1 /*
2 * Copyright (C) 2013 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_ALLOCATOR_H_
18 #define ART_LIBARTBASE_BASE_ALLOCATOR_H_
19
20 #include <type_traits>
21
22 #include "atomic.h"
23 #include "macros.h"
24
25 namespace art {
26
27 static constexpr bool kEnableTrackingAllocator = false;
28
29 class Allocator {
30 public:
31 static Allocator* GetMallocAllocator();
32 static Allocator* GetNoopAllocator();
33
Allocator()34 Allocator() {}
~Allocator()35 virtual ~Allocator() {}
36
37 virtual void* Alloc(size_t) = 0;
38 virtual void Free(void*) = 0;
39
40 private:
41 DISALLOW_COPY_AND_ASSIGN(Allocator);
42 };
43
44 // Used by TrackedAllocators.
45 enum AllocatorTag {
46 kAllocatorTagHeap,
47 kAllocatorTagMonitorList,
48 kAllocatorTagClassTable,
49 kAllocatorTagInternTable,
50 kAllocatorTagMaps,
51 kAllocatorTagLOS,
52 kAllocatorTagSafeMap,
53 kAllocatorTagLOSMaps,
54 kAllocatorTagReferenceTable,
55 kAllocatorTagHeapBitmap,
56 kAllocatorTagHeapBitmapLOS,
57 kAllocatorTagMonitorPool,
58 kAllocatorTagLOSFreeList,
59 kAllocatorTagVerifier,
60 kAllocatorTagRememberedSet,
61 kAllocatorTagModUnionCardSet,
62 kAllocatorTagModUnionReferenceArray,
63 kAllocatorTagJNILibraries,
64 kAllocatorTagCompileTimeClassPath,
65 kAllocatorTagOatFile,
66 kAllocatorTagDexFileVerifier,
67 kAllocatorTagRosAlloc,
68 kAllocatorTagCount, // Must always be last element.
69 };
70 std::ostream& operator<<(std::ostream& os, AllocatorTag tag);
71
72 namespace TrackedAllocators {
73
74 // We use memory_order_relaxed updates of the following counters. Values are treated as approximate
75 // wherever concurrent updates are possible.
76 // Running count of number of bytes used for this kind of allocation. Increased by allocations,
77 // decreased by deallocations.
78 extern Atomic<size_t> g_bytes_used[kAllocatorTagCount];
79
80 // Largest value of bytes used seen.
81 extern Atomic<size_t> g_max_bytes_used[kAllocatorTagCount];
82
83 // Total number of bytes allocated of this kind.
84 extern Atomic<uint64_t> g_total_bytes_used[kAllocatorTagCount];
85
86 void Dump(std::ostream& os);
87
RegisterAllocation(AllocatorTag tag,size_t bytes)88 inline void RegisterAllocation(AllocatorTag tag, size_t bytes) {
89 g_total_bytes_used[tag].fetch_add(bytes, std::memory_order_relaxed);
90 size_t new_bytes = g_bytes_used[tag].fetch_add(bytes, std::memory_order_relaxed) + bytes;
91 size_t max_bytes = g_max_bytes_used[tag].load(std::memory_order_relaxed);
92 while (max_bytes < new_bytes
93 && !g_max_bytes_used[tag].compare_exchange_weak(max_bytes /* updated */, new_bytes,
94 std::memory_order_relaxed)) {
95 }
96 }
97
RegisterFree(AllocatorTag tag,size_t bytes)98 inline void RegisterFree(AllocatorTag tag, size_t bytes) {
99 g_bytes_used[tag].fetch_sub(bytes, std::memory_order_relaxed);
100 }
101
102 } // namespace TrackedAllocators
103
104 // Tracking allocator for use with STL types, tracks how much memory is used.
105 template<class T, AllocatorTag kTag>
106 class TrackingAllocatorImpl : public std::allocator<T> {
107 public:
108 typedef typename std::allocator<T>::value_type value_type;
109 typedef typename std::allocator<T>::size_type size_type;
110 typedef typename std::allocator<T>::difference_type difference_type;
111 typedef typename std::allocator<T>::pointer pointer;
112 typedef typename std::allocator<T>::const_pointer const_pointer;
113 typedef typename std::allocator<T>::reference reference;
114 typedef typename std::allocator<T>::const_reference const_reference;
115
116 // Used internally by STL data structures.
117 template <class U>
TrackingAllocatorImpl(const TrackingAllocatorImpl<U,kTag> & alloc ATTRIBUTE_UNUSED)118 TrackingAllocatorImpl(
119 const TrackingAllocatorImpl<U, kTag>& alloc ATTRIBUTE_UNUSED) noexcept {}
120
121 // Used internally by STL data structures.
TrackingAllocatorImpl()122 TrackingAllocatorImpl() noexcept {
123 static_assert(kTag < kAllocatorTagCount, "kTag must be less than kAllocatorTagCount");
124 }
125
126 // Enables an allocator for objects of one type to allocate storage for objects of another type.
127 // Used internally by STL data structures.
128 template <class U>
129 struct rebind {
130 typedef TrackingAllocatorImpl<U, kTag> other;
131 };
132
133 pointer allocate(size_type n, const_pointer hint ATTRIBUTE_UNUSED = 0) {
134 const size_t size = n * sizeof(T);
135 TrackedAllocators::RegisterAllocation(GetTag(), size);
136 return reinterpret_cast<pointer>(malloc(size));
137 }
138
139 template <typename PT>
deallocate(PT p,size_type n)140 void deallocate(PT p, size_type n) {
141 const size_t size = n * sizeof(T);
142 TrackedAllocators::RegisterFree(GetTag(), size);
143 free(p);
144 }
145
GetTag()146 static constexpr AllocatorTag GetTag() {
147 return kTag;
148 }
149 };
150
151 template<class T, AllocatorTag kTag>
152 // C++ doesn't allow template typedefs. This is a workaround template typedef which is
153 // TrackingAllocatorImpl<T> if kEnableTrackingAllocator is true, std::allocator<T> otherwise.
154 using TrackingAllocator = typename std::conditional<kEnableTrackingAllocator,
155 TrackingAllocatorImpl<T, kTag>,
156 std::allocator<T>>::type;
157
158 } // namespace art
159
160 #endif // ART_LIBARTBASE_BASE_ALLOCATOR_H_
161