From patchwork Tue Sep 5 13:29:05 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Hajnoczi X-Patchwork-Id: 810171 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=nongnu.org (client-ip=2001:4830:134:3::11; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3xmndb4XMZz9t2S for ; Tue, 5 Sep 2017 23:30:11 +1000 (AEST) Received: from localhost ([::1]:58948 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dpDvd-0000nz-KV for incoming@patchwork.ozlabs.org; Tue, 05 Sep 2017 09:30:09 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:51265) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dpDus-0000jQ-L7 for qemu-devel@nongnu.org; Tue, 05 Sep 2017 09:29:27 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dpDun-0003rA-SE for qemu-devel@nongnu.org; Tue, 05 Sep 2017 09:29:22 -0400 Received: from mx1.redhat.com ([209.132.183.28]:55656) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dpDun-0003qB-MG for qemu-devel@nongnu.org; Tue, 05 Sep 2017 09:29:17 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 84101267C5; Tue, 5 Sep 2017 13:29:16 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 84101267C5 Authentication-Results: ext-mx06.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx06.extmail.prod.ext.phx2.redhat.com; spf=fail smtp.mailfrom=stefanha@redhat.com Received: from localhost (ovpn-117-180.ams2.redhat.com [10.36.117.180]) by smtp.corp.redhat.com (Postfix) with ESMTP id 6BF726A0A5; Tue, 5 Sep 2017 13:29:13 +0000 (UTC) From: Stefan Hajnoczi To: Date: Tue, 5 Sep 2017 14:29:05 +0100 Message-Id: <20170905132908.30931-2-stefanha@redhat.com> In-Reply-To: <20170905132908.30931-1-stefanha@redhat.com> References: <20170905132908.30931-1-stefanha@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.30]); Tue, 05 Sep 2017 13:29:16 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PULL 1/4] qemu.py: make VM() a context manager X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Peter Maydell , Eduardo Habkost , Stefan Hajnoczi Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" There are a number of ways to ensure that the QEMU process is shut down when the test ends, including atexit.register(), try: finally:, or unittest.teardown() methods. All of these require extra code and the programmer must remember to add vm.shutdown(). A nice solution is context managers: with VM(binary) as vm: ... # vm is guaranteed to be shut down here Cc: Eduardo Habkost Signed-off-by: Stefan Hajnoczi Reviewed-by: Eduardo Habkost Message-id: 20170824072202.26818-2-stefanha@redhat.com Signed-off-by: Stefan Hajnoczi --- scripts/qemu.py | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-) diff --git a/scripts/qemu.py b/scripts/qemu.py index 880e3e8219..4d8ee10943 100644 --- a/scripts/qemu.py +++ b/scripts/qemu.py @@ -21,7 +21,14 @@ import qmp.qmp class QEMUMachine(object): - '''A QEMU VM''' + '''A QEMU VM + + Use this object as a context manager to ensure the QEMU process terminates:: + + with VM(binary) as vm: + ... + # vm is guaranteed to be shut down here + ''' def __init__(self, binary, args=[], wrapper=[], name=None, test_dir="/var/tmp", monitor_address=None, socket_scm_helper=None, debug=False): @@ -40,6 +47,13 @@ class QEMUMachine(object): self._socket_scm_helper = socket_scm_helper self._debug = debug + def __enter__(self): + return self + + def __exit__(self, exc_type, exc_val, exc_tb): + self.shutdown() + return False + # This can be used to add an unused monitor instance. def add_monitor_telnet(self, ip, port): args = 'tcp:%s:%d,server,nowait,telnet' % (ip, port)