2 // detail/posix_global.hpp
3 // ~~~~~~~~~~~~~~~~~~~~~~~
5 // Copyright (c) 2003-2019 Christopher M. Kohlhoff (chris at kohlhoff dot com)
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)
11 #ifndef BOOST_ASIO_DETAIL_POSIX_GLOBAL_HPP
12 #define BOOST_ASIO_DETAIL_POSIX_GLOBAL_HPP
14 #if defined(_MSC_VER) && (_MSC_VER >= 1200)
16 #endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
18 #include <boost/asio/detail/config.hpp>
20 #if defined(BOOST_ASIO_HAS_PTHREADS)
25 #include <boost/asio/detail/push_options.hpp>
32 struct posix_global_impl
34 // Helper function to perform initialisation.
37 instance_.static_ptr_ = instance_.ptr_ = new T;
40 // Destructor automatically cleans up the global.
46 static ::pthread_once_t init_once_;
47 static T* static_ptr_;
48 static posix_global_impl instance_;
53 ::pthread_once_t posix_global_impl<T>::init_once_ = PTHREAD_ONCE_INIT;
56 T* posix_global_impl<T>::static_ptr_ = 0;
59 posix_global_impl<T> posix_global_impl<T>::instance_;
64 int result = ::pthread_once(
65 &posix_global_impl<T>::init_once_,
66 &posix_global_impl<T>::do_init);
71 return *posix_global_impl<T>::instance_.ptr_;
78 #include <boost/asio/detail/pop_options.hpp>
80 #endif // defined(BOOST_ASIO_HAS_PTHREADS)
82 #endif // BOOST_ASIO_DETAIL_POSIX_GLOBAL_HPP