https://github.com/python/cpython/commit/388e72f5485f8a3bb5f90cf2db277188dc2b1f48 commit: 388e72f5485f8a3bb5f90cf2db277188dc2b1f48 branch: 3.14 author: Miss Islington (bot) <[email protected]> committer: kumaraditya303 <[email protected]> date: 2026-07-18T19:35:44+05:30 summary:
[3.14] gh-153761: Fix asyncio sock_accept() dropping a connection when cancelled (GH-153762) (#153828) gh-153761: Fix asyncio sock_accept() dropping a connection when cancelled (GH-153762) (cherry picked from commit b090d06e7331c40b3c94e70b35a09f785b279e17) Co-authored-by: Timofei <[email protected]> files: A Misc/NEWS.d/next/Library/2026-07-15-14-24-18.gh-issue-153761.8jqs67.rst M Lib/asyncio/selector_events.py M Lib/test/test_asyncio/test_sock_lowlevel.py diff --git a/Lib/asyncio/selector_events.py b/Lib/asyncio/selector_events.py index 7c2062e3dd5ffd2..5c07f5d31c5a6ae 100644 --- a/Lib/asyncio/selector_events.py +++ b/Lib/asyncio/selector_events.py @@ -714,6 +714,9 @@ async def sock_accept(self, sock): return await fut def _sock_accept(self, fut, sock): + # gh-153761: _sock_accept must not scheduled with already cancelled future + if fut.done(): + return fd = sock.fileno() try: conn, address = sock.accept() diff --git a/Lib/test/test_asyncio/test_sock_lowlevel.py b/Lib/test/test_asyncio/test_sock_lowlevel.py index f32dcd589e2de22..8380342e2947123 100644 --- a/Lib/test/test_asyncio/test_sock_lowlevel.py +++ b/Lib/test/test_asyncio/test_sock_lowlevel.py @@ -1,5 +1,6 @@ import socket import asyncio +import select import sys import unittest @@ -257,6 +258,38 @@ async def _basetest_sock_connect_racing(self, listener, sock): self.skipTest(skip_reason) + async def _basetest_sock_accept_racing(self, listener, sock): + # gh-153761: cancelling sock_accept() must not let a scheduled + # _sock_accept run on the cancelled future. + listener.setblocking(False) + listener.bind(('127.0.0.1', 0)) + listener.listen(1) + addr = listener.getsockname() + + errors = [] + self.loop.set_exception_handler(lambda loop, ctx: errors.append(ctx)) + task = asyncio.create_task(self.loop.sock_accept(listener)) + await asyncio.sleep(0) + + sock.connect(addr) + select.select([listener], [], [], support.SHORT_TIMEOUT) + + self.loop.call_soon(task.cancel) + await asyncio.sleep(0) + await asyncio.sleep(0) + + with self.assertRaises(asyncio.CancelledError): + await task + self.assertEqual(errors, []) + + # The pending connection must survive + conn, conn_addr = await self.loop.sock_accept(listener) + with conn: + self.assertEqual(conn_addr, sock.getsockname()) + sock.setblocking(False) + await self.loop.sock_sendall(conn, b'ping') + self.assertEqual(await self.loop.sock_recv(sock, 4), b'ping') + def test_sock_client_racing(self): with test_utils.run_test_server() as httpd: sock = socket.socket() @@ -280,6 +313,16 @@ def test_sock_client_connect_racing(self): self.loop.run_until_complete(asyncio.wait_for( self._basetest_sock_connect_racing(listener, sock), 10)) + def test_sock_accept_racing(self): + if sys.platform == 'win32': + if isinstance(self.loop, asyncio.ProactorEventLoop): + raise unittest.SkipTest('Not relevant to ProactorEventLoop') + listener = socket.socket() + sock = socket.socket() + with listener, sock: + self.loop.run_until_complete(asyncio.wait_for( + self._basetest_sock_accept_racing(listener, sock), 10)) + async def _basetest_huge_content(self, address): sock = socket.socket() sock.setblocking(False) diff --git a/Misc/NEWS.d/next/Library/2026-07-15-14-24-18.gh-issue-153761.8jqs67.rst b/Misc/NEWS.d/next/Library/2026-07-15-14-24-18.gh-issue-153761.8jqs67.rst new file mode 100644 index 000000000000000..68e007e66e0396c --- /dev/null +++ b/Misc/NEWS.d/next/Library/2026-07-15-14-24-18.gh-issue-153761.8jqs67.rst @@ -0,0 +1 @@ +Fix cancelling :meth:`asyncio.loop.sock_accept` dropping a pending connection. _______________________________________________ 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]
