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., 51 Franklin St, Fifth Floor,
21 * Boston, MA 02110-1301, USA.
27 * @short_description: Base class for the GStreamer object hierarchy
29 * #GstObject provides a root for the object hierarchy tree filed in by the
30 * GStreamer library. It is currently a thin wrapper on top of
31 * #GInitiallyUnowned. It is an abstract class that is not very usable on its own.
33 * #GstObject gives us basic refcounting, parenting functionality and locking.
34 * Most of the functions are just extended for special GStreamer needs and can be
35 * found under the same name in the base class of #GstObject which is #GObject
36 * (e.g. g_object_ref() becomes gst_object_ref()).
38 * Since #GstObject derives from #GInitiallyUnowned, it also inherits the
39 * floating reference. Be aware that functions such as gst_bin_add() and
40 * gst_element_add_pad() take ownership of the floating reference.
42 * In contrast to #GObject instances, #GstObject adds a name property. The functions
43 * gst_object_set_name() and gst_object_get_name() are used to set/get the name
46 * ## controlled properties
48 * Controlled properties offers a lightweight way to adjust gobject properties
49 * over stream-time. It works by using time-stamped value pairs that are queued
50 * for element-properties. At run-time the elements continuously pull value
51 * changes for the current stream-time.
53 * What needs to be changed in a #GstElement?
54 * Very little - it is just two steps to make a plugin controllable!
56 * * mark gobject-properties paramspecs that make sense to be controlled,
57 * by GST_PARAM_CONTROLLABLE.
59 * * when processing data (get, chain, loop function) at the beginning call
60 * gst_object_sync_values(element,timestamp).
61 * This will make the controller update all GObject properties that are
62 * under its control with the current values based on the timestamp.
64 * What needs to be done in applications? Again it's not a lot to change.
66 * * create a #GstControlSource.
67 * csource = gst_interpolation_control_source_new ();
68 * g_object_set (csource, "mode", GST_INTERPOLATION_MODE_LINEAR, NULL);
70 * * Attach the #GstControlSource on the controller to a property.
71 * gst_object_add_control_binding (object, gst_direct_control_binding_new (object, "prop1", csource));
73 * * Set the control values
74 * gst_timed_value_control_source_set ((GstTimedValueControlSource *)csource,0 * GST_SECOND, value1);
75 * gst_timed_value_control_source_set ((GstTimedValueControlSource *)csource,1 * GST_SECOND, value2);
77 * * start your pipeline
80 #include "gst_private.h"
81 #include "glib-compat-private.h"
83 #include "gstobject.h"
85 #include "gstcontrolbinding.h"
86 #include "gstcontrolsource.h"
88 #include "gstparamspecs.h"
91 #define DEBUG_REFCOUNT
93 /* Object signals and args */
114 /* maps type name quark => count */
115 static GData *object_name_counts = NULL;
117 G_LOCK_DEFINE_STATIC (object_name_mutex);
119 static void gst_object_set_property (GObject * object, guint prop_id,
120 const GValue * value, GParamSpec * pspec);
121 static void gst_object_get_property (GObject * object, guint prop_id,
122 GValue * value, GParamSpec * pspec);
124 static void gst_object_dispatch_properties_changed (GObject * object,
125 guint n_pspecs, GParamSpec ** pspecs);
127 static void gst_object_dispose (GObject * object);
128 static void gst_object_finalize (GObject * object);
130 static gboolean gst_object_set_name_default (GstObject * object);
132 static guint gst_object_signals[LAST_SIGNAL] = { 0 };
134 static GParamSpec *properties[PROP_LAST];
136 G_DEFINE_ABSTRACT_TYPE (GstObject, gst_object, G_TYPE_INITIALLY_UNOWNED);
139 gst_object_constructed (GObject * object)
141 GST_TRACER_OBJECT_CREATED (GST_OBJECT_CAST (object));
143 ((GObjectClass *) gst_object_parent_class)->constructed (object);
147 gst_object_class_init (GstObjectClass * klass)
149 GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
151 gobject_class->set_property = gst_object_set_property;
152 gobject_class->get_property = gst_object_get_property;
154 properties[PROP_NAME] =
155 g_param_spec_string ("name", "Name", "The name of the object", NULL,
156 G_PARAM_READWRITE | G_PARAM_CONSTRUCT | G_PARAM_STATIC_STRINGS);
161 * The parent of the object. Please note, that when changing the 'parent'
162 * property, we don't emit #GObject::notify and #GstObject::deep-notify
163 * signals due to locking issues. In some cases one can use
164 * #GstBin::element-added or #GstBin::element-removed signals on the parent to
165 * achieve a similar effect.
