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 _DNS_LOCKED_QUEUE_H 18 #define _DNS_LOCKED_QUEUE_H 19 20 #include <algorithm> 21 #include <deque> 22 #include <mutex> 23 24 #include <android-base/thread_annotations.h> 25 26 namespace android { 27 namespace net { 28 29 template <typename T> 30 class LockedQueue { 31 public: 32 // Push an item onto the queue. push(T item)33 void push(T item) { 34 std::lock_guard guard(mLock); 35 mQueue.push_front(std::move(item)); 36 } 37 38 // Swap out the contents of the queue swap(std::deque<T> & other)39 void swap(std::deque<T>& other) { 40 std::lock_guard guard(mLock); 41 mQueue.swap(other); 42 } 43 44 private: 45 std::mutex mLock; 46 std::deque<T> mQueue GUARDED_BY(mLock); 47 }; 48 49 template <typename T> 50 class LockedRingBuffer { 51 public: LockedRingBuffer(size_t size)52 explicit LockedRingBuffer(size_t size) : mCapacity(size) {} 53 push(T && record)54 void push(T&& record) { 55 std::lock_guard guard(mLock); 56 mQueue.push_back(std::move(record)); 57 if (mQueue.size() > mCapacity) { 58 mQueue.pop_front(); 59 } 60 } 61 copy()62 std::deque<T> copy() const { 63 std::lock_guard guard(mLock); 64 return mQueue; 65 } 66 67 private: 68 mutable std::mutex mLock; 69 const size_t mCapacity; 70 std::deque<T> mQueue GUARDED_BY(mLock); 71 }; 72 73 } // end of namespace net 74 } // end of namespace android 75 76 #endif // _DNS_LOCKEDQUEUE_H 77