* SECTION:gstminiobject
* @short_description: Lightweight base class for the GStreamer object hierarchy
*
- * #GstMiniObject is a baseclass like #GObject, but has been stripped down of
- * features to be fast and small.
- * It offers sub-classing and ref-counting in the same way as #GObject does.
- * It has no properties and no signal-support though.
+ * #GstMiniObject is a simple structure that can be used to implement refcounted
+ * types.
*
- * Last reviewed on 2005-11-23 (0.9.5)
+ * Subclasses will include #GstMiniObject as the first member in their structure
+ * and then call gst_mini_object_init() to initialize the #GstMiniObject fields.
+ *
+ * gst_mini_object_ref() and gst_mini_object_unref() increment and decrement the
+ * refcount respectively. When the refcount of a mini-object reaches 0, the
+ * dispose function is called first and when this returns %TRUE, the free
+ * function of the miniobject is called.
+ *
+ * A copy can be made with gst_mini_object_copy().
+ *
+ * gst_mini_object_is_writable() will return %TRUE when the refcount of the
+ * object is exactly 1, meaning the current caller has the only reference to the
+ * object. gst_mini_object_make_writable() will return a writable version of the
+ * object, which might be a new copy when the refcount was not 1.
+ *
+ * Last reviewed on 2012-03-28 (0.11.3)
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#include "gst/gstinfo.h"
#include <gobject/gvaluecollector.h>
-#define GST_DISABLE_TRACE
-
#ifndef GST_DISABLE_TRACE
#include "gsttrace.h"
static GstAllocTrace *_gst_mini_object_trace;
/* Mutex used for weak referencing */
G_LOCK_DEFINE_STATIC (weak_refs_mutex);
-/* boxed copy and free functions. Don't real copy or free but simply
- * change the refcount */
-static GstMiniObject *
-_gst_mini_object_boxed_copy (GstMiniObject * mini_object)
-{
- if (mini_object)
- return gst_mini_object_ref (mini_object);
- else
- return NULL;
-}
-
-static void
-_gst_mini_object_boxed_free (GstMiniObject * mini_object)
-{
- if (mini_object)
- gst_mini_object_unref (mini_object);
-}
-
-/**
- * gst_mini_object_register:
- * @name: name of the new boxed type
- *
- * This function creates a new G_TYPE_BOXED derived type id for a new boxed type
- * with name @name. The default miniobject refcounting copy and free function
- * are used for the boxed type.
- *
- * Returns: a new G_TYPE_BOXED derived type id for @name.
- */
-GType
-gst_mini_object_register (const gchar * name)
+void
+_priv_gst_mini_object_initialize (void)
{
- GType type;
-
- g_return_val_if_fail (name != NULL, 0);
-
- type = g_boxed_type_register_static (name,
- (GBoxedCopyFunc) _gst_mini_object_boxed_copy,
- (GBoxedFreeFunc) _gst_mini_object_boxed_free);
-
- return type;
+#ifndef GST_DISABLE_TRACE
+ _gst_mini_object_trace = _gst_alloc_trace_register ("GstMiniObject", 0);
+#endif
}
/**
mini_object->size = size;
mini_object->n_weak_refs = 0;
mini_object->weak_refs = NULL;
+
+#ifndef GST_DISABLE_TRACE
+ _gst_alloc_trace_new (_gst_mini_object_trace, mini_object);
+#endif
}
/**
* @mini_object: the mini-object to check
*
* Checks if a mini-object is writable. A mini-object is writable
- * if the reference count is one and the #GST_MINI_OBJECT_FLAG_READONLY
- * flag is not set. Modification of a mini-object should only be
- * done after verifying that it is writable.
+ * if the reference count is one. Modification of a mini-object should
+ * only be done after verifying that it is writable.
*
* MT safe
*
gst_mini_object_unref (GstMiniObject * mini_object)
{
g_return_if_fail (mini_object != NULL);
- g_return_if_fail (mini_object->refcount > 0);
GST_CAT_TRACE (GST_CAT_REFCOUNTING, "%p unref %d->%d",
mini_object,
GST_MINI_OBJECT_REFCOUNT_VALUE (mini_object),
GST_MINI_OBJECT_REFCOUNT_VALUE (mini_object) - 1);
+ g_return_if_fail (mini_object->refcount > 0);
+
if (G_UNLIKELY (g_atomic_int_dec_and_test (&mini_object->refcount))) {
- /* At this point, the refcount of the object is 0. We increase the refcount
- * here because if a subclass recycles the object and gives out a new
- * reference we don't want to free the instance anymore. */
- gst_mini_object_ref (mini_object);
+ gboolean do_free;
if (mini_object->dispose)
- mini_object->dispose (mini_object);
+ do_free = mini_object->dispose (mini_object);
+ else
+ do_free = TRUE;
- /* decrement the refcount again, if the subclass recycled the object we don't
+ /* if the subclass recycled the object (and returned FALSE) we don't
* want to free the instance anymore */
- if (G_LIKELY (g_atomic_int_dec_and_test (&mini_object->refcount))) {
+ if (G_LIKELY (do_free)) {
/* The weak reference stack is freed in the notification function */
if (mini_object->n_weak_refs)
weak_refs_notify (mini_object);
#ifndef GST_DISABLE_TRACE
- gst_alloc_trace_free (_gst_mini_object_trace, mini_object);
+ _gst_alloc_trace_free (_gst_mini_object_trace, mini_object);
#endif
if (mini_object->free)
mini_object->free (mini_object);
* gst_mini_object_take:
* @olddata: (inout) (transfer full): pointer to a pointer to a mini-object to
* be replaced
+ * @newdata: pointer to new mini-object
*
* Modifies a pointer to point to a new mini-object. The modification
* is done atomically. This version is similar to gst_mini_object_replace()
projects / platform / upstream / gstreamer.git / blobdiff