def acquire(self, blocking=True):
        """Decrement the value of the semaphore, block if requested and
        required."""
        if blocking:
            self.wait()
            return True
        else:
            return self.trywait()
Decrement the value of the semaphore, block if requested and
        required.
recipes/Python/577655_POSIX_Semaphore_FreeBSD/recipe-577655.py