2 * Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
3 * 2000 Wim Taymans <wtay@chello.be>
4 * 2005 Wim Taymans <wim@fluendo.com>
6 * gstobject.c: Fundamental class used for all of GStreamer
8 * This library is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Library General Public
10 * License as published by the Free Software Foundation; either
11 * version 2 of the License, or (at your option) any later version.
13 * This library is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Library General Public License for more details.
18 * You should have received a copy of the GNU Library General Public
19 * License along with this library; if not, write to the
20 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
21 * Boston, MA 02111-1307, USA.
26 * @short_description: Base class for the GStreamer object hierarchy
28 * #GstObject provides a root for the object hierarchy tree filed in by the
29 * GStreamer library. It is currently a thin wrapper on top of
30 * #GObject. It is an abstract class that is not very usable on its own.
32 * #GstObject gives us basic refcounting, parenting functionality and locking.
33 * Most of the function are just extended for special GStreamer needs and can be
34 * found under the same name in the base class of #GstObject which is #GObject
35 * (e.g. g_object_ref() becomes gst_object_ref()).
37 * The most interesting difference between #GstObject and #GObject is the
38 * "floating" reference count. A #GObject is created with a reference count of
39 * 1, owned by the creator of the #GObject. (The owner of a reference is the
40 * code section that has the right to call gst_object_unref() in order to
41 * remove that reference.) A #GstObject is created with a reference count of 1
42 * also, but it isn't owned by anyone; Instead, the initial reference count
43 * of a #GstObject is "floating". The floating reference can be removed by
44 * anyone at any time, by calling gst_object_sink(). gst_object_sink() does
45 * nothing if an object is already sunk (has no floating reference).
47 * When you add a #GstElement to its parent container, the parent container will
51 * gst_object_ref (GST_OBJECT (child_element));
52 * gst_object_sink (GST_OBJECT (child_element));
55 * This means that the container now owns a reference to the child element
56 * (since it called gst_object_ref()), and the child element has no floating
59 * The purpose of the floating reference is to keep the child element alive
60 * until you add it to a parent container, which then manages the lifetime of
64 * element = gst_element_factory_make (factoryname, name);
65 * // element has one floating reference to keep it alive
66 * gst_bin_add (GST_BIN (bin), element);
67 * // element has one non-floating reference owned by the container
71 * Another effect of this is, that calling gst_object_unref() on a bin object,
72 * will also destoy all the #GstElement objects in it. The same is true for
73 * calling gst_bin_remove().
75 * Special care has to be taken for all methods that gst_object_sink() an object
76 * since if the caller of those functions had a floating reference to the object,
77 * the object reference is now invalid.
79 * In contrast to #GObject instances, #GstObject adds a name property. The functions
80 * gst_object_set_name() and gst_object_get_name() are used to set/get the name
83 * Last reviewed on 2005-11-09 (0.9.4)
86 #include "gst_private.h"
88 #include "gstobject.h"
89 #include "gstmarshal.h"
93 #ifndef GST_DISABLE_TRACE
95 static GstAllocTrace *_gst_object_trace;
98 #define DEBUG_REFCOUNT
100 /* Object signals and args */
105 #ifndef GST_DISABLE_LOADSAVE
125 /* maps type name quark => count */
126 static GData *object_name_counts = NULL;
128 G_LOCK_DEFINE_STATIC (object_name_mutex);
130 typedef struct _GstSignalObject GstSignalObject;
131 typedef struct _GstSignalObjectClass GstSignalObjectClass;
133 static GType gst_signal_object_get_type (void);