167 properties[PROP_PARENT] =
168 g_param_spec_object ("parent", "Parent", "The parent of the object",
169 GST_TYPE_OBJECT, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS);
171 g_object_class_install_properties (gobject_class, PROP_LAST, properties);
174 * GstObject::deep-notify:
175 * @gstobject: a #GstObject
176 * @prop_object: the object that originated the signal
177 * @prop: the property that changed
179 * The deep notify signal is used to be notified of property changes. It is
180 * typically attached to the toplevel bin to receive notifications from all
181 * the elements contained in that bin.
183 gst_object_signals[DEEP_NOTIFY] =
184 g_signal_new ("deep-notify", G_TYPE_FROM_CLASS (klass),
185 G_SIGNAL_RUN_FIRST | G_SIGNAL_NO_RECURSE | G_SIGNAL_DETAILED |
186 G_SIGNAL_NO_HOOKS, G_STRUCT_OFFSET (GstObjectClass, deep_notify), NULL,
187 NULL, g_cclosure_marshal_generic, G_TYPE_NONE, 2, GST_TYPE_OBJECT,
190 klass->path_string_separator = "/";
192 /* see the comments at gst_object_dispatch_properties_changed */
193 gobject_class->dispatch_properties_changed
194 = GST_DEBUG_FUNCPTR (gst_object_dispatch_properties_changed);
196 gobject_class->constructed = gst_object_constructed;
197 gobject_class->dispose = gst_object_dispose;
198 gobject_class->finalize = gst_object_finalize;
202 gst_object_init (GstObject * object)
204 g_mutex_init (&object->lock);
205 object->parent = NULL;
207 GST_CAT_TRACE_OBJECT (GST_CAT_REFCOUNTING, object, "%p new", object);
211 object->control_rate = 100 * GST_MSECOND;
212 object->last_sync = GST_CLOCK_TIME_NONE;
217 * @object: (type Gst.Object): a #GstObject to reference
219 * Increments the reference count on @object. This function
220 * does not take the lock on @object because it relies on
221 * atomic refcounting.
223 * This object returns the input parameter to ease writing
225 * result = gst_object_ref (object->parent);
227 * Returns: (transfer full) (type Gst.Object): A pointer to @object
230 gst_object_ref (gpointer object)
232 g_return_val_if_fail (object != NULL, NULL);
234 GST_TRACER_OBJECT_REFFED (object, ((GObject *) object)->ref_count + 1);
235 #ifdef DEBUG_REFCOUNT
236 GST_CAT_TRACE_OBJECT (GST_CAT_REFCOUNTING, object, "%p ref %d->%d", object,
237 ((GObject *) object)->ref_count, ((GObject *) object)->ref_count + 1);
239 g_object_ref (object);
246 * @object: (type Gst.Object): a #GstObject to unreference
248 * Decrements the reference count on @object. If reference count hits
249 * zero, destroy @object. This function does not take the lock
250 * on @object as it relies on atomic refcounting.
252 * The unref method should never be called with the LOCK held since
253 * this might deadlock the dispose function.
256 gst_object_unref (gpointer object)
258 g_return_if_fail (object != NULL);
259 g_return_if_fail (((GObject *) object)->ref_count > 0);
261 GST_TRACER_OBJECT_UNREFFED (object, ((GObject *) object)->ref_count - 1);
262 #ifdef DEBUG_REFCOUNT
263 GST_CAT_TRACE_OBJECT (GST_CAT_REFCOUNTING, object, "%p unref %d->%d", object,
264 ((GObject *) object)->ref_count, ((GObject *) object)->ref_count - 1);
266 g_object_unref (object);
270 * gst_object_ref_sink: (skip)
271 * @object: a #GstObject to sink
273 * Increase the reference count of @object, and possibly remove the floating
274 * reference, if @object has a floating reference.
276 * In other words, if the object is floating, then this call "assumes ownership"
277 * of the floating reference, converting it to a normal reference by clearing
278 * the floating flag while leaving the reference count unchanged. If the object
279 * is not floating, then this call adds a new normal reference increasing the
280 * reference count by one.
282 * For more background on "floating references" please see the #GObject
286 gst_object_ref_sink (gpointer object)
288 g_return_val_if_fail (object != NULL, NULL);
290 #ifdef DEBUG_REFCOUNT
291 GST_CAT_TRACE_OBJECT (GST_CAT_REFCOUNTING, object, "%p ref_sink %d->%d",
292 object, ((GObject *) object)->ref_count,
293 ((GObject *) object)->ref_count + 1);
295 return g_object_ref_sink (object);
299 * gst_object_replace:
300 * @oldobj: (inout) (transfer full) (nullable): pointer to a place of
301 * a #GstObject to replace
302 * @newobj: (transfer none) (allow-none): a new #GstObject
304 * Atomically modifies a pointer to point to a new object.
305 * The reference count of @oldobj is decreased and the reference count of
306 * @newobj is increased.
308 * Either @newobj and the value pointed to by @oldobj may be %NULL.
