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);
136 static void gst_signal_object_class_init (GstSignalObjectClass * klass);
137 static void gst_signal_object_init (GstSignalObject * object);
139 #ifndef GST_DISABLE_LOADSAVE
140 static guint gst_signal_object_signals[SO_LAST_SIGNAL] = { 0 };
143 static void gst_object_set_property (GObject * object, guint prop_id,
144 const GValue * value, GParamSpec * pspec);
145 static void gst_object_get_property (GObject * object, guint prop_id,
146 GValue * value, GParamSpec * pspec);
147 static void gst_object_dispatch_properties_changed (GObject * object,
148 guint n_pspecs, GParamSpec ** pspecs);
150 static void gst_object_dispose (GObject * object);
151 static void gst_object_finalize (GObject * object);
153 static gboolean gst_object_set_name_default (GstObject * object);
155 #ifndef GST_DISABLE_LOADSAVE
156 static void gst_object_real_restore_thyself (GstObject * object,
160 static GObjectClass *parent_class = NULL;
161 static guint gst_object_signals[LAST_SIGNAL] = { 0 };
163 G_DEFINE_ABSTRACT_TYPE (GstObject, gst_object, G_TYPE_OBJECT);
166 gst_object_class_init (GstObjectClass * klass)
168 GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
170 parent_class = g_type_class_peek_parent (klass);
172 #ifndef GST_DISABLE_TRACE
173 _gst_object_trace = gst_alloc_trace_register (g_type_name (GST_TYPE_OBJECT));
176 gobject_class->set_property = gst_object_set_property;
177 gobject_class->get_property = gst_object_get_property;
179 g_object_class_install_property (gobject_class, ARG_NAME,
180 g_param_spec_string ("name", "Name", "The name of the object",
182 G_PARAM_READWRITE | G_PARAM_CONSTRUCT | G_PARAM_STATIC_STRINGS));
185 * GstObject::parent-set:
186 * @gstobject: a #GstObject
187 * @parent: the new parent
189 * Emitted when the parent of an object is set.
191 gst_object_signals[PARENT_SET] =
192 g_signal_new ("parent-set", G_TYPE_FROM_CLASS (klass), G_SIGNAL_RUN_LAST,
193 G_STRUCT_OFFSET (GstObjectClass, parent_set), NULL, NULL,
194 g_cclosure_marshal_VOID__OBJECT, G_TYPE_NONE, 1, GST_TYPE_OBJECT);
197 * GstObject::parent-unset:
198 * @gstobject: a #GstObject
199 * @parent: the old parent
201 * Emitted when the parent of an object is unset.
203 gst_object_signals[PARENT_UNSET] =
204 g_signal_new ("parent-unset", G_TYPE_FROM_CLASS (klass),
205 G_SIGNAL_RUN_LAST, G_STRUCT_OFFSET (GstObjectClass, parent_unset), NULL,
206 NULL, g_cclosure_marshal_VOID__OBJECT, G_TYPE_NONE, 1, GST_TYPE_OBJECT);
208 #ifndef GST_DISABLE_LOADSAVE
210 * GstObject::object-saved:
211 * @gstobject: a #GstObject
212 * @xml_node: the xmlNodePtr of the parent node
214 * Trigered whenever a new object is saved to XML. You can connect to this
215 * signal to insert custom XML tags into the core XML.
217 /* FIXME This should be the GType of xmlNodePtr instead of G_TYPE_POINTER
218 * (if libxml would use GObject)
220 gst_object_signals[OBJECT_SAVED] =
221 g_signal_new ("object-saved", G_TYPE_FROM_CLASS (klass),
222 G_SIGNAL_RUN_LAST, G_STRUCT_OFFSET (GstObjectClass, object_saved), NULL,
223 NULL, g_cclosure_marshal_VOID__POINTER, G_TYPE_NONE, 1, G_TYPE_POINTER);
225 klass->restore_thyself = gst_object_real_restore_thyself;
229 * GstObject::deep-notify:
230 * @gstobject: a #GstObject
231 * @prop_object: the object that originated the signal
232 * @prop: the property that changed
234 * The deep notify signal is used to be notified of property changes. It is
235 * typically attached to the toplevel bin to receive notifications from all
236 * the elements contained in that bin.
