diff options
| -rw-r--r-- | Lib/selectors.py | 5 | ||||
| -rw-r--r-- | Lib/test/test_selectors.py | 13 | ||||
| -rw-r--r-- | Misc/NEWS.d/next/Library/2020-04-14-11-31-07.bpo-29255.4EcyIN.rst | 1 |
3 files changed, 18 insertions, 1 deletions
diff --git a/Lib/selectors.py b/Lib/selectors.py index a9a0801ef0..90251dc34a 100644 --- a/Lib/selectors.py +++ b/Lib/selectors.py @@ -552,7 +552,10 @@ if hasattr(select, 'kqueue'): def select(self, timeout=None): timeout = None if timeout is None else max(timeout, 0) - max_ev = len(self._fd_to_key) + # If max_ev is 0, kqueue will ignore the timeout. For consistent + # behavior with the other selector classes, we prevent that here + # (using max). See https://bugs.python.org/issue29255 + max_ev = max(len(self._fd_to_key), 1) ready = [] try: kev_list = self._selector.control(None, max_ev, timeout) diff --git a/Lib/test/test_selectors.py b/Lib/test/test_selectors.py index 31611224dc..c449155c4b 100644 --- a/Lib/test/test_selectors.py +++ b/Lib/test/test_selectors.py @@ -543,6 +543,19 @@ class KqueueSelectorTestCase(BaseSelectorTestCase, ScalableSelectorMixIn): with self.assertRaises(KeyError): s.get_key(bad_f) + def test_empty_select_timeout(self): + # Issues #23009, #29255: Make sure timeout is applied when no fds + # are registered. + s = self.SELECTOR() + self.addCleanup(s.close) + + t0 = time() + self.assertEqual(s.select(1), []) + t1 = time() + dt = t1 - t0 + # Tolerate 2.0 seconds for very slow buildbots + self.assertTrue(0.8 <= dt <= 2.0, dt) + @unittest.skipUnless(hasattr(selectors, 'DevpollSelector'), "Test needs selectors.DevpollSelector") diff --git a/Misc/NEWS.d/next/Library/2020-04-14-11-31-07.bpo-29255.4EcyIN.rst b/Misc/NEWS.d/next/Library/2020-04-14-11-31-07.bpo-29255.4EcyIN.rst new file mode 100644 index 0000000000..18fbddf2ce --- /dev/null +++ b/Misc/NEWS.d/next/Library/2020-04-14-11-31-07.bpo-29255.4EcyIN.rst @@ -0,0 +1 @@ +Wait in `KqueueSelector.select` when no fds are registered |