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1 | // |
2 | // detail/winsock_init.hpp | |
3 | // ~~~~~~~~~~~~~~~~~~~~~~~ | |
4 | // | |
1e59de90 | 5 | // Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com) |
7c673cae FG |
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_WINSOCK_INIT_HPP | |
12 | #define BOOST_ASIO_DETAIL_WINSOCK_INIT_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_WINDOWS) || defined(__CYGWIN__) | |
21 | ||
22 | #include <boost/asio/detail/push_options.hpp> | |
23 | ||
24 | namespace boost { | |
25 | namespace asio { | |
26 | namespace detail { | |
27 | ||
28 | class winsock_init_base | |
29 | { | |
30 | protected: | |
31 | // Structure to track result of initialisation and number of uses. POD is used | |
32 | // to ensure that the values are zero-initialised prior to any code being run. | |
33 | struct data | |
34 | { | |
35 | long init_count_; | |
36 | long result_; | |
37 | }; | |
38 | ||
39 | BOOST_ASIO_DECL static void startup(data& d, | |
40 | unsigned char major, unsigned char minor); | |
41 | ||
42 | BOOST_ASIO_DECL static void manual_startup(data& d); | |
43 | ||
44 | BOOST_ASIO_DECL static void cleanup(data& d); | |
45 | ||
46 | BOOST_ASIO_DECL static void manual_cleanup(data& d); | |
47 | ||
48 | BOOST_ASIO_DECL static void throw_on_error(data& d); | |
49 | }; | |
50 | ||
51 | template <int Major = 2, int Minor = 0> | |
52 | class winsock_init : private winsock_init_base | |
53 | { | |
54 | public: | |
55 | winsock_init(bool allow_throw = true) | |
56 | { | |
57 | startup(data_, Major, Minor); | |
58 | if (allow_throw) | |
59 | throw_on_error(data_); | |
60 | } | |
61 | ||
62 | winsock_init(const winsock_init&) | |
63 | { | |
64 | startup(data_, Major, Minor); | |
65 | throw_on_error(data_); | |
66 | } | |
67 | ||
68 | ~winsock_init() | |
69 | { | |
70 | cleanup(data_); | |
71 | } | |
72 | ||
73 | // This class may be used to indicate that user code will manage Winsock | |
74 | // initialisation and cleanup. This may be required in the case of a DLL, for | |
75 | // example, where it is not safe to initialise Winsock from global object | |
76 | // constructors. | |
77 | // | |
78 | // To prevent asio from initialising Winsock, the object must be constructed | |
79 | // before any Asio's own global objects. With MSVC, this may be accomplished | |
80 | // by adding the following code to the DLL: | |
81 | // | |
82 | // #pragma warning(push) | |
83 | // #pragma warning(disable:4073) | |
84 | // #pragma init_seg(lib) | |
85 | // boost::asio::detail::winsock_init<>::manual manual_winsock_init; | |
86 | // #pragma warning(pop) | |
87 | class manual | |
88 | { | |
89 | public: | |
90 | manual() | |
91 | { | |
92 | manual_startup(data_); | |
93 | } | |
94 | ||
95 | manual(const manual&) | |
96 | { | |
97 | manual_startup(data_); | |
98 | } | |
99 | ||
100 | ~manual() | |
101 | { | |
102 | manual_cleanup(data_); | |
103 | } | |
104 | }; | |
105 | ||
106 | private: | |
107 | friend class manual; | |
108 | static data data_; | |
109 | }; | |
110 | ||
111 | template <int Major, int Minor> | |
112 | winsock_init_base::data winsock_init<Major, Minor>::data_; | |
113 | ||
114 | // Static variable to ensure that winsock is initialised before main, and | |
115 | // therefore before any other threads can get started. | |
116 | static const winsock_init<>& winsock_init_instance = winsock_init<>(false); | |
117 | ||
118 | } // namespace detail | |
119 | } // namespace asio | |
120 | } // namespace boost | |
121 | ||
122 | #include <boost/asio/detail/pop_options.hpp> | |
123 | ||
124 | #if defined(BOOST_ASIO_HEADER_ONLY) | |
125 | # include <boost/asio/detail/impl/winsock_init.ipp> | |
126 | #endif // defined(BOOST_ASIO_HEADER_ONLY) | |
127 | ||
128 | #endif // defined(BOOST_ASIO_WINDOWS) || defined(__CYGWIN__) | |
129 | ||
130 | #endif // BOOST_ASIO_DETAIL_WINSOCK_INIT_HPP |