| /* |
| * Copyright (C) 2018 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| #ifndef ANDROID_FRAMEWORKS_BUFFERHUB_V1_0_ID_GENERATOR_H |
| #define ANDROID_FRAMEWORKS_BUFFERHUB_V1_0_ID_GENERATOR_H |
| |
| #include <mutex> |
| #include <set> |
| |
| #include <utils/Mutex.h> |
| |
| namespace android { |
| namespace frameworks { |
| namespace bufferhub { |
| namespace V1_0 { |
| namespace implementation { |
| |
| // A thread-safe, non-negative, incremental, int id generator. |
| class BufferHubIdGenerator { |
| public: |
| // Get the singleton instance of this class |
| static BufferHubIdGenerator& getInstance(); |
| |
| // Gets next available id. If next id is greater than std::numeric_limits<int32_t>::max(), it |
| // will try to get an id start from 0 again. |
| int getId(); |
| |
| // Free a specific id. |
| void freeId(int id); |
| |
| private: |
| BufferHubIdGenerator() = default; |
| ~BufferHubIdGenerator() = default; |
| |
| // Start from -1 so all valid ids will be >= 0 |
| int mLastId = -1; |
| |
| std::mutex mIdsInUseMutex; |
| std::set<int> mIdsInUse GUARDED_BY(mIdsInUseMutex); |
| }; |
| |
| } // namespace implementation |
| } // namespace V1_0 |
| } // namespace bufferhub |
| } // namespace frameworks |
| } // namespace android |
| |
| #endif // ANDROID_FRAMEWORKS_BUFFERHUB_V1_0_ID_GENERATOR_H |