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 #if !defined(GST_DISABLE_LOADSAVE) && !defined(GST_REMOVE_DEPRECATED)
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 #if !defined(GST_DISABLE_LOADSAVE) && !defined(GST_REMOVE_DEPRECATED)
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 #ifdef GST_DISABLE_DEPRECATED
154 #if !defined(GST_DISABLE_LOADSAVE) && !defined(GST_REMOVE_DEPRECATED)
156 #define GstXmlNodePtr xmlNodePtr
157 #include <libxml/parser.h>
158 GstXmlNodePtr gst_object_save_thyself (GstObject * object,
159 GstXmlNodePtr parent);
160 void gst_object_restore_thyself (GstObject * object, GstXmlNodePtr parent);
161 void gst_class_signal_emit_by_name (GstObject * object, const gchar * name,
166 #if !defined(GST_DISABLE_LOADSAVE) && !defined(GST_REMOVE_DEPRECATED)
167 static void gst_object_real_restore_thyself (GstObject * object,
171 static GObjectClass *parent_class = NULL;
172 static guint gst_object_signals[LAST_SIGNAL] = { 0 };
174 G_DEFINE_ABSTRACT_TYPE (GstObject, gst_object, G_TYPE_OBJECT);
177 gst_object_class_init (GstObjectClass * klass)
179 GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
181 parent_class = g_type_class_peek_parent (klass);
183 #ifndef GST_DISABLE_TRACE
184 _gst_object_trace = gst_alloc_trace_register (g_type_name (GST_TYPE_OBJECT));
187 gobject_class->set_property = gst_object_set_property;
188 gobject_class->get_property = gst_object_get_property;
190 g_object_class_install_property (gobject_class, ARG_NAME,
191 g_param_spec_string ("name", "Name", "The name of the object",
193 G_PARAM_READWRITE | G_PARAM_CONSTRUCT | G_PARAM_STATIC_STRINGS));
196 * GstObject::parent-set:
197 * @gstobject: a #GstObject
198 * @parent: the new parent
200 * Emitted when the parent of an object is set.
202 gst_object_signals[PARENT_SET] =
203 g_signal_new ("parent-set", G_TYPE_FROM_CLASS (klass), G_SIGNAL_RUN_LAST,
204 G_STRUCT_OFFSET (GstObjectClass, parent_set), NULL, NULL,
205 g_cclosure_marshal_VOID__OBJECT, G_TYPE_NONE, 1, GST_TYPE_OBJECT);
208 * GstObject::parent-unset:
209 * @gstobject: a #GstObject
210 * @parent: the old parent
212 * Emitted when the parent of an object is unset.
214 gst_object_signals[PARENT_UNSET] =
215 g_signal_new ("parent-unset", G_TYPE_FROM_CLASS (klass),
216 G_SIGNAL_RUN_LAST, G_STRUCT_OFFSET (GstObjectClass, parent_unset), NULL,
217 NULL, g_cclosure_marshal_VOID__OBJECT, G_TYPE_NONE, 1, GST_TYPE_OBJECT);
219 #if !defined(GST_DISABLE_LOADSAVE) && !defined(GST_REMOVE_DEPRECATED)
221 * GstObject::object-saved:
222 * @gstobject: a #GstObject
223 * @xml_node: the xmlNodePtr of the parent node
225 * Trigered whenever a new object is saved to XML. You can connect to this
226 * signal to insert custom XML tags into the core XML.
228 /* FIXME This should be the GType of xmlNodePtr instead of G_TYPE_POINTER
229 * (if libxml would use GObject)
231 gst_object_signals[OBJECT_SAVED] =
232 g_signal_new ("object-saved", G_TYPE_FROM_CLASS (klass),
233 G_SIGNAL_RUN_LAST, G_STRUCT_OFFSET (GstObjectClass, object_saved), NULL,
234 NULL, g_cclosure_marshal_VOID__POINTER, G_TYPE_NONE, 1, G_TYPE_POINTER);
236 klass->restore_thyself =
237 ((void (*)(GstObject * object,
238 gpointer self)) *gst_object_real_restore_thyself);
242 * GstObject::deep-notify:
243 * @gstobject: a #GstObject
244 * @prop_object: the object that originated the signal
245 * @prop: the property that changed
247 * The deep notify signal is used to be notified of property changes. It is
248 * typically attached to the toplevel bin to receive notifications from all
249 * the elements contained in that bin.