238 gst_object_signals[DEEP_NOTIFY] =
239 g_signal_new ("deep-notify", G_TYPE_FROM_CLASS (klass),
240 G_SIGNAL_RUN_FIRST | G_SIGNAL_NO_RECURSE | G_SIGNAL_DETAILED |
241 G_SIGNAL_NO_HOOKS, G_STRUCT_OFFSET (GstObjectClass, deep_notify), NULL,
242 NULL, gst_marshal_VOID__OBJECT_PARAM, G_TYPE_NONE, 2, GST_TYPE_OBJECT,
245 klass->path_string_separator = "/";
246 klass->lock = g_new0 (GStaticRecMutex, 1);
247 g_static_rec_mutex_init (klass->lock);
249 klass->signal_object = g_object_newv (gst_signal_object_get_type (), 0, NULL);
251 /* see the comments at gst_object_dispatch_properties_changed */
252 gobject_class->dispatch_properties_changed
253 = GST_DEBUG_FUNCPTR (gst_object_dispatch_properties_changed);
255 gobject_class->dispose = gst_object_dispose;
256 gobject_class->finalize = gst_object_finalize;
260 gst_object_init (GstObject * object)
262 object->lock = g_mutex_new ();
263 object->parent = NULL;
265 GST_CAT_LOG_OBJECT (GST_CAT_REFCOUNTING, object, "%p new", object);
267 #ifndef GST_DISABLE_TRACE
268 gst_alloc_trace_new (_gst_object_trace, object);
272 GST_OBJECT_FLAG_SET (object, GST_OBJECT_FLOATING);
277 * @object: a #GstObject to reference
279 * Increments the reference count on @object. This function
280 * does not take the lock on @object because it relies on
281 * atomic refcounting.
283 * This object returns the input parameter to ease writing
285 * result = gst_object_ref (object->parent);
287 * Returns: A pointer to @object
290 gst_object_ref (gpointer object)
292 g_return_val_if_fail (object != NULL, NULL);
294 #ifdef DEBUG_REFCOUNT
295 GST_CAT_LOG_OBJECT (GST_CAT_REFCOUNTING, object, "%p ref %d->%d",
297 ((GObject *) object)->ref_count, ((GObject *) object)->ref_count + 1);
299 g_object_ref (object);
306 * @object: a #GstObject to unreference
308 * Decrements the reference count on @object. If reference count hits
309 * zero, destroy @object. This function does not take the lock
310 * on @object as it relies on atomic refcounting.
312 * The unref method should never be called with the LOCK held since
313 * this might deadlock the dispose function.
316 gst_object_unref (gpointer object)
318 g_return_if_fail (object != NULL);
319 g_return_if_fail (((GObject *) object)->ref_count > 0);
321 #ifdef DEBUG_REFCOUNT
322 GST_CAT_LOG_OBJECT (GST_CAT_REFCOUNTING, object, "%p unref %d->%d",
324 ((GObject *) object)->ref_count, ((GObject *) object)->ref_count - 1);
326 g_object_unref (object);
330 * gst_object_ref_sink:
331 * @object: a #GstObject to sink
333 * Increase the reference count of @object, and possibly remove the floating
334 * reference, if @object has a floating reference.
336 * In other words, if the object is floating, then this call "assumes ownership"
337 * of the floating reference, converting it to a normal reference by clearing
338 * the floating flag while leaving the reference count unchanged. If the object
339 * is not floating, then this call adds a new normal reference increasing the
340 * reference count by one.
342 * MT safe. This function grabs and releases @object lock.
