From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from [140.186.70.92] (port=44735 helo=eggs.gnu.org)
	by lists.gnu.org with esmtp (Exim 4.43) id 1Pwb0l-0007h5-UB
	for qemu-devel@nongnu.org; Mon, 07 Mar 2011 09:02:13 -0500
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <anthony@codemonkey.ws>) id 1Pwb0l-00055B-0A
	for qemu-devel@nongnu.org; Mon, 07 Mar 2011 09:02:11 -0500
Received: from mail-gx0-f173.google.com ([209.85.161.173]:54879)
	by eggs.gnu.org with esmtp (Exim 4.71)
	(envelope-from <anthony@codemonkey.ws>) id 1Pwb0k-00054z-UD
	for qemu-devel@nongnu.org; Mon, 07 Mar 2011 09:02:10 -0500
Received: by gxk28 with SMTP id 28so2037466gxk.4
	for <qemu-devel@nongnu.org>; Mon, 07 Mar 2011 06:02:10 -0800 (PST)
Message-ID: <4D74E561.4070405@codemonkey.ws>
Date: Mon, 07 Mar 2011 08:02:09 -0600
From: Anthony Liguori <anthony@codemonkey.ws>
MIME-Version: 1.0
Subject: Re: [Qemu-devel] [PATCH 15/22] qapi: add new QMP server that uses
	CharDriverState
References: <1299460984-15849-1-git-send-email-aliguori@us.ibm.com>	<1299460984-15849-16-git-send-email-aliguori@us.ibm.com>
	<AANLkTikdZta19BsTxmmOnQvB8APCHsPp8HKy8BaSUNN0@mail.gmail.com>
In-Reply-To: <AANLkTikdZta19BsTxmmOnQvB8APCHsPp8HKy8BaSUNN0@mail.gmail.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
List-Id: qemu-devel.nongnu.org
List-Unsubscribe: <http://lists.nongnu.org/mailman/listinfo/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: <http://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=subscribe>
To: Stefan Hajnoczi <stefanha@gmail.com>
Cc: qemu-devel@nongnu.org, Adam Litke <aglitke@linux.vnet.ibm.com>, Markus Armbruster <armbru@redhat.com>, Luiz Capitulino <lcapitulino@redhat.com>

On 03/07/2011 07:52 AM, Stefan Hajnoczi wrote:
> On Mon, Mar 7, 2011 at 1:22 AM, Anthony Liguori<aliguori@us.ibm.com>  wrote:
>    
>> +static void qmp_chr_send_greeting(QmpSession *s)
>> +{
>> +    VersionInfo *info;
>> +    QObject *vers;
>> +    QObject *greeting;
>> +    QString *str;
>> +
>> +    info = qmp_query_version(NULL);
>> +    vers = qmp_marshal_type_VersionInfo(info);
>> +    qmp_free_version_info(info);
>> +
>> +    greeting = qobject_from_jsonf("{'QMP': {'version': %p, 'capabilities': []} }",
>> +                                  vers);
>> +    str = qobject_to_json(greeting);
>> +    qobject_decref(greeting);
>> +
>> +    qemu_chr_write(s->chr, (void *)str->string, str->length);
>> +    qemu_chr_write(s->chr, (void *)"\n", 1);
>> +    QDECREF(str);
>> +}
>>      
> Is vers leaked?
>    

No, %p takes ownership of the object.  qdict_put* also does FWIW.

The ownership semantics of QObject functions are very challenging.  We 
really need a concept of floating references to let stuff like this 
continue to work without explicitly transferring ownership.

But really, a big part of this refactoring is isolating QObject so that 
we can eventually replace it with GVariant so it may not be worth 
worrying about.

Regards,

Anthony Liguori

> Stefan
>
>