From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 47005C433EF for ; Fri, 25 Feb 2022 21:18:39 +0000 (UTC) Received: from localhost ([::1]:42460 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1nNhz4-0001eZ-63 for qemu-devel@archiver.kernel.org; Fri, 25 Feb 2022 16:18:38 -0500 Received: from eggs.gnu.org ([209.51.188.92]:59682) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nNhi5-0003Q3-SZ for qemu-devel@nongnu.org; Fri, 25 Feb 2022 16:01:06 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]:40213) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nNhi1-0005C8-Mi for qemu-devel@nongnu.org; Fri, 25 Feb 2022 16:01:05 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1645822859; 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=Kty20zDPVDZu37iUldxjKjAUv3Ng8RgUyV5Q1uvJlqA=; b=iKCf4XyIvdj4e1w+EJSgDb5wqqt7+kED5oUGWRjeL3fTRBNTRmvnrnAVdkcywp2N8xWSkY ul/FIS/eEhHuBnOxXYD8d/d6T1pgHm10i0QIig6OccoSxkSvBRITCI33PfFjom8sbiizLf 3H+mxNGf9NCAMY/oMGJVJHJGRF3e/wE= 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-121-1p2Elzh_NxOR8dppIdC7FA-1; Fri, 25 Feb 2022 16:00:56 -0500 X-MC-Unique: 1p2Elzh_NxOR8dppIdC7FA-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 3E9EF520E; Fri, 25 Feb 2022 21:00:55 +0000 (UTC) Received: from scv.redhat.com (unknown [10.22.34.166]) by smtp.corp.redhat.com (Postfix) with ESMTP id 580C51081302; Fri, 25 Feb 2022 21:00:54 +0000 (UTC) From: John Snow To: qemu-devel@nongnu.org Subject: [PATCH 08/10] python/aqmp: add start_server() and accept() methods Date: Fri, 25 Feb 2022 15:59:46 -0500 Message-Id: <20220225205948.3693480-9-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 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset="US-ASCII" 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+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Add start_server() and accept() methods that can be used instead of start_server_and_accept() to allow more fine-grained control over the incoming connection process. (Eagle-eyed reviewers will surely notice that it's a bit weird that "CONNECTING" is a state that's shared between both the start_server() and connect() states. That's absolutely true, and it's very true that checking on the presence of _accepted as an indicator of state is a hack. That's also very certainly true. But ... this keeps client code an awful lot simpler, as it doesn't have to care exactly *how* the connection is being made, just that it *is*. Is it worth disrupting that simplicity in order to provide a better state guard on `accept()`? Hm.) Signed-off-by: John Snow --- python/qemu/aqmp/protocol.py | 67 +++++++++++++++++++++++++++++++++--- python/tests/protocol.py | 7 ++++ 2 files changed, 69 insertions(+), 5 deletions(-) diff --git a/python/qemu/aqmp/protocol.py b/python/qemu/aqmp/protocol.py index cdbc9cba0d..2ecba14555 100644 --- a/python/qemu/aqmp/protocol.py +++ b/python/qemu/aqmp/protocol.py @@ -280,6 +280,8 @@ async def start_server_and_accept( Accept a connection and begin processing message queues. If this call fails, `runstate` is guaranteed to be set back to `IDLE`. + This method is precisely equivalent to calling `start_server()` + followed by `accept()`. :param address: Address to listen on; UNIX socket path or TCP address/port. @@ -294,9 +296,62 @@ async def start_server_and_accept( protocol-level failure occurs while establishing a new session, the wrapped error may also be an `QMPError`. """ + await self.start_server(address, ssl) + await self.accept() + assert self.runstate == Runstate.RUNNING + + @upper_half + @require(Runstate.IDLE) + async def start_server(self, address: SocketAddrT, + ssl: Optional[SSLContext] = None) -> None: + """ + Start listening for an incoming connection, but do not wait for a peer. + + This method starts listening for an incoming connection, but + does not block waiting for a peer. This call will return + immediately after binding and listening on a socket. A later + call to `accept()` must be made in order to finalize the + incoming connection. + + :param address: + Address to listen on; UNIX socket path or TCP address/port. + :param ssl: SSL context to use, if any. + + :raise StateError: When the `Runstate` is not `IDLE`. + :raise ConnectError: + When the server could not start listening on this address. + + This exception will wrap a more concrete one. In most cases, + the wrapped exception will be `OSError`. + """ await self._session_guard( self._do_start_server(address, ssl), 'Failed to establish connection') + assert self.runstate == Runstate.CONNECTING + + @upper_half + @require(Runstate.CONNECTING) + async def accept(self) -> None: + """ + Accept an incoming connection and begin processing message queues. + + If this call fails, `runstate` is guaranteed to be set back to `IDLE`. + + :raise StateError: When the `Runstate` is not `CONNECTING`. + :raise QMPError: When `start_server()` was not called yet. + :raise ConnectError: + When a connection or session cannot be established. + + This exception will wrap a more concrete one. In most cases, + the wrapped exception will be `OSError` or `EOFError`. If a + protocol-level failure occurs while establishing a new + session, the wrapped error may also be an `QMPError`. + """ + if self._accepted is None: + raise QMPError("Cannot call accept() before start_server().") + await self._session_guard( + self._do_accept(), + 'Failed to establish connection') await self._session_guard( self._establish_session(), 'Failed to establish session') @@ -512,7 +567,12 @@ def _bind_hack(self, address: Union[str, Tuple[str, int]]) -> None: async def _do_start_server(self, address: SocketAddrT, ssl: Optional[SSLContext] = None) -> None: """ - Acting as the transport server, accept a single connection. + Start listening for an incoming connection, but do not wait for a peer. + + This method starts listening for an incoming connection, but does not + block waiting for a peer. This call will return immediately after + binding and listening to a socket. A later call to accept() must be + made in order to finalize the incoming connection. :param address: Address to listen on; UNIX socket path or TCP address/port. @@ -554,10 +614,7 @@ async def _do_start_server(self, address: SocketAddrT, # This will start the server (bind(2), listen(2)). It will also # call accept(2) if we yield, but we don't block on that here. self._server = await coro - - # Just for this one commit, wait for a peer. - # This gets split out in the next patch. - await self._do_accept() + self.logger.debug("Server listening on %s", address) @upper_half async def _do_accept(self) -> None: diff --git a/python/tests/protocol.py b/python/tests/protocol.py index 5e442e1efb..d6849ad306 100644 --- a/python/tests/protocol.py +++ b/python/tests/protocol.py @@ -43,11 +43,18 @@ async def _establish_session(self): async def _do_start_server(self, address, ssl=None): if self.fake_session: + self._accepted = asyncio.Event() self._set_state(Runstate.CONNECTING) await asyncio.sleep(0) else: await super()._do_start_server(address, ssl) + async def _do_accept(self): + if self.fake_session: + self._accepted = None + else: + await super()._do_accept() + async def _do_connect(self, address, ssl=None): if self.fake_session: self._set_state(Runstate.CONNECTING) -- 2.34.1