1 /* 2 * Copyright (C) 2019 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 _LIBUNWINDSTACK_MEMORY_CACHE_H 18 #define _LIBUNWINDSTACK_MEMORY_CACHE_H 19 20 #include <pthread.h> 21 #include <stdint.h> 22 23 #include <memory> 24 #include <mutex> 25 #include <optional> 26 #include <unordered_map> 27 28 #include <unwindstack/Memory.h> 29 30 namespace unwindstack { 31 32 class MemoryCacheBase : public Memory { 33 public: MemoryCacheBase(Memory * memory)34 MemoryCacheBase(Memory* memory) : impl_(memory) {} 35 virtual ~MemoryCacheBase() = default; 36 AsMemoryCacheBase()37 MemoryCacheBase* AsMemoryCacheBase() override { return this; } 38 UnderlyingMemory()39 const std::shared_ptr<Memory>& UnderlyingMemory() { return impl_; } 40 Read(uint64_t addr,void * dst,size_t size)41 size_t Read(uint64_t addr, void* dst, size_t size) override { 42 // Only look at the cache for small reads. 43 if (size > 64) { 44 return impl_->Read(addr, dst, size); 45 } 46 return CachedRead(addr, dst, size); 47 } 48 ReadTag(uint64_t addr)49 long ReadTag(uint64_t addr) override { return impl_->ReadTag(addr); } 50 51 protected: 52 constexpr static size_t kCacheBits = 12; 53 constexpr static size_t kCacheMask = (1 << kCacheBits) - 1; 54 constexpr static size_t kCacheSize = 1 << kCacheBits; 55 56 using CacheDataType = std::unordered_map<uint64_t, uint8_t[kCacheSize]>; 57 58 virtual size_t CachedRead(uint64_t addr, void* dst, size_t size) = 0; 59 60 size_t InternalCachedRead(uint64_t addr, void* dst, size_t size, CacheDataType* cache); 61 62 std::shared_ptr<Memory> impl_; 63 }; 64 65 class MemoryCache : public MemoryCacheBase { 66 public: MemoryCache(Memory * memory)67 MemoryCache(Memory* memory) : MemoryCacheBase(memory) {} 68 virtual ~MemoryCache() = default; 69 70 size_t CachedRead(uint64_t addr, void* dst, size_t size) override; 71 72 void Clear() override; 73 74 protected: 75 CacheDataType cache_; 76 77 std::mutex cache_lock_; 78 }; 79 80 class MemoryThreadCache : public MemoryCacheBase { 81 public: 82 MemoryThreadCache(Memory* memory); 83 virtual ~MemoryThreadCache(); 84 85 size_t CachedRead(uint64_t addr, void* dst, size_t size) override; 86 87 void Clear() override; 88 89 protected: 90 std::optional<pthread_key_t> thread_cache_; 91 }; 92 93 } // namespace unwindstack 94 95 #endif // _LIBUNWINDSTACK_MEMORY_CACHE_H 96