diff mbox

[03/13] qom: add support for weak referenced object: aka UnownedObject

Message ID 1422439417-5031-4-git-send-email-imammedo@redhat.com
State New
Headers show

Commit Message

Igor Mammedov Jan. 28, 2015, 10:03 a.m. UTC 
it adds support for weak reference model used by glib's
GInitiallyUnowned to QEMU's QOM model.

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
---
 include/qom/object.h | 20 ++++++++++++++++++++
 qom/object.c         | 20 +++++++++++++++++++-
 2 files changed, 39 insertions(+), 1 deletion(-)

Comments

Paolo Bonzini Jan. 28, 2015, 10:09 a.m. UTC | #1 
On 28/01/2015 11:03, Igor Mammedov wrote:
> it adds support for weak reference model used by glib's
> GInitiallyUnowned to QEMU's QOM model.
> 
> Signed-off-by: Igor Mammedov <imammedo@redhat.com>
> ---
>  include/qom/object.h | 20 ++++++++++++++++++++
>  qom/object.c         | 20 +++++++++++++++++++-
>  2 files changed, 39 insertions(+), 1 deletion(-)
> 
> diff --git a/include/qom/object.h b/include/qom/object.h
> index 89c3092..e0e4cc8 100644
> --- a/include/qom/object.h
> +++ b/include/qom/object.h
> @@ -1314,5 +1314,25 @@ int object_child_foreach(Object *obj, int (*fn)(Object *child, void *opaque),
>   */
>  Object *container_get(Object *root, const char *path);
>  
> +#define TYPE_UNOWNED_OBJECT "unowned-object"
> +#define UNOWNED_OBJECT(obj) \
> +     OBJECT_CHECK(UnownedObject, (obj), TYPE_UNOWNED_OBJECT)
> +#define UNOWNED_OBJECT_CLASS(klass) \
> +     OBJECT_CLASS_CHECK(UnownedObjectClass, (klass), TYPE_UNOWNED_OBJECT)
> +#define UNOWNED_OBJECT_GET_CLASS \
> +     OBJECT_GET_CLASS(UnownedObjectClass, (obj), TYPE_UNOWNED_OBJECT)
> +#define OBJECT_WEAK_REF (1UL << 31)
> +
> +typedef struct UnownedObjectClass
> +{
> +    /*< private >*/
> +    ObjectClass parent_class;
> +} UnownedObjectClass;
> +
> +typedef struct UnownedObject
> +{
> +    /*< private >*/
> +    Object parent_obj;
> +} UnownedObject;
>  
>  #endif
> diff --git a/qom/object.c b/qom/object.c
> index 1812c73..96842c7 100644
> --- a/qom/object.c
> +++ b/qom/object.c
> @@ -705,6 +705,10 @@ void object_ref(Object *obj)
>      if (!obj) {
>          return;
>      }
> +    if (atomic_fetch_and(&obj->ref, ~OBJECT_WEAK_REF) & OBJECT_WEAK_REF)

Please first do a non-atomic test, since this is unlikely to happen but
atomic_fetch_and is quite expensive (it compiles into a cmpxchg loop).

Paolo

> +    {
> +        return;
> +    }
>       atomic_inc(&obj->ref);
>  }
>  
> @@ -713,7 +717,7 @@ void object_unref(Object *obj)
>      if (!obj) {
>          return;
>      }
> -    g_assert(obj->ref > 0);
> +    g_assert((obj->ref & ~OBJECT_WEAK_REF) > 0);
>  
>      /* parent always holds a reference to its children */
>      if (atomic_fetch_dec(&obj->ref) == 1) {
> @@ -1709,6 +1713,12 @@ static void object_instance_init(Object *obj)
>      object_property_add_str(obj, "type", qdev_get_type, NULL, NULL);
>  }
>  
> +
> +static void unowned_object_instance_init(Object *obj)
> +{
> +    obj->ref |= OBJECT_WEAK_REF;
> +}
> +
>  static void register_types(void)
>  {
>      static TypeInfo interface_info = {
> @@ -1724,8 +1734,16 @@ static void register_types(void)
>          .abstract = true,
>      };
>  
> +    static TypeInfo unowned_object_info = {
> +        .name = TYPE_UNOWNED_OBJECT,
> +        .instance_size = sizeof(UnownedObject),
> +        .instance_init = unowned_object_instance_init,
> +        .abstract = true,
> +    };
> +
>      type_interface = type_register_internal(&interface_info);
>      type_register_internal(&object_info);
> +    type_register_internal(&unowned_object_info);
>  }
>  
>  type_init(register_types)
>
Igor Mammedov Jan. 28, 2015, 12:55 p.m. UTC | #2 
On Wed, 28 Jan 2015 11:09:22 +0100
Paolo Bonzini <pbonzini@redhat.com> wrote:

