Program Listing for File Semaphore.hpp

↰ Return to documentation for file (host/include/Semaphore.hpp)

#pragma once

#include <condition_variable>
#include <mutex>

namespace PowerSensor3 {

class Semaphore {
 public:
    explicit Semaphore(unsigned initialLevel = 0): level(initialLevel) {}

    void up(unsigned count = 1) {
      std::unique_lock<std::mutex> lock(mutex);
      level += count;
      if (count == 1)
        cv.notify_one();
      else
        cv.notify_all();
    }

    void down(unsigned count = 1) {
      std::unique_lock<std::mutex> lock(mutex);
      cv.wait(lock, [this, count] { return level >= count; });
      level -= count;
    }

 private:
    std::mutex mutex;
    std::condition_variable cv;
    unsigned level;
};

}  // namespace PowerSensor3