https://github.com/python/cpython/commit/482cf6b930999334794f400ff5b5cbc48df7d2d9 commit: 482cf6b930999334794f400ff5b5cbc48df7d2d9 branch: 3.15 author: Miss Islington (bot) <[email protected]> committer: kumaraditya303 <[email protected]> date: 2026-10-21T23:24:43+05:30 summary:
[3.15] gh-156784: do not ignore error port unreachable in proactor event loop implementation (GH-156788) (#159872) gh-156784: do not ignore error port unreachable in proactor event loop implementation (GH-156788) (cherry picked from commit 0815fe3afc001e4cedc44cc8007ce8597eba7c51) Co-authored-by: Thomas Grainger <[email protected]> files: A Misc/NEWS.d/next/Library/2026-09-01-00-00-00.gh-issue-156784.8gvtt4.rst M Lib/asyncio/windows_events.py M Lib/test/test_asyncio/test_events.py M Lib/test/test_asyncio/test_sock_lowlevel.py diff --git a/Lib/asyncio/windows_events.py b/Lib/asyncio/windows_events.py index c905db1016807f..e51a88df9e1cd7 100644 --- a/Lib/asyncio/windows_events.py +++ b/Lib/asyncio/windows_events.py @@ -8,7 +8,6 @@ import _overlapped import _winapi import errno -from functools import partial import math import msvcrt import socket @@ -462,24 +461,20 @@ def finish_socket_func(trans, key, ov): try: return ov.getresult() except OSError as exc: + # ERROR_PORT_UNREACHABLE is reported by WSARecvFrom when the + # same socket was previously used to send to an address that + # isn't listening (gh-91227). Surface it as a + # ConnectionResetError, like the other recoverable codes here, + # so it propagates to the caller the same way a plain + # socket.recvfrom() already does on SelectorEventLoop, instead + # of being silently swallowed. if exc.winerror in (_overlapped.ERROR_NETNAME_DELETED, - _overlapped.ERROR_OPERATION_ABORTED): + _overlapped.ERROR_OPERATION_ABORTED, + _overlapped.ERROR_PORT_UNREACHABLE): raise ConnectionResetError(*exc.args) else: raise - @classmethod - def _finish_recvfrom(cls, trans, key, ov, *, empty_result): - try: - return cls.finish_socket_func(trans, key, ov) - except OSError as exc: - # WSARecvFrom will report ERROR_PORT_UNREACHABLE when the same - # socket is used to send to an address that is not listening. - if exc.winerror == _overlapped.ERROR_PORT_UNREACHABLE: - return empty_result, None - else: - raise - def recv(self, conn, nbytes, flags=0): self._register_with_iocp(conn) ov = _overlapped.Overlapped(NULL) @@ -514,8 +509,7 @@ def recvfrom(self, conn, nbytes, flags=0): except BrokenPipeError: return self._result((b'', None)) - return self._register(ov, conn, partial(self._finish_recvfrom, - empty_result=b'')) + return self._register(ov, conn, self.finish_socket_func) def recvfrom_into(self, conn, buf, flags=0): self._register_with_iocp(conn) @@ -525,8 +519,7 @@ def recvfrom_into(self, conn, buf, flags=0): except BrokenPipeError: return self._result((0, None)) - return self._register(ov, conn, partial(self._finish_recvfrom, - empty_result=0)) + return self._register(ov, conn, self.finish_socket_func) def sendto(self, conn, buf, flags=0, addr=None): self._register_with_iocp(conn) diff --git a/Lib/test/test_asyncio/test_events.py b/Lib/test/test_asyncio/test_events.py index 5c4136df214175..a3093d4dc8a748 100644 --- a/Lib/test/test_asyncio/test_events.py +++ b/Lib/test/test_asyncio/test_events.py @@ -1523,9 +1523,18 @@ class Protocol(asyncio.DatagramProtocol): _received_datagram = None + def connection_made(self, transport): + self.errors = [] + self.error_received_event = loop.create_future() + def datagram_received(self, data, addr): self._received_datagram.set_result(data) + def error_received(self, exc): + self.errors.append(exc) + if not self.error_received_event.done(): + self.error_received_event.set_result(None) + async def wait_for_datagram_received(self): self._received_datagram = loop.create_future() result = await asyncio.wait_for(self._received_datagram, 10) @@ -1580,6 +1589,15 @@ def create_socket(): protocol_1.wait_for_datagram_received() ), b'd') + if sys.platform == 'win32': + # The bad send to addr_3 should be surfaced to the protocol + # via error_received() instead of being silently dropped, + # while transport_1 keeps working as shown above. + loop.run_until_complete( + asyncio.wait_for(protocol_1.error_received_event, 10)) + self.assertTrue(protocol_1.errors) + self.assertIsInstance(protocol_1.errors[0], ConnectionResetError) + transport_1.close() transport_2.close() diff --git a/Lib/test/test_asyncio/test_sock_lowlevel.py b/Lib/test/test_asyncio/test_sock_lowlevel.py index 8380342e294712..6ce029008f1446 100644 --- a/Lib/test/test_asyncio/test_sock_lowlevel.py +++ b/Lib/test/test_asyncio/test_sock_lowlevel.py @@ -613,19 +613,10 @@ def test_create_connection_sock(self): if sys.platform == 'win32': - class SelectEventLoopTests(BaseSockTestsMixin, - test_utils.TestCase): - - def create_event_loop(self): - return asyncio.SelectorEventLoop() - - - class ProactorEventLoopTests(BaseSockTestsMixin, - test_utils.TestCase): - - def create_event_loop(self): - return asyncio.ProactorEventLoop() - + class _DatagramSendToNonListeningAddressMixin: + # Shared by SelectEventLoopTests and ProactorEventLoopTests so that + # sock_recvfrom()/sock_recvfrom_into() behave identically on both + # event loop implementations. async def _basetest_datagram_send_to_non_listening_address(self, recvfrom): @@ -634,8 +625,9 @@ async def _basetest_datagram_send_to_non_listening_address(self, # https://github.com/python/cpython/issues/88906 # https://bugs.python.org/issue47071 # https://bugs.python.org/issue44743 - # The Proactor event loop would fail to receive datagram messages - # after sending a message to an address that wasn't listening. + # Sending a datagram to an address that isn't listening can + # surface as a ConnectionResetError on a later receive; the + # socket must still be usable afterwards. def create_socket(): sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM) @@ -670,7 +662,8 @@ def create_socket(): # this should send to an address that isn't listening await self.loop.sock_sendto(socket_1, b'c', addr_3) - self.assertEqual(await socket_1_recv_task, b'') + with self.assertRaises(ConnectionResetError): + await socket_1_recv_task socket_1_recv_task = self.loop.create_task(recvfrom(socket_1)) await asyncio.sleep(0) @@ -706,6 +699,22 @@ async def recvfrom_into(socket): self._basetest_datagram_send_to_non_listening_address( recvfrom_into)) + + class SelectEventLoopTests(_DatagramSendToNonListeningAddressMixin, + BaseSockTestsMixin, + test_utils.TestCase): + + def create_event_loop(self): + return asyncio.SelectorEventLoop() + + + class ProactorEventLoopTests(_DatagramSendToNonListeningAddressMixin, + BaseSockTestsMixin, + test_utils.TestCase): + + def create_event_loop(self): + return asyncio.ProactorEventLoop() + else: import selectors diff --git a/Misc/NEWS.d/next/Library/2026-09-01-00-00-00.gh-issue-156784.8gvtt4.rst b/Misc/NEWS.d/next/Library/2026-09-01-00-00-00.gh-issue-156784.8gvtt4.rst new file mode 100644 index 00000000000000..699448059114ec --- /dev/null +++ b/Misc/NEWS.d/next/Library/2026-09-01-00-00-00.gh-issue-156784.8gvtt4.rst @@ -0,0 +1,3 @@ +:class:`asyncio.ProactorEventLoop` no longer silently ignores +:exc:`ConnectionResetError` on UDP sockets, matching +:class:`asyncio.SelectorEventLoop`. _______________________________________________ Python-checkins mailing list -- [email protected] To unsubscribe send an email to [email protected] https://mail.python.org/mailman3//lists/python-checkins.python.org Member address: [email protected]