251 gst_object_signals[DEEP_NOTIFY] =
252 g_signal_new ("deep-notify", G_TYPE_FROM_CLASS (klass),
253 G_SIGNAL_RUN_FIRST | G_SIGNAL_NO_RECURSE | G_SIGNAL_DETAILED |
254 G_SIGNAL_NO_HOOKS, G_STRUCT_OFFSET (GstObjectClass, deep_notify), NULL,
255 NULL, gst_marshal_VOID__OBJECT_PARAM, G_TYPE_NONE, 2, GST_TYPE_OBJECT,
258 klass->path_string_separator = "/";
259 /* FIXME 0.11: Store this directly in the class struct */
260 klass->lock = g_slice_new (GStaticRecMutex);
261 g_static_rec_mutex_init (klass->lock);
263 klass->signal_object = g_object_newv (gst_signal_object_get_type (), 0, NULL);
265 /* see the comments at gst_object_dispatch_properties_changed */
266 gobject_class->dispatch_properties_changed
267 = GST_DEBUG_FUNCPTR (gst_object_dispatch_properties_changed);
269 gobject_class->dispose = gst_object_dispose;
270 gobject_class->finalize = gst_object_finalize;
274 gst_object_init (GstObject * object)
276 object->lock = g_mutex_new ();
277 object->parent = NULL;
279 GST_CAT_TRACE_OBJECT (GST_CAT_REFCOUNTING, object, "%p new", object);
281 #ifndef GST_DISABLE_TRACE
282 gst_alloc_trace_new (_gst_object_trace, object);
286 GST_OBJECT_FLAG_SET (object, GST_OBJECT_FLOATING);
291 * @object: a #GstObject to reference
293 * Increments the reference count on @object. This function
294 * does not take the lock on @object because it relies on
295 * atomic refcounting.
297 * This object returns the input parameter to ease writing
299 * result = gst_object_ref (object->parent);
301 * Returns: (transfer full): A pointer to @object
304 gst_object_ref (gpointer object)
306 g_return_val_if_fail (object != NULL, NULL);
308 #ifdef DEBUG_REFCOUNT
309 GST_CAT_TRACE_OBJECT (GST_CAT_REFCOUNTING, object, "%p ref %d->%d", object,
310 ((GObject *) object)->ref_count, ((GObject *) object)->ref_count + 1);
312 g_object_ref (object);
319 * @object: a #GstObject to unreference
321 * Decrements the reference count on @object. If reference count hits
322 * zero, destroy @object. This function does not take the lock
323 * on @object as it relies on atomic refcounting.
325 * The unref method should never be called with the LOCK held since
326 * this might deadlock the dispose function.
329 gst_object_unref (gpointer object)
331 g_return_if_fail (object != NULL);
332 g_return_if_fail (((GObject *) object)->ref_count > 0);
334 #ifdef DEBUG_REFCOUNT
335 GST_CAT_TRACE_OBJECT (GST_CAT_REFCOUNTING, object, "%p unref %d->%d", object,
336 ((GObject *) object)->ref_count, ((GObject *) object)->ref_count - 1);
338 g_object_unref (object);
342 * gst_object_ref_sink:
343 * @object: a #GstObject to sink
345 * Increase the reference count of @object, and possibly remove the floating
346 * reference, if @object has a floating reference.
348 * In other words, if the object is floating, then this call "assumes ownership"
349 * of the floating reference, converting it to a normal reference by clearing
350 * the floating flag while leaving the reference count unchanged. If the object
351 * is not floating, then this call adds a new normal reference increasing the
352 * reference count by one.
354 * MT safe. This function grabs and releases @object lock.
359 gst_object_ref_sink (gpointer object)
361 g_return_if_fail (GST_IS_OBJECT (object));
363 GST_OBJECT_LOCK (object);
364 if (G_LIKELY (GST_OBJECT_IS_FLOATING (object))) {
365 GST_CAT_TRACE_OBJECT (GST_CAT_REFCOUNTING, object,
366 "unsetting floating flag");
367 GST_OBJECT_FLAG_UNSET (object, GST_OBJECT_FLOATING);
368 GST_OBJECT_UNLOCK (object);
370 GST_OBJECT_UNLOCK (object);
371 gst_object_ref (object);
377 * @object: a #GstObject to sink
379 * If @object was floating, the #GST_OBJECT_FLOATING flag is removed
380 * and @object is unreffed. When @object was not floating,
381 * this function does nothing.
