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 */
101 /* FIXME-0.11: have a read-only parent property instead of the two signals
102 * then we get notify::parent for free */
107 #ifndef GST_DISABLE_LOADSAVE
127 /* maps type name quark => count */
128 static GData *object_name_counts = NULL;
130 G_LOCK_DEFINE_STATIC (object_name_mutex);
132 typedef struct _GstSignalObject GstSignalObject;
133 typedef struct _GstSignalObjectClass GstSignalObjectClass;
135 static GType gst_signal_object_get_type (void);
137 #ifndef GST_DISABLE_LOADSAVE
138 static guint gst_signal_object_signals[SO_LAST_SIGNAL] = { 0 };
141 static void gst_object_set_property (GObject * object, guint prop_id,
142 const GValue * value, GParamSpec * pspec);
143 static void gst_object_get_property (GObject * object, guint prop_id,
144 GValue * value, GParamSpec * pspec);
145 static void gst_object_dispatch_properties_changed (GObject * object,
146 guint n_pspecs, GParamSpec ** pspecs);
148 static void gst_object_dispose (GObject * object);
149 static void gst_object_finalize (GObject * object);
151 static gboolean gst_object_set_name_default (GstObject * object);
153 #ifndef GST_DISABLE_LOADSAVE
154 static void gst_object_real_restore_thyself (GstObject * object,
158 static GObjectClass *parent_class = NULL;
159 static guint gst_object_signals[LAST_SIGNAL] = { 0 };
161 G_DEFINE_ABSTRACT_TYPE (GstObject, gst_object, G_TYPE_OBJECT);
164 gst_object_class_init (GstObjectClass * klass)
166 GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
168 parent_class = g_type_class_peek_parent (klass);
170 #ifndef GST_DISABLE_TRACE
171 _gst_object_trace = gst_alloc_trace_register (g_type_name (GST_TYPE_OBJECT));
174 gobject_class->set_property = gst_object_set_property;
175 gobject_class->get_property = gst_object_get_property;
177 g_object_class_install_property (gobject_class, ARG_NAME,
178 g_param_spec_string ("name", "Name", "The name of the object",
180 G_PARAM_READWRITE | G_PARAM_CONSTRUCT | G_PARAM_STATIC_STRINGS));
183 * GstObject::parent-set:
184 * @gstobject: a #GstObject
185 * @parent: the new parent
187 * Emitted when the parent of an object is set.
189 gst_object_signals[PARENT_SET] =
190 g_signal_new ("parent-set", G_TYPE_FROM_CLASS (klass), G_SIGNAL_RUN_LAST,
191 G_STRUCT_OFFSET (GstObjectClass, parent_set), NULL, NULL,
192 g_cclosure_marshal_VOID__OBJECT, G_TYPE_NONE, 1, GST_TYPE_OBJECT);
195 * GstObject::parent-unset:
196 * @gstobject: a #GstObject
197 * @parent: the old parent
199 * Emitted when the parent of an object is unset.
201 gst_object_signals[PARENT_UNSET] =
202 g_signal_new ("parent-unset", G_TYPE_FROM_CLASS (klass),
203 G_SIGNAL_RUN_LAST, G_STRUCT_OFFSET (GstObjectClass, parent_unset), NULL,
204 NULL, g_cclosure_marshal_VOID__OBJECT, G_TYPE_NONE, 1, GST_TYPE_OBJECT);
206 #ifndef GST_DISABLE_LOADSAVE
208 * GstObject::object-saved:
209 * @gstobject: a #GstObject
210 * @xml_node: the xmlNodePtr of the parent node
212 * Trigered whenever a new object is saved to XML. You can connect to this
213 * signal to insert custom XML tags into the core XML.