347 gst_object_ref_sink (gpointer object)
349 g_return_if_fail (GST_IS_OBJECT (object));
351 GST_OBJECT_LOCK (object);
352 if (G_LIKELY (GST_OBJECT_IS_FLOATING (object))) {
353 GST_CAT_LOG_OBJECT (GST_CAT_REFCOUNTING, object, "unsetting floating flag");
354 GST_OBJECT_FLAG_UNSET (object, GST_OBJECT_FLOATING);
355 GST_OBJECT_UNLOCK (object);
357 GST_OBJECT_UNLOCK (object);
358 gst_object_ref (object);
364 * @object: a #GstObject to sink
366 * If @object was floating, the #GST_OBJECT_FLOATING flag is removed
367 * and @object is unreffed. When @object was not floating,
368 * this function does nothing.
370 * Any newly created object has a refcount of 1 and is floating.
371 * This function should be used when creating a new object to
372 * symbolically 'take ownership' of @object. This done by first doing a
373 * gst_object_ref() to keep a reference to @object and then gst_object_sink()
374 * to remove and unref any floating references to @object.
375 * Use gst_object_set_parent() to have this done for you.
377 * MT safe. This function grabs and releases @object lock.
380 gst_object_sink (gpointer object)
382 g_return_if_fail (GST_IS_OBJECT (object));
384 GST_CAT_LOG_OBJECT (GST_CAT_REFCOUNTING, object, "sink");
386 GST_OBJECT_LOCK (object);
387 if (G_LIKELY (GST_OBJECT_IS_FLOATING (object))) {
388 GST_CAT_LOG_OBJECT (GST_CAT_REFCOUNTING, object, "clear floating flag");
389 GST_OBJECT_FLAG_UNSET (object, GST_OBJECT_FLOATING);
390 GST_OBJECT_UNLOCK (object);
391 gst_object_unref (object);
393 GST_OBJECT_UNLOCK (object);
398 * gst_object_replace:
399 * @oldobj: pointer to a place of a #GstObject to replace
400 * @newobj: a new #GstObject
402 * Unrefs the #GstObject pointed to by @oldobj, refs @newobj and
403 * puts @newobj in *@oldobj. Be carefull when calling this
404 * function, it does not take any locks. You might want to lock
405 * the object owning @oldobj pointer before calling this
408 * Make sure not to LOCK @oldobj because it might be unreffed
409 * which could cause a deadlock when it is disposed.
412 gst_object_replace (GstObject ** oldobj, GstObject * newobj)
414 g_return_if_fail (oldobj != NULL);
415 g_return_if_fail (*oldobj == NULL || GST_IS_OBJECT (*oldobj));
416 g_return_if_fail (newobj == NULL || GST_IS_OBJECT (newobj));
418 #ifdef DEBUG_REFCOUNT
419 GST_CAT_LOG (GST_CAT_REFCOUNTING, "replace %p %s (%d) with %p %s (%d)",
420 *oldobj, *oldobj ? GST_STR_NULL (GST_OBJECT_NAME (*oldobj)) : "(NONE)",
421 *oldobj ? G_OBJECT (*oldobj)->ref_count : 0,
422 newobj, newobj ? GST_STR_NULL (GST_OBJECT_NAME (newobj)) : "(NONE)",
423 newobj ? G_OBJECT (newobj)->ref_count : 0);
426 if (G_LIKELY (*oldobj != newobj)) {
428 gst_object_ref (newobj);
430 gst_object_unref (*oldobj);
436 /* dispose is called when the object has to release all links
437 * to other objects */
439 gst_object_dispose (GObject * object)
443 GST_CAT_LOG_OBJECT (GST_CAT_REFCOUNTING, object, "dispose");
445 GST_OBJECT_LOCK (object);
446 if ((parent = GST_OBJECT_PARENT (object)))
448 GST_OBJECT_PARENT (object) = NULL;
449 GST_OBJECT_UNLOCK (object);
451 parent_class->dispose (object);
458 g_critical ("\nTrying to dispose object \"%s\", but it still has a "
459 "parent \"%s\".\nYou need to let the parent manage the "
460 "object instead of unreffing the object directly.\n",
461 GST_OBJECT_NAME (object), GST_OBJECT_NAME (parent));
462 GST_OBJECT_UNLOCK (object);
463 /* ref the object again to revive it in this error case */
464 gst_object_ref (object);
