1 // Copyright 2021 The Dawn Authors 2 // 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 COMMON_CONCURRENT_CACHE_H_ 16 #define COMMON_CONCURRENT_CACHE_H_ 17 18 #include "common/NonCopyable.h" 19 20 #include <mutex> 21 #include <unordered_set> 22 #include <utility> 23 24 template <typename T> 25 class ConcurrentCache : public NonMovable { 26 public: 27 ConcurrentCache() = default; 28 Find(T * object)29 T* Find(T* object) { 30 std::lock_guard<std::mutex> lock(mMutex); 31 auto iter = mCache.find(object); 32 if (iter == mCache.end()) { 33 return nullptr; 34 } 35 return *iter; 36 } 37 Insert(T * object)38 std::pair<T*, bool> Insert(T* object) { 39 std::lock_guard<std::mutex> lock(mMutex); 40 auto insertion = mCache.insert(object); 41 return std::make_pair(*(insertion.first), insertion.second); 42 } 43 Erase(T * object)44 size_t Erase(T* object) { 45 std::lock_guard<std::mutex> lock(mMutex); 46 return mCache.erase(object); 47 } 48 49 private: 50 std::mutex mMutex; 51 std::unordered_set<T*, typename T::HashFunc, typename T::EqualityFunc> mCache; 52 }; 53 54 #endif 55