#pragma once #ifndef __semaphore_h__ #define __semaphore_h__ #include <mutex> #include <condition_variable> /* * C++ doesn't actually have semaphores. It has mutexes and condition variables, * which we can use to make a semaphore. */ class semaphore { public: semaphore(int init): m_value(init) { } /* Semaphore down operation. */ void down(); /* Semaphore up operation. */ void up(); private: int m_value; // Value of semaphore. std::mutex m_mux; // Controls access. std::condition_variable m_waitcond; // Controls waiting and restart }; #endif