[libvirt PATCH 6/6] src: make virObject inherit from GObject
Daniel P. Berrangé
berrange at redhat.com
Tue May 19 17:41:31 UTC 2020
To avoid bugs with mixing of g_object_(ref|unref) vs
virObject(Ref|Unref), we want every virObject to be
a GObject.
Signed-off-by: Daniel P. Berrangé <berrange at redhat.com>
---
src/util/virobject.c | 141 +++++++++++++++++++++++++------------------
src/util/virobject.h | 25 +++-----
2 files changed, 90 insertions(+), 76 deletions(-)
diff --git a/src/util/virobject.c b/src/util/virobject.c
index 4060d7307b..3f0bcc38ea 100644
--- a/src/util/virobject.c
+++ b/src/util/virobject.c
@@ -39,6 +39,7 @@ static unsigned int magicCounter = 0xCAFE0000;
struct _virClass {
virClassPtr parent;
+ GType type;
unsigned int magic;
char *name;
size_t objectSize;
@@ -46,25 +47,28 @@ struct _virClass {
virObjectDisposeCallback dispose;
};
-#define VIR_OBJECT_NOTVALID(obj) (!obj || ((obj->u.s.magic & 0xFFFF0000) != 0xCAFE0000))
+typedef struct _virObjectPrivate virObjectPrivate;
+struct _virObjectPrivate {
+ virClassPtr klass;
+};
+
+
+G_DEFINE_TYPE_WITH_PRIVATE(virObject, vir_object, G_TYPE_OBJECT)
+
+#define VIR_OBJECT_NOTVALID(obj) (!obj || !VIR_IS_OBJECT(obj))
#define VIR_OBJECT_USAGE_PRINT_WARNING(anyobj, objclass) \
do { \
virObjectPtr obj = anyobj; \
- if (VIR_OBJECT_NOTVALID(obj)) { \
- if (!obj) \
- VIR_WARN("Object cannot be NULL"); \
- else \
- VIR_WARN("Object %p has a bad magic number %X", \
- obj, obj->u.s.magic); \
- } else { \
+ if (!obj) \
+ VIR_WARN("Object cannot be NULL"); \
+ if (VIR_OBJECT_NOTVALID(obj)) \
VIR_WARN("Object %p (%s) is not a %s instance", \
- anyobj, obj->klass->name, #objclass); \
- } \
+ anyobj, g_type_name_from_instance((void*)anyobj), #objclass); \
} while (0)
-static virClassPtr virObjectClass;
+static virClassPtr virObjectClassImpl;
static virClassPtr virObjectLockableClass;
static virClassPtr virObjectRWLockableClass;
@@ -74,17 +78,17 @@ static void virObjectRWLockableDispose(void *anyobj);
static int
virObjectOnceInit(void)
{
- if (!(virObjectClass = virClassNew(NULL,
- "virObject",
- sizeof(virObject),
- 0,
- NULL)))
+ if (!(virObjectClassImpl = virClassNew(NULL,
+ "virObject",
+ sizeof(virObject),
+ 0,
+ NULL)))
return -1;
- if (!VIR_CLASS_NEW(virObjectLockable, virObjectClass))
+ if (!VIR_CLASS_NEW(virObjectLockable, virObjectClassImpl))
return -1;
- if (!VIR_CLASS_NEW(virObjectRWLockable, virObjectClass))
+ if (!VIR_CLASS_NEW(virObjectRWLockable, virObjectClassImpl))
return -1;
return 0;
@@ -104,7 +108,7 @@ virClassForObject(void)
if (virObjectInitialize() < 0)
return NULL;
- return virObjectClass;
+ return virObjectClassImpl;
}
@@ -138,6 +142,14 @@ virClassForObjectRWLockable(void)
}
+static void virClassDummyInit(void *klass G_GNUC_UNUSED)
+{
+}
+
+static void virObjectDummyInit(void *obj G_GNUC_UNUSED)
+{
+}
+
/**
* virClassNew:
* @parent: the parent class
@@ -177,25 +189,26 @@ virClassNew(virClassPtr parent,
return NULL;
}
- if (VIR_ALLOC(klass) < 0)
- goto error;
-
+ klass = g_new0(virClass, 1);
klass->parent = parent;
klass->magic = g_atomic_int_add(&magicCounter, 1);
- if (klass->magic > 0xCAFEFFFF) {
- virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
- _("too many object classes defined"));
- goto error;
- }
klass->name = g_strdup(name);
klass->objectSize = objectSize;
+ if (parent == NULL) {
+ klass->type = vir_object_get_type();
+ } else {
+ klass->type =
+ g_type_register_static_simple(parent->type,
+ name,
+ sizeof(virObjectClass),
+ (GClassInitFunc)virClassDummyInit,
+ objectSize,
+ (GInstanceInitFunc)virObjectDummyInit,
+ 0);
+ }
klass->dispose = dispose;
return klass;
-
- error:
- VIR_FREE(klass);
- return NULL;
}
@@ -237,17 +250,13 @@ void *
virObjectNew(virClassPtr klass)