215 /* FIXME This should be the GType of xmlNodePtr instead of G_TYPE_POINTER
216 * (if libxml would use GObject)
218 gst_object_signals[OBJECT_SAVED] =
219 g_signal_new ("object-saved", G_TYPE_FROM_CLASS (klass),
220 G_SIGNAL_RUN_LAST, G_STRUCT_OFFSET (GstObjectClass, object_saved), NULL,
221 NULL, g_cclosure_marshal_VOID__POINTER, G_TYPE_NONE, 1, G_TYPE_POINTER);
223 klass->restore_thyself = gst_object_real_restore_thyself;
227 * GstObject::deep-notify:
228 * @gstobject: a #GstObject
229 * @prop_object: the object that originated the signal
230 * @prop: the property that changed
232 * The deep notify signal is used to be notified of property changes. It is
233 * typically attached to the toplevel bin to receive notifications from all
234 * the elements contained in that bin.
236 gst_object_signals[DEEP_NOTIFY] =
237 g_signal_new ("deep-notify", G_TYPE_FROM_CLASS (klass),
238 G_SIGNAL_RUN_FIRST | G_SIGNAL_NO_RECURSE | G_SIGNAL_DETAILED |
239 G_SIGNAL_NO_HOOKS, G_STRUCT_OFFSET (GstObjectClass, deep_notify), NULL,
240 NULL, gst_marshal_VOID__OBJECT_PARAM, G_TYPE_NONE, 2, GST_TYPE_OBJECT,
243 klass->path_string_separator = "/";
244 klass->lock = g_new0 (GStaticRecMutex, 1);
245 g_static_rec_mutex_init (klass->lock);
247 klass->signal_object = g_object_newv (gst_signal_object_get_type (), 0, NULL);
249 /* see the comments at gst_object_dispatch_properties_changed */
250 gobject_class->dispatch_properties_changed
251 = GST_DEBUG_FUNCPTR (gst_object_dispatch_properties_changed);
253 gobject_class->dispose = gst_object_dispose;
254 gobject_class->finalize = gst_object_finalize;
258 gst_object_init (GstObject * object)
260 object->lock = g_mutex_new ();
261 object->parent = NULL;
263 GST_CAT_LOG_OBJECT (GST_CAT_REFCOUNTING, object, "%p new", object);
265 #ifndef GST_DISABLE_TRACE
266 gst_alloc_trace_new (_gst_object_trace, object);
270 GST_OBJECT_FLAG_SET (object, GST_OBJECT_FLOATING);
275 * @object: a #GstObject to reference
277 * Increments the reference count on @object. This function
278 * does not take the lock on @object because it relies on
279 * atomic refcounting.
281 * This object returns the input parameter to ease writing
283 * result = gst_object_ref (object->parent);
285 * Returns: A pointer to @object
288 gst_object_ref (gpointer object)
290 g_return_val_if_fail (object != NULL, NULL);
292 #ifdef DEBUG_REFCOUNT
293 GST_CAT_LOG_OBJECT (GST_CAT_REFCOUNTING, object, "%p ref %d->%d",
295 ((GObject *) object)->ref_count, ((GObject *) object)->ref_count + 1);
297 g_object_ref (object);
304 * @object: a #GstObject to unreference
306 * Decrements the reference count on @object. If reference count hits
307 * zero, destroy @object. This function does not take the lock
308 * on @object as it relies on atomic refcounting.
310 * The unref method should never be called with the LOCK held since
311 * this might deadlock the dispose function.
314 gst_object_unref (gpointer object)
316 g_return_if_fail (object != NULL);
317 g_return_if_fail (((GObject *) object)->ref_count > 0);
319 #ifdef DEBUG_REFCOUNT
320 GST_CAT_LOG_OBJECT (GST_CAT_REFCOUNTING, object, "%p unref %d->%d",
322 ((GObject *) object)->ref_count, ((GObject *) object)->ref_count - 1);
324 g_object_unref (object);
328 * gst_object_ref_sink:
329 * @object: a #GstObject to sink
331 * Increase the reference count of @object, and possibly remove the floating
332 * reference, if @object has a floating reference.
334 * In other words, if the object is floating, then this call "assumes ownership"
335 * of the floating reference, converting it to a normal reference by clearing
336 * the floating flag while leaving the reference count unchanged. If the object
337 * is not floating, then this call adds a new normal reference increasing the
338 * reference count by one.
340 * MT safe. This function grabs and releases @object lock.
