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_RUNTIME_GC_SPACE_MALLOC_SPACE_H_ 18 #define ART_RUNTIME_GC_SPACE_MALLOC_SPACE_H_ 19 20 #include "space.h" 21 22 #include <iosfwd> 23 24 #include "base/memory_tool.h" 25 #include "base/mutex.h" 26 27 namespace art { 28 namespace gc { 29 30 namespace collector { 31 class MarkSweep; 32 } // namespace collector 33 34 namespace space { 35 36 class ZygoteSpace; 37 38 // A common parent of DlMallocSpace and RosAllocSpace. 39 class MallocSpace : public ContinuousMemMapAllocSpace { 40 public: 41 typedef void(*WalkCallback)(void *start, void *end, size_t num_bytes, void* callback_arg); 42 43 SpaceType GetType() const override { 44 return kSpaceTypeMallocSpace; 45 } 46 47 // Allocate num_bytes allowing the underlying space to grow. 48 virtual mirror::Object* AllocWithGrowth(Thread* self, size_t num_bytes, 49 size_t* bytes_allocated, size_t* usable_size, 50 size_t* bytes_tl_bulk_allocated) = 0; 51 // Allocate num_bytes without allowing the underlying space to grow. 52 mirror::Object* Alloc(Thread* self, size_t num_bytes, size_t* bytes_allocated, 53 size_t* usable_size, size_t* bytes_tl_bulk_allocated) override = 0; 54 // Return the storage space required by obj. If usable_size isn't null then it is set to the 55 // amount of the storage space that may be used by obj. 56 size_t AllocationSize(mirror::Object* obj, size_t* usable_size) override = 0; 57 size_t Free(Thread* self, mirror::Object* ptr) override 58 REQUIRES_SHARED(Locks::mutator_lock_) = 0; 59 size_t FreeList(Thread* self, size_t num_ptrs, mirror::Object** ptrs) override 60 REQUIRES_SHARED(Locks::mutator_lock_) = 0; 61 62 // Returns the maximum bytes that could be allocated for the given 63 // size in bulk, that is the maximum value for the 64 // bytes_allocated_bulk out param returned by MallocSpace::Alloc(). 65 virtual size_t MaxBytesBulkAllocatedFor(size_t num_bytes) = 0; 66 67 #ifndef NDEBUG 68 virtual void CheckMoreCoreForPrecondition() {} // to be overridden in the debug build. 69 #else 70 void CheckMoreCoreForPrecondition() {} // no-op in the non-debug build. 71 #endif 72 73 void* MoreCore(intptr_t increment); 74 75 // Hands unused pages back to the system. 76 virtual size_t Trim() = 0; 77 78 // Perform a mspace_inspect_all which calls back for each allocation chunk. The chunk may not be 79 // in use, indicated by num_bytes equaling zero. 80 virtual void Walk(WalkCallback callback, void* arg) = 0; 81 82 // Returns the number of bytes that the space has currently obtained from the system. This is 83 // greater or equal to the amount of live data in the space. 84 virtual size_t GetFootprint() = 0; 85 86 // Returns the number of bytes that the heap is allowed to obtain from the system via MoreCore. 87 virtual size_t GetFootprintLimit() = 0; 88 89 // Set the maximum number of bytes that the heap is allowed to obtain from the system via 90 // MoreCore. Note this is used to stop the mspace growing beyond the limit to Capacity. When 91 // allocations fail we GC before increasing the footprint limit and allowing the mspace to grow. 92 virtual void SetFootprintLimit(size_t limit) = 0; 93 94 // Removes the fork time growth limit on capacity, allowing the application to allocate up to the 95 // maximum reserved size of the heap. 96 void ClearGrowthLimit() { 97 growth_limit_ = NonGrowthLimitCapacity(); 98 } 99 100 // Override capacity so that we only return the possibly limited capacity 101 size_t Capacity() const override { 102 return growth_limit_; 103 } 104 105 // The total amount of memory reserved for the alloc space. 