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

   1 //
   2 // detail/recycling_allocator.hpp
   3 // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   4 //
   5 // Copyright (c) 2003-2019 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_RECYCLING_ALLOCATOR_HPP
  12 #define BOOST_ASIO_DETAIL_RECYCLING_ALLOCATOR_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 #include <boost/asio/detail/memory.hpp>
  20 #include <boost/asio/detail/thread_context.hpp>
  21 #include <boost/asio/detail/thread_info_base.hpp>
  22
  23 #include <boost/asio/detail/push_options.hpp>
  24
  25 namespace boost {
  26 namespace asio {
  27 namespace detail {
  28
  29 template <typename T, typename Purpose = thread_info_base::default_tag>
  30 class recycling_allocator
  31 {
  32 public:
  33   typedef T value_type;
  34
  35   template <typename U>
  36   struct rebind
  37   {
  38     typedef recycling_allocator<U, Purpose> other;
  39   };
  40
  41   recycling_allocator()
  42   {
  43   }
  44
  45   template <typename U>
  46   recycling_allocator(const recycling_allocator<U, Purpose>&)
  47   {
  48   }
  49
  50   T* allocate(std::size_t n)
  51   {
  52     typedef thread_context::thread_call_stack call_stack;
  53     void* p = thread_info_base::allocate(Purpose(),
  54         call_stack::top(), sizeof(T) * n);
  55     return static_cast<T*>(p);
  56   }
  57
  58   void deallocate(T* p, std::size_t n)
  59   {
  60     typedef thread_context::thread_call_stack call_stack;
  61     thread_info_base::deallocate(Purpose(),
  62         call_stack::top(), p, sizeof(T) * n);
  63   }
  64 };
  65
  66 template <typename Purpose>
  67 class recycling_allocator<void, Purpose>
  68 {
  69 public:
  70   typedef void value_type;
  71
  72   template <typename U>
  73   struct rebind
  74   {
  75     typedef recycling_allocator<U, Purpose> other;
  76   };
  77
  78   recycling_allocator()
  79   {
  80   }
  81
  82   template <typename U>
  83   recycling_allocator(const recycling_allocator<U, Purpose>&)
  84   {
  85   }
  86 };
  87
  88 template <typename Allocator, typename Purpose>
  89 struct get_recycling_allocator
  90 {
  91   typedef Allocator type;
  92   static type get(const Allocator& a) { return a; }
  93 };
  94
  95 template <typename T, typename Purpose>
  96 struct get_recycling_allocator<std::allocator<T>, Purpose>
  97 {
  98   typedef recycling_allocator<T, Purpose> type;
  99   static type get(const std::allocator<T>&) { return type(); }
 100 };
 101
 102 } // namespace detail
 103 } // namespace asio
 104 } // namespace boost
 105
 106 #include <boost/asio/detail/pop_options.hpp>
 107
 108 #endif // BOOST_ASIO_DETAIL_RECYCLING_ALLOCATOR_HPP