310 * Returns: %TRUE if @newobj was different from @oldobj
313 gst_object_replace (GstObject ** oldobj, GstObject * newobj)
317 g_return_val_if_fail (oldobj != NULL, FALSE);
319 #ifdef DEBUG_REFCOUNT
320 GST_CAT_TRACE (GST_CAT_REFCOUNTING, "replace %p %s (%d) with %p %s (%d)",
321 *oldobj, *oldobj ? GST_STR_NULL (GST_OBJECT_NAME (*oldobj)) : "(NONE)",
322 *oldobj ? G_OBJECT (*oldobj)->ref_count : 0,
323 newobj, newobj ? GST_STR_NULL (GST_OBJECT_NAME (newobj)) : "(NONE)",
324 newobj ? G_OBJECT (newobj)->ref_count : 0);
327 oldptr = g_atomic_pointer_get ((gpointer *) oldobj);
329 if (G_UNLIKELY (oldptr == newobj))
333 gst_object_ref (newobj);
335 while (G_UNLIKELY (!g_atomic_pointer_compare_and_exchange ((gpointer *)
336 oldobj, oldptr, newobj))) {
337 oldptr = g_atomic_pointer_get ((gpointer *) oldobj);
338 if (G_UNLIKELY (oldptr == newobj))
343 gst_object_unref (oldptr);
345 return oldptr != newobj;
348 /* dispose is called when the object has to release all links
349 * to other objects */
351 gst_object_dispose (GObject * object)
353 GstObject *self = (GstObject *) object;
356 GST_CAT_TRACE_OBJECT (GST_CAT_REFCOUNTING, object, "%p dispose", object);
358 GST_OBJECT_LOCK (object);
359 if ((parent = GST_OBJECT_PARENT (object)))
361 GST_OBJECT_PARENT (object) = NULL;
362 GST_OBJECT_UNLOCK (object);
364 if (self->control_bindings) {
367 for (node = self->control_bindings; node; node = g_list_next (node)) {
368 gst_object_unparent (node->data);
370 g_list_free (self->control_bindings);
371 self->control_bindings = NULL;
374 ((GObjectClass *) gst_object_parent_class)->dispose (object);
381 g_critical ("\nTrying to dispose object \"%s\", but it still has a "
382 "parent \"%s\".\nYou need to let the parent manage the "
383 "object instead of unreffing the object directly.\n",
384 GST_OBJECT_NAME (object), GST_OBJECT_NAME (parent));
385 GST_OBJECT_UNLOCK (object);
386 /* ref the object again to revive it in this error case */
387 gst_object_ref (object);
392 /* finalize is called when the object has to free its resources */
394 gst_object_finalize (GObject * object)
396 GstObject *gstobject = GST_OBJECT_CAST (object);
398 GST_CAT_TRACE_OBJECT (GST_CAT_REFCOUNTING, object, "%p finalize", object);
400 g_signal_handlers_destroy (object);
402 g_free (gstobject->name);
403 g_mutex_clear (&gstobject->lock);
405 GST_TRACER_OBJECT_DESTROYED (gstobject);
407 ((GObjectClass *) gst_object_parent_class)->finalize (object);
410 /* Changing a GObject property of a GstObject will result in "deep-notify"
411 * signals being emitted by the object itself, as well as in each parent
412 * object. This is so that an application can connect a listener to the
413 * top-level bin to catch property-change notifications for all contained
419 gst_object_dispatch_properties_changed (GObject * object,
420 guint n_pspecs, GParamSpec ** pspecs)
422 GstObject *gst_object, *parent, *old_parent;
424 #ifndef GST_DISABLE_GST_DEBUG
426 const gchar *debug_name;
429 /* do the standard dispatching */
431 gst_object_parent_class)->dispatch_properties_changed (object, n_pspecs,
434 gst_object = GST_OBJECT_CAST (object);
435 #ifndef GST_DISABLE_GST_DEBUG
436 if (G_UNLIKELY (_gst_debug_min >= GST_LEVEL_LOG)) {
437 name = gst_object_get_name (gst_object);
438 debug_name = GST_STR_NULL (name);
443 /* now let the parent dispatch those, too */
444 parent = gst_object_get_parent (gst_object);
446 for (i = 0; i < n_pspecs; i++) {
447 GST_CAT_LOG_OBJECT (GST_CAT_PROPERTIES, parent,
448 "deep notification from %s (%s)", debug_name, pspecs[i]->name);
450 g_signal_emit (parent, gst_object_signals[DEEP_NOTIFY],
451 g_quark_from_string (pspecs[i]->name), gst_object, pspecs[i]);
455 parent = gst_object_get_parent (old_parent);
456 gst_object_unref (old_parent);
458 #ifndef GST_DISABLE_GST_DEBUG
464 * gst_object_default_deep_notify:
465 * @object: the #GObject that signalled the notify.
466 * @orig: a #GstObject that initiated the notify.