345 gst_object_ref_sink (gpointer object)
347 g_return_if_fail (GST_IS_OBJECT (object));
349 GST_OBJECT_LOCK (object);
350 if (G_LIKELY (GST_OBJECT_IS_FLOATING (object))) {
351 GST_CAT_LOG_OBJECT (GST_CAT_REFCOUNTING, object, "unsetting floating flag");
352 GST_OBJECT_FLAG_UNSET (object, GST_OBJECT_FLOATING);
353 GST_OBJECT_UNLOCK (object);
355 GST_OBJECT_UNLOCK (object);
356 gst_object_ref (object);
362 * @object: a #GstObject to sink
364 * If @object was floating, the #GST_OBJECT_FLOATING flag is removed
365 * and @object is unreffed. When @object was not floating,
366 * this function does nothing.
368 * Any newly created object has a refcount of 1 and is floating.
369 * This function should be used when creating a new object to
370 * symbolically 'take ownership' of @object. This done by first doing a
371 * gst_object_ref() to keep a reference to @object and then gst_object_sink()
372 * to remove and unref any floating references to @object.
373 * Use gst_object_set_parent() to have this done for you.
375 * MT safe. This function grabs and releases @object lock.
378 gst_object_sink (gpointer object)
380 g_return_if_fail (GST_IS_OBJECT (object));
382 GST_CAT_LOG_OBJECT (GST_CAT_REFCOUNTING, object, "sink");
384 GST_OBJECT_LOCK (object);
385 if (G_LIKELY (GST_OBJECT_IS_FLOATING (object))) {
386 GST_CAT_LOG_OBJECT (GST_CAT_REFCOUNTING, object, "clear floating flag");
387 GST_OBJECT_FLAG_UNSET (object, GST_OBJECT_FLOATING);
388 GST_OBJECT_UNLOCK (object);
389 gst_object_unref (object);
391 GST_OBJECT_UNLOCK (object);
396 * gst_object_replace:
397 * @oldobj: pointer to a place of a #GstObject to replace
398 * @newobj: a new #GstObject
400 * Unrefs the #GstObject pointed to by @oldobj, refs @newobj and
401 * puts @newobj in *@oldobj. Be carefull when calling this
402 * function, it does not take any locks. You might want to lock
403 * the object owning @oldobj pointer before calling this
406 * Make sure not to LOCK @oldobj because it might be unreffed
407 * which could cause a deadlock when it is disposed.
410 gst_object_replace (GstObject ** oldobj, GstObject * newobj)
412 g_return_if_fail (oldobj != NULL);
413 g_return_if_fail (*oldobj == NULL || GST_IS_OBJECT (*oldobj));
414 g_return_if_fail (newobj == NULL || GST_IS_OBJECT (newobj));
416 #ifdef DEBUG_REFCOUNT
417 GST_CAT_LOG (GST_CAT_REFCOUNTING, "replace %p %s (%d) with %p %s (%d)",
418 *oldobj, *oldobj ? GST_STR_NULL (GST_OBJECT_NAME (*oldobj)) : "(NONE)",
419 *oldobj ? G_OBJECT (*oldobj)->ref_count : 0,
420 newobj, newobj ? GST_STR_NULL (GST_OBJECT_NAME (newobj)) : "(NONE)",
421 newobj ? G_OBJECT (newobj)->ref_count : 0);
424 if (G_LIKELY (*oldobj != newobj)) {
426 gst_object_ref (newobj);
428 gst_object_unref (*oldobj);
434 /* dispose is called when the object has to release all links
435 * to other objects */
437 gst_object_dispose (GObject * object)
441 GST_CAT_LOG_OBJECT (GST_CAT_REFCOUNTING, object, "dispose");
443 GST_OBJECT_LOCK (object);
444 if ((parent = GST_OBJECT_PARENT (object)))
446 GST_OBJECT_PARENT (object) = NULL;
447 GST_OBJECT_UNLOCK (object);
449 parent_class->dispose (object);
456 g_critical ("\nTrying to dispose object \"%s\", but it still has a "
457 "parent \"%s\".\nYou need to let the parent manage the "
458 "object instead of unreffing the object directly.\n",
459 GST_OBJECT_NAME (object), GST_OBJECT_NAME (parent));
460 GST_OBJECT_UNLOCK (object);
461 /* ref the object again to revive it in this error case */
462 gst_object_ref (object);
467 /* finalize is called when the object has to free its resources */
469 gst_object_finalize (GObject * object)
471 GstObject *gstobject = GST_OBJECT_CAST (object);
473 GST_CAT_LOG_OBJECT (GST_CAT_REFCOUNTING, object, "finalize");
475 g_signal_handlers_destroy (object);
477 g_free (gstobject->name);
478 g_mutex_free (gstobject->lock);
480 #ifndef GST_DISABLE_TRACE
481 gst_alloc_trace_free (_gst_object_trace, object);
484 parent_class->finalize (object);
487 /* Changing a GObject property of a GstObject will result in "deep-notify"
488 * signals being emitted by the object itself, as well as in each parent
489 * object. This is so that an application can connect a listener to the
490 * top-level bin to catch property-change notifications for all contained
493 * This function is not MT safe in glib < 2.8 so we need to lock it with a
494 * classwide mutex in that case.
