From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from [140.186.70.92] (port=55043 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1Q4G73-0005tL-Gb for qemu-devel@nongnu.org; Mon, 28 Mar 2011 13:20:23 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Q4G71-0002z0-Di for qemu-devel@nongnu.org; Mon, 28 Mar 2011 13:20:20 -0400 Received: from mail-yi0-f45.google.com ([209.85.218.45]:47384) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Q4G70-0002yu-WD for qemu-devel@nongnu.org; Mon, 28 Mar 2011 13:20:19 -0400 Received: by yib19 with SMTP id 19so1490899yib.4 for ; Mon, 28 Mar 2011 10:20:18 -0700 (PDT) Message-ID: <4D90C339.9040204@codemonkey.ws> Date: Mon, 28 Mar 2011 12:19:53 -0500 From: Anthony Liguori MIME-Version: 1.0 Subject: Re: [Qemu-devel] Re: [RFC][PATCH v1 05/12] qapi: fix handling for null-return async callbacks References: <1301082479-4058-1-git-send-email-mdroth@linux.vnet.ibm.com> <1301082479-4058-6-git-send-email-mdroth@linux.vnet.ibm.com> <4D8D0788.7070700@us.ibm.com> <20110328134747.5c9fbc8e@doriath> <4D90BEDC.6050207@us.ibm.com> <20110328140651.13f10e43@doriath> In-Reply-To: <20110328140651.13f10e43@doriath> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Luiz Capitulino Cc: Jes.Sorensen@redhat.com, agl@linux.vnet.ibm.com, Michael Roth , qemu-devel@nongnu.org On 03/28/2011 12:06 PM, Luiz Capitulino wrote: > On Mon, 28 Mar 2011 12:01:16 -0500 > Anthony Liguori wrote: > >> On 03/28/2011 11:47 AM, Luiz Capitulino wrote: >>> On Fri, 25 Mar 2011 16:22:16 -0500 >>> Anthony Liguori wrote: >>> >>>> On 03/25/2011 02:47 PM, Michael Roth wrote: >>>>> Async commands like 'guest-ping' have NULL retvals. Handle these by >>>>> inserting an empty dictionary in the response's "return" field. >>>>> >>>>> Signed-off-by: Michael Roth >>>>> --- >>>>> qmp-core.c | 5 ++++- >>>>> 1 files changed, 4 insertions(+), 1 deletions(-) >>>>> >>>>> diff --git a/qmp-core.c b/qmp-core.c >>>>> index e33f7a4..9f3d182 100644 >>>>> --- a/qmp-core.c >>>>> +++ b/qmp-core.c >>>>> @@ -922,9 +922,12 @@ void qmp_async_complete_command(QmpCommandState *cmd, QObject *retval, Error *er >>>>> rsp = qdict_new(); >>>>> if (err) { >>>>> qdict_put_obj(rsp, "error", error_get_qobject(err)); >>>>> - } else { >>>>> + } else if (retval) { >>>>> qobject_incref(retval); >>>>> qdict_put_obj(rsp, "return", retval); >>>>> + } else { >>>>> + /* add empty "return" dict, this is the standard for NULL returns */ >>>>> + qdict_put_obj(rsp, "return", QOBJECT(qdict_new())); >>>> Luiz, I know we decided to return empty dicts because it lets us extend >>>> things better, but did we want to rule out the use of a 'null' return >>>> value entirely? >>> For asynchronous commands you mean? No we didn't. >> No, nothing to do with asynchronous commands. Just in general. >> >> The question is, is it legal for a command to return 'null'. It's >> certain valid JSON, but is it valid QMP? > No, it's not valid. Do we have a reason for this? Regards, Anthony Liguori