467 * @pspec: a #GParamSpec of the property.
468 * @excluded_props: (array zero-terminated=1) (element-type gchar*) (allow-none):
469 * a set of user-specified properties to exclude or %NULL to show
472 * A default deep_notify signal callback for an object. The user data
473 * should contain a pointer to an array of strings that should be excluded
474 * from the notify. The default handler will print the new value of the property
477 * MT safe. This function grabs and releases @object's LOCK for getting its
481 gst_object_default_deep_notify (GObject * object, GstObject * orig,
482 GParamSpec * pspec, gchar ** excluded_props)
484 GValue value = { 0, }; /* the important thing is that value.type = 0 */
488 if (pspec->flags & G_PARAM_READABLE) {
489 /* let's not print these out for excluded properties... */
490 while (excluded_props != NULL && *excluded_props != NULL) {
491 if (strcmp (pspec->name, *excluded_props) == 0)
495 g_value_init (&value, pspec->value_type);
496 g_object_get_property (G_OBJECT (orig), pspec->name, &value);
498 if (G_VALUE_HOLDS_STRING (&value))
499 str = g_value_dup_string (&value);
501 str = gst_value_serialize (&value);
502 name = gst_object_get_path_string (orig);
503 g_print ("%s: %s = %s\n", name, pspec->name, str);
506 g_value_unset (&value);
508 name = gst_object_get_path_string (orig);
509 g_warning ("Parameter %s not readable in %s.", pspec->name, name);
515 gst_object_set_name_default (GstObject * object)
517 const gchar *type_name;
523 /* to ensure guaranteed uniqueness across threads, only one thread
524 * may ever assign a name */
525 G_LOCK (object_name_mutex);
527 if (!object_name_counts) {
528 g_datalist_init (&object_name_counts);
531 q = g_type_qname (G_OBJECT_TYPE (object));
532 count = GPOINTER_TO_INT (g_datalist_id_get_data (&object_name_counts, q));
533 g_datalist_id_set_data (&object_name_counts, q, GINT_TO_POINTER (count + 1));
535 G_UNLOCK (object_name_mutex);
537 /* GstFooSink -> foosink<N> */
538 type_name = g_quark_to_string (q);
539 if (strncmp (type_name, "Gst", 3) == 0)
541 /* give the 20th "queue" element and the first "queue2" different names */
542 l = strlen (type_name);
543 if (l > 0 && g_ascii_isdigit (type_name[l - 1])) {
544 name = g_strdup_printf ("%s-%d", type_name, count);
546 name = g_strdup_printf ("%s%d", type_name, count);
550 for (i = 0; i < l; i++)
551 name[i] = g_ascii_tolower (name[i]);
553 GST_OBJECT_LOCK (object);
554 if (G_UNLIKELY (object->parent != NULL))
557 g_free (object->name);
560 GST_OBJECT_UNLOCK (object);
567 GST_WARNING ("parented objects can't be renamed");
568 GST_OBJECT_UNLOCK (object);
574 * gst_object_set_name:
575 * @object: a #GstObject
576 * @name: (allow-none): new name of object
578 * Sets the name of @object, or gives @object a guaranteed unique
579 * name (if @name is %NULL).
580 * This function makes a copy of the provided name, so the caller
581 * retains ownership of the name it sent.
583 * Returns: %TRUE if the name could be set. Since Objects that have
584 * a parent cannot be renamed, this function returns %FALSE in those
587 * MT safe. This function grabs and releases @object's LOCK.
590 gst_object_set_name (GstObject * object, const gchar * name)
594 g_return_val_if_fail (GST_IS_OBJECT (object), FALSE);
596 GST_OBJECT_LOCK (object);
598 /* parented objects cannot be renamed */
599 if (G_UNLIKELY (object->parent != NULL))
603 g_free (object->name);
604 object->name = g_strdup (name);
605 GST_OBJECT_UNLOCK (object);
608 GST_OBJECT_UNLOCK (object);
609 result = gst_object_set_name_default (object);
612 g_object_notify (G_OBJECT (object), "name");
618 GST_WARNING ("parented objects can't be renamed");
619 GST_OBJECT_UNLOCK (object);
625 * gst_object_get_name:
626 * @object: a #GstObject
628 * Returns a copy of the name of @object.
629 * Caller should g_free() the return value after usage.
630 * For a nameless object, this returns %NULL, which you can safely g_free()
633 * Free-function: g_free
635 * Returns: (transfer full) (nullable): the name of @object. g_free()
638 * MT safe. This function grabs and releases @object's LOCK.
641 gst_object_get_name (GstObject * object)
643 gchar *result = NULL;
645 g_return_val_if_fail (GST_IS_OBJECT (object), NULL);
647 GST_OBJECT_LOCK (object);
648 result = g_strdup (object->name);
649 GST_OBJECT_UNLOCK (object);
655 * gst_object_set_parent:
656 * @object: (transfer floating): a #GstObject
657 * @parent: new parent of object
659 * Sets the parent of @object to @parent. The object's reference count will
660 * be incremented, and any floating reference will be removed (see gst_object_ref_sink()).
