From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from eggs.gnu.org ([208.118.235.92]:47392)
	by lists.gnu.org with esmtp (Exim 4.71)
	(envelope-from <afaerber@suse.de>) id 1T0yap-0008Qw-GH
	for qemu-devel@nongnu.org; Mon, 13 Aug 2012 13:38:20 -0400
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <afaerber@suse.de>) id 1T0yan-00054m-BR
	for qemu-devel@nongnu.org; Mon, 13 Aug 2012 13:38:19 -0400
Received: from cantor2.suse.de ([195.135.220.15]:46030 helo=mx2.suse.de)
	by eggs.gnu.org with esmtp (Exim 4.71)
	(envelope-from <afaerber@suse.de>) id 1T0yan-00054Z-4n
	for qemu-devel@nongnu.org; Mon, 13 Aug 2012 13:38:17 -0400
Message-ID: <50293B84.2090805@suse.de>
Date: Mon, 13 Aug 2012 19:38:12 +0200
From: =?UTF-8?B?QW5kcmVhcyBGw6RyYmVy?= <afaerber@suse.de>
MIME-Version: 1.0
References: <1344507137-11173-1-git-send-email-xiawenc@linux.vnet.ibm.com>
	<5024E6FD.6030507@redhat.com> <5028D680.7040108@linux.vnet.ibm.com>
In-Reply-To: <5028D680.7040108@linux.vnet.ibm.com>
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: quoted-printable
Subject: Re: [Qemu-devel] [qemu-devel] [PATCH V2 2/3] [RFC] libqblock-API
 design
List-Id: <qemu-devel.nongnu.org>
List-Unsubscribe: <https://lists.nongnu.org/mailman/options/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>
List-Archive: <http://lists.nongnu.org/archive/html/qemu-devel>
List-Post: <mailto:qemu-devel@nongnu.org>
List-Help: <mailto:qemu-devel-request@nongnu.org?subject=help>
List-Subscribe: <https://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=subscribe>
To: Wenchao Xia <xiawenc@linux.vnet.ibm.com>
Cc: Blue Swirl <blauwirbel@gmail.com>, Paolo Bonzini <pbonzini@redhat.com>, Anthony Liguori <aliguori@us.ibm.com>, qemu-devel@nongnu.org, Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>

Am 13.08.2012 12:27, schrieb Wenchao Xia:
> =E4=BA=8E 2012-8-10 18:48, Paolo Bonzini =E5=86=99=E9=81=93:
>> Il 09/08/2012 12:12, Wenchao Xia ha scritto:
>>> +        assert(0 =3D=3D set_option_parameter_int(param,
>>> +                                BLOCK_OPT_SIZE, o_cow->virt_size));
>>
>> Assertions should not have side effects.
>>
>    what side effects would this line have?

It sets some BLOCK_OPT_SIZE parameter. :)

What Paolo probably meant is to extract that part from the assert():
ret =3D set_option_...(...);
assert(ret =3D=3D 0);
eliminating the kraxelism at the same time. ;)
Then you can more safely do, e.g., #define assert(x) do {} while (0)

Regards,
Andreas

--=20
SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 N=C3=BCrnberg, Germany
GF: Jeff Hawn, Jennifer Guild, Felix Imend=C3=B6rffer; HRB 16746 AG N=C3=BC=
rnberg