499 gst_object_dispatch_properties_changed (GObject * object,
500 guint n_pspecs, GParamSpec ** pspecs)
502 GstObject *gst_object, *parent, *old_parent;
504 gchar *name, *debug_name;
506 /* do the standard dispatching */
507 parent_class->dispatch_properties_changed (object, n_pspecs, pspecs);
509 gst_object = GST_OBJECT_CAST (object);
510 name = gst_object_get_name (gst_object);
511 debug_name = GST_STR_NULL (name);
513 /* now let the parent dispatch those, too */
514 parent = gst_object_get_parent (gst_object);
516 for (i = 0; i < n_pspecs; i++) {
517 GST_CAT_LOG_OBJECT (GST_CAT_PROPERTIES, parent,
518 "deep notification from %s (%s)", debug_name, pspecs[i]->name);
520 g_signal_emit (parent, gst_object_signals[DEEP_NOTIFY],
521 g_quark_from_string (pspecs[i]->name), gst_object, pspecs[i]);
525 parent = gst_object_get_parent (old_parent);
526 gst_object_unref (old_parent);
532 * gst_object_default_deep_notify:
533 * @object: the #GObject that signalled the notify.
534 * @orig: a #GstObject that initiated the notify.
535 * @pspec: a #GParamSpec of the property.
536 * @excluded_props: a set of user-specified properties to exclude or
537 * NULL to show all changes.
539 * A default deep_notify signal callback for an object. The user data
540 * should contain a pointer to an array of strings that should be excluded
541 * from the notify. The default handler will print the new value of the property
544 * MT safe. This function grabs and releases @object's LOCK for getting its
548 gst_object_default_deep_notify (GObject * object, GstObject * orig,
549 GParamSpec * pspec, gchar ** excluded_props)
551 GValue value = { 0, }; /* the important thing is that value.type = 0 */
555 if (pspec->flags & G_PARAM_READABLE) {
556 /* let's not print these out for excluded properties... */
557 while (excluded_props != NULL && *excluded_props != NULL) {
558 if (strcmp (pspec->name, *excluded_props) == 0)
562 g_value_init (&value, G_PARAM_SPEC_VALUE_TYPE (pspec));
563 g_object_get_property (G_OBJECT (orig), pspec->name, &value);
565 /* FIXME: handle flags */
566 if (G_IS_PARAM_SPEC_ENUM (pspec)) {
567 GEnumValue *enum_value;
568 GEnumClass *klass = G_ENUM_CLASS (g_type_class_ref (pspec->value_type));
570 enum_value = g_enum_get_value (klass, g_value_get_enum (&value));
572 str = g_strdup_printf ("%s (%d)", enum_value->value_nick,
574 g_type_class_unref (klass);
576 str = g_strdup_value_contents (&value);
578 name = gst_object_get_path_string (orig);
579 g_print ("%s: %s = %s\n", name, pspec->name, str);
582 g_value_unset (&value);
584 name = gst_object_get_path_string (orig);
585 g_warning ("Parameter %s not readable in %s.", pspec->name, name);
591 gst_object_set_name_default (GstObject * object)
593 const gchar *type_name;
598 /* to ensure guaranteed uniqueness across threads, only one thread
599 * may ever assign a name */
600 G_LOCK (object_name_mutex);
602 if (!object_name_counts) {
603 g_datalist_init (&object_name_counts);
606 q = g_type_qname (G_OBJECT_TYPE (object));
607 count = GPOINTER_TO_INT (g_datalist_id_get_data (&object_name_counts, q));
608 g_datalist_id_set_data (&object_name_counts, q, GINT_TO_POINTER (count + 1));
610 G_UNLOCK (object_name_mutex);