134 static void gst_signal_object_class_init (GstSignalObjectClass * klass);
135 static void gst_signal_object_init (GstSignalObject * object);
137 #ifndef GST_DISABLE_LOADSAVE
138 static guint gst_signal_object_signals[SO_LAST_SIGNAL] = { 0 };
141 static void gst_object_class_init (GstObjectClass * klass);
142 static void gst_object_init (GTypeInstance * instance, gpointer g_class);
144 static void gst_object_set_property (GObject * object, guint prop_id,
145 const GValue * value, GParamSpec * pspec);
146 static void gst_object_get_property (GObject * object, guint prop_id,
147 GValue * value, GParamSpec * pspec);
148 static void gst_object_dispatch_properties_changed (GObject * object,
149 guint n_pspecs, GParamSpec ** pspecs);
151 static void gst_object_dispose (GObject * object);
152 static void gst_object_finalize (GObject * object);
154 static gboolean gst_object_set_name_default (GstObject * object);
156 #ifndef GST_DISABLE_LOADSAVE
157 static void gst_object_real_restore_thyself (GstObject * object,
161 static GObjectClass *parent_class = NULL;
162 static guint gst_object_signals[LAST_SIGNAL] = { 0 };
165 gst_object_get_type (void)
167 static GType gst_object_type = 0;
169 if (G_UNLIKELY (gst_object_type == 0)) {
170 static const GTypeInfo object_info = {
171 sizeof (GstObjectClass),
174 (GClassInitFunc) gst_object_class_init,
184 g_type_register_static (G_TYPE_OBJECT, "GstObject", &object_info,
185 G_TYPE_FLAG_ABSTRACT);
187 return gst_object_type;
191 gst_object_class_init (GstObjectClass * klass)
193 GObjectClass *gobject_class;
195 gobject_class = G_OBJECT_CLASS (klass);
197 parent_class = g_type_class_peek_parent (klass);
199 #ifndef GST_DISABLE_TRACE
200 _gst_object_trace = gst_alloc_trace_register (g_type_name (GST_TYPE_OBJECT));
203 gobject_class->set_property = GST_DEBUG_FUNCPTR (gst_object_set_property);
204 gobject_class->get_property = GST_DEBUG_FUNCPTR (gst_object_get_property);
206 g_object_class_install_property (gobject_class, ARG_NAME,
207 g_param_spec_string ("name", "Name", "The name of the object",
208 NULL, G_PARAM_READWRITE | G_PARAM_CONSTRUCT));
211 * GstObject::parent-set:
212 * @gstobject: a #GstObject
213 * @parent: the new parent
215 * Emitted when the parent of an object is set.
217 gst_object_signals[PARENT_SET] =
218 g_signal_new ("parent-set", G_TYPE_FROM_CLASS (klass), G_SIGNAL_RUN_LAST,
219 G_STRUCT_OFFSET (GstObjectClass, parent_set), NULL, NULL,
220 g_cclosure_marshal_VOID__OBJECT, G_TYPE_NONE, 1, G_TYPE_OBJECT);
223 * GstObject::parent-unset:
224 * @gstobject: a #GstObject
225 * @parent: the old parent
227 * Emitted when the parent of an object is unset.
229 gst_object_signals[PARENT_UNSET] =
230 g_signal_new ("parent-unset", G_TYPE_FROM_CLASS (klass),
231 G_SIGNAL_RUN_LAST, G_STRUCT_OFFSET (GstObjectClass, parent_unset), NULL,
232 NULL, g_cclosure_marshal_VOID__OBJECT, G_TYPE_NONE, 1, G_TYPE_OBJECT);
234 #ifndef GST_DISABLE_LOADSAVE
236 * GstObject::object-saved:
237 * @gstobject: a #GstObject
238 * @xml_node: the xmlNodePtr of the parent node
240 * Trigered whenever a new object is saved to XML. You can connect to this
241 * signal to insert custom XML tags into the core XML.
243 /* FIXME This should be the GType of xmlNodePtr instead of G_TYPE_POINTER
244 * (if libxml would use GObject)
246 gst_object_signals[OBJECT_SAVED] =
247 g_signal_new ("object-saved", G_TYPE_FROM_CLASS (klass),
248 G_SIGNAL_RUN_LAST, G_STRUCT_OFFSET (GstObjectClass, object_saved), NULL,
249 NULL, g_cclosure_marshal_VOID__POINTER, G_TYPE_NONE, 1, G_TYPE_POINTER);
251 klass->restore_thyself = gst_object_real_restore_thyself;
255 * GstObject::deep-notify:
256 * @gstobject: a #GstObject
257 * @prop_object: the object that originated the signal
258 * @prop: the property that changed
260 * The deep notify signal is used to be notified of property changes. It is
261 * typically attached to the toplevel bin to receive notifications from all
262 * the elements contained in that bin.
