.. _program_listing_file_host_include_Semaphore.hpp:

Program Listing for File Semaphore.hpp
======================================

|exhale_lsh| :ref:`Return to documentation for file <file_host_include_Semaphore.hpp>` (``host/include/Semaphore.hpp``)

.. |exhale_lsh| unicode:: U+021B0 .. UPWARDS ARROW WITH TIP LEFTWARDS

.. code-block:: cpp

   #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