383 * Any newly created object has a refcount of 1 and is floating.
384 * This function should be used when creating a new object to
385 * symbolically 'take ownership' of @object. This done by first doing a
386 * gst_object_ref() to keep a reference to @object and then gst_object_sink()
387 * to remove and unref any floating references to @object.
388 * Use gst_object_set_parent() to have this done for you.
390 * MT safe. This function grabs and releases @object lock.
393 gst_object_sink (gpointer object)
395 g_return_if_fail (GST_IS_OBJECT (object));
397 GST_CAT_TRACE_OBJECT (GST_CAT_REFCOUNTING, object, "sink");
399 GST_OBJECT_LOCK (object);
400 if (G_LIKELY (GST_OBJECT_IS_FLOATING (object))) {
401 GST_CAT_TRACE_OBJECT (GST_CAT_REFCOUNTING, object, "clear floating flag");
402 GST_OBJECT_FLAG_UNSET (object, GST_OBJECT_FLOATING);
403 GST_OBJECT_UNLOCK (object);
404 gst_object_unref (object);
406 GST_OBJECT_UNLOCK (object);
411 * gst_object_replace:
412 * @oldobj: (inout) (transfer full): pointer to a place of a #GstObject to
414 * @newobj: (transfer none): a new #GstObject
416 * Unrefs the #GstObject pointed to by @oldobj, refs @newobj and
417 * puts @newobj in *@oldobj. Be carefull when calling this
418 * function, it does not take any locks. You might want to lock
419 * the object owning @oldobj pointer before calling this
422 * Make sure not to LOCK @oldobj because it might be unreffed
423 * which could cause a deadlock when it is disposed.
426 gst_object_replace (GstObject ** oldobj, GstObject * newobj)
428 g_return_if_fail (oldobj != NULL);
429 g_return_if_fail (*oldobj == NULL || GST_IS_OBJECT (*oldobj));
430 g_return_if_fail (newobj == NULL || GST_IS_OBJECT (newobj));
432 #ifdef DEBUG_REFCOUNT
433 GST_CAT_TRACE (GST_CAT_REFCOUNTING, "replace %p %s (%d) with %p %s (%d)",
434 *oldobj, *oldobj ? GST_STR_NULL (GST_OBJECT_NAME (*oldobj)) : "(NONE)",
435 *oldobj ? G_OBJECT (*oldobj)->ref_count : 0,
436 newobj, newobj ? GST_STR_NULL (GST_OBJECT_NAME (newobj)) : "(NONE)",
437 newobj ? G_OBJECT (newobj)->ref_count : 0);
440 if (G_LIKELY (*oldobj != newobj)) {
442 gst_object_ref (newobj);
444 gst_object_unref (*oldobj);
450 /* dispose is called when the object has to release all links
451 * to other objects */
453 gst_object_dispose (GObject * object)
457 GST_CAT_TRACE_OBJECT (GST_CAT_REFCOUNTING, object, "dispose");
459 GST_OBJECT_LOCK (object);
460 if ((parent = GST_OBJECT_PARENT (object)))
462 GST_OBJECT_PARENT (object) = NULL;
463 GST_OBJECT_UNLOCK (object);
465 parent_class->dispose (object);
472 g_critical ("\nTrying to dispose object \"%s\", but it still has a "
473 "parent \"%s\".\nYou need to let the parent manage the "
474 "object instead of unreffing the object directly.\n",
475 GST_OBJECT_NAME (object), GST_OBJECT_NAME (parent));
476 GST_OBJECT_UNLOCK (object);
477 /* ref the object again to revive it in this error case */
478 gst_object_ref (object);
483 /* finalize is called when the object has to free its resources */
485 gst_object_finalize (GObject * object)
487 GstObject *gstobject = GST_OBJECT_CAST (object);
489 GST_CAT_TRACE_OBJECT (GST_CAT_REFCOUNTING, object, "finalize");
491 g_signal_handlers_destroy (object);
493 g_free (gstobject->name);
494 g_mutex_free (gstobject->lock);
496 #ifndef GST_DISABLE_TRACE
497 gst_alloc_trace_free (_gst_object_trace, object);
500 parent_class->finalize (object);
503 /* Changing a GObject property of a GstObject will result in "deep-notify"
504 * signals being emitted by the object itself, as well as in each parent
505 * object. This is so that an application can connect a listener to the
506 * top-level bin to catch property-change notifications for all contained
509 * This function is not MT safe in glib < 2.8 so we need to lock it with a
510 * classwide mutex in that case.
