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Diffstat (limited to 'lib/asio/detail/winsock_init.hpp')
-rw-r--r-- | lib/asio/detail/winsock_init.hpp | 128 |
1 files changed, 128 insertions, 0 deletions
diff --git a/lib/asio/detail/winsock_init.hpp b/lib/asio/detail/winsock_init.hpp new file mode 100644 index 0000000..9094363 --- /dev/null +++ b/lib/asio/detail/winsock_init.hpp @@ -0,0 +1,128 @@ +// +// detail/winsock_init.hpp +// ~~~~~~~~~~~~~~~~~~~~~~~ +// +// Copyright (c) 2003-2018 Christopher M. Kohlhoff (chris at kohlhoff dot com) +// +// Distributed under the Boost Software License, Version 1.0. (See accompanying +// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) +// + +#ifndef ASIO_DETAIL_WINSOCK_INIT_HPP +#define ASIO_DETAIL_WINSOCK_INIT_HPP + +#if defined(_MSC_VER) && (_MSC_VER >= 1200) +# pragma once +#endif // defined(_MSC_VER) && (_MSC_VER >= 1200) + +#include "asio/detail/config.hpp" + +#if defined(ASIO_WINDOWS) || defined(__CYGWIN__) + +#include "asio/detail/push_options.hpp" + +namespace asio { +namespace detail { + +class winsock_init_base +{ +protected: + // Structure to track result of initialisation and number of uses. POD is used + // to ensure that the values are zero-initialised prior to any code being run. + struct data + { + long init_count_; + long result_; + }; + + ASIO_DECL static void startup(data& d, + unsigned char major, unsigned char minor); + + ASIO_DECL static void manual_startup(data& d); + + ASIO_DECL static void cleanup(data& d); + + ASIO_DECL static void manual_cleanup(data& d); + + ASIO_DECL static void throw_on_error(data& d); +}; + +template <int Major = 2, int Minor = 0> +class winsock_init : private winsock_init_base +{ +public: + winsock_init(bool allow_throw = true) + { + startup(data_, Major, Minor); + if (allow_throw) + throw_on_error(data_); + } + + winsock_init(const winsock_init&) + { + startup(data_, Major, Minor); + throw_on_error(data_); + } + + ~winsock_init() + { + cleanup(data_); + } + + // This class may be used to indicate that user code will manage Winsock + // initialisation and cleanup. This may be required in the case of a DLL, for + // example, where it is not safe to initialise Winsock from global object + // constructors. + // + // To prevent asio from initialising Winsock, the object must be constructed + // before any Asio's own global objects. With MSVC, this may be accomplished + // by adding the following code to the DLL: + // + // #pragma warning(push) + // #pragma warning(disable:4073) + // #pragma init_seg(lib) + // asio::detail::winsock_init<>::manual manual_winsock_init; + // #pragma warning(pop) + class manual + { + public: + manual() + { + manual_startup(data_); + } + + manual(const manual&) + { + manual_startup(data_); + } + + ~manual() + { + manual_cleanup(data_); + } + }; + +private: + friend class manual; + static data data_; +}; + +template <int Major, int Minor> +winsock_init_base::data winsock_init<Major, Minor>::data_; + +// Static variable to ensure that winsock is initialised before main, and +// therefore before any other threads can get started. +static const winsock_init<>& winsock_init_instance = winsock_init<>(false); + +} // namespace detail +} // namespace asio + +#include "asio/detail/pop_options.hpp" + +#if defined(ASIO_HEADER_ONLY) +# include "asio/detail/impl/winsock_init.ipp" +#endif // defined(ASIO_HEADER_ONLY) + +#endif // defined(ASIO_WINDOWS) || defined(__CYGWIN__) + +#endif // ASIO_DETAIL_WINSOCK_INIT_HPP |