> 
> 
> On 28/01/2015 11:03, Igor Mammedov wrote:
> > it adds support for weak reference model used by glib's
> > GInitiallyUnowned to QEMU's QOM model.
> > 
> > Signed-off-by: Igor Mammedov <imammedo@redhat.com>
> > ---
> >  include/qom/object.h | 20 ++++++++++++++++++++
> >  qom/object.c         | 20 +++++++++++++++++++-
> >  2 files changed, 39 insertions(+), 1 deletion(-)
> > 
> > diff --git a/include/qom/object.h b/include/qom/object.h
> > index 89c3092..e0e4cc8 100644
> > --- a/include/qom/object.h
> > +++ b/include/qom/object.h
> > @@ -1314,5 +1314,25 @@ int object_child_foreach(Object *obj, int (*fn)(Object *child, void *opaque),
> >   */
> >  Object *container_get(Object *root, const char *path);
> >  
> > +#define TYPE_UNOWNED_OBJECT "unowned-object"
> > +#define UNOWNED_OBJECT(obj) \
> > +     OBJECT_CHECK(UnownedObject, (obj), TYPE_UNOWNED_OBJECT)
> > +#define UNOWNED_OBJECT_CLASS(klass) \
> > +     OBJECT_CLASS_CHECK(UnownedObjectClass, (klass), TYPE_UNOWNED_OBJECT)
> > +#define UNOWNED_OBJECT_GET_CLASS \
> > +     OBJECT_GET_CLASS(UnownedObjectClass, (obj), TYPE_UNOWNED_OBJECT)
> > +#define OBJECT_WEAK_REF (1UL << 31)
> > +
> > +typedef struct UnownedObjectClass
> > +{
> > +    /*< private >*/
> > +    ObjectClass parent_class;
> > +} UnownedObjectClass;
> > +
> > +typedef struct UnownedObject
> > +{
> > +    /*< private >*/
> > +    Object parent_obj;
> > +} UnownedObject;
> >  
> >  #endif
> > diff --git a/qom/object.c b/qom/object.c
> > index 1812c73..96842c7 100644
> > --- a/qom/object.c
> > +++ b/qom/object.c
> > @@ -705,6 +705,10 @@ void object_ref(Object *obj)
> >      if (!obj) {
> >          return;
> >      }
> > +    if (atomic_fetch_and(&obj->ref, ~OBJECT_WEAK_REF) & OBJECT_WEAK_REF)
> 
> Please first do a non-atomic test, since this is unlikely to happen but
> atomic_fetch_and is quite expensive (it compiles into a cmpxchg loop).
sure

