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author | DongHun Kwak <dh0128.kwak@samsung.com> | 2019-12-05 15:11:01 +0900 |
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committer | DongHun Kwak <dh0128.kwak@samsung.com> | 2019-12-05 15:11:01 +0900 |
commit | 3fdc3e5ee96dca5b11d1694975a65200787eab86 (patch) | |
tree | 5c1733853892b8397d67706fa453a9bd978d2102 /boost/asio/detail/std_global.hpp | |
parent | 88e602c57797660ebe0f9e15dbd64c1ff16dead3 (diff) | |
download | boost-3fdc3e5ee96dca5b11d1694975a65200787eab86.tar.gz boost-3fdc3e5ee96dca5b11d1694975a65200787eab86.tar.bz2 boost-3fdc3e5ee96dca5b11d1694975a65200787eab86.zip |
Imported Upstream version 1.66.0upstream/1.66.0
Diffstat (limited to 'boost/asio/detail/std_global.hpp')
-rw-r--r-- | boost/asio/detail/std_global.hpp | 72 |
1 files changed, 72 insertions, 0 deletions
diff --git a/boost/asio/detail/std_global.hpp b/boost/asio/detail/std_global.hpp new file mode 100644 index 0000000000..f0936e5ea9 --- /dev/null +++ b/boost/asio/detail/std_global.hpp @@ -0,0 +1,72 @@ +// +// detail/std_global.hpp +// ~~~~~~~~~~~~~~~~~~~~~ +// +// Copyright (c) 2003-2017 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 BOOST_ASIO_DETAIL_STD_GLOBAL_HPP +#define BOOST_ASIO_DETAIL_STD_GLOBAL_HPP + +#if defined(_MSC_VER) && (_MSC_VER >= 1200) +# pragma once +#endif // defined(_MSC_VER) && (_MSC_VER >= 1200) + +#include <boost/asio/detail/config.hpp> + +#if defined(BOOST_ASIO_HAS_STD_CALL_ONCE) + +#include <exception> +#include <mutex> + +#include <boost/asio/detail/push_options.hpp> + +namespace boost { +namespace asio { +namespace detail { + +template <typename T> +struct std_global_impl +{ + // Helper function to perform initialisation. + static void do_init() + { + instance_.ptr_ = new T; + } + + // Destructor automatically cleans up the global. + ~std_global_impl() + { + delete ptr_; + } + + static std::once_flag init_once_; + static std_global_impl instance_; + T* ptr_; +}; + +template <typename T> +std::once_flag std_global_impl<T>::init_once_; + +template <typename T> +std_global_impl<T> std_global_impl<T>::instance_; + +template <typename T> +T& std_global() +{ + std::call_once(std_global_impl<T>::init_once_, &std_global_impl<T>::do_init); + return *std_global_impl<T>::instance_.ptr_; +} + +} // namespace detail +} // namespace asio +} // namespace boost + +#include <boost/asio/detail/pop_options.hpp> + +#endif // defined(BOOST_ASIO_HAS_STD_CALL_ONCE) + +#endif // BOOST_ASIO_DETAIL_STD_GLOBAL_HPP |