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 #define BOOST_CONTAINER_SOURCE
12 #include <boost/container/detail/config_begin.hpp>
13 #include <boost/container/detail/workaround.hpp>
14
15 #include <boost/container/pmr/monotonic_buffer_resource.hpp>
16 #include <boost/container/pmr/global_resource.hpp>
17
18 #include <boost/container/detail/min_max.hpp>
19 #include <boost/intrusive/detail/math.hpp>
20 #include <boost/container/throw_exception.hpp>
21 #include <new>
22
23
24 #include <cstddef>
25
26 namespace {
27
28 #ifdef BOOST_HAS_INTPTR_T
29 typedef boost::uintptr_t uintptr_type;
30 #else
31 typedef std::size_t uintptr_type;
32 #endif
33
34 static const std::size_t minimum_buffer_size = 2*sizeof(void*);
35
36 } //namespace {
37
38 namespace boost {
39 namespace container {
40 namespace pmr {
41
increase_next_buffer()42 void monotonic_buffer_resource::increase_next_buffer()
43 {
44 m_next_buffer_size = (std::size_t(-1)/2 < m_next_buffer_size) ? std::size_t(-1) : m_next_buffer_size*2;
45 }
46
increase_next_buffer_at_least_to(std::size_t minimum_size)47 void monotonic_buffer_resource::increase_next_buffer_at_least_to(std::size_t minimum_size)
48 {
49 if(m_next_buffer_size < minimum_size){
50 if(bi::detail::is_pow2(minimum_size)){
51 m_next_buffer_size = minimum_size;
52 }
53 else if(std::size_t(-1)/2 < minimum_size){
54 m_next_buffer_size = minimum_size;
55 }
56 else{
57 m_next_buffer_size = bi::detail::ceil_pow2(minimum_size);
58 }
59 }
60 }
61
monotonic_buffer_resource(memory_resource * upstream)62 monotonic_buffer_resource::monotonic_buffer_resource(memory_resource* upstream) BOOST_NOEXCEPT
63 : m_memory_blocks(upstream ? *upstream : *get_default_resource())
64 , m_current_buffer(0)
65 , m_current_buffer_size(0u)
66 , m_next_buffer_size(initial_next_buffer_size)
67 , m_initial_buffer(0)
68 , m_initial_buffer_size(0u)
69 {}
70
monotonic_buffer_resource(std::size_t initial_size,memory_resource * upstream)71 monotonic_buffer_resource::monotonic_buffer_resource(std::size_t initial_size, memory_resource* upstream) BOOST_NOEXCEPT
72 : m_memory_blocks(upstream ? *upstream : *get_default_resource())
73 , m_current_buffer(0)
74 , m_current_buffer_size(0u)
75 , m_next_buffer_size(minimum_buffer_size)
76 , m_initial_buffer(0)
77 , m_initial_buffer_size(0u)
78 { //In case initial_size is zero
79 this->increase_next_buffer_at_least_to(initial_size + !initial_size);
80 }
81
monotonic_buffer_resource(void * buffer,std::size_t buffer_size,memory_resource * upstream)82 monotonic_buffer_resource::monotonic_buffer_resource(void* buffer, std::size_t buffer_size, memory_resource* upstream) BOOST_NOEXCEPT
83 : m_memory_blocks(upstream ? *upstream : *get_default_resource())
84 , m_current_buffer(buffer)
85 , m_current_buffer_size(buffer_size)
86 , m_next_buffer_size
87 (bi::detail::previous_or_equal_pow2
88 (boost::container::dtl::max_value(buffer_size, std::size_t(initial_next_buffer_size))))
89 , m_initial_buffer(buffer)
90 , m_initial_buffer_size(buffer_size)
91 { this->increase_next_buffer(); }
92
~monotonic_buffer_resource()93 monotonic_buffer_resource::~monotonic_buffer_resource()
94 { this->release(); }
95
release()96 void monotonic_buffer_resource::release() BOOST_NOEXCEPT
97 {
98 m_memory_blocks.release();
99 m_current_buffer = m_initial_buffer;
100 m_current_buffer_size = m_initial_buffer_size;
101 m_next_buffer_size = initial_next_buffer_size;
102 }
103