{
virObjectPtr obj = NULL;
+ virObjectPrivate *priv;
- if (VIR_ALLOC_VAR(obj,
- char,
- klass->objectSize - sizeof(virObject)) < 0)
- return NULL;
-
- obj->u.s.magic = klass->magic;
- obj->klass = klass;
- g_atomic_int_set(&obj->u.s.refs, 1);
+ obj = g_object_new(klass->type, NULL);
- PROBE(OBJECT_NEW, "obj=%p classname=%s", obj, obj->klass->name);
+ priv = vir_object_get_instance_private(obj);
+ priv->klass = klass;
+ PROBE(OBJECT_NEW, "obj=%p classname=%s", obj, priv->klass->name);
return obj;
}
@@ -304,6 +313,33 @@ virObjectRWLockableNew(virClassPtr klass)
return obj;
}
+static void vir_object_finalize(GObject *gobj)
+{
+ PROBE(OBJECT_DISPOSE, "obj=%p", gobj);
+ virObjectPtr obj = VIR_OBJECT(gobj);
+ virObjectPrivate *priv = vir_object_get_instance_private(obj);
+
+ virClassPtr klass = priv->klass;
+ while (klass) {
+ if (klass->dispose)
+ klass->dispose(obj);
+ klass = klass->parent;
+ }
+
+ G_OBJECT_CLASS(vir_object_parent_class)->finalize(gobj);
+}
+
+static void vir_object_init(virObject *obj G_GNUC_UNUSED)
+{
+}
+
+
+static void vir_object_class_init(virObjectClass *klass)
+{
+ GObjectClass *obj = G_OBJECT_CLASS(klass);
+
+ obj->finalize = vir_object_finalize;
+}
static void
virObjectLockableDispose(void *anyobj)
@@ -340,23 +376,8 @@ virObjectUnref(void *anyobj)
if (VIR_OBJECT_NOTVALID(obj))
return;
- bool lastRef = !!g_atomic_int_dec_and_test(&obj->u.s.refs);
+ g_object_unref(anyobj);
PROBE(OBJECT_UNREF, "obj=%p", obj);
- if (lastRef) {
- PROBE(OBJECT_DISPOSE, "obj=%p", obj);
- virClassPtr klass = obj->klass;
- while (klass) {
- if (klass->dispose)
- klass->dispose(obj);
- klass = klass->parent;
- }
-
- /* Clear & poison object */
- memset(obj, 0, obj->klass->objectSize);
- obj->u.s.magic = 0xDEADBEEF;
- obj->klass = (void*)0xDEADBEEF;
- VIR_FREE(obj);
- }
}
@@ -376,7 +397,8 @@ virObjectRef(void *anyobj)
if (VIR_OBJECT_NOTVALID(obj))
return NULL;
- g_atomic_int_add(&obj->u.s.refs, 1);
+
+ g_object_ref(obj);
PROBE(OBJECT_REF, "obj=%p", obj);
return anyobj;
}
@@ -539,10 +561,13 @@ virObjectIsClass(void *anyobj,
virClassPtr klass)
{
virObjectPtr obj = anyobj;
+ virObjectPrivate *priv;
+
if (VIR_OBJECT_NOTVALID(obj))
return false;
- return virClassIsDerivedFrom(obj->klass, klass);
+ priv = vir_object_get_instance_private(obj);
+ return virClassIsDerivedFrom(priv->klass, klass);
}
diff --git a/src/util/virobject.h b/src/util/virobject.h
index cfedb19b13..18a9f098a6 100644
--- a/src/util/virobject.h
+++ b/src/util/virobject.h
@@ -24,6 +24,8 @@
#include "internal.h"
#include "virthread.h"
+#include <glib-object.h>
+
typedef struct _virClass virClass;
typedef virClass *virClassPtr;
@@ -38,22 +40,11 @@ typedef virObjectRWLockable *virObjectRWLockablePtr;
typedef void (*virObjectDisposeCallback)(void *obj);
-/* Most code should not play with the contents of this struct; however,
- * the struct itself is public so that it can be embedded as the first
- * field of a subclassed object. */
-struct _virObject {
- /* Ensure correct alignment of this and all subclasses, even on
- * platforms where 'long long' or function pointers have stricter
- * requirements than 'void *'. */
- union {
- long long dummy_align1;
- void (*dummy_align2) (void);
- struct {
- unsigned int magic;
- int refs;
- } s;
- } u;
- virClassPtr klass;
+#define VIR_TYPE_OBJECT vir_object_get_type()
+G_DECLARE_DERIVABLE_TYPE(virObject, vir_object, VIR, OBJECT, GObject);
+
+struct _virObjectClass {
+ GObjectClass parent;
};
struct _virObjectLockable {
@@ -109,8 +100,6 @@ virObjectNew(virClassPtr klass)
void
virObjectUnref(void *obj);
-G_DEFINE_AUTOPTR_CLEANUP_FUNC(virObject, virObjectUnref);
-
void *
virObjectRef(void *obj);
--
2.24.1
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