264 gst_object_signals[DEEP_NOTIFY] =
265 g_signal_new ("deep-notify", G_TYPE_FROM_CLASS (klass),
266 G_SIGNAL_RUN_FIRST | G_SIGNAL_NO_RECURSE | G_SIGNAL_DETAILED |
267 G_SIGNAL_NO_HOOKS, G_STRUCT_OFFSET (GstObjectClass, deep_notify), NULL,
268 NULL, gst_marshal_VOID__OBJECT_PARAM, G_TYPE_NONE, 2, GST_TYPE_OBJECT,
271 klass->path_string_separator = "/";
272 klass->lock = g_new0 (GStaticRecMutex, 1);
273 g_static_rec_mutex_init (klass->lock);
275 klass->signal_object = g_object_new (gst_signal_object_get_type (), NULL);
277 /* see the comments at gst_object_dispatch_properties_changed */
278 gobject_class->dispatch_properties_changed
279 = GST_DEBUG_FUNCPTR (gst_object_dispatch_properties_changed);
281 gobject_class->dispose = gst_object_dispose;
282 gobject_class->finalize = gst_object_finalize;
286 gst_object_init (GTypeInstance * instance, gpointer g_class)
288 GstObject *object = GST_OBJECT (instance);
290 object->lock = g_mutex_new ();
291 object->parent = NULL;
293 GST_CAT_LOG_OBJECT (GST_CAT_REFCOUNTING, object, "%p new", object);
295 #ifndef GST_DISABLE_TRACE
296 gst_alloc_trace_new (_gst_object_trace, object);
300 GST_OBJECT_FLAG_SET (object, GST_OBJECT_FLOATING);
305 * @object: a #GstObject to reference
307 * Increments the refence count on @object. This function
308 * does not take the lock on @object because it relies on
309 * atomic refcounting.
311 * This object returns the input parameter to ease writing
313 * result = gst_object_ref (object->parent);
315 * Returns: A pointer to @object
318 gst_object_ref (gpointer object)
320 g_return_val_if_fail (object != NULL, NULL);
322 #ifdef DEBUG_REFCOUNT
323 GST_CAT_LOG_OBJECT (GST_CAT_REFCOUNTING, object, "%p ref %d->%d",
325 ((GObject *) object)->ref_count, ((GObject *) object)->ref_count + 1);
327 g_object_ref (object);
334 * @object: a #GstObject to unreference
336 * Decrements the refence count on @object. If reference count hits
337 * zero, destroy @object. This function does not take the lock
338 * on @object as it relies on atomic refcounting.
340 * The unref method should never be called with the LOCK held since
341 * this might deadlock the dispose function.
344 gst_object_unref (gpointer object)
346 g_return_if_fail (object != NULL);
347 g_return_if_fail (((GObject *) object)->ref_count > 0);
349 #ifdef DEBUG_REFCOUNT
350 GST_CAT_LOG_OBJECT (GST_CAT_REFCOUNTING, object, "%p unref %d->%d",
352 ((GObject *) object)->ref_count, ((GObject *) object)->ref_count - 1);
354 g_object_unref (object);
359 * @object: a #GstObject to sink
361 * If @object was floating, the #GST_OBJECT_FLOATING flag is removed
362 * and @object is unreffed. When @object was not floating,
363 * this function does nothing.
365 * Any newly created object has a refcount of 1 and is floating.
366 * This function should be used when creating a new object to
367 * symbolically 'take ownership' of @object. This done by first doing a
368 * gst_object_ref() to keep a reference to @object and then gst_object_sink()
369 * to remove and unref any floating references to @object.
370 * Use gst_object_set_parent() to have this done for you.
372 * MT safe. This function grabs and releases @object lock.
375 gst_object_sink (gpointer object)
377 g_return_if_fail (GST_IS_OBJECT (object));
379 GST_CAT_LOG_OBJECT (GST_CAT_REFCOUNTING, object, "sink");
381 GST_OBJECT_LOCK (object);
382 if (G_LIKELY (GST_OBJECT_IS_FLOATING (object))) {
383 GST_CAT_LOG_OBJECT (GST_CAT_REFCOUNTING, object, "clear floating flag");
384 GST_OBJECT_FLAG_UNSET (object, GST_OBJECT_FLOATING);
385 GST_OBJECT_UNLOCK (object);
386 gst_object_unref (object);
388 GST_OBJECT_UNLOCK (object);
393 * gst_object_replace:
394 * @oldobj: pointer to a place of a #GstObject to replace
395 * @newobj: a new #GstObject
397 * Unrefs the #GstObject pointed to by @oldobj, refs @newobj and
398 * puts @newobj in *@oldobj. Be carefull when calling this
399 * function, it does not take any locks. You might want to lock
400 * the object owning @oldobj pointer before calling this
403 * Make sure not to LOCK @oldobj because it might be unreffed
404 * which could cause a deadlock when it is disposed.
