From 3d139d8ed6712f39f4e91dc084ed421b76af09ae Mon Sep 17 00:00:00 2001 From: Guido van Rossum Date: Tue, 6 May 2014 14:42:40 -0700 Subject: [PATCH] asyncio: Fix the second half of issue #21447: race in _write_to_self(). --- Lib/asyncio/selector_events.py | 15 +++++++++++---- Lib/test/test_asyncio/test_selector_events.py | 5 +++-- 2 files changed, 14 insertions(+), 6 deletions(-) diff --git a/Lib/asyncio/selector_events.py b/Lib/asyncio/selector_events.py index 367c5fbe3f5..c7df8d8dd00 100644 --- a/Lib/asyncio/selector_events.py +++ b/Lib/asyncio/selector_events.py @@ -87,10 +87,17 @@ class BaseSelectorEventLoop(base_events.BaseEventLoop): pass def _write_to_self(self): - try: - self._csock.send(b'x') - except (BlockingIOError, InterruptedError): - pass + # This may be called from a different thread, possibly after + # _close_self_pipe() has been called or even while it is + # running. Guard for self._csock being None or closed. When + # a socket is closed, send() raises OSError (with errno set to + # EBADF, but let's not rely on the exact error code). + csock = self._csock + if csock is not None: + try: + csock.send(b'x') + except OSError: + pass def _start_serving(self, protocol_factory, sock, sslcontext=None, server=None): diff --git a/Lib/test/test_asyncio/test_selector_events.py b/Lib/test/test_asyncio/test_selector_events.py index 964b2e8ec80..0735237ccad 100644 --- a/Lib/test/test_asyncio/test_selector_events.py +++ b/Lib/test/test_asyncio/test_selector_events.py @@ -121,8 +121,9 @@ class BaseSelectorEventLoopTests(unittest.TestCase): self.assertIsNone(self.loop._write_to_self()) def test_write_to_self_exception(self): - self.loop._csock.send.side_effect = OSError() - self.assertRaises(OSError, self.loop._write_to_self) + # _write_to_self() swallows OSError + self.loop._csock.send.side_effect = RuntimeError() + self.assertRaises(RuntimeError, self.loop._write_to_self) def test_sock_recv(self): sock = mock.Mock()