662 * Returns: %TRUE if @parent could be set or %FALSE when @object
663 * already had a parent or @object and @parent are the same.
665 * MT safe. Grabs and releases @object's LOCK.
668 gst_object_set_parent (GstObject * object, GstObject * parent)
670 g_return_val_if_fail (GST_IS_OBJECT (object), FALSE);
671 g_return_val_if_fail (GST_IS_OBJECT (parent), FALSE);
672 g_return_val_if_fail (object != parent, FALSE);
674 GST_CAT_DEBUG_OBJECT (GST_CAT_REFCOUNTING, object,
675 "set parent (ref and sink)");
677 GST_OBJECT_LOCK (object);
678 if (G_UNLIKELY (object->parent != NULL))
681 object->parent = parent;
682 gst_object_ref_sink (object);
683 GST_OBJECT_UNLOCK (object);
685 /* FIXME-2.0: this does not work, the deep notify takes the lock from the
686 * parent object and deadlocks when the parent holds its lock when calling
687 * this function (like _element_add_pad()), we need to use a GRecMutex
688 * for locking the parent instead.
690 /* g_object_notify_by_pspec ((GObject *)object, properties[PROP_PARENT]); */
697 GST_CAT_DEBUG_OBJECT (GST_CAT_REFCOUNTING, object,
698 "set parent failed, object already had a parent");
699 gst_object_ref_sink (object);
700 gst_object_unref (object);
701 GST_OBJECT_UNLOCK (object);
707 * gst_object_get_parent:
708 * @object: a #GstObject
710 * Returns the parent of @object. This function increases the refcount
711 * of the parent object so you should gst_object_unref() it after usage.
713 * Returns: (transfer full) (nullable): parent of @object, this can be
714 * %NULL if @object has no parent. unref after usage.
716 * MT safe. Grabs and releases @object's LOCK.
719 gst_object_get_parent (GstObject * object)
721 GstObject *result = NULL;
723 g_return_val_if_fail (GST_IS_OBJECT (object), NULL);
725 GST_OBJECT_LOCK (object);
726 result = object->parent;
727 if (G_LIKELY (result))
728 gst_object_ref (result);
729 GST_OBJECT_UNLOCK (object);
735 * gst_object_unparent:
736 * @object: a #GstObject to unparent
738 * Clear the parent of @object, removing the associated reference.
739 * This function decreases the refcount of @object.
741 * MT safe. Grabs and releases @object's lock.
744 gst_object_unparent (GstObject * object)
748 g_return_if_fail (GST_IS_OBJECT (object));
750 GST_OBJECT_LOCK (object);
751 parent = object->parent;
753 if (G_LIKELY (parent != NULL)) {
754 GST_CAT_TRACE_OBJECT (GST_CAT_REFCOUNTING, object, "unparent");
755 object->parent = NULL;
756 GST_OBJECT_UNLOCK (object);
758 /* g_object_notify_by_pspec ((GObject *)object, properties[PROP_PARENT]); */
760 gst_object_unref (object);
762 GST_OBJECT_UNLOCK (object);
767 * gst_object_has_as_parent:
768 * @object: a #GstObject to check
769 * @parent: a #GstObject to check as parent
771 * Check if @parent is the parent of @object.
772 * E.g. a #GstElement can check if it owns a given #GstPad.
774 * Returns: %FALSE if either @object or @parent is %NULL. %TRUE if @parent is
775 * the parent of @object. Otherwise %FALSE.
777 * MT safe. Grabs and releases @object's locks.
781 gst_object_has_as_parent (GstObject * object, GstObject * parent)
783 gboolean result = FALSE;
785 if (G_LIKELY (GST_IS_OBJECT (object) && GST_IS_OBJECT (parent))) {
786 GST_OBJECT_LOCK (object);
787 result = GST_OBJECT_PARENT (object) == parent;
788 GST_OBJECT_UNLOCK (object);
795 * gst_object_has_as_ancestor:
796 * @object: a #GstObject to check
797 * @ancestor: a #GstObject to check as ancestor
799 * Check if @object has an ancestor @ancestor somewhere up in
800 * the hierarchy. One can e.g. check if a #GstElement is inside a #GstPipeline.
802 * Returns: %TRUE if @ancestor is an ancestor of @object.
804 * MT safe. Grabs and releases @object's locks.