612 /* GstFooSink -> foosinkN */
613 type_name = g_quark_to_string (q);
614 if (strncmp (type_name, "Gst", 3) == 0)
616 tmp = g_strdup_printf ("%s%d", type_name, count);
617 name = g_ascii_strdown (tmp, -1);
620 GST_OBJECT_LOCK (object);
621 if (G_UNLIKELY (object->parent != NULL))
623 g_free (object->name);
626 GST_OBJECT_UNLOCK (object);
632 GST_WARNING ("parented objects can't be renamed");
633 GST_OBJECT_UNLOCK (object);
639 * gst_object_set_name:
640 * @object: a #GstObject
641 * @name: new name of object
643 * Sets the name of @object, or gives @object a guaranteed unique
644 * name (if @name is NULL).
645 * This function makes a copy of the provided name, so the caller
646 * retains ownership of the name it sent.
648 * Returns: TRUE if the name could be set. Since Objects that have
649 * a parent cannot be renamed, this function returns FALSE in those
652 * MT safe. This function grabs and releases @object's LOCK.
655 gst_object_set_name (GstObject * object, const gchar * name)
659 g_return_val_if_fail (GST_IS_OBJECT (object), FALSE);
661 GST_OBJECT_LOCK (object);
663 /* parented objects cannot be renamed */
664 if (G_UNLIKELY (object->parent != NULL))
668 g_free (object->name);
669 object->name = g_strdup (name);
670 GST_OBJECT_UNLOCK (object);
673 GST_OBJECT_UNLOCK (object);
674 result = gst_object_set_name_default (object);
676 /* FIXME-0.11: this misses a g_object_notify (object, "name"); unless called
677 * from gst_object_set_property.
678 * Ideally remove such custom setters (or make it static).
685 GST_WARNING ("parented objects can't be renamed");
686 GST_OBJECT_UNLOCK (object);
692 * gst_object_get_name:
693 * @object: a #GstObject
695 * Returns a copy of the name of @object.
696 * Caller should g_free() the return value after usage.
697 * For a nameless object, this returns NULL, which you can safely g_free()
700 * Returns: the name of @object. g_free() after usage.
702 * MT safe. This function grabs and releases @object's LOCK.
705 gst_object_get_name (GstObject * object)
707 gchar *result = NULL;
709 g_return_val_if_fail (GST_IS_OBJECT (object), NULL);
711 GST_OBJECT_LOCK (object);
712 result = g_strdup (object->name);
713 GST_OBJECT_UNLOCK (object);
719 * gst_object_set_name_prefix:
720 * @object: a #GstObject
721 * @name_prefix: new name prefix of @object
723 * Sets the name prefix of @object to @name_prefix.
724 * This function makes a copy of the provided name prefix, so the caller
725 * retains ownership of the name prefix it sent.
727 * MT safe. This function grabs and releases @object's LOCK.
730 gst_object_set_name_prefix (GstObject * object, const gchar * name_prefix)
732 g_return_if_fail (GST_IS_OBJECT (object));
734 GST_OBJECT_LOCK (object);
735 g_free (object->name_prefix);
736 object->name_prefix = g_strdup (name_prefix); /* NULL gives NULL */
737 GST_OBJECT_UNLOCK (object);
741 * gst_object_get_name_prefix:
742 * @object: a #GstObject
744 * Returns a copy of the name prefix of @object.
745 * Caller should g_free() the return value after usage.
746 * For a prefixless object, this returns NULL, which you can safely g_free()
749 * Returns: the name prefix of @object. g_free() after usage.