407 gst_object_replace (GstObject ** oldobj, GstObject * newobj)
409 g_return_if_fail (oldobj != NULL);
410 g_return_if_fail (*oldobj == NULL || GST_IS_OBJECT (*oldobj));
411 g_return_if_fail (newobj == NULL || GST_IS_OBJECT (newobj));
413 #ifdef DEBUG_REFCOUNT
414 GST_CAT_LOG (GST_CAT_REFCOUNTING, "replace %s (%d) with %s (%d)",
415 *oldobj ? GST_STR_NULL (GST_OBJECT_NAME (*oldobj)) : "(NONE)",
416 *oldobj ? G_OBJECT (*oldobj)->ref_count : 0,
417 newobj ? GST_STR_NULL (GST_OBJECT_NAME (newobj)) : "(NONE)",
418 newobj ? G_OBJECT (newobj)->ref_count : 0);
421 if (G_LIKELY (*oldobj != newobj)) {
423 gst_object_ref (newobj);
425 gst_object_unref (*oldobj);
431 /* dispose is called when the object has to release all links
432 * to other objects */
434 gst_object_dispose (GObject * object)
438 GST_CAT_LOG_OBJECT (GST_CAT_REFCOUNTING, object, "dispose");
440 GST_OBJECT_LOCK (object);
441 if ((parent = GST_OBJECT_PARENT (object)))
443 GST_OBJECT_PARENT (object) = NULL;
444 GST_OBJECT_UNLOCK (object);
446 parent_class->dispose (object);
453 g_critical ("\nTrying to dispose object \"%s\", but it still has a "
454 "parent \"%s\".\nYou need to let the parent manage the "
455 "object instead of unreffing the object directly.\n",
456 GST_OBJECT_NAME (object), GST_OBJECT_NAME (parent));
457 GST_OBJECT_UNLOCK (object);
458 /* ref the object again to revive it in this error case */
459 object = gst_object_ref (object);
464 /* finalize is called when the object has to free its resources */
466 gst_object_finalize (GObject * object)
468 GstObject *gstobject = GST_OBJECT (object);
470 GST_CAT_LOG_OBJECT (GST_CAT_REFCOUNTING, object, "finalize");
472 g_signal_handlers_destroy (object);
474 g_free (gstobject->name);
475 g_mutex_free (gstobject->lock);
477 #ifndef GST_DISABLE_TRACE
478 gst_alloc_trace_free (_gst_object_trace, object);
481 parent_class->finalize (object);
484 /* Changing a GObject property of a GstObject will result in "deep_notify"
485 * signals being emitted by the object itself, as well as in each parent
486 * object. This is so that an application can connect a listener to the
487 * top-level bin to catch property-change notifications for all contained
490 * This function is not MT safe in glib < 2.8 so we need to lock it with a
491 * classwide mutex in that case.
496 gst_object_dispatch_properties_changed (GObject * object,
497 guint n_pspecs, GParamSpec ** pspecs)
499 GstObject *gst_object, *parent, *old_parent;
501 gchar *name, *debug_name;
502 GstObjectClass *klass;
504 /* we fail when this is not a GstObject */
505 g_return_if_fail (GST_IS_OBJECT (object));
507 klass = GST_OBJECT_GET_CLASS (object);
509 /* do the standard dispatching */
510 G_OBJECT_CLASS (parent_class)->dispatch_properties_changed (object, n_pspecs,
513 gst_object = GST_OBJECT_CAST (object);
514 name = gst_object_get_name (gst_object);
515 debug_name = GST_STR_NULL (name);
517 /* now let the parent dispatch those, too */
518 parent = gst_object_get_parent (gst_object);
520 /* for debugging ... */
521 gchar *parent_name = gst_object_get_name (parent);
523 #ifndef GST_DISABLE_GST_DEBUG
524 gchar *debug_parent_name = GST_STR_NULL (parent_name);
527 /* need own category? */
528 for (i = 0; i < n_pspecs; i++) {
529 GST_CAT_LOG (GST_CAT_EVENT, "deep notification from %s to %s (%s)",
530 debug_name, debug_parent_name, pspecs[i]->name);
532 g_signal_emit (parent, gst_object_signals[DEEP_NOTIFY],
533 g_quark_from_string (pspecs[i]->name), GST_OBJECT_CAST (object),
536 g_free (parent_name);
539 parent = gst_object_get_parent (old_parent);
540 gst_object_unref (old_parent);
546 * gst_object_default_deep_notify:
547 * @object: the #GObject that signalled the notify.
548 * @orig: a #GstObject that initiated the notify.
549 * @pspec: a #GParamSpec of the property.