807 gst_object_has_as_ancestor (GstObject * object, GstObject * ancestor)
809 GstObject *parent, *tmp;
811 if (!ancestor || !object)
814 parent = gst_object_ref (object);
816 if (parent == ancestor) {
817 gst_object_unref (parent);
821 tmp = gst_object_get_parent (parent);
822 gst_object_unref (parent);
830 * gst_object_has_ancestor:
831 * @object: a #GstObject to check
832 * @ancestor: a #GstObject to check as ancestor
834 * Check if @object has an ancestor @ancestor somewhere up in
835 * the hierarchy. One can e.g. check if a #GstElement is inside a #GstPipeline.
837 * Returns: %TRUE if @ancestor is an ancestor of @object.
839 * Deprecated: Use gst_object_has_as_ancestor() instead.
841 * MT safe. Grabs and releases @object's locks.
843 #ifndef GST_REMOVE_DEPRECATED
845 gst_object_has_ancestor (GstObject * object, GstObject * ancestor)
847 return gst_object_has_as_ancestor (object, ancestor);
852 * gst_object_check_uniqueness:
853 * @list: (transfer none) (element-type Gst.Object): a list of #GstObject to
855 * @name: the name to search for
857 * Checks to see if there is any object named @name in @list. This function
858 * does not do any locking of any kind. You might want to protect the
859 * provided list with the lock of the owner of the list. This function
860 * will lock each #GstObject in the list to compare the name, so be
861 * careful when passing a list with a locked object.
863 * Returns: %TRUE if a #GstObject named @name does not appear in @list,
866 * MT safe. Grabs and releases the LOCK of each object in the list.
869 gst_object_check_uniqueness (GList * list, const gchar * name)
871 gboolean result = TRUE;
873 g_return_val_if_fail (name != NULL, FALSE);
875 for (; list; list = g_list_next (list)) {
879 child = GST_OBJECT_CAST (list->data);
881 GST_OBJECT_LOCK (child);
882 eq = strcmp (GST_OBJECT_NAME (child), name) == 0;
883 GST_OBJECT_UNLOCK (child);
885 if (G_UNLIKELY (eq)) {
895 gst_object_set_property (GObject * object, guint prop_id,
896 const GValue * value, GParamSpec * pspec)
898 GstObject *gstobject;
900 gstobject = GST_OBJECT_CAST (object);
904 gst_object_set_name (gstobject, g_value_get_string (value));
907 gst_object_set_parent (gstobject, g_value_get_object (value));
910 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
916 gst_object_get_property (GObject * object, guint prop_id,
917 GValue * value, GParamSpec * pspec)
919 GstObject *gstobject;
921 gstobject = GST_OBJECT_CAST (object);
925 g_value_take_string (value, gst_object_get_name (gstobject));
928 g_value_take_object (value, gst_object_get_parent (gstobject));
931 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
937 * gst_object_get_path_string:
938 * @object: a #GstObject
940 * Generates a string describing the path of @object in
941 * the object hierarchy. Only useful (or used) for debugging.
943 * Free-function: g_free
945 * Returns: (transfer full): a string describing the path of @object. You must
946 * g_free() the string after usage.
948 * MT safe. Grabs and releases the #GstObject's LOCK for all objects
952 gst_object_get_path_string (GstObject * object)
957 gchar *prevpath, *path;
958 const gchar *typename;
960 const gchar *separator;
962 /* ref object before adding to list */
963 gst_object_ref (object);
964 parentage = g_slist_prepend (NULL, object);
966 path = g_strdup ("");
968 /* first walk the object hierarchy to build a list of the parents,
969 * be careful here with refcounting. */
971 if (GST_IS_OBJECT (object)) {
972 parent = gst_object_get_parent (object);
973 /* add parents to list, refcount remains increased while
974 * we handle the object */
976 parentage = g_slist_prepend (parentage, parent);
981 } while (object != NULL);
983 /* then walk the parent list and print them out. we need to
984 * decrease the refcounting on each element after we handled
986 for (parents = parentage; parents; parents = g_slist_next (parents)) {
987 if (G_IS_OBJECT (parents->data)) {
988 typename = G_OBJECT_TYPE_NAME (parents->data);
992 if (GST_IS_OBJECT (parents->data)) {
993 GstObject *item = GST_OBJECT_CAST (parents->data);
994 GstObjectClass *oclass = GST_OBJECT_GET_CLASS (item);
995 gchar *objname = gst_object_get_name (item);
997 component = g_strdup_printf ("%s:%s", typename, objname);
998 separator = oclass->path_string_separator;
1000 gst_object_unref (item);
1004 component = g_strdup_printf ("%s:%p", typename, parents->data);
1006 component = g_strdup_printf ("%p", parents->data);
1012 path = g_strjoin (separator, prevpath, component, NULL);
1017 g_slist_free (parentage);
1022 /* controller helper functions */
1025 * gst_object_find_control_binding:
1026 * @self: the gobject to search for a property in
1027 * @name: the gobject property name to look for
1029 * Searches the list of properties under control.
1031 * Returns: (nullable): a #GstControlBinding or %NULL if the property
1032 * is not being controlled.
