 private:
86   Handler handler_;
87   handler_work<Handler, IoExecutor> work_;
88 };
89 
90 } // namespace detail
91 } // namespace asio
92 } // namespace boost
93 
94 #include <boost/asio/detail/pop_options.hpp>
95 
96 #endif // defined(BOOST_ASIO_HAS_IOCP)
97 
98 #endif // BOOST_ASIO_DETAIL_WIN_IOCP_OVERLAPPED_OP_HPP
99