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1 /*
2  * Copyright (C) 2014 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #ifndef ART_LIBARTBASE_BASE_SCOPED_ARENA_CONTAINERS_H_
18 #define ART_LIBARTBASE_BASE_SCOPED_ARENA_CONTAINERS_H_
19 
20 #include <deque>
21 #include <forward_list>
22 #include <queue>
23 #include <set>
24 #include <type_traits>
25 #include <unordered_map>
26 #include <utility>
27 
28 #include "arena_containers.h"  // For ArenaAllocatorAdapterKind.
29 #include "dchecked_vector.h"
30 #include "hash_map.h"
31 #include "hash_set.h"
32 #include "safe_map.h"
33 #include "scoped_arena_allocator.h"
34 
35 namespace art {
36 
37 // Adapter for use of ScopedArenaAllocator in STL containers.
38 // Use ScopedArenaAllocator::Adapter() to create an adapter to pass to container constructors.
39 // For example,
40 //   void foo(ScopedArenaAllocator* allocator) {
41 //     ScopedArenaVector<int> foo_vector(allocator->Adapter(kArenaAllocMisc));
42 //     ScopedArenaSafeMap<int, int> foo_map(std::less<int>(), allocator->Adapter());
43 //     // Use foo_vector and foo_map...
44 //   }
45 template <typename T>
46 class ScopedArenaAllocatorAdapter;
47 
48 template <typename T>
49 using ScopedArenaDeque = std::deque<T, ScopedArenaAllocatorAdapter<T>>;
50 
51 template <typename T>
52 using ScopedArenaForwardList = std::forward_list<T, ScopedArenaAllocatorAdapter<T>>;
53 
54 template <typename T>
55 using ScopedArenaQueue = std::queue<T, ScopedArenaDeque<T>>;
56 
57 template <typename T>
58 using ScopedArenaVector = dchecked_vector<T, ScopedArenaAllocatorAdapter<T>>;
59 
60 template <typename T, typename Comparator = std::less<T>>
61 using ScopedArenaPriorityQueue = std::priority_queue<T, ScopedArenaVector<T>, Comparator>;
62 
63 template <typename T>
64 using ScopedArenaStdStack = std::stack<T, ScopedArenaDeque<T>>;
65 
66 template <typename T, typename Comparator = std::less<T>>
67 using ScopedArenaSet = std::set<T, Comparator, ScopedArenaAllocatorAdapter<T>>;
68 
69 template <typename K, typename V, typename Comparator = std::less<K>>
70 using ScopedArenaSafeMap =
71     SafeMap<K, V, Comparator, ScopedArenaAllocatorAdapter<std::pair<const K, V>>>;
72 
73 template <typename T,
74           typename EmptyFn = DefaultEmptyFn<T>,
75           typename HashFn = DefaultHashFn<T>,
76           typename Pred = DefaultPred<T>>
77 using ScopedArenaHashSet = HashSet<T, EmptyFn, HashFn, Pred, ScopedArenaAllocatorAdapter<T>>;
78 
79 template <typename Key,
80           typename Value,
81           typename EmptyFn = DefaultMapEmptyFn<Key, Value>,
82           typename HashFn = DefaultHashFn<Key>,
83           typename Pred = DefaultPred<Key>>
84 using ScopedArenaHashMap = HashMap<Key,
85                                    Value,
86                                    EmptyFn,
87                                    HashFn,
88                                    Pred,
89                                    ScopedArenaAllocatorAdapter<std::pair<Key, Value>>>;
90 
91 template <typename K, typename V, class Hash = std::hash<K>, class KeyEqual = std::equal_to<K>>
92 using ScopedArenaUnorderedMap =
93     std::unordered_map<K, V, Hash, KeyEqual, ScopedArenaAllocatorAdapter<std::pair<const K, V>>>;
94 
95 template <typename K, typename V, class Hash = std::hash<K>, class KeyEqual = std::equal_to<K>>
96 using ScopedArenaUnorderedMultimap =
97     std::unordered_multimap<K,
98                             V,
99                             Hash,
100                             KeyEqual,
101                             ScopedArenaAllocatorAdapter<std::pair<const K, V>>>;
102 
103 // Implementation details below.