> 
> Paolo
> 
> > +    {
> > +        return;
> > +    }
> >       atomic_inc(&obj->ref);
> >  }
> >  
> > @@ -713,7 +717,7 @@ void object_unref(Object *obj)
> >      if (!obj) {
> >          return;
> >      }
> > -    g_assert(obj->ref > 0);
> > +    g_assert((obj->ref & ~OBJECT_WEAK_REF) > 0);
> >  
> >      /* parent always holds a reference to its children */
> >      if (atomic_fetch_dec(&obj->ref) == 1) {
> > @@ -1709,6 +1713,12 @@ static void object_instance_init(Object *obj)
> >      object_property_add_str(obj, "type", qdev_get_type, NULL, NULL);
> >  }
> >  
> > +
> > +static void unowned_object_instance_init(Object *obj)
> > +{
> > +    obj->ref |= OBJECT_WEAK_REF;
> > +}
> > +
> >  static void register_types(void)
> >  {
> >      static TypeInfo interface_info = {
> > @@ -1724,8 +1734,16 @@ static void register_types(void)
> >          .abstract = true,
> >      };
> >  
> > +    static TypeInfo unowned_object_info = {
> > +        .name = TYPE_UNOWNED_OBJECT,
> > +        .instance_size = sizeof(UnownedObject),
> > +        .instance_init = unowned_object_instance_init,
> > +        .abstract = true,
> > +    };
> > +
> >      type_interface = type_register_internal(&interface_info);
> >      type_register_internal(&object_info);
> > +    type_register_internal(&unowned_object_info);
> >  }
> >  
> >  type_init(register_types)
> >
diff mbox

Patch

diff --git a/include/qom/object.h b/include/qom/object.h
index 89c3092..e0e4cc8 100644
--- a/include/qom/object.h
+++ b/include/qom/object.h
@@ -1314,5 +1314,25 @@  int object_child_foreach(Object *obj, int (*fn)(Object *child, void *opaque),
  */
 Object *container_get(Object *root, const char *path);
 
+#define TYPE_UNOWNED_OBJECT "unowned-object"
+#define UNOWNED_OBJECT(obj) \
+     OBJECT_CHECK(UnownedObject, (obj), TYPE_UNOWNED_OBJECT)
+#define UNOWNED_OBJECT_CLASS(klass) \
+     OBJECT_CLASS_CHECK(UnownedObjectClass, (klass), TYPE_UNOWNED_OBJECT)
+#define UNOWNED_OBJECT_GET_CLASS \
+     OBJECT_GET_CLASS(UnownedObjectClass, (obj), TYPE_UNOWNED_OBJECT)
+#define OBJECT_WEAK_REF (1UL << 31)
+
+typedef struct UnownedObjectClass
+{
+    /*< private >*/
+    ObjectClass parent_class;
+} UnownedObjectClass;
+
+typedef struct UnownedObject
+{
+    /*< private >*/
+    Object parent_obj;
+} UnownedObject;
 
 #endif
diff --git a/qom/object.c b/qom/object.c
index 1812c73..96842c7 100644
--- a/qom/object.c
+++ b/qom/object.c
@@ -705,6 +705,10 @@  void object_ref(Object *obj)
     if (!obj) {
         return;
     }
+    if (atomic_fetch_and(&obj->ref, ~OBJECT_WEAK_REF) & OBJECT_WEAK_REF)
+    {
+        return;
+    }
      atomic_inc(&obj->ref);
 }
 
@@ -713,7 +717,7 @@  void object_unref(Object *obj)
     if (!obj) {
         return;
     }
-    g_assert(obj->ref > 0);
+    g_assert((obj->ref & ~OBJECT_WEAK_REF) > 0);
 
     /* parent always holds a reference to its children */
     if (atomic_fetch_dec(&obj->ref) == 1) {
@@ -1709,6 +1713,12 @@  static void object_instance_init(Object *obj)
     object_property_add_str(obj, "type", qdev_get_type, NULL, NULL);
 }
 
+
+static void unowned_object_instance_init(Object *obj)
+{
+    obj->ref |= OBJECT_WEAK_REF;
+}
+
 static void register_types(void)
 {
     static TypeInfo interface_info = {
@@ -1724,8 +1734,16 @@  static void register_types(void)
         .abstract = true,
     };
 
+    static TypeInfo unowned_object_info = {
+        .name = TYPE_UNOWNED_OBJECT,
+        .instance_size = sizeof(UnownedObject),
+        .instance_init = unowned_object_instance_init,
+        .abstract = true,
+    };
+
     type_interface = type_register_internal(&interface_info);
     type_register_internal(&object_info);
+    type_register_internal(&unowned_object_info);
 }
 
 type_init(register_types)