| // Copyright 2019 Google LLC |
| // |
| // 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 |
| // |
| // https://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 dap_chan_h |
| #define dap_chan_h |
| |
| #include "dap/optional.h" |
| |
| #include <condition_variable> |
| #include <mutex> |
| #include <queue> |
| |
| namespace dap { |
| |
| template <typename T> |
| struct Chan { |
| public: |
| void reset(); |
| void close(); |
| optional<T> take(); |
| void put(T&& in); |
| void put(const T& in); |
| |
| private: |
| bool closed = false; |
| std::queue<T> queue; |
| std::condition_variable cv; |
| std::mutex mutex; |
| }; |
| |
| template <typename T> |
| void Chan<T>::reset() { |
| std::unique_lock<std::mutex> lock(mutex); |
| queue = {}; |
| closed = false; |
| } |
| |
| template <typename T> |
| void Chan<T>::close() { |
| std::unique_lock<std::mutex> lock(mutex); |
| closed = true; |
| cv.notify_all(); |
| } |
| |
| template <typename T> |
| optional<T> Chan<T>::take() { |
| std::unique_lock<std::mutex> lock(mutex); |
| cv.wait(lock, [&] { return queue.size() > 0 || closed; }); |
| if (queue.size() == 0) { |
| return optional<T>(); |
| } |
| auto out = std::move(queue.front()); |
| queue.pop(); |
| return optional<T>(std::move(out)); |
| } |
| |
| template <typename T> |
| void Chan<T>::put(T&& in) { |
| std::unique_lock<std::mutex> lock(mutex); |
| auto notify = queue.size() == 0 && !closed; |
| queue.push(std::move(in)); |
| if (notify) { |
| cv.notify_all(); |
| } |
| } |
| |
| template <typename T> |
| void Chan<T>::put(const T& in) { |
| std::unique_lock<std::mutex> lock(mutex); |
| auto notify = queue.size() == 0 && !closed; |
| queue.push(in); |
| if (notify) { |
| cv.notify_all(); |
| } |
| } |
| |
| } // namespace dap |
| |
| #endif // dap_chan_h |