104 
105 template <>
106 class ScopedArenaAllocatorAdapter<void>
107     : private DebugStackReference, private DebugStackIndirectTopRef,
108       private ArenaAllocatorAdapterKind {
109  public:
110   using value_type    = void;
111   using pointer       = void*;
112   using const_pointer = const void*;
113 
114   template <typename U>
115   struct rebind {
116     using other = ScopedArenaAllocatorAdapter<U>;
117   };
118 
119   explicit ScopedArenaAllocatorAdapter(ScopedArenaAllocator* allocator,
120                                        ArenaAllocKind kind = kArenaAllocSTL)
DebugStackReference(allocator)121       : DebugStackReference(allocator),
122         DebugStackIndirectTopRef(allocator),
123         ArenaAllocatorAdapterKind(kind),
124         arena_stack_(allocator->arena_stack_) {
125   }
126   template <typename U>
ScopedArenaAllocatorAdapter(const ScopedArenaAllocatorAdapter<U> & other)127   ScopedArenaAllocatorAdapter(const ScopedArenaAllocatorAdapter<U>& other)
128       : DebugStackReference(other),
129         DebugStackIndirectTopRef(other),
130         ArenaAllocatorAdapterKind(other),
131         arena_stack_(other.arena_stack_) {
132   }
133   ScopedArenaAllocatorAdapter(const ScopedArenaAllocatorAdapter&) = default;
134   ScopedArenaAllocatorAdapter& operator=(const ScopedArenaAllocatorAdapter&) = default;
135   ~ScopedArenaAllocatorAdapter() = default;
136 
137  private:
138   ArenaStack* arena_stack_;
139 
140   template <typename U>
141   friend class ScopedArenaAllocatorAdapter;
142 };
143 
144 template <typename T>
145 class ScopedArenaAllocatorAdapter
146     : private DebugStackReference, private DebugStackIndirectTopRef,
147       private ArenaAllocatorAdapterKind {
148  public:
149   using value_type      = T;
150   using pointer         = T*;
151   using reference       = T&;
152   using const_pointer   = const T*;
153   using const_reference = const T&;
154   using size_type       = size_t;
155   using difference_type = ptrdiff_t;
156 
157   template <typename U>
158   struct rebind {
159     using other = ScopedArenaAllocatorAdapter<U>;
160   };
161 
162   explicit ScopedArenaAllocatorAdapter(ScopedArenaAllocator* allocator,
163                                        ArenaAllocKind kind = kArenaAllocSTL)
DebugStackReference(allocator)164       : DebugStackReference(allocator),
165         DebugStackIndirectTopRef(allocator),
166         ArenaAllocatorAdapterKind(kind),
167         arena_stack_(allocator->arena_stack_) {
168   }
169   template <typename U>
ScopedArenaAllocatorAdapter(const ScopedArenaAllocatorAdapter<U> & other)170   ScopedArenaAllocatorAdapter(const ScopedArenaAllocatorAdapter<U>& other)
171       : DebugStackReference(other),
172         DebugStackIndirectTopRef(other),
173         ArenaAllocatorAdapterKind(other),
174         arena_stack_(other.arena_stack_) {
175   }
176   ScopedArenaAllocatorAdapter(const ScopedArenaAllocatorAdapter&) = default;
177   ScopedArenaAllocatorAdapter& operator=(const ScopedArenaAllocatorAdapter&) = default;
178   ~ScopedArenaAllocatorAdapter() = default;
179 
max_size()180   size_type max_size() const {
181     return static_cast<size_type>(-1) / sizeof(T);
182   }
183 
address(reference x)184   pointer address(reference x) const { return &x; }
address(const_reference x)185   const_pointer address(const_reference x) const { return &x; }
186 
187   pointer allocate(size_type n,
188                    ScopedArenaAllocatorAdapter<void>::pointer hint ATTRIBUTE_UNUSED = nullptr) {
189     DCHECK_LE(n, max_size());
190     DebugStackIndirectTopRef::CheckTop();
191     return reinterpret_cast<T*>(arena_stack_->Alloc(n * sizeof(T),
192                                                     ArenaAllocatorAdapterKind::Kind()));
193   }
deallocate(pointer p,size_type n)194   void deallocate(pointer p, size_type n) {
195     DebugStackIndirectTopRef::CheckTop();
196     arena_stack_->MakeInaccessible(p, sizeof(T) * n);
197   }
198 
199   template <typename U, typename... Args>
construct(U * p,Args &&...args)200   void construct(U* p, Args&&... args) {
201     // Don't CheckTop(), allow reusing existing capacity of a vector/deque below the top.