469 /* finalize is called when the object has to free its resources */
471 gst_object_finalize (GObject * object)
473 GstObject *gstobject = GST_OBJECT_CAST (object);
475 GST_CAT_LOG_OBJECT (GST_CAT_REFCOUNTING, object, "finalize");
477 g_signal_handlers_destroy (object);
479 g_free (gstobject->name);
480 g_mutex_free (gstobject->lock);
482 #ifndef GST_DISABLE_TRACE
483 gst_alloc_trace_free (_gst_object_trace, object);
486 parent_class->finalize (object);
489 /* Changing a GObject property of a GstObject will result in "deep-notify"
490 * signals being emitted by the object itself, as well as in each parent
491 * object. This is so that an application can connect a listener to the
492 * top-level bin to catch property-change notifications for all contained
495 * This function is not MT safe in glib < 2.8 so we need to lock it with a
496 * classwide mutex in that case.
501 gst_object_dispatch_properties_changed (GObject * object,
502 guint n_pspecs, GParamSpec ** pspecs)
504 GstObject *gst_object, *parent, *old_parent;
506 gchar *name, *debug_name;
508 /* do the standard dispatching */
509 parent_class->dispatch_properties_changed (object, n_pspecs, pspecs);
511 gst_object = GST_OBJECT_CAST (object);
512 name = gst_object_get_name (gst_object);
513 debug_name = GST_STR_NULL (name);
515 /* now let the parent dispatch those, too */
516 parent = gst_object_get_parent (gst_object);
518 for (i = 0; i < n_pspecs; i++) {
519 GST_CAT_LOG_OBJECT (GST_CAT_PROPERTIES, parent,
520 "deep notification from %s (%s)", debug_name, pspecs[i]->name);
522 g_signal_emit (parent, gst_object_signals[DEEP_NOTIFY],
523 g_quark_from_string (pspecs[i]->name), gst_object, pspecs[i]);
527 parent = gst_object_get_parent (old_parent);
528 gst_object_unref (old_parent);
534 * gst_object_default_deep_notify:
535 * @object: the #GObject that signalled the notify.
536 * @orig: a #GstObject that initiated the notify.
537 * @pspec: a #GParamSpec of the property.
538 * @excluded_props: a set of user-specified properties to exclude or
539 * NULL to show all changes.
541 * A default deep_notify signal callback for an object. The user data
542 * should contain a pointer to an array of strings that should be excluded
543 * from the notify. The default handler will print the new value of the property
546 * MT safe. This function grabs and releases @object's LOCK for getting its
550 gst_object_default_deep_notify (GObject * object, GstObject * orig,
551 GParamSpec * pspec, gchar ** excluded_props)
553 GValue value = { 0, }; /* the important thing is that value.type = 0 */
557 if (pspec->flags & G_PARAM_READABLE) {
558 /* let's not print these out for excluded properties... */
559 while (excluded_props != NULL && *excluded_props != NULL) {
560 if (strcmp (pspec->name, *excluded_props) == 0)
564 g_value_init (&value, G_PARAM_SPEC_VALUE_TYPE (pspec));
565 g_object_get_property (G_OBJECT (orig), pspec->name, &value);
567 /* FIXME: handle flags */
568 if (G_IS_PARAM_SPEC_ENUM (pspec)) {
569 GEnumValue *enum_value;
570 GEnumClass *klass = G_ENUM_CLASS (g_type_class_ref (pspec->value_type));
572 enum_value = g_enum_get_value (klass, g_value_get_enum (&value));
574 str = g_strdup_printf ("%s (%d)", enum_value->value_nick,
576 g_type_class_unref (klass);
578 str = g_strdup_value_contents (&value);
580 name = gst_object_get_path_string (orig);
581 g_print ("%s: %s = %s\n", name, pspec->name, str);
584 g_value_unset (&value);
586 name = gst_object_get_path_string (orig);
