1//
2// windows/overlapped_ptr.hpp
3// ~~~~~~~~~~~~~~~~~~~~~~~~~~
4//
5// Copyright (c) 2003-2024 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_WINDOWS_OVERLAPPED_PTR_HPP
12#define BOOST_ASIO_WINDOWS_OVERLAPPED_PTR_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_WINDOWS_OVERLAPPED_PTR) \
21 || defined(GENERATING_DOCUMENTATION)
22
23#include <boost/asio/detail/noncopyable.hpp>
24#include <boost/asio/detail/win_iocp_overlapped_ptr.hpp>
25#include <boost/asio/io_context.hpp>
26
27#include <boost/asio/detail/push_options.hpp>
28
29namespace boost {
30namespace asio {
31namespace windows {
32
33/// Wraps a handler to create an OVERLAPPED object for use with overlapped I/O.
34/**
35 * A special-purpose smart pointer used to wrap an application handler so that
36 * it can be passed as the LPOVERLAPPED argument to overlapped I/O functions.
37 *
38 * @par Thread Safety
39 * @e Distinct @e objects: Safe.@n
40 * @e Shared @e objects: Unsafe.
41 */
42class overlapped_ptr
43 : private noncopyable
44{
45public:
46 /// Construct an empty overlapped_ptr.
47 overlapped_ptr()
48 : impl_()
49 {
50 }
51
52 /// Construct an overlapped_ptr to contain the specified handler.
53 template <typename ExecutionContext, typename Handler>
54 explicit overlapped_ptr(ExecutionContext& context,
55 Handler&& handler,
56 constraint_t<
57 is_convertible<ExecutionContext&, execution_context&>::value
58 > = 0)
59 : impl_(context.get_executor(), static_cast<Handler&&>(handler))
60 {
61 }
62
63 /// Construct an overlapped_ptr to contain the specified handler.
64 template <typename Executor, typename Handler>
65 explicit overlapped_ptr(const Executor& ex,
66 Handler&& handler,
67 constraint_t<
68 execution::is_executor<Executor>::value
69 || is_executor<Executor>::value
70 > = 0)
71 : impl_(ex, static_cast<Handler&&>(handler))
72 {
73 }
74
75 /// Destructor automatically frees the OVERLAPPED object unless released.
76 ~overlapped_ptr()
77 {
78 }
79
80 /// Reset to empty.
81 void reset()
82 {
83 impl_.reset();
84 }
85
86 /// Reset to contain the specified handler, freeing any current OVERLAPPED
87 /// object.
88 template <typename ExecutionContext, typename Handler>
89 void reset(ExecutionContext& context, Handler&& handler,
90 constraint_t<
91 is_convertible<ExecutionContext&, execution_context&>::value
92 > = 0)
93 {
94 impl_.reset(context.get_executor(), static_cast<Handler&&>(handler));
95 }
96
97 /// Reset to contain the specified handler, freeing any current OVERLAPPED
98 /// object.
99 template <typename Executor, typename Handler>
100 void reset(const Executor& ex, Handler&& handler,
101 constraint_t<
102 execution::is_executor<Executor>::value
103 || is_executor<Executor>::value
104 > = 0)
105 {
106 impl_.reset(ex, static_cast<Handler&&>(handler));
107 }
108
109 /// Get the contained OVERLAPPED object.
110 OVERLAPPED* get()
111 {
112 return impl_.get();
113 }
114
115 /// Get the contained OVERLAPPED object.
116 const OVERLAPPED* get() const
117 {
118 return impl_.get();
119 }
120
121 /// Release ownership of the OVERLAPPED object.
122 OVERLAPPED* release()
123 {
124 return impl_.release();
125 }
126
127 /// Post completion notification for overlapped operation. Releases ownership.
128 void complete(const boost::system::error_code& ec,
129 std::size_t bytes_transferred)
130 {
131 impl_.complete(ec, bytes_transferred);
132 }
133
134private:
135 detail::win_iocp_overlapped_ptr impl_;
136};
137
138} // namespace windows
139} // namespace asio
140} // namespace boost
141
142#include <boost/asio/detail/pop_options.hpp>
143
144#endif // defined(BOOST_ASIO_HAS_WINDOWS_OVERLAPPED_PTR)
145 // || defined(GENERATING_DOCUMENTATION)
146
147#endif // BOOST_ASIO_WINDOWS_OVERLAPPED_PTR_HPP
148

source code of boost/libs/asio/include/boost/asio/windows/overlapped_ptr.hpp