diff --git a/Doc/library/asyncio-eventloop.rst b/Doc/library/asyncio-eventloop.rst index 06c5c877ccc173e..d6ed817b13676fc 100644 --- a/Doc/library/asyncio-eventloop.rst +++ b/Doc/library/asyncio-eventloop.rst @@ -1641,6 +1641,31 @@ Do not instantiate the :class:`Server` class directly. coroutine to wait until the server is closed (and no more connections are active). + .. method:: close_clients() + + Close all existing incoming client connections. + + Calls :meth:`~asyncio.BaseTransport.close` on all associated + transports. + + :meth:`close` should be called before :meth:`close_clients` when + closing the server to avoid races with new clients connecting. + + .. versionadded:: 3.13 + + .. method:: abort_clients() + + Close all existing incoming client connections immediately, + without waiting for pending operations to complete. + + Calls :meth:`~asyncio.WriteTransport.abort` on all associated + transports. + + :meth:`close` should be called before :meth:`abort_clients` when + closing the server to avoid races with new clients connecting. + + .. versionadded:: 3.13 + .. method:: get_loop() Return the event loop associated with the server object. diff --git a/Doc/whatsnew/3.13.rst b/Doc/whatsnew/3.13.rst index b665e6f1c859157..0553cc97c5c75af 100644 --- a/Doc/whatsnew/3.13.rst +++ b/Doc/whatsnew/3.13.rst @@ -270,6 +270,11 @@ asyncio the buffer size. (Contributed by Jamie Phan in :gh:`115199`.) +* Add :meth:`asyncio.Server.close_clients` and + :meth:`asyncio.Server.abort_clients` methods which allow to more + forcefully close an asyncio server. + (Contributed by Pierre Ossman in :gh:`113538`.) + base64 --- diff --git a/Lib/asyncio/base_events.py b/Lib/asyncio/base_events.py index 6c5cf28e7c59d42..f0e690b61a73dd1 100644 --- a/Lib/asyncio/base_events.py +++ b/Lib/asyncio/base_events.py @@ -279,7 +279,9 @@ def __init__(self, loop, sockets, protocol_factory, ssl_context, backlog, ssl_handshake_timeout, ssl_shutdown_timeout=None): self._loop = loop self._sockets = sockets - self._active_count = 0 + # Weak references so we don't break Transport's ability to + # detect abandoned transports + self._clients = weakref.WeakSet() self._waiters = [] self._protocol_factory = protocol_factory self._backlog = backlog @@ -292,14 +294,13 @@ def __init__(self, loop, sockets, protocol_factory, ssl_context, backlog, def __repr__(self): return f'<{self.__class__.__name__} sockets={self.sockets!r}>' - def _attach(self): + def _attach(self, transport): assert self._sockets is not None - self._active_count += 1 + self._clients.add(transport) - def _detach(self): - assert self._active_count > 0 - self._active_count -= 1 - if self._active_count == 0 and self._sockets is None: + def _detach(self, transport): + self._clients.discard(transport) + if len(self._clients) == 0 and self._sockets is None: self._wakeup() def _wakeup(self): @@ -348,9 +349,17 @@ def close(self): self._serving_forever_fut.cancel() self._serving_forever_fut = None - if self._active_count == 0: + if len(self._clients) == 0: self._wakeup() + def close_clients(self): + for transport in self._clients.copy(): + transport.close() + + def abort_clients(self): + for transport in self._clients.copy(): + transport.abort() + async def start_serving(self): self._start_serving() # Skip one loop iteration so that all 'loop.add_reader' diff --git a/Lib/asyncio/events.py b/Lib/asyncio/events.py index 680749325025db3..be495469a0558b9 100644 --- a/Lib/asyncio/events.py +++ b/Lib/asyncio/events.py @@ -175,6 +175,14 @@ def close(self): """Stop serving. This leaves existing connections open.""" raise NotImplementedError + def close_clients(self): + """Close all active connections.""" + raise NotImplementedError + + def abort_clients(self): + """Close all active connections immediately.""" + raise NotImplementedError + def get_loop(self): """Get the event loop the Server object is attached to.""" raise NotImplementedError diff --git a/Lib/asyncio/proactor_events.py b/Lib/asyncio/proactor_events.py index a512db6367b20ac..397a8cda7578950 100644 --- a/Lib/asyncio/proactor_events.py +++ b/Lib/asyncio/proactor_events.py @@ -63,7 +63,7 @@ def __init__(self, loop, sock, protocol, waiter=None, self._called_connection_lost = False self._eof_written = False if self._server is not None: - self._server._attach() + self._server._attach(self) self._loop.call_soon(self._protocol.connection_made, self) if waiter is not None: # only wake up the waiter when connection_made() has been called @@ -167,7 +167,7 @@ def _call_connection_lost(self, exc): self._sock = None server = self._server if server is not None: - server._detach() + server._detach(self) self._server = None self._called_connection_lost = True diff --git a/Lib/asyncio/selector_events.py b/Lib/asyncio/selector_events.py index 8e888d26ea07377..f94bf10b4225e79 100644 --- a/Lib/asyncio/selector_events.py +++ b/Lib/asyncio/selector_events.py @@ -791,7 +791,7 @@ def __init__(self, loop, sock, protocol, extra=None, server=None): self._paused = False # Set when pause_reading() called if self._server is not None: - self._server._attach() + self._server._attach(self) loop._transports[self._sock_fd] = self def __repr__(self): @@ -868,6 +868,8 @@ def __del__(self, _warn=warnings.warn): if self._sock is not None: _warn(f"unclosed transport {self!r}", ResourceWarning, source=self) self._sock.close() + if self._server is not None: + self._server._detach(self) def _fatal_error(self, exc, message='Fatal error on transport'): # Should be called from exception handler only. @@ -906,7 +908,7 @@ def _call_connection_lost(self, exc): self._loop = None server = self._server if server is not None: - server._detach() + server._detach(self) self._server = None def get_write_buffer_size(self): diff --git a/Lib/test/test_asyncio/test_server.py b/Lib/test/test_asyncio/test_server.py index 918faac909b9bfd..4ca8a166a0f1a1f 100644 --- a/Lib/test/test_asyncio/test_server.py +++ b/Lib/test/test_asyncio/test_server.py @@ -125,8 +125,12 @@ async def main(srv): class TestServer2(unittest.IsolatedAsyncioTestCase): async def test_wait_closed_basic(self): - async def serve(*args): - pass + async def serve(rd, wr): + try: + await rd.read() + finally: + wr.close() + await wr.wait_closed() srv = await asyncio.start_server(serve, socket_helper.HOSTv4, 0) self.addCleanup(srv.close) @@ -137,7 +141,8 @@ async def serve(*args): self.assertFalse(task1.done()) # active count != 0, not closed: should block - srv._attach() + addr = srv.sockets[0].getsockname() + (rd, wr) = await asyncio.open_connection(addr[0], addr[1]) task2 = asyncio.create_task(srv.wait_closed()) await asyncio.sleep(0) self.assertFalse(task1.done()) @@ -152,7 +157,8 @@ async def serve(*args): self.assertFalse(task2.done()) self.assertFalse(task3.done()) - srv._detach() + wr.close() + await wr.wait_closed() # active count == 0, closed: should unblock await task1 await task2 @@ -161,8 +167,12 @@ async def serve(*args): async def test_wait_closed_race(self): # Test a regression in 3.12.0, should be fixed in 3.12.1 - async def serve(*args): - pass + async def serve(rd, wr): + try: + await rd.read() + finally: + wr.close() + await wr.wait_closed() srv = await asyncio.start_server(serve, socket_helper.HOSTv4, 0) self.addCleanup(srv.close) @@ -170,13 +180,83 @@ async def serve(*args): task = asyncio.create_task(srv.wait_closed()) await asyncio.sleep(0) self.assertFalse(task.done()) - srv._attach() + addr = srv.sockets[0].getsockname() + (rd, wr) = await asyncio.open_connection(addr[0], addr[1]) loop = asyncio.get_running_loop() loop.call_soon(srv.close) - loop.call_soon(srv._detach) + loop.call_soon(wr.close) await srv.wait_closed() + async def test_close_clients(self): + async def serve(rd, wr): + try: + await rd.read() + finally: + wr.close() + await wr.wait_closed() + + srv = await asyncio.start_server(serve, socket_helper.HOSTv4, 0) + self.addCleanup(srv.close) + + addr = srv.sockets[0].getsockname() + (rd, wr) = await asyncio.open_connection(addr[0], addr[1]) + self.addCleanup(wr.close) + + task = asyncio.create_task(srv.wait_closed()) + await asyncio.sleep(0) + self.assertFalse(task.done()) + + srv.close() + srv.close_clients() + await asyncio.sleep(0) + await asyncio.sleep(0) + self.assertTrue(task.done()) + + async def test_abort_clients(self): + async def serve(rd, wr): + fut.set_result((rd, wr)) + await wr.wait_closed() + + fut = asyncio.Future() + srv = await asyncio.start_server(serve, socket_helper.HOSTv4, 0) + self.addCleanup(srv.close) + + addr = srv.sockets[0].getsockname() + (c_rd, c_wr) = await asyncio.open_connection(addr[0], addr[1], limit=4096) + self.addCleanup(c_wr.close) + + (s_rd, s_wr) = await fut + + # Limit the socket buffers so we can reliably overfill them + s_sock = s_wr.get_extra_info('socket') + s_sock.setsockopt(socket.SOL_SOCKET, socket.SO_SNDBUF, 65536) + c_sock = c_wr.get_extra_info('socket') + c_sock.setsockopt(socket.SOL_SOCKET, socket.SO_RCVBUF, 65536) + + # Get the reader in to a paused state by sending more than twice + # the configured limit + s_wr.write(b'a' * 4096) + s_wr.write(b'a' * 4096) + s_wr.write(b'a' * 4096) + while c_wr.transport.is_reading(): + await asyncio.sleep(0) + + # Get the writer in a waiting state by sending data until the + # socket buffers are full on both server and client sockets and + # the kernel stops accepting more data + s_wr.write(b'a' * c_sock.getsockopt(socket.SOL_SOCKET, socket.SO_RCVBUF)) + s_wr.write(b'a' * s_sock.getsockopt(socket.SOL_SOCKET, socket.SO_SNDBUF)) + self.assertNotEqual(s_wr.transport.get_write_buffer_size(), 0) + + task = asyncio.create_task(srv.wait_closed()) + await asyncio.sleep(0) + self.assertFalse(task.done()) + srv.close() + srv.abort_clients() + await asyncio.sleep(0) + await asyncio.sleep(0) + self.assertTrue(task.done()) # Test the various corner cases of Unix server socket removal diff --git a/Misc/NEWS.d/next/Library/2024-01-22-15-50-58.gh-issue-113538.v2wrwg.rst b/Misc/NEWS.d/next/Library/2024-01-22-15-50-58.gh-issue-113538.v2wrwg.rst new file mode 100644 index 000000000000000..5c59af98e136bba --- /dev/null +++ b/Misc/NEWS.d/next/Library/2024-01-22-15-50-58.gh-issue-113538.v2wrwg.rst @@ -0,0 +1,3 @@ +Add :meth:`asyncio.Server.close_clients` and +:meth:`asyncio.Server.abort_clients` methods which allow to more forcefully +close an asyncio server.