106 size_t NonGrowthLimitCapacity() const override { 107 return GetMemMap()->Size(); 108 } 109 110 // Change the non growth limit capacity by shrinking or expanding the map. Currently, only 111 // shrinking is supported. 112 void ClampGrowthLimit(); 113 114 void Dump(std::ostream& os) const override; 115 116 void SetGrowthLimit(size_t growth_limit); 117 118 virtual MallocSpace* CreateInstance(MemMap&& mem_map, 119 const std::string& name, 120 void* allocator, 121 uint8_t* begin, 122 uint8_t* end, 123 uint8_t* limit, 124 size_t growth_limit, 125 bool can_move_objects) = 0; 126 127 // Splits ourself into a zygote space and new malloc space which has our unused memory. When true, 128 // the low memory mode argument specifies that the heap wishes the created space to be more 129 // aggressive in releasing unused pages. Invalidates the space its called on. 130 ZygoteSpace* CreateZygoteSpace(const char* alloc_space_name, bool low_memory_mode, 131 MallocSpace** out_malloc_space) NO_THREAD_SAFETY_ANALYSIS; 132 uint64_t GetBytesAllocated() override = 0; 133 uint64_t GetObjectsAllocated() override = 0; 134 135 // Returns the class of a recently freed object. 136 mirror::Class* FindRecentFreedObject(const mirror::Object* obj); 137 138 bool CanMoveObjects() const override { 139 return can_move_objects_; 140 } 141 142 void DisableMovingObjects() { 143 can_move_objects_ = false; 144 } 145 146 protected: 147 MallocSpace(const std::string& name, 148 MemMap&& mem_map, 149 uint8_t* begin, 150 uint8_t* end, 151 uint8_t* limit, 152 size_t growth_limit, 153 bool create_bitmaps, 154 bool can_move_objects, 155 size_t starting_size, 156 size_t initial_size); 157 158 static MemMap CreateMemMap(const std::string& name, 159 size_t starting_size, 160 size_t* initial_size, 161 size_t* growth_limit, 162 size_t* capacity); 163 164 // When true the low memory mode argument specifies that the heap wishes the created allocator to 165 // be more aggressive in releasing unused pages. 166 virtual void* CreateAllocator(void* base, size_t morecore_start, size_t initial_size, 167 size_t maximum_size, bool low_memory_mode) = 0; 168 169 virtual void RegisterRecentFree(mirror::Object* ptr) 170 REQUIRES_SHARED(Locks::mutator_lock_) 171 REQUIRES(lock_); 172 173 accounting::ContinuousSpaceBitmap::SweepCallback* GetSweepCallback() override { 174 return &SweepCallback; 175 } 176 177 // Recent allocation buffer. 178 static constexpr size_t kRecentFreeCount = kDebugSpaces ? (1 << 16) : 0; 179 static constexpr size_t kRecentFreeMask = kRecentFreeCount - 1; 180 std::pair<const mirror::Object*, mirror::Class*> recent_freed_objects_[kRecentFreeCount]; 181 size_t recent_free_pos_; 182 183 static size_t bitmap_index_; 184 185 // Used to ensure mutual exclusion when the allocation spaces data structures are being modified. 186 Mutex lock_ DEFAULT_MUTEX_ACQUIRED_AFTER; 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 // True if objects in the space are movable. 198 bool can_move_objects_; 199 200 // Starting and initial sized, used when you reset the space. 201 const size_t starting_size_; 202 const size_t initial_size_; 203 204 private: 205 static void SweepCallback(size_t num_ptrs, mirror::Object** ptrs, void* arg) 206 REQUIRES_SHARED(Locks::mutator_lock_); 207 208 DISALLOW_COPY_AND_ASSIGN(MallocSpace); 209 }; 210 211 } // namespace space 212 } // namespace gc 213 } // namespace art 214 215 #endif // ART_RUNTIME_GC_SPACE_MALLOC_SPACE_H_ 216
