From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:35982) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1f3XRw-00057o-DB for qemu-devel@nongnu.org; Tue, 03 Apr 2018 21:42:58 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1f3XRt-00017K-A8 for qemu-devel@nongnu.org; Tue, 03 Apr 2018 21:42:56 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:55958 helo=mx1.redhat.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1f3XRt-000177-3u for qemu-devel@nongnu.org; Tue, 03 Apr 2018 21:42:53 -0400 Date: Wed, 4 Apr 2018 09:42:41 +0800 From: Peter Xu Message-ID: <20180404014241.GG26441@xz-mi> References: <20180326061157.24865-1-peterx@redhat.com> <20180326104739.GC5267@localhost.localdomain> <20180327022155.GE17789@xz-mi> <20180403125918.GF4467@stefanha-x1.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20180403125918.GF4467@stefanha-x1.localdomain> Subject: Re: [Qemu-devel] [PATCH] iotests: fix wait_until_completed() List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Stefan Hajnoczi Cc: Kevin Wolf , qemu-devel@nongnu.org, Max Reitz On Tue, Apr 03, 2018 at 01:59:18PM +0100, Stefan Hajnoczi wrote: > On Tue, Mar 27, 2018 at 10:21:55AM +0800, Peter Xu wrote: > > On Mon, Mar 26, 2018 at 12:47:39PM +0200, Kevin Wolf wrote: > > > Am 26.03.2018 um 08:11 hat Peter Xu geschrieben: > > > > If there are more than one events, wait_until_completed() might return > > > > the 2nd event even if the 1st event is JOB_COMPLETED, since the for loop > > > > will continue to run even if completed is set to True. > > > > > > > > It never happened before, but it can be triggered when OOB is enabled > > > > due to the RESUME startup message. Fix that up by removing the boolean > > > > and make sure we return the correct event. > > > > > > > > Signed-off-by: Peter Xu > > > > --- > > > > tests/qemu-iotests/iotests.py | 20 ++++++++------------ > > > > 1 file changed, 8 insertions(+), 12 deletions(-) > > > > > > > > diff --git a/tests/qemu-iotests/iotests.py b/tests/qemu-iotests/iotests.py > > > > index b5d7945af8..11704e6583 100644 > > > > --- a/tests/qemu-iotests/iotests.py > > > > +++ b/tests/qemu-iotests/iotests.py > > > > @@ -470,18 +470,14 @@ class QMPTestCase(unittest.TestCase): > > > > > > > > def wait_until_completed(self, drive='drive0', check_offset=True): > > > > '''Wait for a block job to finish, returning the event''' > > > > - completed = False > > > > - while not completed: > > > > - for event in self.vm.get_qmp_events(wait=True): > > > > - if event['event'] == 'BLOCK_JOB_COMPLETED': > > > > - self.assert_qmp(event, 'data/device', drive) > > > > - self.assert_qmp_absent(event, 'data/error') > > > > - if check_offset: > > > > - self.assert_qmp(event, 'data/offset', event['data']['len']) > > > > - completed = True > > > > - > > > > - self.assert_no_active_block_jobs() > > > > - return event > > > > + for event in self.vm.get_qmp_events(wait=True): > > > > + if event['event'] == 'BLOCK_JOB_COMPLETED': > > > > + self.assert_qmp(event, 'data/device', drive) > > > > + self.assert_qmp_absent(event, 'data/error') > > > > + if check_offset: > > > > + self.assert_qmp(event, 'data/offset', event['data']['len']) > > > > + self.assert_no_active_block_jobs() > > > > + return event > > > > > > > > def wait_ready(self, drive='drive0'): > > > > '''Wait until a block job BLOCK_JOB_READY event''' > > > > > > If an event is pending, but it's not the expected event, won't we return > > > None now instead of waiting for the BLOCK_JOB_COMPLETED event? > > > > If so, we'll return none. > > Kevin is pointing out that this patch is broken. Previously the > function waited for BLOCK_JOB_COMPLETED, even when other events were > pending when we entered the function. Now it returns None and does not > wait for BLOCK_JOB_COMPLETED! Aha! Surely I missed that. :) > > > The patch fixes the other case when there > > are two events: one JOB_COMPLETED plus another (e.g., RESUME) event. > > When that happens, logically we should return one JOB_COMPLETED event, > > but the old code will return the other event (e.g., RESUME). > > > > > > > > Wouldn't it be much easier to just add a 'break'? > > > > Yes, it's the same. But IMHO those logics (e.g., the completed > > variable) are not really needed at all. This one is simpler. > > No, the outer loop is needed so that the function waits until > BLOCK_JOB_COMPLETED is received. It's not possible to do it with a > single for loop. Indeed. But then I would still slightly prefer removing the "completed" var: def wait_until_completed(self, drive='drive0', check_offset=True): '''Wait for a block job to finish, returning the event''' while True: for event in self.vm.get_qmp_events(wait=True): if event['event'] == 'BLOCK_JOB_COMPLETED': self.assert_qmp(event, 'data/device', drive) self.assert_qmp_absent(event, 'data/error') if check_offset: self.assert_qmp(event, 'data/offset', event['data']['len']) self.assert_no_active_block_jobs() return event Or a single break would work too. Do either of you have any preference? I can repost in either way. Thanks, -- Peter Xu