upstream_resource() const104 memory_resource* monotonic_buffer_resource::upstream_resource() const BOOST_NOEXCEPT
105 { return &m_memory_blocks.upstream_resource(); }
106
remaining_storage(std::size_t alignment,std::size_t & wasted_due_to_alignment) const107 std::size_t monotonic_buffer_resource::remaining_storage(std::size_t alignment, std::size_t &wasted_due_to_alignment) const BOOST_NOEXCEPT
108 {
109 const uintptr_type up_alignment_minus1 = alignment - 1u;
110 const uintptr_type up_alignment_mask = ~up_alignment_minus1;
111 const uintptr_type up_addr = uintptr_type(m_current_buffer);
112 const uintptr_type up_aligned_addr = (up_addr + up_alignment_minus1) & up_alignment_mask;
113 wasted_due_to_alignment = std::size_t(up_aligned_addr - up_addr);
114 return m_current_buffer_size <= wasted_due_to_alignment ? 0u : m_current_buffer_size - wasted_due_to_alignment;
115 }
116
remaining_storage(std::size_t alignment) const117 std::size_t monotonic_buffer_resource::remaining_storage(std::size_t alignment) const BOOST_NOEXCEPT
118 {
119 std::size_t ignore_this;
120 return this->remaining_storage(alignment, ignore_this);
121 }
122
current_buffer() const123 const void *monotonic_buffer_resource::current_buffer() const BOOST_NOEXCEPT
124 { return m_current_buffer; }
125
next_buffer_size() const126 std::size_t monotonic_buffer_resource::next_buffer_size() const BOOST_NOEXCEPT
127 { return m_next_buffer_size; }
128
allocate_from_current(std::size_t aligner,std::size_t bytes)129 void *monotonic_buffer_resource::allocate_from_current(std::size_t aligner, std::size_t bytes)
130 {
131 char * p = (char*)m_current_buffer + aligner;
132 m_current_buffer = p + bytes;
133 m_current_buffer_size -= aligner + bytes;
134 return p;
135 }
136
do_allocate(std::size_t bytes,std::size_t alignment)137 void* monotonic_buffer_resource::do_allocate(std::size_t bytes, std::size_t alignment)
138 {
139 if(alignment > memory_resource::max_align){
140 (void)bytes; (void)alignment;
141 #if defined(BOOST_CONTAINER_USER_DEFINED_THROW_CALLBACKS) || defined(BOOST_NO_EXCEPTIONS)
142 throw_bad_alloc();
143 #else
144 throw std::bad_alloc();
145 #endif
146 }
147
148 //See if there is room in current buffer
149 std::size_t aligner = 0u;
150 if(this->remaining_storage(alignment, aligner) < bytes){
151 //The new buffer will be aligned to the strictest alignment so reset
152 //the aligner, which was needed for the old buffer.
153 aligner = 0u;
154 //Update next_buffer_size to at least bytes
155 this->increase_next_buffer_at_least_to(bytes);
156 //Now allocate and update internal data
157 m_current_buffer = (char*)m_memory_blocks.allocate(m_next_buffer_size);
158 m_current_buffer_size = m_next_buffer_size;
159 this->increase_next_buffer();
160 }
161 //Enough internal storage, extract from it
162 return this->allocate_from_current(aligner, bytes);
163 }
164
do_deallocate(void * p,std::size_t bytes,std::size_t alignment)165 void monotonic_buffer_resource::do_deallocate(void* p, std::size_t bytes, std::size_t alignment) BOOST_NOEXCEPT
166 { (void)p; (void)bytes; (void)alignment; }
167
do_is_equal(const memory_resource & other) const168 bool monotonic_buffer_resource::do_is_equal(const memory_resource& other) const BOOST_NOEXCEPT
169 { return this == dynamic_cast<const monotonic_buffer_resource*>(&other); }
170
171 } //namespace pmr {
172 } //namespace container {
173 } //namespace boost {
174
175 #include <boost/container/detail/config_end.hpp>
176