515 gst_object_dispatch_properties_changed (GObject * object,
516 guint n_pspecs, GParamSpec ** pspecs)
518 GstObject *gst_object, *parent, *old_parent;
520 #ifndef GST_DISABLE_GST_DEBUG
522 const gchar *debug_name;
525 /* do the standard dispatching */
526 parent_class->dispatch_properties_changed (object, n_pspecs, pspecs);
528 gst_object = GST_OBJECT_CAST (object);
529 #ifndef GST_DISABLE_GST_DEBUG
530 if (G_UNLIKELY (__gst_debug_min >= GST_LEVEL_LOG)) {
531 name = gst_object_get_name (gst_object);
532 debug_name = GST_STR_NULL (name);
537 /* now let the parent dispatch those, too */
538 parent = gst_object_get_parent (gst_object);
540 for (i = 0; i < n_pspecs; i++) {
541 GST_CAT_LOG_OBJECT (GST_CAT_PROPERTIES, parent,
542 "deep notification from %s (%s)", debug_name, pspecs[i]->name);
544 g_signal_emit (parent, gst_object_signals[DEEP_NOTIFY],
545 g_quark_from_string (pspecs[i]->name), gst_object, pspecs[i]);
549 parent = gst_object_get_parent (old_parent);
550 gst_object_unref (old_parent);
552 #ifndef GST_DISABLE_GST_DEBUG
558 * gst_object_default_deep_notify:
559 * @object: the #GObject that signalled the notify.
560 * @orig: a #GstObject that initiated the notify.
561 * @pspec: a #GParamSpec of the property.
562 * @excluded_props: (array zero-terminated=1) (element-type gchar*)
563 * (allow-none):a set of user-specified properties to exclude or
564 * NULL to show all changes.
566 * A default deep_notify signal callback for an object. The user data
567 * should contain a pointer to an array of strings that should be excluded
568 * from the notify. The default handler will print the new value of the property
571 * MT safe. This function grabs and releases @object's LOCK for getting its
575 gst_object_default_deep_notify (GObject * object, GstObject * orig,
576 GParamSpec * pspec, gchar ** excluded_props)
578 GValue value = { 0, }; /* the important thing is that value.type = 0 */
582 if (pspec->flags & G_PARAM_READABLE) {
583 /* let's not print these out for excluded properties... */
584 while (excluded_props != NULL && *excluded_props != NULL) {
585 if (strcmp (pspec->name, *excluded_props) == 0)
589 g_value_init (&value, pspec->value_type);
590 g_object_get_property (G_OBJECT (orig), pspec->name, &value);
592 /* FIXME: handle flags */
593 if (G_IS_PARAM_SPEC_ENUM (pspec)) {
594 GEnumValue *enum_value;
595 GEnumClass *klass = G_ENUM_CLASS (g_type_class_ref (pspec->value_type));
597 enum_value = g_enum_get_value (klass, g_value_get_enum (&value));
599 str = g_strdup_printf ("%s (%d)", enum_value->value_nick,
601 g_type_class_unref (klass);
603 str = g_strdup_value_contents (&value);
605 name = gst_object_get_path_string (orig);
606 g_print ("%s: %s = %s\n", name, pspec->name, str);
609 g_value_unset (&value);
611 name = gst_object_get_path_string (orig);
612 g_warning ("Parameter %s not readable in %s.", pspec->name, name);
618 gst_object_set_name_default (GstObject * object)
620 const gchar *type_name;
626 /* to ensure guaranteed uniqueness across threads, only one thread
627 * may ever assign a name */
628 G_LOCK (object_name_mutex);
630 if (!object_name_counts) {
631 g_datalist_init (&object_name_counts);
634 q = g_type_qname (G_OBJECT_TYPE (object));
635 count = GPOINTER_TO_INT (g_datalist_id_get_data (&object_name_counts, q));
636 g_datalist_id_set_data (&object_name_counts, q, GINT_TO_POINTER (count + 1));
638 G_UNLOCK (object_name_mutex);
640 /* GstFooSink -> foosink<N> */
641 type_name = g_quark_to_string (q);
642 if (strncmp (type_name, "Gst", 3) == 0)
644 name = g_strdup_printf ("%s%d", type_name, count);
646 for (i = 0; i < l; i++)
647 name[i] = g_ascii_tolower (name[i]);
649 GST_OBJECT_LOCK (object);
650 if (G_UNLIKELY (object->parent != NULL))
653 g_free (object->name);
656 GST_OBJECT_UNLOCK (object);
663 GST_WARNING ("parented objects can't be renamed");
664 GST_OBJECT_UNLOCK (object);
670 * gst_object_set_name:
671 * @object: a #GstObject
672 * @name: new name of object
674 * Sets the name of @object, or gives @object a guaranteed unique
675 * name (if @name is NULL).
