ceph/src/boost/boost/asio/detail/posix_global.hpp

   1 //
   2 // detail/posix_global.hpp
   3 // ~~~~~~~~~~~~~~~~~~~~~~~
   4 //
   5 // Copyright (c) 2003-2017 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_DETAIL_POSIX_GLOBAL_HPP
  12 #define BOOST_ASIO_DETAIL_POSIX_GLOBAL_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_PTHREADS)
  21
  22 #include <exception>
  23 #include <pthread.h>
  24
  25 #include <boost/asio/detail/push_options.hpp>
  26
  27 namespace boost {
  28 namespace asio {
  29 namespace detail {
  30
  31 template <typename T>
  32 struct posix_global_impl
  33 {
  34   // Helper function to perform initialisation.
  35   static void do_init()
  36   {
  37     instance_.static_ptr_ = instance_.ptr_ = new T;
  38   }
  39
  40   // Destructor automatically cleans up the global.
  41   ~posix_global_impl()
  42   {
  43     delete static_ptr_;
  44   }
  45
  46   static ::pthread_once_t init_once_;
  47   static T* static_ptr_;
  48   static posix_global_impl instance_;
  49   T* ptr_;
  50 };
  51
  52 template <typename T>
  53 ::pthread_once_t posix_global_impl<T>::init_once_ = PTHREAD_ONCE_INIT;
  54
  55 template <typename T>
  56 T* posix_global_impl<T>::static_ptr_ = 0;
  57
  58 template <typename T>
  59 posix_global_impl<T> posix_global_impl<T>::instance_;
  60
  61 template <typename T>
  62 T& posix_global()
  63 {
  64   int result = ::pthread_once(
  65       &posix_global_impl<T>::init_once_,
  66       &posix_global_impl<T>::do_init);
  67
  68   if (result != 0)
  69     std::terminate();
  70
  71   return *posix_global_impl<T>::instance_.ptr_;
  72 }
  73
  74 } // namespace detail
  75 } // namespace asio
  76 } // namespace boost
  77
  78 #include <boost/asio/detail/pop_options.hpp>
  79
  80 #endif // defined(BOOST_ASIO_HAS_PTHREADS)
  81
  82 #endif // BOOST_ASIO_DETAIL_POSIX_GLOBAL_HPP