mutex

  class  mutex
  {
        public:
          mutex(int process = 0);                // set process to 1 for
          virtual ~mutex();                // mutexes between processes
  
          void unlock();                        // unlock mutex
          void lock();                        // lock mutex, block if already locked
          int trylock();                        // 1-success; 0-failure (semaphore=0)
  
        private:
          void* mp;
  };