1 /** 2 * Copyright (c) 2021-2022 Huawei Device Co., Ltd. 3 * Licensed under the Apache License, Version 2.0 (the "License"); 4 * you may not use this file except in compliance with the License. 5 * You may obtain a copy of the License at 6 * 7 * http://www.apache.org/licenses/LICENSE-2.0 8 * 9 * Unless required by applicable law or agreed to in writing, software 10 * distributed under the License is distributed on an "AS IS" BASIS, 11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 * See the License for the specific language governing permissions and 13 * limitations under the License. 14 */ 15 #ifndef PANDA_RUNTIME_MEM_FRAME_ALLOCATOR_H 16 #define PANDA_RUNTIME_MEM_FRAME_ALLOCATOR_H 17 18 #include <securec.h> 19 #include <array> 20 21 #include "libpandabase/mem/arena-inl.h" 22 #include "libpandabase/mem/mem.h" 23 #include "libpandabase/mem/mmap_mem_pool-inl.h" 24 25 namespace panda::mem { 26 27 // Allocation flow looks like that: 28 // 29 // Allocate arenas for frames Frames free Return arenas Second allocated arena 30 // (stage 1) (stage 2) (stage 3) will be bigger than the 31 // second at stage 1 32 // |-----| |-----| |-----| 33 // | | | | | | 34 // |-----| | | |-----| | | | | 35 // |xxxxx| | | | | | | | | 36 // |-----| |xxxxx| |xxxxx| |-----| | | | | |-----| |-----| | | 37 // |xxxxx| |xxxxx| |xxxxx| ----> | | | | | | ----> | | ----> |xxxxx| |xxxxx| 38 // |xxxxx| |xxxxx| |xxxxx| | | | | | | | | |xxxxx| |xxxxx| 39 // |xxxxx| |xxxxx| |xxxxx| | | | | | | | | |xxxxx| |xxxxx| 40 // |xxxxx| |xxxxx| |xxxxx| | | | | | | | | |xxxxx| |xxxxx| 41 // |xxxxx| |xxxxx| |xxxxx| |xxxxx| | | | | |xxxxx| |xxxxx| |xxxxx| 42 // |-----| |-----| |-----| |-----| |-----| |-----| |-----| |-----| |-----| 43 44 // Frame allocator uses arenas and works like a stack - 45 // it will give memory from the top and can delete only last allocated memory. 46 template <Alignment AlignmenT = DEFAULT_FRAME_ALIGNMENT, bool UseMemsetT = true> 47 class FrameAllocator { 48 public: 49 explicit FrameAllocator(bool use_malloc = false); 50 ~FrameAllocator(); 51 FrameAllocator(const FrameAllocator &) noexcept = delete; 52 FrameAllocator(FrameAllocator &&) noexcept = default; 53 FrameAllocator &operator=(const FrameAllocator &) noexcept = delete; 54 FrameAllocator &operator=(FrameAllocator &&) noexcept = default; 55 56 [[nodiscard]] void *Alloc(size_t size); 57 58 // We must free objects allocated by this allocator strictly in reverse order 59 void Free(void *mem); 60 61 /** 62 * \brief Returns true if address inside current allocator. 63 */ 64 bool Contains(void *mem); 65 GetAllocatorType()66 static constexpr AllocatorType GetAllocatorType() 67 { 68 return AllocatorType::FRAME_ALLOCATOR; 69 } 70 GetAllocatedSize()71 size_t GetAllocatedSize() const 72 { 73 return allocated_size_; 74 } 75 76 private: 77 using FramesArena = DoubleLinkedAlignedArena<AlignmenT>; 78 static constexpr size_t FIRST_ARENA_SIZE = 256_KB; 79 static_assert(FIRST_ARENA_SIZE % PANDA_POOL_ALIGNMENT_IN_BYTES == 0); 80 static constexpr size_t ARENA_SIZE_GREW_LEVEL = FIRST_ARENA_SIZE; 81 static constexpr size_t FRAME_ALLOC_MIN_FREE_MEMORY_THRESHOLD = FIRST_ARENA_SIZE / 2; 82 static constexpr size_t FRAME_ALLOC_MAX_FREE_ARENAS_THRESHOLD = 1; 83 84 /** 85 * \brief Heuristic for arena size increase. 86 * @return new size 87 */ 88 size_t GetNextArenaSize(size_t size); 89 90 /** 91 * \brief Try to allocate an arena from the memory. 92 * @return true on success, or false on fail 93 */ 94 bool TryAllocateNewArena(size_t size = ARENA_SIZE_GREW_LEVEL); 95 96 /** 97 * \brief Try to allocate memory for a frame in the current arena or in the next one if it exists. 98 * @param size - size of the allocated memory 99 * @return pointer to the allocated memory on success, or nullptr on fail 100 */ 101 void *TryToAllocate(size_t size); 102 103 /** 104 * \brief Free last_allocated_arena_, i.e., free last arena in the list. 105 */ 106 void FreeLastArena(); 107 108 /** 109 * \brief Try to allocate an arena from the memory. 110 * @param size - size of the required arena 111 * @return pointer on success, or nullptr on fail 112 */ 113 FramesArena *AllocateArenaImpl(size_t size); 114 115 /** 116 * \brief Free given arena 117 * @param arena - arena to free 118 */ 119 void FreeArenaImpl(FramesArena *arena); 120 121 // A pointer to the current arena with the last allocated frame 122 FramesArena *cur_arena_ {nullptr}; 123 124 // A pointer to the last allocated arena (so it is equal to the top arena in the list) 125 FramesArena *last_alloc_arena_ {nullptr}; 126 127 // The biggest arena size during FrameAllocator workflow. Needed for computing a new arena size. 128 size_t biggest_arena_size_ {0}; 129 130 // A marker which tells us if we need to increase the size of a new arena or not. 131 bool arena_size_need_to_grow_ {true}; 132 133 size_t empty_arenas_count_ {0}; 134 135 // Total allocated size 136 size_t allocated_size_ {0}; 137 138 MmapMemPool *mem_pool_alloc_ {nullptr}; 139 140 bool use_malloc_ {false}; 141 142 friend class FrameAllocatorTest; 143 }; 144 145 } // namespace panda::mem 146 147 #endif // PANDA_RUNTIME_MEM_FRAME_ALLOCATOR_H 148