gh-155941: Close the transport when client_connected_cb raises in asyncio (#155942)
kumaraditya303 <[email protected]>
| Newsgroups | gmane.comp.python.cvs |
|---|---|
| Message-ID | <[email protected]> |
https://github.com/python/cpython/commit/95e32ba8262b2f08d4c574bce55425589cbf9885 commit: 95e32ba8262b2f08d4c574bce55425589cbf9885 branch: main author: Seungki Kim <[email protected]> committer: kumaraditya303 <[email protected]> date: 2026-08-18T19:06:16+05:30 summary: gh-155941: Close the transport when client_connected_cb raises in asyncio (#155942) files: A Misc/NEWS.d/next/Library/2026-08-17-21-00-00.gh-issue-155941.strmCb.rst M Lib/asyncio/streams.py M Lib/test/test_asyncio/test_streams.py diff --git a/Lib/asyncio/streams.py b/Lib/asyncio/streams.py index f5c4f0b0c3297ba..954e132617ce42b 100644 --- a/Lib/asyncio/streams.py +++ b/Lib/asyncio/streams.py @@ -239,7 +239,17 @@ def connection_made(self, transport): self._over_ssl = transport.get_extra_info('sslcontext') is not None if self._client_connected_cb is not None: writer = StreamWriter(transport, self, reader, self._loop) - res = self._client_connected_cb(reader, writer) + try: + res = self._client_connected_cb(reader, writer) + except Exception as exc: + self._loop.call_exception_handler({ + 'message': 'Unhandled exception in client_connected_cb', + 'exception': exc, + 'transport': transport, + }) + transport.close() + self._strong_reader = None + return if coroutines.iscoroutine(res): def callback(task): if task.cancelled(): diff --git a/Lib/test/test_asyncio/test_streams.py b/Lib/test/test_asyncio/test_streams.py index 911087a128f9713..172f183849c3057 100644 --- a/Lib/test/test_asyncio/test_streams.py +++ b/Lib/test/test_asyncio/test_streams.py @@ -1267,6 +1267,38 @@ async def handle_echo(reader, writer): messages = self._basetest_unhandled_exceptions(handle_echo) self.assertEqual(messages, []) + def test_unhandled_exception_sync_callback(self): + # An exception raised by a plain-function client_connected_cb is + # reported like the coroutine case and the transport is closed. + port = socket_helper.find_unused_port() + + messages = [] + self.loop.set_exception_handler(lambda loop, ctx: messages.append(ctx)) + + async def client(): + rd, wr = await asyncio.open_connection('localhost', port) + async with asyncio.timeout(60): + data = await rd.read() + self.assertEqual(data, b'') # the server closed the connection + wr.close() + await wr.wait_closed() + + async def main(): + def handle_echo(reader, writer): + raise Exception('test') + + server = await asyncio.start_server( + handle_echo, 'localhost', port) + await server.start_serving() + await client() + server.close() + await server.wait_closed() + + self.loop.run_until_complete(main()) + + self.assertEqual(messages[0]['message'], + 'Unhandled exception in client_connected_cb') + def test_open_connection_happy_eyeball_refcycles(self): port = socket_helper.find_unused_port() async def main(): diff --git a/Misc/NEWS.d/next/Library/2026-08-17-21-00-00.gh-issue-155941.strmCb.rst b/Misc/NEWS.d/next/Library/2026-08-17-21-00-00.gh-issue-155941.strmCb.rst new file mode 100644 index 000000000000000..6cee7eb4eb9090e --- /dev/null +++ b/Misc/NEWS.d/next/Library/2026-08-17-21-00-00.gh-issue-155941.strmCb.rst @@ -0,0 +1,4 @@ +Fix :func:`asyncio.start_server` when a plain-function *client_connected_cb* +raises: the error is now reported like the coroutine case and the transport +is closed, instead of leaving the connection open forever (which also made +:meth:`asyncio.Server.wait_closed` hang). _______________________________________________ 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]