550 * @excluded_props: a set of user-specified properties to exclude or
551 * NULL to show all changes.
553 * A default deep_notify signal callback for an object. The user data
554 * should contain a pointer to an array of strings that should be excluded
555 * from the notify. The default handler will print the new value of the property
558 * MT safe. This function grabs and releases @object's LOCK for getting its
562 gst_object_default_deep_notify (GObject * object, GstObject * orig,
563 GParamSpec * pspec, gchar ** excluded_props)
565 GValue value = { 0, }; /* the important thing is that value.type = 0 */
569 if (pspec->flags & G_PARAM_READABLE) {
570 /* let's not print these out for excluded properties... */
571 while (excluded_props != NULL && *excluded_props != NULL) {
572 if (strcmp (pspec->name, *excluded_props) == 0)
576 g_value_init (&value, G_PARAM_SPEC_VALUE_TYPE (pspec));
577 g_object_get_property (G_OBJECT (orig), pspec->name, &value);
579 if (G_IS_PARAM_SPEC_ENUM (pspec)) {
580 GEnumValue *enum_value;
583 g_enum_get_value (G_ENUM_CLASS (g_type_class_ref (pspec->value_type)),
584 g_value_get_enum (&value));
586 str = g_strdup_printf ("%s (%d)", enum_value->value_nick,
589 str = g_strdup_value_contents (&value);
591 name = gst_object_get_path_string (orig);
592 g_print ("%s: %s = %s\n", name, pspec->name, str);
595 g_value_unset (&value);
597 name = gst_object_get_path_string (orig);
598 g_warning ("Parameter %s not readable in %s.", pspec->name, name);
604 gst_object_set_name_default (GstObject * object)
606 const gchar *type_name;
612 /* to ensure guaranteed uniqueness across threads, only one thread
613 * may ever assign a name */
614 G_LOCK (object_name_mutex);
616 if (!object_name_counts) {
617 g_datalist_init (&object_name_counts);
620 q = g_type_qname (G_OBJECT_TYPE (object));
621 count = GPOINTER_TO_INT (g_datalist_id_get_data (&object_name_counts, q));
622 g_datalist_id_set_data (&object_name_counts, q, GINT_TO_POINTER (count + 1));
624 G_UNLOCK (object_name_mutex);
626 /* GstFooSink -> foosinkN */
627 type_name = g_quark_to_string (q);
628 if (strncmp (type_name, "Gst", 3) == 0)
630 tmp = g_strdup_printf ("%s%d", type_name, count);
631 name = g_ascii_strdown (tmp, strlen (tmp));
634 result = gst_object_set_name (object, name);
641 * gst_object_set_name:
642 * @object: a #GstObject
643 * @name: new name of object
645 * Sets the name of @object, or gives @object a guaranteed unique
646 * name (if @name is NULL).
647 * This function makes a copy of the provided name, so the caller
648 * retains ownership of the name it sent.
650 * Returns: TRUE if the name could be set. Since Objects that have
651 * a parent cannot be renamed, this function returns FALSE in those
654 * MT safe. This function grabs and releases @object's LOCK.
657 gst_object_set_name (GstObject * object, const gchar * name)
661 g_return_val_if_fail (GST_IS_OBJECT (object), FALSE);
663 GST_OBJECT_LOCK (object);
665 /* parented objects cannot be renamed */
666 if (G_UNLIKELY (object->parent != NULL))
670 g_free (object->name);
671 object->name = g_strdup (name);
672 GST_OBJECT_UNLOCK (object);
675 GST_OBJECT_UNLOCK (object);
676 result = gst_object_set_name_default (object);
683 GST_WARNING ("parented objects can't be renamed");
684 GST_OBJECT_UNLOCK (object);
690 * gst_object_get_name:
691 * @object: a #GstObject
693 * Returns a copy of the name of @object.
694 * Caller should g_free() the return value after usage.
695 * For a nameless object, this returns NULL, which you can safely g_free()
698 * Returns: the name of @object. g_free() after usage.
700 * MT safe. This function grabs and releases @object's LOCK.
703 gst_object_get_name (GstObject * object)
705 gchar *result = NULL;
707 g_return_val_if_fail (GST_IS_OBJECT (object), NULL);
709 GST_OBJECT_LOCK (object);
710 result = g_strdup (object->name);
711 GST_OBJECT_UNLOCK (object);
717 * gst_object_set_name_prefix:
718 * @object: a #GstObject
719 * @name_prefix: new name prefix of @object
721 * Sets the name prefix of @object to @name_prefix.
