From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:44763) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WnEeK-0005ra-Ae for qemu-devel@nongnu.org; Wed, 21 May 2014 18:06:21 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WnEe8-0004e5-U1 for qemu-devel@nongnu.org; Wed, 21 May 2014 18:06:12 -0400 Received: from mail-ee0-x230.google.com ([2a00:1450:4013:c00::230]:35664) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WnEe8-0004dq-KD for qemu-devel@nongnu.org; Wed, 21 May 2014 18:06:00 -0400 Received: by mail-ee0-f48.google.com with SMTP id e49so2003191eek.35 for ; Wed, 21 May 2014 15:05:59 -0700 (PDT) Sender: Paolo Bonzini Message-ID: <537D2342.3000300@redhat.com> Date: Thu, 22 May 2014 00:05:54 +0200 From: Paolo Bonzini MIME-Version: 1.0 References: <1400703772-3324-1-git-send-email-stefanha@redhat.com> <1400703772-3324-2-git-send-email-stefanha@redhat.com> In-Reply-To: <1400703772-3324-2-git-send-email-stefanha@redhat.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH 1/7] qom: add object_property_add_alias() List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Stefan Hajnoczi , qemu-devel@nongnu.org Cc: Peter Crosthwaite , Andreas Faerber , Frederic Konrad Il 21/05/2014 22:22, Stefan Hajnoczi ha scritto: > Sometimes an object needs to present a property which is actually on > another object, or it needs to provide an alias name for an existing > property. > > Examples: > a.foo -> b.foo > a.old_name -> a.new_name > > The new object_property_add_alias() API allows objects to alias a > property on another object. The source and target names can be > different. > > Signed-off-by: Stefan Hajnoczi > --- > include/qom/object.h | 18 ++++++++++++++++++ > qom/object.c | 52 ++++++++++++++++++++++++++++++++++++++++++++++++++++ > 2 files changed, 70 insertions(+) > > diff --git a/include/qom/object.h b/include/qom/object.h > index a641dcd..70cbd13 100644 > --- a/include/qom/object.h > +++ b/include/qom/object.h > @@ -1203,6 +1203,24 @@ void object_property_add_uint64_ptr(Object *obj, const char *name, > const uint64_t *v, Error **Errp); > > /** > + * object_property_add_alias: > + * @obj: the object to add a property to > + * @name: the name of the property > + * @target_obj: the object to forward property access property to > + * @target_name: the name of the property on the forwarded object > + * @errp: if an error occurs, a pointer to an area to store the error > + * > + * Add an alias for a property on an object. This function will add a property > + * of the same type as the forwarded property. > + * > + * The caller must ensure that @target_obj stays alive as long as > + * this property exists. > + */ > +void object_property_add_alias(Object *obj, const char *name, > + Object *target_obj, const char *target_name, > + Error **errp); > + > +/** > * object_child_foreach: > * @obj: the object whose children will be navigated > * @fn: the iterator function to be called > diff --git a/qom/object.c b/qom/object.c > index e42b254..ff50f37 100644 > --- a/qom/object.c > +++ b/qom/object.c > @@ -1515,6 +1515,58 @@ void object_property_add_uint64_ptr(Object *obj, const char *name, > NULL, NULL, (void *)v, errp); > } > > +typedef struct > +{ > + Object *target_obj; > + const char *target_name; > +} AliasProperty; > + > +static void property_get_alias(Object *obj, struct Visitor *v, void *opaque, > + const char *name, Error **errp) > +{ > + AliasProperty *prop = opaque; > + > + object_property_get(prop->target_obj, v, prop->target_name, errp); > +} > + > +static void property_set_alias(Object *obj, struct Visitor *v, void *opaque, > + const char *name, Error **errp) > +{ > + AliasProperty *prop = opaque; > + > + object_property_set(prop->target_obj, v, prop->target_name, errp); > +} > + > +static void property_release_alias(Object *obj, const char *name, void *opaque) > +{ > + AliasProperty *prop = opaque; > + > + g_free(prop); > +} > + > +void object_property_add_alias(Object *obj, const char *name, > + Object *target_obj, const char *target_name, > + Error **errp) > +{ > + AliasProperty *prop; > + ObjectProperty *target_prop; > + > + target_prop = object_property_find(target_obj, target_name, errp); > + if (!target_prop) { > + return; > + } > + > + prop = g_malloc(sizeof(*prop)); > + prop->target_obj = target_obj; > + prop->target_name = target_name; > + > + object_property_add(obj, name, target_prop->type, > + property_get_alias, > + property_set_alias, > + property_release_alias, > + prop, errp); > +} ref target_obj here, and unref in property_release_alias? Paolo > static void object_instance_init(Object *obj) > { > object_property_add_str(obj, "type", qdev_get_type, NULL, NULL); >