202     ::new (static_cast<void*>(p)) U(std::forward<Args>(args)...);
203   }
204   template <typename U>
destroy(U * p)205   void destroy(U* p) {
206     // Don't CheckTop(), allow reusing existing capacity of a vector/deque below the top.
207     p->~U();
208   }
209 
210  private:
211   ArenaStack* arena_stack_;
212 
213   template <typename U>
214   friend class ScopedArenaAllocatorAdapter;
215 
216   template <typename U>
217   friend bool operator==(const ScopedArenaAllocatorAdapter<U>& lhs,
218                          const ScopedArenaAllocatorAdapter<U>& rhs);
219 };
220 
221 template <typename T>
222 inline bool operator==(const ScopedArenaAllocatorAdapter<T>& lhs,
223                        const ScopedArenaAllocatorAdapter<T>& rhs) {
224   return lhs.arena_stack_ == rhs.arena_stack_;
225 }
226 
227 template <typename T>
228 inline bool operator!=(const ScopedArenaAllocatorAdapter<T>& lhs,
229                        const ScopedArenaAllocatorAdapter<T>& rhs) {
230   return !(lhs == rhs);
231 }
232 
Adapter(ArenaAllocKind kind)233 inline ScopedArenaAllocatorAdapter<void> ScopedArenaAllocator::Adapter(ArenaAllocKind kind) {
234   return ScopedArenaAllocatorAdapter<void>(this, kind);
235 }
236 
237 // Special deleter that only calls the destructor. Also checks for double free errors.
238 template <typename T>
239 class ArenaDelete {
240   static constexpr uint8_t kMagicFill = 0xCE;
241 
242  protected:
243   // Used for variable sized objects such as RegisterLine.
ProtectMemory(T * ptr,size_t size)244   ALWAYS_INLINE void ProtectMemory(T* ptr, size_t size) const {
245     if (kRunningOnMemoryTool) {
246       // Writing to the memory will fail ift we already destroyed the pointer with
247       // DestroyOnlyDelete since we make it no access.
248       memset(ptr, kMagicFill, size);
249       MEMORY_TOOL_MAKE_NOACCESS(ptr, size);
250     } else if (kIsDebugBuild) {
251       CHECK(ArenaStack::ArenaTagForAllocation(reinterpret_cast<void*>(ptr)) == ArenaFreeTag::kUsed)
252           << "Freeing invalid object " << ptr;
253       ArenaStack::ArenaTagForAllocation(reinterpret_cast<void*>(ptr)) = ArenaFreeTag::kFree;
254       // Write a magic value to try and catch use after free error.
255       memset(ptr, kMagicFill, size);
256     }
257   }
258 
259  public:
operator()260   void operator()(T* ptr) const {
261     if (ptr != nullptr) {
262       ptr->~T();
263       ProtectMemory(ptr, sizeof(T));
264     }
265   }
266 };
267 
268 // In general we lack support for arrays. We would need to call the destructor on each element,
269 // which requires access to the array size. Support for that is future work.
270 //
271 // However, we can support trivially destructible component types, as then a destructor doesn't
272 // need to be called.
273 template <typename T>
274 class ArenaDelete<T[]> {
275  public:
operator()276   void operator()(T* ptr ATTRIBUTE_UNUSED) const {
277     static_assert(std::is_trivially_destructible_v<T>,
278                   "ArenaUniquePtr does not support non-trivially-destructible arrays.");
279     // TODO: Implement debug checks, and MEMORY_TOOL support.
280   }
281 };
282 
283 // Arena unique ptr that only calls the destructor of the element.
284 template <typename T>
285 using ArenaUniquePtr = std::unique_ptr<T, ArenaDelete<T>>;
286 
287 }  // namespace art
288 
289 #endif  // ART_LIBARTBASE_BASE_SCOPED_ARENA_CONTAINERS_H_
290