722 * This function makes a copy of the provided name prefix, so the caller
723 * retains ownership of the name prefix it sent.
725 * MT safe. This function grabs and releases @object's LOCK.
728 gst_object_set_name_prefix (GstObject * object, const gchar * name_prefix)
730 g_return_if_fail (GST_IS_OBJECT (object));
732 GST_OBJECT_LOCK (object);
733 g_free (object->name_prefix);
734 object->name_prefix = g_strdup (name_prefix); /* NULL gives NULL */
735 GST_OBJECT_UNLOCK (object);
739 * gst_object_get_name_prefix:
740 * @object: a #GstObject
742 * Returns a copy of the name prefix of @object.
743 * Caller should g_free() the return value after usage.
744 * For a prefixless object, this returns NULL, which you can safely g_free()
747 * Returns: the name prefix of @object. g_free() after usage.
749 * MT safe. This function grabs and releases @object's LOCK.
752 gst_object_get_name_prefix (GstObject * object)
754 gchar *result = NULL;
756 g_return_val_if_fail (GST_IS_OBJECT (object), NULL);
758 GST_OBJECT_LOCK (object);
759 result = g_strdup (object->name_prefix);
760 GST_OBJECT_UNLOCK (object);
766 * gst_object_set_parent:
767 * @object: a #GstObject
768 * @parent: new parent of object
770 * Sets the parent of @object to @parent. The object's reference count will
771 * be incremented, and any floating reference will be removed (see gst_object_sink()).
773 * This function causes the parent-set signal to be emitted when the parent
774 * was successfully set.
776 * Returns: TRUE if @parent could be set or FALSE when @object
777 * already had a parent or @object and @parent are the same.
779 * MT safe. Grabs and releases @object's LOCK.
782 gst_object_set_parent (GstObject * object, GstObject * parent)
784 g_return_val_if_fail (GST_IS_OBJECT (object), FALSE);
785 g_return_val_if_fail (GST_IS_OBJECT (parent), FALSE);
786 g_return_val_if_fail (object != parent, FALSE);
788 GST_CAT_DEBUG_OBJECT (GST_CAT_REFCOUNTING, object,
789 "set parent (ref and sink)");
791 GST_OBJECT_LOCK (object);
792 if (G_UNLIKELY (object->parent != NULL))
795 /* sink object, we don't call our own function because we don't
796 * need to release/acquire the lock needlessly or touch the refcount
797 * in the floating case. */
798 object->parent = parent;
799 if (G_LIKELY (GST_OBJECT_IS_FLOATING (object))) {
800 GST_CAT_LOG_OBJECT (GST_CAT_REFCOUNTING, object, "unsetting floating flag");
801 GST_OBJECT_FLAG_UNSET (object, GST_OBJECT_FLOATING);
802 GST_OBJECT_UNLOCK (object);
804 GST_OBJECT_UNLOCK (object);
805 gst_object_ref (object);
808 g_signal_emit (G_OBJECT (object), gst_object_signals[PARENT_SET], 0, parent);
815 GST_CAT_DEBUG_OBJECT (GST_CAT_REFCOUNTING, object,
816 "set parent failed, object already had a parent");
817 GST_OBJECT_UNLOCK (object);
823 * gst_object_get_parent:
824 * @object: a #GstObject
826 * Returns the parent of @object. This function increases the refcount
827 * of the parent object so you should gst_object_unref() it after usage.
829 * Returns: parent of @object, this can be NULL if @object has no
830 * parent. unref after usage.
832 * MT safe. Grabs and releases @object's LOCK.
835 gst_object_get_parent (GstObject * object)
837 GstObject *result = NULL;
839 g_return_val_if_fail (GST_IS_OBJECT (object), NULL);
841 GST_OBJECT_LOCK (object);
842 result = object->parent;
843 if (G_LIKELY (result))
844 gst_object_ref (result);
845 GST_OBJECT_UNLOCK (object);
851 * gst_object_unparent:
852 * @object: a #GstObject to unparent
854 * Clear the parent of @object, removing the associated reference.
855 * This function decreases the refcount of @object.
857 * MT safe. Grabs and releases @object's lock.