676 * This function makes a copy of the provided name, so the caller
677 * retains ownership of the name it sent.
679 * Returns: TRUE if the name could be set. Since Objects that have
680 * a parent cannot be renamed, this function returns FALSE in those
683 * MT safe. This function grabs and releases @object's LOCK.
686 gst_object_set_name (GstObject * object, const gchar * name)
690 g_return_val_if_fail (GST_IS_OBJECT (object), FALSE);
692 GST_OBJECT_LOCK (object);
694 /* parented objects cannot be renamed */
695 if (G_UNLIKELY (object->parent != NULL))
699 g_free (object->name);
700 object->name = g_strdup (name);
701 GST_OBJECT_UNLOCK (object);
704 GST_OBJECT_UNLOCK (object);
705 result = gst_object_set_name_default (object);
707 /* FIXME-0.11: this misses a g_object_notify (object, "name"); unless called
708 * from gst_object_set_property.
709 * Ideally remove such custom setters (or make it static).
716 GST_WARNING ("parented objects can't be renamed");
717 GST_OBJECT_UNLOCK (object);
723 * gst_object_get_name:
724 * @object: a #GstObject
726 * Returns a copy of the name of @object.
727 * Caller should g_free() the return value after usage.
728 * For a nameless object, this returns NULL, which you can safely g_free()
731 * Free-function: g_free
733 * Returns: (transfer full): the name of @object. g_free() after usage.
735 * MT safe. This function grabs and releases @object's LOCK.
738 gst_object_get_name (GstObject * object)
740 gchar *result = NULL;
742 g_return_val_if_fail (GST_IS_OBJECT (object), NULL);
744 GST_OBJECT_LOCK (object);
745 result = g_strdup (object->name);
746 GST_OBJECT_UNLOCK (object);
752 * gst_object_set_name_prefix:
753 * @object: a #GstObject
754 * @name_prefix: new name prefix of @object
756 * Sets the name prefix of @object to @name_prefix.
757 * This function makes a copy of the provided name prefix, so the caller
758 * retains ownership of the name prefix it sent.
760 * MT safe. This function grabs and releases @object's LOCK.
762 * Deprecated: deprecated because the name prefix has never actually been used
765 #ifndef GST_REMOVE_DEPRECATED
766 #ifdef GST_DISABLE_DEPRECATED
767 void gst_object_set_name_prefix (GstObject * object, const gchar * name_prefix);
770 gst_object_set_name_prefix (GstObject * object, const gchar * name_prefix)
772 g_return_if_fail (GST_IS_OBJECT (object));
774 GST_OBJECT_LOCK (object);
775 g_free (object->name_prefix);
776 object->name_prefix = g_strdup (name_prefix); /* NULL gives NULL */
777 GST_OBJECT_UNLOCK (object);
779 #endif /* GST_REMOVE_DEPRECATED */
782 * gst_object_get_name_prefix:
783 * @object: a #GstObject
785 * Returns a copy of the name prefix of @object.
786 * Caller should g_free() the return value after usage.
787 * For a prefixless object, this returns NULL, which you can safely g_free()
790 * Returns: the name prefix of @object. g_free() after usage.
792 * MT safe. This function grabs and releases @object's LOCK.
