1 /* 2 * Copyright (C) 2017 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 #pragma once 18 19 #include <atomic> 20 #include <limits> 21 22 namespace android { 23 24 template<typename T> 25 class HandleGenerator { 26 protected: 27 static T getNextHandle(); 28 }; 29 30 template<typename T> 31 T HandleGenerator<T>::getNextHandle() { 32 static std::atomic<uint32_t> mNextUniqueId(1); 33 uint32_t id = mNextUniqueId++; 34 while (id > std::numeric_limits<T>::max()) { 35 id -= std::numeric_limits<T>::max(); 36 } 37 return static_cast<T>(id); 38 } 39 40 } // namespace android 41