860 gst_object_unparent (GstObject * object)
864 g_return_if_fail (GST_IS_OBJECT (object));
866 GST_OBJECT_LOCK (object);
867 parent = object->parent;
869 if (G_LIKELY (parent != NULL)) {
870 GST_CAT_LOG_OBJECT (GST_CAT_REFCOUNTING, object, "unparent");
871 object->parent = NULL;
872 GST_OBJECT_UNLOCK (object);
874 g_signal_emit (G_OBJECT (object), gst_object_signals[PARENT_UNSET], 0,
877 gst_object_unref (object);
879 GST_OBJECT_UNLOCK (object);
884 * gst_object_has_ancestor:
885 * @object: a #GstObject to check
886 * @ancestor: a #GstObject to check as ancestor
888 * Check if @object has an ancestor @ancestor somewhere up in
891 * Returns: TRUE if @ancestor is an ancestor of @object.
893 * MT safe. Grabs and releases @object's locks.
896 gst_object_has_ancestor (GstObject * object, GstObject * ancestor)
899 gboolean result = FALSE;
904 if (object == ancestor)
907 parent = gst_object_get_parent (object);
908 result = gst_object_has_ancestor (parent, ancestor);
910 gst_object_unref (parent);
916 * gst_object_check_uniqueness:
917 * @list: a list of #GstObject to check through
918 * @name: the name to search for
920 * Checks to see if there is any object named @name in @list. This function
921 * does not do any locking of any kind. You might want to protect the
922 * provided list with the lock of the owner of the list. This function
923 * will lock each #GstObject in the list to compare the name, so be
924 * carefull when passing a list with a locked object.
926 * Returns: TRUE if a #GstObject named @name does not appear in @list,
929 * MT safe. Grabs and releases the LOCK of each object in the list.
932 gst_object_check_uniqueness (GList * list, const gchar * name)
934 gboolean result = TRUE;
936 g_return_val_if_fail (name != NULL, FALSE);
938 for (; list; list = g_list_next (list)) {
942 child = GST_OBJECT (list->data);
944 GST_OBJECT_LOCK (child);
945 eq = strcmp (GST_OBJECT_NAME (child), name) == 0;
946 GST_OBJECT_UNLOCK (child);
948 if (G_UNLIKELY (eq)) {
957 #ifndef GST_DISABLE_LOADSAVE
959 * gst_object_save_thyself:
960 * @object: a #GstObject to save
961 * @parent: The parent XML node to save @object into
963 * Saves @object into the parent XML node.
965 * Returns: the new xmlNodePtr with the saved object
968 gst_object_save_thyself (GstObject * object, xmlNodePtr parent)
970 GstObjectClass *oclass;
972 g_return_val_if_fail (GST_IS_OBJECT (object), parent);
973 g_return_val_if_fail (parent != NULL, parent);
975 oclass = GST_OBJECT_GET_CLASS (object);
977 if (oclass->save_thyself)
978 oclass->save_thyself (object, parent);
980 g_signal_emit (G_OBJECT (object), gst_object_signals[OBJECT_SAVED], 0,
987 * gst_object_restore_thyself:
988 * @object: a #GstObject to load into
989 * @self: The XML node to load @object from
991 * Restores @object with the data from the parent XML node.
994 gst_object_restore_thyself (GstObject * object, xmlNodePtr self)
996 GstObjectClass *oclass;
998 g_return_if_fail (GST_IS_OBJECT (object));
999 g_return_if_fail (self != NULL);
1001 oclass = GST_OBJECT_GET_CLASS (object);
1003 if (oclass->restore_thyself)
1004 oclass->restore_thyself (object, self);
1008 gst_object_real_restore_thyself (GstObject * object, xmlNodePtr self)
1010 g_return_if_fail (GST_IS_OBJECT (object));
1011 g_return_if_fail (self != NULL);
1013 gst_class_signal_emit_by_name (object, "object_loaded", self);
1015 #endif /* GST_DISABLE_LOADSAVE */
1018 gst_object_set_property (GObject * object, guint prop_id,
1019 const GValue * value, GParamSpec * pspec)
1021 GstObject *gstobject;
1023 gstobject = GST_OBJECT (object);
1027 gst_object_set_name (gstobject, g_value_get_string (value));
1030 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
1036 gst_object_get_property (GObject * object, guint prop_id,
1037 GValue * value, GParamSpec * pspec)
1039 GstObject *gstobject;
1041 gstobject = GST_OBJECT (object);
1045 g_value_take_string (value, gst_object_get_name (gstobject));
1048 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
1054 * gst_object_get_path_string:
1055 * @object: a #GstObject
1057 * Generates a string describing the path of @object in
1058 * the object hierarchy. Only useful (or used) for debugging.