587 g_warning ("Parameter %s not readable in %s.", pspec->name, name);
593 gst_object_set_name_default (GstObject * object)
595 const gchar *type_name;
600 /* to ensure guaranteed uniqueness across threads, only one thread
601 * may ever assign a name */
602 G_LOCK (object_name_mutex);
604 if (!object_name_counts) {
605 g_datalist_init (&object_name_counts);
608 q = g_type_qname (G_OBJECT_TYPE (object));
609 count = GPOINTER_TO_INT (g_datalist_id_get_data (&object_name_counts, q));
610 g_datalist_id_set_data (&object_name_counts, q, GINT_TO_POINTER (count + 1));
612 G_UNLOCK (object_name_mutex);
614 /* GstFooSink -> foosinkN */
615 type_name = g_quark_to_string (q);
616 if (strncmp (type_name, "Gst", 3) == 0)
618 tmp = g_strdup_printf ("%s%d", type_name, count);
619 name = g_ascii_strdown (tmp, -1);
622 GST_OBJECT_LOCK (object);
623 if (G_UNLIKELY (object->parent != NULL))
625 g_free (object->name);
628 GST_OBJECT_UNLOCK (object);
634 GST_WARNING ("parented objects can't be renamed");
635 GST_OBJECT_UNLOCK (object);
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);
678 /* FIXME-0.11: this misses a g_object_notify (object, "name"); unless called
679 * from gst_object_set_property.
680 * Ideally remove such custom setters (or make it static).
687 GST_WARNING ("parented objects can't be renamed");
688 GST_OBJECT_UNLOCK (object);
694 * gst_object_get_name:
695 * @object: a #GstObject
697 * Returns a copy of the name of @object.
698 * Caller should g_free() the return value after usage.
699 * For a nameless object, this returns NULL, which you can safely g_free()
702 * Returns: the name of @object. g_free() after usage.
704 * MT safe. This function grabs and releases @object's LOCK.
707 gst_object_get_name (GstObject * object)
709 gchar *result = NULL;
711 g_return_val_if_fail (GST_IS_OBJECT (object), NULL);
713 GST_OBJECT_LOCK (object);
714 result = g_strdup (object->name);
715 GST_OBJECT_UNLOCK (object);
721 * gst_object_set_name_prefix:
722 * @object: a #GstObject
723 * @name_prefix: new name prefix of @object
725 * Sets the name prefix of @object to @name_prefix.
726 * This function makes a copy of the provided name prefix, so the caller
727 * retains ownership of the name prefix it sent.
729 * MT safe. This function grabs and releases @object's LOCK.
732 gst_object_set_name_prefix (GstObject * object, const gchar * name_prefix)
734 g_return_if_fail (GST_IS_OBJECT (object));
736 GST_OBJECT_LOCK (object);
737 g_free (object->name_prefix);
738 object->name_prefix = g_strdup (name_prefix); /* NULL gives NULL */
739 GST_OBJECT_UNLOCK (object);
743 * gst_object_get_name_prefix:
744 * @object: a #GstObject
746 * Returns a copy of the name prefix of @object.
747 * Caller should g_free() the return value after usage.
748 * For a prefixless object, this returns NULL, which you can safely g_free()
751 * Returns: the name prefix of @object. g_free() after usage.
753 * MT safe. This function grabs and releases @object's LOCK.
756 gst_object_get_name_prefix (GstObject * object)
758 gchar *result = NULL;
760 g_return_val_if_fail (GST_IS_OBJECT (object), NULL);
762 GST_OBJECT_LOCK (object);
763 result = g_strdup (object->name_prefix);
764 GST_OBJECT_UNLOCK (object);
770 * gst_object_set_parent:
771 * @object: a #GstObject
772 * @parent: new parent of object
774 * Sets the parent of @object to @parent. The object's reference count will
775 * be incremented, and any floating reference will be removed (see gst_object_sink()).
