1 /* 2 * Copyright (C) 2011 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_RUNTIME_GC_SPACE_DLMALLOC_SPACE_H_ 18 #define ART_RUNTIME_GC_SPACE_DLMALLOC_SPACE_H_ 19 20 #include "gc/allocator/dlmalloc.h" 21 #include "space.h" 22 23 namespace art { 24 namespace gc { 25 26 namespace collector { 27 class MarkSweep; 28 } // namespace collector 29 30 namespace space { 31 32 // An alloc space is a space where objects may be allocated and garbage collected. 33 class DlMallocSpace : public MemMapSpace, public AllocSpace { 34 public: 35 typedef void(*WalkCallback)(void *start, void *end, size_t num_bytes, void* callback_arg); 36 37 SpaceType GetType() const { 38 if (GetGcRetentionPolicy() == kGcRetentionPolicyFullCollect) { 39 return kSpaceTypeZygoteSpace; 40 } else { 41 return kSpaceTypeAllocSpace; 42 } 43 } 44 45 // Create a AllocSpace with the requested sizes. The requested 46 // base address is not guaranteed to be granted, if it is required, 47 // the caller should call Begin on the returned space to confirm 48 // the request was granted. 49 static DlMallocSpace* Create(const std::string& name, size_t initial_size, size_t growth_limit, 50 size_t capacity, byte* requested_begin); 51 52 // Allocate num_bytes without allowing the underlying mspace to grow. 53 virtual mirror::Object* AllocWithGrowth(Thread* self, size_t num_bytes, 54 size_t* bytes_allocated) LOCKS_EXCLUDED(lock_); 55 56 // Allocate num_bytes allowing the underlying mspace to grow. 57 virtual mirror::Object* Alloc(Thread* self, size_t num_bytes, size_t* bytes_allocated); 58 59 // Return the storage space required by obj. 60 virtual size_t AllocationSize(const mirror::Object* obj); 61 virtual size_t Free(Thread* self, mirror::Object* ptr); 62 virtual size_t FreeList(Thread* self, size_t num_ptrs, mirror::Object** ptrs); 63 64 mirror::Object* AllocNonvirtual(Thread* self, size_t num_bytes, size_t* bytes_allocated); 65 66 size_t AllocationSizeNonvirtual(const mirror::Object* obj) { 67 return mspace_usable_size(const_cast<void*>(reinterpret_cast<const void*>(obj))) + 68 kChunkOverhead; 69 } 70 71 void* MoreCore(intptr_t increment); 72 73 void* GetMspace() const { 74 return mspace_; 75 } 76 77 // Hands unused pages back to the system. 78 size_t Trim(); 79 80 // Perform a mspace_inspect_all which calls back for each allocation chunk. The chunk may not be 81 // in use, indicated by num_bytes equaling zero. 82 void Walk(WalkCallback callback, void* arg) LOCKS_EXCLUDED(lock_); 83 84 // Returns the number of bytes that the space has currently obtained from the system. This is 85 // greater or equal to the amount of live data in the space. 86 size_t GetFootprint(); 87 88 // Returns the number of bytes that the heap is allowed to obtain from the system via MoreCore. 89 size_t GetFootprintLimit(); 90 91 // Set the maximum number of bytes that the heap is allowed to obtain from the system via 92 // MoreCore. Note this is used to stop the mspace growing beyond the limit to Capacity. When 93 // allocations fail we GC before increasing the footprint limit and allowing the mspace to grow. 94 void SetFootprintLimit(size_t limit); 95 96 // Removes the fork time growth limit on capacity, allowing the application to allocate up to the 97 // maximum reserved size of the heap. 98 void ClearGrowthLimit() { 99 growth_limit_ = NonGrowthLimitCapacity(); 100 } 101 102 // Override capacity so that we only return the possibly limited capacity 103 size_t Capacity() const { 104 return growth_limit_; 105 } 106 107 // The total amount of memory reserved for the alloc space. 