751 * MT safe. This function grabs and releases @object's LOCK.
754 gst_object_get_name_prefix (GstObject * object)
756 gchar *result = NULL;
758 g_return_val_if_fail (GST_IS_OBJECT (object), NULL);
760 GST_OBJECT_LOCK (object);
761 result = g_strdup (object->name_prefix);
762 GST_OBJECT_UNLOCK (object);
768 * gst_object_set_parent:
769 * @object: a #GstObject
770 * @parent: new parent of object
772 * Sets the parent of @object to @parent. The object's reference count will
773 * be incremented, and any floating reference will be removed (see gst_object_sink()).
775 * This function causes the parent-set signal to be emitted when the parent
776 * was successfully set.
778 * Returns: TRUE if @parent could be set or FALSE when @object
779 * already had a parent or @object and @parent are the same.
781 * MT safe. Grabs and releases @object's LOCK.
784 gst_object_set_parent (GstObject * object, GstObject * parent)
786 g_return_val_if_fail (GST_IS_OBJECT (object), FALSE);
787 g_return_val_if_fail (GST_IS_OBJECT (parent), FALSE);
788 g_return_val_if_fail (object != parent, FALSE);
790 GST_CAT_DEBUG_OBJECT (GST_CAT_REFCOUNTING, object,
791 "set parent (ref and sink)");
793 GST_OBJECT_LOCK (object);
794 if (G_UNLIKELY (object->parent != NULL))
797 /* sink object, we don't call our own function because we don't
798 * need to release/acquire the lock needlessly or touch the refcount
799 * in the floating case. */
800 object->parent = parent;
801 if (G_LIKELY (GST_OBJECT_IS_FLOATING (object))) {
802 GST_CAT_LOG_OBJECT (GST_CAT_REFCOUNTING, object, "unsetting floating flag");
803 GST_OBJECT_FLAG_UNSET (object, GST_OBJECT_FLOATING);
804 GST_OBJECT_UNLOCK (object);
806 GST_OBJECT_UNLOCK (object);
807 gst_object_ref (object);
810 g_signal_emit (object, gst_object_signals[PARENT_SET], 0, parent);
817 GST_CAT_DEBUG_OBJECT (GST_CAT_REFCOUNTING, object,
818 "set parent failed, object already had a parent");
819 GST_OBJECT_UNLOCK (object);
825 * gst_object_get_parent:
826 * @object: a #GstObject
828 * Returns the parent of @object. This function increases the refcount
829 * of the parent object so you should gst_object_unref() it after usage.
831 * Returns: parent of @object, this can be NULL if @object has no
832 * parent. unref after usage.
834 * MT safe. Grabs and releases @object's LOCK.
837 gst_object_get_parent (GstObject * object)
839 GstObject *result = NULL;
841 g_return_val_if_fail (GST_IS_OBJECT (object), NULL);
843 GST_OBJECT_LOCK (object);
844 result = object->parent;
845 if (G_LIKELY (result))
846 gst_object_ref (result);
847 GST_OBJECT_UNLOCK (object);
853 * gst_object_unparent:
854 * @object: a #GstObject to unparent
856 * Clear the parent of @object, removing the associated reference.
857 * This function decreases the refcount of @object.
859 * MT safe. Grabs and releases @object's lock.
862 gst_object_unparent (GstObject * object)
866 g_return_if_fail (GST_IS_OBJECT (object));
868 GST_OBJECT_LOCK (object);
869 parent = object->parent;
871 if (G_LIKELY (parent != NULL)) {
872 GST_CAT_LOG_OBJECT (GST_CAT_REFCOUNTING, object, "unparent");
873 object->parent = NULL;
874 GST_OBJECT_UNLOCK (object);
876 g_signal_emit (object, gst_object_signals[PARENT_UNSET], 0, parent);
878 gst_object_unref (object);
880 GST_OBJECT_UNLOCK (object);
885 * gst_object_has_ancestor:
886 * @object: a #GstObject to check
887 * @ancestor: a #GstObject to check as ancestor
889 * Check if @object has an ancestor @ancestor somewhere up in
892 * Returns: TRUE if @ancestor is an ancestor of @object.
