Patchwork [qom-next,v2,3/7] qom: Add "realized" property

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Submitter Andreas Färber
Date June 10, 2012, 1:09 a.m.
Message ID <1339290549-3789-4-git-send-email-afaerber@suse.de>
Download mbox | patch
Permalink /patch/163968/
State New
Headers show

Comments

Andreas Färber - June 10, 2012, 1:09 a.m.
Since we had to move the state field from DeviceState to Object, we cannot
delay the implementation of the "realized" property.  The property is
a trigger for two actions that propagate through the composition tree.
"Realize" is called when the property becomes true, and propagates in
pre-order; realize can fail if the values of the properties are not valid.
"Unrealize" is called when the property becomes false, and propagates in
post-order; unrealize cannot fail.

Realize/unrealize is separate from reset.  Reset propagation is a thorny
issue of its own.  We expect classes that care to implement a reset method
and call it from realize or realize_children, depending on whether
pre-order or post-order is more appropriate.

This patch adds four methods (realize, realize_children, unrealize,
unrealize_children) to ObjectClass, together with a default implementation
of realize_children and unrealize_children.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
[PB: Added unrealize and (un)realize_children]
Signed-off-by: Andreas Färber <afaerber@suse.de>
---
 include/qemu/object.h |   22 ++++++++++++
 qom/object.c          |   91 +++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 113 insertions(+), 0 deletions(-)

Patch

diff --git a/include/qemu/object.h b/include/qemu/object.h
index 0a3828d..274c839 100644
--- a/include/qemu/object.h
+++ b/include/qemu/object.h
@@ -239,6 +239,12 @@  struct ObjectClass
 {
     /*< private >*/
     Type type;
+
+    /*< public >*/
+    void (*realize)(Object *obj, struct Error **errp);
+    void (*realize_children)(Object *obj, struct Error **errp);
+    void (*unrealize)(Object *obj);
+    void (*unrealize_children)(Object *obj);
 };
 
 /**
@@ -452,6 +458,22 @@  Object *object_new_with_type(Type type);
 void object_delete(Object *obj);
 
 /**
+ * object_realize_children:
+ * @obj: The object whose children should be realized.
+ *
+ * The default implementation of realize_children.
+ */
+void object_realize_children(Object *obj, struct Error **errp);
+
+/**
+ * object_unrealize_children:
+ * @obj: The object whose children should be unrealized.
+ *
+ * The default implementation of unrealize_children.
+ */
+void object_unrealize_children(Object *obj);
+
+/**
  * object_initialize_with_type:
  * @obj: A pointer to the memory to be used for the object.
  * @type: The type of the object to instantiate.
diff --git a/qom/object.c b/qom/object.c
index 8d10a27..c1f1bb4 100644
--- a/qom/object.c
+++ b/qom/object.c
@@ -265,6 +265,85 @@  static void object_interface_init(Object *obj, InterfaceImpl *iface)
     obj->interfaces = g_slist_prepend(obj->interfaces, iface_obj);
 }
 
+static void object_get_realized(Object *obj, Visitor *v, void *opaque,
+                                const char *name, Error **errp)
+{
+    visit_type_bool(v, &obj->realized, name, errp);
+}
+
+static void object_unrealize(Object *obj)
+{
+    ObjectClass *klass = object_get_class(obj);
+
+    if (klass->unrealize_children) {
+        klass->unrealize_children(obj);
+    }
+    if (obj->realized && klass->unrealize) {
+        klass->unrealize(obj);
+    }
+    obj->realized = false;
+}
+
+static int object_unrealize_one(Object *obj, void *unused)
+{
+    object_unrealize(obj);
+    return 0;
+}
+
+void object_unrealize_children(Object *obj)
+{
+    object_child_foreach(obj, object_unrealize_one, NULL);
+}
+
+static void object_realize(Object *obj, Error **errp)
+{
+    ObjectClass *klass = object_get_class(obj);
+
+    if (!obj->realized && klass->realize) {
+        klass->realize(obj, errp);
+    }
+    obj->realized = true;
+    if (klass->realize_children) {
+        klass->realize_children(obj, errp);
+    }
+}
+
+static int object_realize_one(Object *obj, void *errp)
+{
+    Error *err = NULL;
+    object_realize(obj, &err);
+    if (err) {
+        error_propagate((Error **)errp, err);
+        return 1;
+    }
+
+    return 0;
+}
+
+void object_realize_children(Object *obj, Error **errp)
+{
+    object_child_foreach(obj, object_realize_one, errp);
+}
+
+static void object_set_realized(Object *obj, Visitor *v, void *opaque,
+                                const char *name, Error **errp)
+{
+    bool value;
+    Error *err = NULL;
+
+    visit_type_bool(v, &value, name, &err);
+    if (err) {
+        error_propagate(errp, err);
+        return;
+    }
+
+    if (value) {
+        object_realize(obj, errp);
+    } else {
+        object_unrealize(obj);
+    }
+}
+
 static void object_init_with_type(Object *obj, TypeImpl *ti)
 {
     int i;
@@ -353,6 +432,8 @@  void object_unparent(Object *obj)
 
 static void object_deinit(Object *obj, TypeImpl *type)
 {
+    object_property_set_bool(obj, false, "realized", NULL);
+
     if (type->instance_finalize) {
         type->instance_finalize(obj);
     }
@@ -1245,6 +1326,15 @@  bool object_is_realized(Object *obj)
 static void object_instance_init(Object *obj)
 {
     object_property_add_str(obj, "type", qdev_get_type, NULL, NULL);
+
+    object_property_add(obj, "realized", "bool", object_get_realized,
+                        object_set_realized, NULL, NULL, NULL);
+}
+
+static void object_class_init(ObjectClass *klass, void *class_data)
+{
+    klass->realize_children = object_realize_children;
+    klass->unrealize_children = object_unrealize_children;
 }
 
 static void register_types(void)
@@ -1258,6 +1348,7 @@  static void register_types(void)
     static TypeInfo object_info = {
         .name = TYPE_OBJECT,
         .instance_size = sizeof(Object),
+        .class_init = object_class_init,
         .instance_init = object_instance_init,
         .abstract = true,
     };