1060 * Returns: a string describing the path of @object. You must
1061 * g_free() the string after usage.
1063 * MT safe. Grabs and releases the #GstObject's LOCK for all objects
1067 gst_object_get_path_string (GstObject * object)
1072 gchar *prevpath, *path;
1076 /* ref object before adding to list */
1077 gst_object_ref (object);
1078 parentage = g_slist_prepend (NULL, object);
1080 path = g_strdup ("");
1082 /* first walk the object hierarchy to build a list of the parents,
1083 * be carefull here with refcounting. */
1085 if (GST_IS_OBJECT (object)) {
1086 parent = gst_object_get_parent (object);
1087 /* add parents to list, refcount remains increased while
1088 * we handle the object */
1090 parentage = g_slist_prepend (parentage, parent);
1095 } while (object != NULL);
1097 /* then walk the parent list and print them out. we need to
1098 * decrease the refcounting on each element after we handled
1100 for (parents = parentage; parents; parents = g_slist_next (parents)) {
1101 if (GST_IS_OBJECT (parents->data)) {
1102 GstObject *item = GST_OBJECT_CAST (parents->data);
1103 GstObjectClass *oclass = GST_OBJECT_GET_CLASS (item);
1105 component = gst_object_get_name (item);
1106 separator = oclass->path_string_separator;
1108 gst_object_unref (item);
1110 component = g_strdup_printf ("%p", parents->data);
1115 path = g_strjoin (separator, prevpath, component, NULL);
1120 g_slist_free (parentage);
1126 struct _GstSignalObject
1131 struct _GstSignalObjectClass
1133 GObjectClass parent_class;
1136 #ifndef GST_DISABLE_LOADSAVE
1137 void (*object_loaded) (GstSignalObject * object, GstObject * new,
1143 gst_signal_object_get_type (void)
1145 static GType signal_object_type = 0;
1147 if (G_UNLIKELY (signal_object_type == 0)) {
1148 static const GTypeInfo signal_object_info = {
1149 sizeof (GstSignalObjectClass),
1152 (GClassInitFunc) gst_signal_object_class_init,
1155 sizeof (GstSignalObject),
1157 (GInstanceInitFunc) gst_signal_object_init,
1161 signal_object_type =
1162 g_type_register_static (G_TYPE_OBJECT, "GstSignalObject",
1163 &signal_object_info, 0);
1165 return signal_object_type;
1169 gst_signal_object_class_init (GstSignalObjectClass * klass)
1171 GObjectClass *gobject_class;
1173 gobject_class = (GObjectClass *) klass;
1175 parent_class = g_type_class_peek_parent (klass);
1177 #ifndef GST_DISABLE_LOADSAVE
1178 gst_signal_object_signals[SO_OBJECT_LOADED] =
1179 g_signal_new ("object-loaded", G_TYPE_FROM_CLASS (klass),
1180 G_SIGNAL_RUN_LAST, G_STRUCT_OFFSET (GstSignalObjectClass, object_loaded),
1181 NULL, NULL, gst_marshal_VOID__OBJECT_POINTER, G_TYPE_NONE, 2,
1182 G_TYPE_OBJECT, G_TYPE_POINTER);
1187 gst_signal_object_init (GstSignalObject * object)
1192 * gst_class_signal_connect
1193 * @klass: a #GstObjectClass to attach the signal to
1194 * @name: the name of the signal to attach to
1195 * @func: the signal function
1196 * @func_data: a pointer to user data
1198 * Connect to a class signal.
1200 * Returns: the signal id.
1203 gst_class_signal_connect (GstObjectClass * klass,
1204 const gchar * name, gpointer func, gpointer func_data)
1206 /* [0.11] func parameter needs to be changed to a GCallback *
1207 * doing so now would be an API break. */
1208 return g_signal_connect (klass->signal_object, name, G_CALLBACK (func),
1212 #ifndef GST_DISABLE_LOADSAVE
1214 * gst_class_signal_emit_by_name:
1215 * @object: a #GstObject that emits the signal
1216 * @name: the name of the signal to emit
1217 * @self: data for the signal
1219 * emits the named class signal.
1222 gst_class_signal_emit_by_name (GstObject * object,
1223 const gchar * name, xmlNodePtr self)
1225 GstObjectClass *oclass;
1227 oclass = GST_OBJECT_GET_CLASS (object);
1229 g_signal_emit_by_name (oclass->signal_object, name, object, self);
1232 #endif /* GST_DISABLE_LOADSAVE */