#if defined OS_WINDOWS
struct Lock //thanks to 'doublep' from StackOverflow for this RAII solution
{
  MUTEX&  mutex;
  bool    locked;

  Lock (MUTEX& mutex)
    : mutex (mutex),
      locked (false)
  { }

  ~Lock ()
  { release (); }

  bool acquire (int timeout = -1)
  {
    if (!locked && WaitForSingleObject (mutex, timeout) == WAIT_OBJECT_0)
      locked = true;
    return locked;
  }

  int release ()
  {
    if (locked)
      locked = (ReleaseMutex (mutex) == 1);
    return !locked;
  }
};

MUTEX mutex_q = NULL;
MUTEX mutex_p = NULL;
#else
struct Lock //and here is my little edit for linux
{
  MUTEX&  mutex;
  bool    locked;

  Lock (MUTEX& mutex)
    : mutex (mutex),
      locked (false)
  { }

  ~Lock ()
  { release (); }

  bool acquire (int timeout = -1)
  {
    if (!locked && pthread_mutex_lock (&mutex) == 0)
      locked = true;
    return locked;
  }

  int release ()
  {
    if (locked)
      locked = (pthread_mutex_unlock (&mutex) == 1);
    return !locked;
  }
};

MUTEX mutex_q = PTHREAD_MUTEX_INITIALIZER;
MUTEX mutex_p = PTHREAD_MUTEX_INITIALIZER;

#endif