1 //////////////////////////////////////////////////////////////////////////////
2 //
3 // (C) Copyright Ion Gaztanaga 2015-2015. Distributed under the Boost
4 // Software License, Version 1.0. (See accompanying file
5 // LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
6 //
7 // See http://www.boost.org/libs/container for documentation.
8 //
9 //////////////////////////////////////////////////////////////////////////////
10 
11 #ifndef BOOST_CONTAINER_DETAIL_BLOCK_LIST_HEADER
12 #define BOOST_CONTAINER_DETAIL_BLOCK_LIST_HEADER
13 
14 #ifndef BOOST_CONFIG_HPP
15 #  include <boost/config.hpp>
16 #endif
17 
18 #if defined(BOOST_HAS_PRAGMA_ONCE)
19 #  pragma once
20 #endif
21 
22 #include <boost/container/detail/config_begin.hpp>
23 #include <boost/container/detail/workaround.hpp>
24 #include <boost/container/container_fwd.hpp>
25 #include <boost/container/pmr/memory_resource.hpp>
26 #include <boost/container/throw_exception.hpp>
27 #include <boost/intrusive/circular_list_algorithms.hpp>
28 #include <boost/move/detail/type_traits.hpp>
29 #include <boost/assert.hpp>
30 #include <boost/container/detail/placement_new.hpp>
31 
32 #include <cstddef>
33 
34 namespace boost {
35 namespace container {
36 namespace pmr {
37 
38 struct list_node
39 {
40    list_node *next;
41    list_node *previous;
42 };
43 
44 struct list_node_traits
45 {
46    typedef list_node         node;
47    typedef list_node*        node_ptr;
48    typedef const list_node*  const_node_ptr;
49 
get_nextboost::container::pmr::list_node_traits50    static node_ptr get_next(const_node_ptr n)
51    {  return n->next;  }
52 
get_previousboost::container::pmr::list_node_traits53    static node_ptr get_previous(const_node_ptr n)
54    {  return n->previous;  }
55 
set_nextboost::container::pmr::list_node_traits56    static void set_next(const node_ptr & n, const node_ptr & next)
57    {  n->next = next;  }
58 
set_previousboost::container::pmr::list_node_traits59    static void set_previous(const node_ptr & n, const node_ptr & previous)
60    {  n->previous = previous;  }
61 };
62 
63 struct block_list_header
64    : public list_node
65 {
66    std::size_t size;
67 };
68 
69 typedef bi::circular_list_algorithms<list_node_traits> list_algo;
70 
71 
72 template<class DerivedFromBlockListHeader = block_list_header>
73 class block_list_base
74 {
75    list_node m_list;
76 
77    static const std::size_t MaxAlignMinus1 = memory_resource::max_align-1u;
78 
79    public:
80 
81    static const std::size_t header_size = std::size_t(sizeof(DerivedFromBlockListHeader) + MaxAlignMinus1) & std::size_t(~MaxAlignMinus1);
82 
block_list_base()83    explicit block_list_base()
84    {  list_algo::init_header(&m_list);  }
85 
86    #if !defined(BOOST_NO_CXX11_DELETED_FUNCTIONS) || defined(BOOST_CONTAINER_DOXYGEN_INVOKED)
87    block_list_base(const block_list_base&) = delete;
88    block_list_base operator=(const block_list_base&) = delete;
89    #else
90    private:
91    block_list_base          (const block_list_base&);
92    block_list_base operator=(const block_list_base&);
93    public:
94    #endif
95 
~block_list_base()96    ~block_list_base()
97    {}
98 
allocate(std::size_t size,memory_resource & mr)99    void *allocate(std::size_t size, memory_resource &mr)
100    {
101       if((size_t(-1) - header_size) < size)
102          throw_bad_alloc();
103       void *p = mr.allocate(size+header_size);
104       block_list_header &mb  = *::new((void*)p, boost_container_new_t()) DerivedFromBlockListHeader;
105       mb.size = size+header_size;
106       list_algo::link_after(&m_list, &mb);
107       return (char *)p + header_size;
108    }
109 
deallocate(void * p,memory_resource & mr)110    void deallocate(void *p, memory_resource &mr) BOOST_NOEXCEPT
111    {
112       DerivedFromBlockListHeader *pheader = static_cast<DerivedFromBlockListHeader*>
113          (static_cast<void*>((char*)p - header_size));
114       list_algo::unlink(pheader);
115       const std::size_t size = pheader->size;
116       static_cast<DerivedFromBlockListHeader*>(pheader)->~DerivedFromBlockListHeader();
117       mr.deallocate(pheader, size, memory_resource::max_align);
118    }
119 
release(memory_resource & mr)120    void release(memory_resource &mr) BOOST_NOEXCEPT
121    {
122       list_node *n = list_algo::node_traits::get_next(&m_list);
123       while(n != &m_list){
124          DerivedFromBlockListHeader &d = static_cast<DerivedFromBlockListHeader&>(*n);
125          n = list_algo::node_traits::get_next(n);
126          std::size_t size = d.size;
127          d.~DerivedFromBlockListHeader();
128          mr.deallocate(reinterpret_cast<char*>(&d), size, memory_resource::max_align);
129       }
130       list_algo::init_header(&m_list);
131    }
132 };
133 
134 }  //namespace pmr {
135 }  //namespace container {
136 }  //namespace boost {
137 
138 #include <boost/container/detail/config_end.hpp>
139 
140 #endif   //BOOST_CONTAINER_DETAIL_BLOCK_LIST_HEADER
141