93 lines
2.3 KiB
C
93 lines
2.3 KiB
C
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/*
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* Copyright (C) 2023 The Android Open Source Project
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#pragma once
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#include <condition_variable>
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#include <deque>
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#include <mutex>
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#include <optional>
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namespace android {
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namespace hardware {
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namespace camera {
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namespace provider {
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namespace implementation {
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template <class T> struct BlockingQueue {
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BlockingQueue() = default;
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bool put(T* x) {
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std::lock_guard lock(mtx);
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if (cancelled) {
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return false;
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} else {
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queue.push_back(std::move(*x));
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available.notify_one();
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return true;
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}
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}
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std::optional<T> get() {
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std::unique_lock lock(mtx);
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while (true) {
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if (!queue.empty()) {
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T x = std::move(queue.front());
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queue.pop_front();
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return x;
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} else if (cancelled) {
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return std::nullopt;
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} else {
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available.wait(lock);
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}
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}
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}
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std::optional<T> tryGet() {
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std::lock_guard lock(mtx);
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if (queue.empty()) {
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return std::nullopt;
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} else {
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T x = std::move(queue.front());
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queue.pop_front();
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return x;
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}
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}
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void cancel() {
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std::lock_guard lock(mtx);
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cancelled = true;
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available.notify_one();
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}
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BlockingQueue(const BlockingQueue&) = delete;
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BlockingQueue(BlockingQueue&&) = delete;
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BlockingQueue& operator=(const BlockingQueue&) = delete;
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BlockingQueue& operator=(BlockingQueue&&) = delete;
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private:
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std::deque<T> queue;
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std::condition_variable available;
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bool cancelled = false;
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std::mutex mtx;
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};
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} // namespace implementation
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} // namespace provider
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} // namespace camera
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} // namespace hardware
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} // namespace android
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