1034 static GstControlBinding *
1035 gst_object_find_control_binding (GstObject * self, const gchar * name)
1037 GstControlBinding *binding;
1040 for (node = self->control_bindings; node; node = g_list_next (node)) {
1041 binding = node->data;
1042 /* FIXME: eventually use GQuark to speed it up */
1043 if (!strcmp (binding->name, name)) {
1044 GST_DEBUG_OBJECT (self, "found control binding for property '%s'", name);
1048 GST_DEBUG_OBJECT (self, "controller does not manage property '%s'", name);
1053 /* controller functions */
1056 * gst_object_suggest_next_sync:
1057 * @object: the object that has controlled properties
1059 * Returns a suggestion for timestamps where buffers should be split
1060 * to get best controller results.
1062 * Returns: Returns the suggested timestamp or %GST_CLOCK_TIME_NONE
1063 * if no control-rate was set.
1066 gst_object_suggest_next_sync (GstObject * object)
1070 g_return_val_if_fail (GST_IS_OBJECT (object), GST_CLOCK_TIME_NONE);
1071 g_return_val_if_fail (object->control_rate != GST_CLOCK_TIME_NONE,
1072 GST_CLOCK_TIME_NONE);
1074 GST_OBJECT_LOCK (object);
1076 /* TODO: Implement more logic, depending on interpolation mode and control
1078 * FIXME: we need playback direction
1080 ret = object->last_sync + object->control_rate;
1082 GST_OBJECT_UNLOCK (object);
1088 * gst_object_sync_values:
1089 * @object: the object that has controlled properties
1090 * @timestamp: the time that should be processed
1092 * Sets the properties of the object, according to the #GstControlSources that
1093 * (maybe) handle them and for the given timestamp.
1095 * If this function fails, it is most likely the application developers fault.
1096 * Most probably the control sources are not setup correctly.
1098 * Returns: %TRUE if the controller values could be applied to the object
1099 * properties, %FALSE otherwise
1102 gst_object_sync_values (GstObject * object, GstClockTime timestamp)
1105 gboolean ret = TRUE;
1107 g_return_val_if_fail (GST_IS_OBJECT (object), FALSE);
1108 g_return_val_if_fail (GST_CLOCK_TIME_IS_VALID (timestamp), FALSE);
1110 GST_LOG_OBJECT (object, "sync_values");
1111 if (!object->control_bindings)
1114 /* FIXME: this deadlocks */
1115 /* GST_OBJECT_LOCK (object); */
1116 g_object_freeze_notify ((GObject *) object);
1117 for (node = object->control_bindings; node; node = g_list_next (node)) {
1118 ret &= gst_control_binding_sync_values ((GstControlBinding *) node->data,
1119 object, timestamp, object->last_sync);
1121 object->last_sync = timestamp;
1122 g_object_thaw_notify ((GObject *) object);
1123 /* GST_OBJECT_UNLOCK (object); */
1130 * gst_object_has_active_control_bindings:
1131 * @object: the object that has controlled properties
1133 * Check if the @object has active controlled properties.
1135 * Returns: %TRUE if the object has active controlled properties
1138 gst_object_has_active_control_bindings (GstObject * object)
1140 gboolean res = FALSE;
1143 g_return_val_if_fail (GST_IS_OBJECT (object), FALSE);
1145 GST_OBJECT_LOCK (object);
1146 for (node = object->control_bindings; node; node = g_list_next (node)) {
1147 res |= !gst_control_binding_is_disabled ((GstControlBinding *) node->data);
1149 GST_OBJECT_UNLOCK (object);
1154 * gst_object_set_control_bindings_disabled:
1155 * @object: the object that has controlled properties
1156 * @disabled: boolean that specifies whether to disable the controller
1159 * This function is used to disable all controlled properties of the @object for
1160 * some time, i.e. gst_object_sync_values() will do nothing.
1163 gst_object_set_control_bindings_disabled (GstObject * object, gboolean disabled)
1167 g_return_if_fail (GST_IS_OBJECT (object));
1169 GST_OBJECT_LOCK (object);
1170 for (node = object->control_bindings; node; node = g_list_next (node)) {
1171 gst_control_binding_set_disabled ((GstControlBinding *) node->data,
1174 GST_OBJECT_UNLOCK (object);
1178 * gst_object_set_control_binding_disabled:
1179 * @object: the object that has controlled properties
1180 * @property_name: property to disable
1181 * @disabled: boolean that specifies whether to disable the controller
1184 * This function is used to disable the control bindings on a property for
1185 * some time, i.e. gst_object_sync_values() will do nothing for the
1189 gst_object_set_control_binding_disabled (GstObject * object,
1190 const gchar * property_name, gboolean disabled)
1192 GstControlBinding *binding;
1194 g_return_if_fail (GST_IS_OBJECT (object));
1195 g_return_if_fail (property_name);
1197 GST_OBJECT_LOCK (object);
1198 if ((binding = gst_object_find_control_binding (object, property_name))) {
1199 gst_control_binding_set_disabled (binding, disabled);
1201 GST_OBJECT_UNLOCK (object);
1206 * gst_object_add_control_binding:
1207 * @object: the controller object
1208 * @binding: (transfer floating): the #GstControlBinding that should be used
1210 * Attach the #GstControlBinding to the object. If there already was a
1211 * #GstControlBinding for this property it will be replaced.
