def test_multi_0_timeout(self):
        # make sure a 0 timeout callback is called as many times
        # as the number of loops
        def fun():
            l.append(None)

        l = []
        self.ioloop.call_every(0, fun)
        for x in range(100):
            self.ioloop.sched.poll()
        self.assertEqual(len(l), 100)