| /* |
| * Copyright (C) 2016 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_HIDL_SYNCHRONIZED_QUEUE_H |
| #define ANDROID_HIDL_SYNCHRONIZED_QUEUE_H |
| |
| #include <condition_variable> |
| #include <mutex> |
| #include <queue> |
| #include <thread> |
| |
| namespace android { |
| namespace hardware { |
| namespace details { |
| /* Threadsafe queue. |
| */ |
| template <typename T> |
| struct SynchronizedQueue { |
| SynchronizedQueue(size_t limit); |
| |
| /* Gets an item from the front of the queue. |
| * |
| * Blocks until the item is available. |
| */ |
| T wait_pop(); |
| |
| /* Puts an item onto the end of the queue. |
| */ |
| bool push(const T& item); |
| |
| /* Gets the size of the array. |
| */ |
| size_t size(); |
| |
| private: |
| std::condition_variable mCondition; |
| std::mutex mMutex; |
| std::queue<T> mQueue; |
| const size_t mQueueLimit; |
| }; |
| |
| template <typename T> |
| SynchronizedQueue<T>::SynchronizedQueue(size_t limit) : mQueueLimit(limit) { |
| } |
| |
| template <typename T> |
| T SynchronizedQueue<T>::wait_pop() { |
| std::unique_lock<std::mutex> lock(mMutex); |
| |
| mCondition.wait(lock, [this]{ |
| return !this->mQueue.empty(); |
| }); |
| |
| T item = mQueue.front(); |
| mQueue.pop(); |
| |
| return item; |
| } |
| |
| template <typename T> |
| bool SynchronizedQueue<T>::push(const T &item) { |
| bool success; |
| { |
| std::unique_lock<std::mutex> lock(mMutex); |
| if (mQueue.size() < mQueueLimit) { |
| mQueue.push(item); |
| success = true; |
| } else { |
| success = false; |
| } |
| } |
| |
| mCondition.notify_one(); |
| return success; |
| } |
| |
| template <typename T> |
| size_t SynchronizedQueue<T>::size() { |
| std::unique_lock<std::mutex> lock(mMutex); |
| |
| return mQueue.size(); |
| } |
| |
| } // namespace details |
| } // namespace hardware |
| } // namespace android |
| |
| #endif // ANDROID_HIDL_SYNCHRONIZED_QUEUE_H |