777 * This function causes the parent-set signal to be emitted when the parent
778 * was successfully set.
780 * Returns: TRUE if @parent could be set or FALSE when @object
781 * already had a parent or @object and @parent are the same.
783 * MT safe. Grabs and releases @object's LOCK.
786 gst_object_set_parent (GstObject * object, GstObject * parent)
788 g_return_val_if_fail (GST_IS_OBJECT (object), FALSE);
789 g_return_val_if_fail (GST_IS_OBJECT (parent), FALSE);
790 g_return_val_if_fail (object != parent, FALSE);
792 GST_CAT_DEBUG_OBJECT (GST_CAT_REFCOUNTING, object,
793 "set parent (ref and sink)");
795 GST_OBJECT_LOCK (object);
796 if (G_UNLIKELY (object->parent != NULL))
799 /* sink object, we don't call our own function because we don't
800 * need to release/acquire the lock needlessly or touch the refcount
801 * in the floating case. */
802 object->parent = parent;
803 if (G_LIKELY (GST_OBJECT_IS_FLOATING (object))) {
804 GST_CAT_LOG_OBJECT (GST_CAT_REFCOUNTING, object, "unsetting floating flag");
805 GST_OBJECT_FLAG_UNSET (object, GST_OBJECT_FLOATING);
806 GST_OBJECT_UNLOCK (object);
808 GST_OBJECT_UNLOCK (object);
809 gst_object_ref (object);
812 g_signal_emit (object, gst_object_signals[PARENT_SET], 0, parent);
819 GST_CAT_DEBUG_OBJECT (GST_CAT_REFCOUNTING, object,
820 "set parent failed, object already had a parent");
821 GST_OBJECT_UNLOCK (object);
827 * gst_object_get_parent:
828 * @object: a #GstObject
830 * Returns the parent of @object. This function increases the refcount
831 * of the parent object so you should gst_object_unref() it after usage.
833 * Returns: parent of @object, this can be NULL if @object has no
834 * parent. unref after usage.
836 * MT safe. Grabs and releases @object's LOCK.
839 gst_object_get_parent (GstObject * object)
841 GstObject *result = NULL;
843 g_return_val_if_fail (GST_IS_OBJECT (object), NULL);
845 GST_OBJECT_LOCK (object);
846 result = object->parent;
847 if (G_LIKELY (result))
848 gst_object_ref (result);
849 GST_OBJECT_UNLOCK (object);
855 * gst_object_unparent:
856 * @object: a #GstObject to unparent
858 * Clear the parent of @object, removing the associated reference.
859 * This function decreases the refcount of @object.
861 * MT safe. Grabs and releases @object's lock.
864 gst_object_unparent (GstObject * object)
868 g_return_if_fail (GST_IS_OBJECT (object));
870 GST_OBJECT_LOCK (object);
871 parent = object->parent;
873 if (G_LIKELY (parent != NULL)) {
874 GST_CAT_LOG_OBJECT (GST_CAT_REFCOUNTING, object, "unparent");
875 object->parent = NULL;
876 GST_OBJECT_UNLOCK (object);
878 g_signal_emit (object, gst_object_signals[PARENT_UNSET], 0, parent);
880 gst_object_unref (object);
882 GST_OBJECT_UNLOCK (object);
887 * gst_object_has_ancestor:
888 * @object: a #GstObject to check
889 * @ancestor: a #GstObject to check as ancestor
891 * Check if @object has an ancestor @ancestor somewhere up in
894 * Returns: TRUE if @ancestor is an ancestor of @object.
896 * MT safe. Grabs and releases @object's locks.