794 * Deprecated: deprecated because the name prefix has never actually been used
797 #ifndef GST_REMOVE_DEPRECATED
798 #ifdef GST_DISABLE_DEPRECATED
799 gchar *gst_object_get_name_prefix (GstObject * object);
802 gst_object_get_name_prefix (GstObject * object)
804 gchar *result = NULL;
806 g_return_val_if_fail (GST_IS_OBJECT (object), NULL);
808 GST_OBJECT_LOCK (object);
809 result = g_strdup (object->name_prefix);
810 GST_OBJECT_UNLOCK (object);
814 #endif /* GST_REMOVE_DEPRECATED */
817 * gst_object_set_parent:
818 * @object: a #GstObject
819 * @parent: new parent of object
821 * Sets the parent of @object to @parent. The object's reference count will
822 * be incremented, and any floating reference will be removed (see gst_object_sink()).
824 * This function causes the parent-set signal to be emitted when the parent
825 * was successfully set.
827 * Returns: TRUE if @parent could be set or FALSE when @object
828 * already had a parent or @object and @parent are the same.
830 * MT safe. Grabs and releases @object's LOCK.
833 gst_object_set_parent (GstObject * object, GstObject * parent)
835 g_return_val_if_fail (GST_IS_OBJECT (object), FALSE);
836 g_return_val_if_fail (GST_IS_OBJECT (parent), FALSE);
837 g_return_val_if_fail (object != parent, FALSE);
839 GST_CAT_DEBUG_OBJECT (GST_CAT_REFCOUNTING, object,
840 "set parent (ref and sink)");
842 GST_OBJECT_LOCK (object);
843 if (G_UNLIKELY (object->parent != NULL))
846 /* sink object, we don't call our own function because we don't
847 * need to release/acquire the lock needlessly or touch the refcount
848 * in the floating case. */
849 object->parent = parent;
850 if (G_LIKELY (GST_OBJECT_IS_FLOATING (object))) {
851 GST_CAT_TRACE_OBJECT (GST_CAT_REFCOUNTING, object,
852 "unsetting floating flag");
853 GST_OBJECT_FLAG_UNSET (object, GST_OBJECT_FLOATING);
854 GST_OBJECT_UNLOCK (object);
856 GST_OBJECT_UNLOCK (object);
857 gst_object_ref (object);
860 g_signal_emit (object, gst_object_signals[PARENT_SET], 0, parent);
867 GST_CAT_DEBUG_OBJECT (GST_CAT_REFCOUNTING, object,
868 "set parent failed, object already had a parent");
869 GST_OBJECT_UNLOCK (object);
875 * gst_object_get_parent:
876 * @object: a #GstObject
878 * Returns the parent of @object. This function increases the refcount
879 * of the parent object so you should gst_object_unref() it after usage.
881 * Returns: (transfer full): parent of @object, this can be NULL if @object
882 * has no parent. unref after usage.
884 * MT safe. Grabs and releases @object's LOCK.
887 gst_object_get_parent (GstObject * object)
889 GstObject *result = NULL;
891 g_return_val_if_fail (GST_IS_OBJECT (object), NULL);
893 GST_OBJECT_LOCK (object);
894 result = object->parent;
895 if (G_LIKELY (result))
896 gst_object_ref (result);
897 GST_OBJECT_UNLOCK (object);
903 * gst_object_unparent:
904 * @object: a #GstObject to unparent
906 * Clear the parent of @object, removing the associated reference.
907 * This function decreases the refcount of @object.
909 * MT safe. Grabs and releases @object's lock.
912 gst_object_unparent (GstObject * object)
916 g_return_if_fail (GST_IS_OBJECT (object));
918 GST_OBJECT_LOCK (object);
919 parent = object->parent;
921 if (G_LIKELY (parent != NULL)) {
922 GST_CAT_TRACE_OBJECT (GST_CAT_REFCOUNTING, object, "unparent");
923 object->parent = NULL;
924 GST_OBJECT_UNLOCK (object);
926 g_signal_emit (object, gst_object_signals[PARENT_UNSET], 0, parent);
928 gst_object_unref (object);
930 GST_OBJECT_UNLOCK (object);
935 * gst_object_has_ancestor:
936 * @object: a #GstObject to check
937 * @ancestor: a #GstObject to check as ancestor
939 * Check if @object has an ancestor @ancestor somewhere up in
940 * the hierarchy. One can e.g. check if a #GstElement is inside a #GstPipeline.
942 * Returns: TRUE if @ancestor is an ancestor of @object.