108 size_t NonGrowthLimitCapacity() const { 109 return GetMemMap()->Size(); 110 } 111 112 accounting::SpaceBitmap* GetLiveBitmap() const { 113 return live_bitmap_.get(); 114 } 115 116 accounting::SpaceBitmap* GetMarkBitmap() const { 117 return mark_bitmap_.get(); 118 } 119 120 void Dump(std::ostream& os) const; 121 122 void SetGrowthLimit(size_t growth_limit); 123 124 // Swap the live and mark bitmaps of this space. This is used by the GC for concurrent sweeping. 125 void SwapBitmaps(); 126 127 // Turn ourself into a zygote space and return a new alloc space which has our unused memory. 128 DlMallocSpace* CreateZygoteSpace(const char* alloc_space_name); 129 130 uint64_t GetBytesAllocated() const { 131 return num_bytes_allocated_; 132 } 133 134 uint64_t GetObjectsAllocated() const { 135 return num_objects_allocated_; 136 } 137 138 uint64_t GetTotalBytesAllocated() const { 139 return total_bytes_allocated_; 140 } 141 142 uint64_t GetTotalObjectsAllocated() const { 143 return total_objects_allocated_; 144 } 145 146 // Returns the class of a recently freed object. 147 mirror::Class* FindRecentFreedObject(const mirror::Object* obj); 148 149 protected: 150 DlMallocSpace(const std::string& name, MemMap* mem_map, void* mspace, byte* begin, byte* end, 151 size_t growth_limit); 152 153 private: 154 size_t InternalAllocationSize(const mirror::Object* obj); 155 mirror::Object* AllocWithoutGrowthLocked(size_t num_bytes, size_t* bytes_allocated) 156 EXCLUSIVE_LOCKS_REQUIRED(lock_); 157 bool Init(size_t initial_size, size_t maximum_size, size_t growth_size, byte* requested_base); 158 void RegisterRecentFree(mirror::Object* ptr); 159 static void* CreateMallocSpace(void* base, size_t morecore_start, size_t initial_size); 160 161 UniquePtr<accounting::SpaceBitmap> live_bitmap_; 162 UniquePtr<accounting::SpaceBitmap> mark_bitmap_; 163 UniquePtr<accounting::SpaceBitmap> temp_bitmap_; 164 165 // Recent allocation buffer. 166 static constexpr size_t kRecentFreeCount = kDebugSpaces ? (1 << 16) : 0; 167 static constexpr size_t kRecentFreeMask = kRecentFreeCount - 1; 168 std::pair<const mirror::Object*, mirror::Class*> recent_freed_objects_[kRecentFreeCount]; 169 size_t recent_free_pos_; 170 171 // Approximate number of bytes which have been allocated into the space. 172 size_t num_bytes_allocated_; 173 size_t num_objects_allocated_; 174 size_t total_bytes_allocated_; 175 size_t total_objects_allocated_; 176 177 static size_t bitmap_index_; 178 179 // The boundary tag overhead. 180 static const size_t kChunkOverhead = kWordSize; 181 182 // Used to ensure mutual exclusion when the allocation spaces data structures are being modified. 183 Mutex lock_ DEFAULT_MUTEX_ACQUIRED_AFTER; 184 185 // Underlying malloc space 186 void* const mspace_; 187 188 // The capacity of the alloc space until such time that ClearGrowthLimit is called. 189 // The underlying mem_map_ controls the maximum size we allow the heap to grow to. The growth 190 // limit is a value <= to the mem_map_ capacity used for ergonomic reasons because of the zygote. 191 // Prior to forking the zygote the heap will have a maximally sized mem_map_ but the growth_limit_ 192 // will be set to a lower value. The growth_limit_ is used as the capacity of the alloc_space_, 193 // however, capacity normally can't vary. In the case of the growth_limit_ it can be cleared 194 // one time by a call to ClearGrowthLimit. 195 size_t growth_limit_; 196 197 friend class collector::MarkSweep; 198 199 DISALLOW_COPY_AND_ASSIGN(DlMallocSpace); 200 }; 201 202 } // namespace space 203 } // namespace gc 204 } // namespace art 205 206 #endif // ART_RUNTIME_GC_SPACE_DLMALLOC_SPACE_H_ 207