899 gst_object_has_ancestor (GstObject * object, GstObject * ancestor)
901 GstObject *parent, *tmp;
903 if (!ancestor || !object)
906 parent = gst_object_ref (object);
908 if (parent == ancestor) {
909 gst_object_unref (parent);
913 tmp = gst_object_get_parent (parent);
914 gst_object_unref (parent);
922 * gst_object_check_uniqueness:
923 * @list: a list of #GstObject to check through
924 * @name: the name to search for
926 * Checks to see if there is any object named @name in @list. This function
927 * does not do any locking of any kind. You might want to protect the
928 * provided list with the lock of the owner of the list. This function
929 * will lock each #GstObject in the list to compare the name, so be
930 * carefull when passing a list with a locked object.
932 * Returns: TRUE if a #GstObject named @name does not appear in @list,
935 * MT safe. Grabs and releases the LOCK of each object in the list.
938 gst_object_check_uniqueness (GList * list, const gchar * name)
940 gboolean result = TRUE;
942 g_return_val_if_fail (name != NULL, FALSE);
944 for (; list; list = g_list_next (list)) {
948 child = GST_OBJECT_CAST (list->data);
950 GST_OBJECT_LOCK (child);
951 eq = strcmp (GST_OBJECT_NAME (child), name) == 0;
952 GST_OBJECT_UNLOCK (child);
954 if (G_UNLIKELY (eq)) {
963 #ifndef GST_DISABLE_LOADSAVE
965 * gst_object_save_thyself:
966 * @object: a #GstObject to save
967 * @parent: The parent XML node to save @object into
969 * Saves @object into the parent XML node.
971 * Returns: the new xmlNodePtr with the saved object
974 gst_object_save_thyself (GstObject * object, xmlNodePtr parent)
976 GstObjectClass *oclass;
978 g_return_val_if_fail (GST_IS_OBJECT (object), parent);
979 g_return_val_if_fail (parent != NULL, parent);
981 oclass = GST_OBJECT_GET_CLASS (object);
983 if (oclass->save_thyself)
984 oclass->save_thyself (object, parent);
986 g_signal_emit (object, gst_object_signals[OBJECT_SAVED], 0, parent);
992 * gst_object_restore_thyself:
993 * @object: a #GstObject to load into
994 * @self: The XML node to load @object from
996 * Restores @object with the data from the parent XML node.
999 gst_object_restore_thyself (GstObject * object, xmlNodePtr self)
1001 GstObjectClass *oclass;
1003 g_return_if_fail (GST_IS_OBJECT (object));
1004 g_return_if_fail (self != NULL);
1006 oclass = GST_OBJECT_GET_CLASS (object);
1008 if (oclass->restore_thyself)
1009 oclass->restore_thyself (object, self);
1013 gst_object_real_restore_thyself (GstObject * object, xmlNodePtr self)
1015 g_return_if_fail (GST_IS_OBJECT (object));
1016 g_return_if_fail (self != NULL);
1018 gst_class_signal_emit_by_name (object, "object_loaded", self);
1020 #endif /* GST_DISABLE_LOADSAVE */
1023 gst_object_set_property (GObject * object, guint prop_id,
1024 const GValue * value, GParamSpec * pspec)
1026 GstObject *gstobject;
1028 gstobject = GST_OBJECT_CAST (object);
1032 gst_object_set_name (gstobject, g_value_get_string (value));
1035 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
1041 gst_object_get_property (GObject * object, guint prop_id,
1042 GValue * value, GParamSpec * pspec)
1044 GstObject *gstobject;
1046 gstobject = GST_OBJECT_CAST (object);
1050 g_value_take_string (value, gst_object_get_name (gstobject));
1053 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
1059 * gst_object_get_path_string:
1060 * @object: a #GstObject
1062 * Generates a string describing the path of @object in
1063 * the object hierarchy. Only useful (or used) for debugging.
1065 * Returns: a string describing the path of @object. You must
1066 * g_free() the string after usage.