894 * MT safe. Grabs and releases @object's locks.
897 gst_object_has_ancestor (GstObject * object, GstObject * ancestor)
899 GstObject *parent, *tmp;
901 if (!ancestor || !object)
904 parent = gst_object_ref (object);
906 if (parent == ancestor) {
907 gst_object_unref (parent);
911 tmp = gst_object_get_parent (parent);
912 gst_object_unref (parent);
920 * gst_object_check_uniqueness:
921 * @list: a list of #GstObject to check through
922 * @name: the name to search for
924 * Checks to see if there is any object named @name in @list. This function
925 * does not do any locking of any kind. You might want to protect the
926 * provided list with the lock of the owner of the list. This function
927 * will lock each #GstObject in the list to compare the name, so be
928 * carefull when passing a list with a locked object.
930 * Returns: TRUE if a #GstObject named @name does not appear in @list,
933 * MT safe. Grabs and releases the LOCK of each object in the list.
936 gst_object_check_uniqueness (GList * list, const gchar * name)
938 gboolean result = TRUE;
940 g_return_val_if_fail (name != NULL, FALSE);
942 for (; list; list = g_list_next (list)) {
946 child = GST_OBJECT_CAST (list->data);
948 GST_OBJECT_LOCK (child);
949 eq = strcmp (GST_OBJECT_NAME (child), name) == 0;
950 GST_OBJECT_UNLOCK (child);
952 if (G_UNLIKELY (eq)) {
961 #ifndef GST_DISABLE_LOADSAVE
963 * gst_object_save_thyself:
964 * @object: a #GstObject to save
965 * @parent: The parent XML node to save @object into
967 * Saves @object into the parent XML node.
969 * Returns: the new xmlNodePtr with the saved object
972 gst_object_save_thyself (GstObject * object, xmlNodePtr parent)
974 GstObjectClass *oclass;
976 g_return_val_if_fail (GST_IS_OBJECT (object), parent);
977 g_return_val_if_fail (parent != NULL, parent);
979 oclass = GST_OBJECT_GET_CLASS (object);
981 if (oclass->save_thyself)
982 oclass->save_thyself (object, parent);
984 g_signal_emit (object, gst_object_signals[OBJECT_SAVED], 0, parent);
990 * gst_object_restore_thyself:
991 * @object: a #GstObject to load into
992 * @self: The XML node to load @object from
994 * Restores @object with the data from the parent XML node.
997 gst_object_restore_thyself (GstObject * object, xmlNodePtr self)
999 GstObjectClass *oclass;
1001 g_return_if_fail (GST_IS_OBJECT (object));
1002 g_return_if_fail (self != NULL);
1004 oclass = GST_OBJECT_GET_CLASS (object);
1006 if (oclass->restore_thyself)
1007 oclass->restore_thyself (object, self);
1011 gst_object_real_restore_thyself (GstObject * object, xmlNodePtr self)
1013 g_return_if_fail (GST_IS_OBJECT (object));
1014 g_return_if_fail (self != NULL);
1016 gst_class_signal_emit_by_name (object, "object_loaded", self);
1018 #endif /* GST_DISABLE_LOADSAVE */
1021 gst_object_set_property (GObject * object, guint prop_id,
1022 const GValue * value, GParamSpec * pspec)
1024 GstObject *gstobject;
1026 gstobject = GST_OBJECT_CAST (object);
1030 gst_object_set_name (gstobject, g_value_get_string (value));
1033 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
1039 gst_object_get_property (GObject * object, guint prop_id,
1040 GValue * value, GParamSpec * pspec)
1042 GstObject *gstobject;
1044 gstobject = GST_OBJECT_CAST (object);
1048 g_value_take_string (value, gst_object_get_name (gstobject));
1051 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
1057 * gst_object_get_path_string:
1058 * @object: a #GstObject
1060 * Generates a string describing the path of @object in
1061 * the object hierarchy. Only useful (or used) for debugging.
1063 * Returns: a string describing the path of @object. You must
1064 * g_free() the string after usage.