944 * MT safe. Grabs and releases @object's locks.
947 gst_object_has_ancestor (GstObject * object, GstObject * ancestor)
949 GstObject *parent, *tmp;
951 if (!ancestor || !object)
954 parent = gst_object_ref (object);
956 if (parent == ancestor) {
957 gst_object_unref (parent);
961 tmp = gst_object_get_parent (parent);
962 gst_object_unref (parent);
970 * gst_object_check_uniqueness:
971 * @list: (transfer none) (element-type Gst.Object): a list of #GstObject to
973 * @name: the name to search for
975 * Checks to see if there is any object named @name in @list. This function
976 * does not do any locking of any kind. You might want to protect the
977 * provided list with the lock of the owner of the list. This function
978 * will lock each #GstObject in the list to compare the name, so be
979 * carefull when passing a list with a locked object.
981 * Returns: TRUE if a #GstObject named @name does not appear in @list,
984 * MT safe. Grabs and releases the LOCK of each object in the list.
987 gst_object_check_uniqueness (GList * list, const gchar * name)
989 gboolean result = TRUE;
991 g_return_val_if_fail (name != NULL, FALSE);
993 for (; list; list = g_list_next (list)) {
997 child = GST_OBJECT_CAST (list->data);
999 GST_OBJECT_LOCK (child);
1000 eq = strcmp (GST_OBJECT_NAME (child), name) == 0;
1001 GST_OBJECT_UNLOCK (child);
1003 if (G_UNLIKELY (eq)) {
1012 #if !defined(GST_DISABLE_LOADSAVE) && !defined(GST_REMOVE_DEPRECATED)
1014 * gst_object_save_thyself:
1015 * @object: a #GstObject to save
1016 * @parent: The parent XML node to save @object into
1018 * Saves @object into the parent XML node.
1020 * Returns: the new xmlNodePtr with the saved object
1023 gst_object_save_thyself (GstObject * object, GstXmlNodePtr parent)
1025 GstObjectClass *oclass;
1027 g_return_val_if_fail (GST_IS_OBJECT (object), parent);
1028 g_return_val_if_fail (parent != NULL, parent);
1030 oclass = GST_OBJECT_GET_CLASS (object);
1032 if (oclass->save_thyself)
1033 oclass->save_thyself (object, parent);
1035 g_signal_emit (object, gst_object_signals[OBJECT_SAVED], 0, parent);
1041 * gst_object_restore_thyself:
1042 * @object: a #GstObject to load into
1043 * @self: The XML node to load @object from
1045 * Restores @object with the data from the parent XML node.
1048 gst_object_restore_thyself (GstObject * object, GstXmlNodePtr self)
1050 GstObjectClass *oclass;
1052 g_return_if_fail (GST_IS_OBJECT (object));
1053 g_return_if_fail (self != NULL);
1055 oclass = GST_OBJECT_GET_CLASS (object);
1057 if (oclass->restore_thyself)
1058 oclass->restore_thyself (object, self);
1062 gst_object_real_restore_thyself (GstObject * object, GstXmlNodePtr self)
1064 g_return_if_fail (GST_IS_OBJECT (object));
1065 g_return_if_fail (self != NULL);
1067 gst_class_signal_emit_by_name (object, "object_loaded", self);
1069 #endif /* GST_DISABLE_LOADSAVE */
1072 gst_object_set_property (GObject * object, guint prop_id,
1073 const GValue * value, GParamSpec * pspec)
1075 GstObject *gstobject;
1077 gstobject = GST_OBJECT_CAST (object);
1081 gst_object_set_name (gstobject, g_value_get_string (value));
1084 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
1090 gst_object_get_property (GObject * object, guint prop_id,
1091 GValue * value, GParamSpec * pspec)
1093 GstObject *gstobject;
1095 gstobject = GST_OBJECT_CAST (object);
1099 g_value_take_string (value, gst_object_get_name (gstobject));
1102 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
1108 * gst_object_get_path_string:
1109 * @object: a #GstObject
1111 * Generates a string describing the path of @object in
1112 * the object hierarchy. Only useful (or used) for debugging.
1114 * Free-function: g_free
1116 * Returns: (transfer full): a string describing the path of @object. You must
1117 * g_free() the string after usage.
