46 lines
1.1 KiB
C
46 lines
1.1 KiB
C
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#ifndef COUNTING_SEMAPHORE_H
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#define COUNTING_SEMAPHORE_H
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#include <mutex>
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#include <condition_variable>
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#include <algorithm>
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#include <thread>
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#include <mutex>
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#include <condition_variable>
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#include <thread>
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class CountingSemaphore {
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public:
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static CountingSemaphore& getInstance()
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{
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static CountingSemaphore instance;
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return instance;
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}
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// Delete copy constructor and assignment operator
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CountingSemaphore(const CountingSemaphore&) = delete;
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CountingSemaphore& operator=(const CountingSemaphore&) = delete;
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void acquire()
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{
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std::unique_lock<std::mutex> lock(mtx_);
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cv_.wait(lock, [this]() { return count_ > 0; });
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--count_;
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}
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void release()
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{
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std::lock_guard<std::mutex> lock(mtx_);
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++count_;
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if (count_ <= max_count_) {
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cv_.notify_one();
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}
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}
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private:
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CountingSemaphore()
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: max_count_(std::max(1u, static_cast<uint>(0.95 * std::thread::hardware_concurrency()))),
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count_(max_count_)
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{
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}
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std::mutex mtx_;
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std::condition_variable cv_;
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const uint max_count_;
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uint count_;
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};
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#endif
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