1068 * MT safe. Grabs and releases the #GstObject's LOCK for all objects
1072 gst_object_get_path_string (GstObject * object)
1077 gchar *prevpath, *path;
1078 const gchar *typename;
1082 /* ref object before adding to list */
1083 gst_object_ref (object);
1084 parentage = g_slist_prepend (NULL, object);
1086 path = g_strdup ("");
1088 /* first walk the object hierarchy to build a list of the parents,
1089 * be carefull here with refcounting. */
1091 if (GST_IS_OBJECT (object)) {
1092 parent = gst_object_get_parent (object);
1093 /* add parents to list, refcount remains increased while
1094 * we handle the object */
1096 parentage = g_slist_prepend (parentage, parent);
1101 } while (object != NULL);
1103 /* then walk the parent list and print them out. we need to
1104 * decrease the refcounting on each element after we handled
1106 for (parents = parentage; parents; parents = g_slist_next (parents)) {
1107 if (G_IS_OBJECT (parents->data)) {
1108 typename = G_OBJECT_TYPE_NAME (parents->data);
1112 if (GST_IS_OBJECT (parents->data)) {
1113 GstObject *item = GST_OBJECT_CAST (parents->data);
1114 GstObjectClass *oclass = GST_OBJECT_GET_CLASS (item);
1115 gchar *objname = gst_object_get_name (item);
1117 component = g_strdup_printf ("%s:%s", typename, objname);
1118 separator = oclass->path_string_separator;
1120 gst_object_unref (item);
1124 component = g_strdup_printf ("%s:%p", typename, parents->data);
1126 component = g_strdup_printf ("%p", parents->data);
1132 path = g_strjoin (separator, prevpath, component, NULL);
1137 g_slist_free (parentage);
1143 struct _GstSignalObject
1148 struct _GstSignalObjectClass
1150 GObjectClass parent_class;
1153 #ifndef GST_DISABLE_LOADSAVE
1154 void (*object_loaded) (GstSignalObject * object, GstObject * new,
1159 G_DEFINE_TYPE (GstSignalObject, gst_signal_object, G_TYPE_OBJECT);
1162 gst_signal_object_class_init (GstSignalObjectClass * klass)
1164 parent_class = g_type_class_peek_parent (klass);
1166 #ifndef GST_DISABLE_LOADSAVE
1167 gst_signal_object_signals[SO_OBJECT_LOADED] =
1168 g_signal_new ("object-loaded", G_TYPE_FROM_CLASS (klass),
1169 G_SIGNAL_RUN_LAST, G_STRUCT_OFFSET (GstSignalObjectClass, object_loaded),
1170 NULL, NULL, gst_marshal_VOID__OBJECT_POINTER, G_TYPE_NONE, 2,
1171 G_TYPE_OBJECT, G_TYPE_POINTER);
1176 gst_signal_object_init (GstSignalObject * object)
1181 * gst_class_signal_connect
1182 * @klass: a #GstObjectClass to attach the signal to
1183 * @name: the name of the signal to attach to
1184 * @func: the signal function
1185 * @func_data: a pointer to user data
1187 * Connect to a class signal.
1189 * Returns: the signal id.
1192 gst_class_signal_connect (GstObjectClass * klass,
1193 const gchar * name, gpointer func, gpointer func_data)
1195 /* [0.11] func parameter needs to be changed to a GCallback *
1196 * doing so now would be an API break. */
1197 return g_signal_connect (klass->signal_object, name, G_CALLBACK (func),
1201 #ifndef GST_DISABLE_LOADSAVE
1203 * gst_class_signal_emit_by_name:
1204 * @object: a #GstObject that emits the signal
1205 * @name: the name of the signal to emit
1206 * @self: data for the signal
1208 * emits the named class signal.
1211 gst_class_signal_emit_by_name (GstObject * object,
1212 const gchar * name, xmlNodePtr self)
1214 GstObjectClass *oclass;
1216 oclass = GST_OBJECT_GET_CLASS (object);
1218 g_signal_emit_by_name (oclass->signal_object, name, object, self);
1221 #endif /* GST_DISABLE_LOADSAVE */