1119 * MT safe. Grabs and releases the #GstObject's LOCK for all objects
1123 gst_object_get_path_string (GstObject * object)
1128 gchar *prevpath, *path;
1129 const gchar *typename;
1131 const gchar *separator;
1133 /* ref object before adding to list */
1134 gst_object_ref (object);
1135 parentage = g_slist_prepend (NULL, object);
1137 path = g_strdup ("");
1139 /* first walk the object hierarchy to build a list of the parents,
1140 * be carefull here with refcounting. */
1142 if (GST_IS_OBJECT (object)) {
1143 parent = gst_object_get_parent (object);
1144 /* add parents to list, refcount remains increased while
1145 * we handle the object */
1147 parentage = g_slist_prepend (parentage, parent);
1152 } while (object != NULL);
1154 /* then walk the parent list and print them out. we need to
1155 * decrease the refcounting on each element after we handled
1157 for (parents = parentage; parents; parents = g_slist_next (parents)) {
1158 if (G_IS_OBJECT (parents->data)) {
1159 typename = G_OBJECT_TYPE_NAME (parents->data);
1163 if (GST_IS_OBJECT (parents->data)) {
1164 GstObject *item = GST_OBJECT_CAST (parents->data);
1165 GstObjectClass *oclass = GST_OBJECT_GET_CLASS (item);
1166 gchar *objname = gst_object_get_name (item);
1168 component = g_strdup_printf ("%s:%s", typename, objname);
1169 separator = oclass->path_string_separator;
1171 gst_object_unref (item);
1175 component = g_strdup_printf ("%s:%p", typename, parents->data);
1177 component = g_strdup_printf ("%p", parents->data);
1183 path = g_strjoin (separator, prevpath, component, NULL);
1188 g_slist_free (parentage);
1194 struct _GstSignalObject
1199 struct _GstSignalObjectClass
1201 GObjectClass parent_class;
1204 #if !defined(GST_DISABLE_LOADSAVE) && !defined(GST_REMOVE_DEPRECATED)
1205 void (*object_loaded) (GstSignalObject * object, GstObject * new,
1206 GstXmlNodePtr self);
1210 G_DEFINE_TYPE (GstSignalObject, gst_signal_object, G_TYPE_OBJECT);
1213 gst_signal_object_class_init (GstSignalObjectClass * klass)
1215 parent_class = g_type_class_peek_parent (klass);
1217 #if !defined(GST_DISABLE_LOADSAVE) && !defined(GST_REMOVE_DEPRECATED)
1218 gst_signal_object_signals[SO_OBJECT_LOADED] =
1219 g_signal_new ("object-loaded", G_TYPE_FROM_CLASS (klass),
1220 G_SIGNAL_RUN_LAST, G_STRUCT_OFFSET (GstSignalObjectClass, object_loaded),
1221 NULL, NULL, gst_marshal_VOID__OBJECT_POINTER, G_TYPE_NONE, 2,
1222 G_TYPE_OBJECT, G_TYPE_POINTER);
1227 gst_signal_object_init (GstSignalObject * object)
1232 * gst_class_signal_connect
1233 * @klass: a #GstObjectClass to attach the signal to
1234 * @name: the name of the signal to attach to
1235 * @func: the signal function
1236 * @func_data: a pointer to user data
1238 * Connect to a class signal.
1240 * Returns: the signal id.
1243 gst_class_signal_connect (GstObjectClass * klass,
1244 const gchar * name, gpointer func, gpointer func_data)
1246 /* [0.11] func parameter needs to be changed to a GCallback *
1247 * doing so now would be an API break. */
1248 return g_signal_connect (klass->signal_object, name, G_CALLBACK (func),
1252 #if !defined(GST_DISABLE_LOADSAVE) && !defined(GST_REMOVE_DEPRECATED)
1254 * gst_class_signal_emit_by_name:
1255 * @object: a #GstObject that emits the signal
1256 * @name: the name of the signal to emit
1257 * @self: data for the signal
1259 * emits the named class signal.
1262 gst_class_signal_emit_by_name (GstObject * object,
1263 const gchar * name, GstXmlNodePtr self)
1265 GstObjectClass *oclass;
1267 oclass = GST_OBJECT_GET_CLASS (object);
1269 g_signal_emit_by_name (oclass->signal_object, name, object, self);
1272 #endif /* GST_DISABLE_LOADSAVE */