gen_test.py 文件源码

def test_replace_context_exception(self):
        # Test exception handling: exceptions thrown into the stack context
        # can be caught and replaced.
        # Note that this test and the following are for behavior that is
        # not really supported any more:  coroutines no longer create a
        # stack context automatically; but one is created after the first
        # YieldPoint (i.e. not a Future).
        @gen.coroutine
        def f2():
            (yield gen.Callback(1))()
            yield gen.Wait(1)
            self.io_loop.add_callback(lambda: 1 / 0)
            try:
                yield gen.Task(self.io_loop.add_timeout,
                               self.io_loop.time() + 10)
            except ZeroDivisionError:
                raise KeyError()

        future = f2()
        with self.assertRaises(KeyError):
            yield future
        self.finished = True