1066 * MT safe. Grabs and releases the #GstObject's LOCK for all objects
1070 gst_object_get_path_string (GstObject * object)
1075 gchar *prevpath, *path;
1076 const gchar *typename;
1080 /* ref object before adding to list */
1081 gst_object_ref (object);
1082 parentage = g_slist_prepend (NULL, object);
1084 path = g_strdup ("");
1086 /* first walk the object hierarchy to build a list of the parents,
1087 * be carefull here with refcounting. */
1089 if (GST_IS_OBJECT (object)) {
1090 parent = gst_object_get_parent (object);
1091 /* add parents to list, refcount remains increased while
1092 * we handle the object */
1094 parentage = g_slist_prepend (parentage, parent);
1099 } while (object != NULL);
1101 /* then walk the parent list and print them out. we need to
1102 * decrease the refcounting on each element after we handled
1104 for (parents = parentage; parents; parents = g_slist_next (parents)) {
1105 if (G_IS_OBJECT (parents->data)) {
1106 typename = G_OBJECT_TYPE_NAME (parents->data);
1110 if (GST_IS_OBJECT (parents->data)) {
1111 GstObject *item = GST_OBJECT_CAST (parents->data);
1112 GstObjectClass *oclass = GST_OBJECT_GET_CLASS (item);
1113 gchar *objname = gst_object_get_name (item);
1115 component = g_strdup_printf ("%s:%s", typename, objname);
1116 separator = oclass->path_string_separator;
1118 gst_object_unref (item);
1122 component = g_strdup_printf ("%s:%p", typename, parents->data);
1124 component = g_strdup_printf ("%p", parents->data);
1130 path = g_strjoin (separator, prevpath, component, NULL);
1135 g_slist_free (parentage);
1141 struct _GstSignalObject
1146 struct _GstSignalObjectClass
1148 GObjectClass parent_class;
1151 #ifndef GST_DISABLE_LOADSAVE
1152 void (*object_loaded) (GstSignalObject * object, GstObject * new,
1157 G_DEFINE_TYPE (GstSignalObject, gst_signal_object, G_TYPE_OBJECT);
1160 gst_signal_object_class_init (GstSignalObjectClass * klass)
1162 parent_class = g_type_class_peek_parent (klass);
1164 #ifndef GST_DISABLE_LOADSAVE
1165 gst_signal_object_signals[SO_OBJECT_LOADED] =
1166 g_signal_new ("object-loaded", G_TYPE_FROM_CLASS (klass),
1167 G_SIGNAL_RUN_LAST, G_STRUCT_OFFSET (GstSignalObjectClass, object_loaded),
1168 NULL, NULL, gst_marshal_VOID__OBJECT_POINTER, G_TYPE_NONE, 2,
1169 G_TYPE_OBJECT, G_TYPE_POINTER);
1174 gst_signal_object_init (GstSignalObject * object)
1179 * gst_class_signal_connect
1180 * @klass: a #GstObjectClass to attach the signal to
1181 * @name: the name of the signal to attach to
1182 * @func: the signal function
1183 * @func_data: a pointer to user data
1185 * Connect to a class signal.
1187 * Returns: the signal id.
1190 gst_class_signal_connect (GstObjectClass * klass,
1191 const gchar * name, gpointer func, gpointer func_data)
1193 /* [0.11] func parameter needs to be changed to a GCallback *
1194 * doing so now would be an API break. */
1195 return g_signal_connect (klass->signal_object, name, G_CALLBACK (func),
1199 #ifndef GST_DISABLE_LOADSAVE
1201 * gst_class_signal_emit_by_name:
1202 * @object: a #GstObject that emits the signal
1203 * @name: the name of the signal to emit
1204 * @self: data for the signal
1206 * emits the named class signal.
1209 gst_class_signal_emit_by_name (GstObject * object,
1210 const gchar * name, xmlNodePtr self)
1212 GstObjectClass *oclass;
1214 oclass = GST_OBJECT_GET_CLASS (object);
1216 g_signal_emit_by_name (oclass->signal_object, name, object, self);
1219 #endif /* GST_DISABLE_LOADSAVE */