From patchwork Fri Feb 25 20:59:42 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: John Snow X-Patchwork-Id: 1597888 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: bilbo.ozlabs.org; dkim=fail reason="signature verification failed" (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=fYz2sXuk; dkim-atps=neutral Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by bilbo.ozlabs.org (Postfix) with ESMTPS id 4K52R72swfz9sGG for ; Sat, 26 Feb 2022 08:07:29 +1100 (AEDT) Received: from localhost ([::1]:46438 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1nNhoE-0000zq-GT for incoming@patchwork.ozlabs.org; Fri, 25 Feb 2022 16:07:26 -0500 Received: from eggs.gnu.org ([209.51.188.92]:59602) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nNhhy-0003Dm-Gr for qemu-devel@nongnu.org; Fri, 25 Feb 2022 16:01:02 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]:36452) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nNhhv-0005BJ-Q0 for qemu-devel@nongnu.org; Fri, 25 Feb 2022 16:00:58 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1645822855; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=S0paPOxauK37bfDsuaHmAZ5y+/SHZYIm5TxPmZk7jns=; b=fYz2sXukyiRZJFsJxch7aKLFJ/l2N7Ae+0yqm1PmWdsqCjf0ZyUOs8N8JgZCImDUPH2Ynf sC4WCkz1y+BugNnOx2pv4mWGu855Hpl0zMjfGZhPl5jQmoRoUbo5750IWaWDZdoe9tNeq9 me+OnamsvQAtSK+4cZyLbZOGGl7bBOM= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-625-mG6LivKkMDezP_YtLRmbvQ-1; Fri, 25 Feb 2022 16:00:51 -0500 X-MC-Unique: mG6LivKkMDezP_YtLRmbvQ-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id EA267824FA9; Fri, 25 Feb 2022 21:00:50 +0000 (UTC) Received: from scv.redhat.com (unknown [10.22.34.166]) by smtp.corp.redhat.com (Postfix) with ESMTP id 443081081302; Fri, 25 Feb 2022 21:00:46 +0000 (UTC) From: John Snow To: qemu-devel@nongnu.org Subject: [PATCH 04/10] python/aqmp: split _client_connected_cb() out as _incoming() Date: Fri, 25 Feb 2022 15:59:42 -0500 Message-Id: <20220225205948.3693480-5-jsnow@redhat.com> In-Reply-To: <20220225205948.3693480-1-jsnow@redhat.com> References: <20220225205948.3693480-1-jsnow@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=jsnow@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Received-SPF: pass client-ip=170.10.129.124; envelope-from=jsnow@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -28 X-Spam_score: -2.9 X-Spam_bar: -- X-Spam_report: (-2.9 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.082, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H5=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Kevin Wolf , Peter Maydell , Daniel Berrange , Beraldo Leal , Cleber Rosa , John Snow Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" As part of disentangling the monolithic nature of _do_accept(), split out the incoming callback to prepare for factoring out the "wait for a peer" step. Namely, this means using an event signal we can wait on from outside of this method. Signed-off-by: John Snow Reviewed-by: Daniel P. Berrangé --- python/qemu/aqmp/protocol.py | 83 +++++++++++++++++++++++++----------- 1 file changed, 58 insertions(+), 25 deletions(-) diff --git a/python/qemu/aqmp/protocol.py b/python/qemu/aqmp/protocol.py index b7e5e635d8..56f05b9030 100644 --- a/python/qemu/aqmp/protocol.py +++ b/python/qemu/aqmp/protocol.py @@ -242,6 +242,10 @@ def __init__(self, name: Optional[str] = None) -> None: # Workaround for bind() self._sock: Optional[socket.socket] = None + # Server state for start_server() and _incoming() + self._server: Optional[asyncio.AbstractServer] = None + self._accepted: Optional[asyncio.Event] = None + def __repr__(self) -> str: cls_name = type(self).__name__ tokens = [] @@ -425,6 +429,54 @@ def _set_state(self, state: Runstate) -> None: self._runstate_event.set() self._runstate_event.clear() + @bottom_half # However, it does not run from the R/W tasks. + async def _stop_server(self) -> None: + """ + Stop listening for / accepting new incoming connections. + """ + if self._server is None: + return + + try: + self.logger.debug("Stopping server.") + self._server.close() + await self._server.wait_closed() + self.logger.debug("Server stopped.") + finally: + self._server = None + + @bottom_half # However, it does not run from the R/W tasks. + async def _incoming(self, + reader: asyncio.StreamReader, + writer: asyncio.StreamWriter) -> None: + """ + Accept an incoming connection and signal the upper_half. + + This method does the minimum necessary to accept a single + incoming connection. It signals back to the upper_half ASAP so + that any errors during session initialization can occur + naturally in the caller's stack. + + :param reader: Incoming `asyncio.StreamReader` + :param writer: Incoming `asyncio.StreamWriter` + """ + peer = writer.get_extra_info('peername', 'Unknown peer') + self.logger.debug("Incoming connection from %s", peer) + + if self._reader or self._writer: + # Sadly, we can have more than one pending connection + # because of https://bugs.python.org/issue46715 + # Close any extra connections we don't actually want. + self.logger.warning("Extraneous connection inadvertently accepted") + writer.close() + return + + # A connection has been accepted; stop listening for new ones. + assert self._accepted is not None + await self._stop_server() + self._reader, self._writer = (reader, writer) + self._accepted.set() + def _bind_hack(self, address: Union[str, Tuple[str, int]]) -> None: """ Used to create a socket in advance of accept(). @@ -469,30 +521,11 @@ async def _do_accept(self, address: SocketAddrT, self._set_state(Runstate.CONNECTING) self.logger.debug("Awaiting connection on %s ...", address) - connected = asyncio.Event() - server: Optional[asyncio.AbstractServer] = None - - async def _client_connected_cb(reader: asyncio.StreamReader, - writer: asyncio.StreamWriter) -> None: - """Used to accept a single incoming connection, see below.""" - nonlocal server - nonlocal connected - - # A connection has been accepted; stop listening for new ones. - assert server is not None - server.close() - await server.wait_closed() - server = None - - # Register this client as being connected - self._reader, self._writer = (reader, writer) - - # Signal back: We've accepted a client! - connected.set() + self._accepted = asyncio.Event() if isinstance(address, tuple): coro = asyncio.start_server( - _client_connected_cb, + self._incoming, host=None if self._sock else address[0], port=None if self._sock else address[1], ssl=ssl, @@ -502,7 +535,7 @@ async def _client_connected_cb(reader: asyncio.StreamReader, ) else: coro = asyncio.start_unix_server( - _client_connected_cb, + self._incoming, path=None if self._sock else address, ssl=ssl, backlog=1, @@ -515,9 +548,9 @@ async def _client_connected_cb(reader: asyncio.StreamReader, # otherwise yield. await asyncio.sleep(0) - server = await coro # Starts listening - await connected.wait() # Waits for the callback to fire (and finish) - assert server is None + self._server = await coro # Starts listening + await self._accepted.wait() # Waits for the callback to finish + assert self._server is None self._sock = None self.logger.debug("Connection accepted.")