1213 * The object's reference count will be incremented, and any floating
1214 * reference will be removed (see gst_object_ref_sink())
1216 * Returns: %FALSE if the given @binding has not been setup for this object or
1217 * has been setup for a non suitable property, %TRUE otherwise.
1220 gst_object_add_control_binding (GstObject * object, GstControlBinding * binding)
1222 GstControlBinding *old;
1224 g_return_val_if_fail (GST_IS_OBJECT (object), FALSE);
1225 g_return_val_if_fail (GST_IS_CONTROL_BINDING (binding), FALSE);
1226 g_return_val_if_fail (binding->pspec, FALSE);
1228 GST_OBJECT_LOCK (object);
1229 if ((old = gst_object_find_control_binding (object, binding->name))) {
1230 GST_DEBUG_OBJECT (object, "controlled property %s removed", old->name);
1231 object->control_bindings = g_list_remove (object->control_bindings, old);
1232 gst_object_unparent (GST_OBJECT_CAST (old));
1234 object->control_bindings = g_list_prepend (object->control_bindings, binding);
1235 gst_object_set_parent (GST_OBJECT_CAST (binding), object);
1236 GST_DEBUG_OBJECT (object, "controlled property %s added", binding->name);
1237 GST_OBJECT_UNLOCK (object);
1243 * gst_object_get_control_binding:
1244 * @object: the object
1245 * @property_name: name of the property
1247 * Gets the corresponding #GstControlBinding for the property. This should be
1248 * unreferenced again after use.
1250 * Returns: (transfer full) (nullable): the #GstControlBinding for
1251 * @property_name or %NULL if the property is not controlled.
1254 gst_object_get_control_binding (GstObject * object, const gchar * property_name)
1256 GstControlBinding *binding;
1258 g_return_val_if_fail (GST_IS_OBJECT (object), NULL);
1259 g_return_val_if_fail (property_name, NULL);
1261 GST_OBJECT_LOCK (object);
1262 if ((binding = gst_object_find_control_binding (object, property_name))) {
1263 gst_object_ref (binding);
1265 GST_OBJECT_UNLOCK (object);
1271 * gst_object_remove_control_binding:
1272 * @object: the object
1273 * @binding: the binding
1275 * Removes the corresponding #GstControlBinding. If it was the
1276 * last ref of the binding, it will be disposed.
1278 * Returns: %TRUE if the binding could be removed.
1281 gst_object_remove_control_binding (GstObject * object,
1282 GstControlBinding * binding)
1285 gboolean ret = FALSE;
1287 g_return_val_if_fail (GST_IS_OBJECT (object), FALSE);
1288 g_return_val_if_fail (GST_IS_CONTROL_BINDING (binding), FALSE);
1290 GST_OBJECT_LOCK (object);
1291 if ((node = g_list_find (object->control_bindings, binding))) {
1292 GST_DEBUG_OBJECT (object, "controlled property %s removed", binding->name);
1293 object->control_bindings =
1294 g_list_delete_link (object->control_bindings, node);
1295 gst_object_unparent (GST_OBJECT_CAST (binding));
1298 GST_OBJECT_UNLOCK (object);
1304 * gst_object_get_value:
1305 * @object: the object that has controlled properties
1306 * @property_name: the name of the property to get
1307 * @timestamp: the time the control-change should be read from
1309 * Gets the value for the given controlled property at the requested time.
1311 * Returns: (nullable): the GValue of the property at the given time,
1312 * or %NULL if the property isn't controlled.
1315 gst_object_get_value (GstObject * object, const gchar * property_name,
1316 GstClockTime timestamp)
1318 GstControlBinding *binding;
1321 g_return_val_if_fail (GST_IS_OBJECT (object), NULL);
1322 g_return_val_if_fail (property_name, NULL);
1323 g_return_val_if_fail (GST_CLOCK_TIME_IS_VALID (timestamp), NULL);
1325 GST_OBJECT_LOCK (object);
1326 if ((binding = gst_object_find_control_binding (object, property_name))) {
1327 val = gst_control_binding_get_value (binding, timestamp);
1329 GST_OBJECT_UNLOCK (object);
1335 * gst_object_get_value_array: (skip)
1336 * @object: the object that has controlled properties
1337 * @property_name: the name of the property to get
1338 * @timestamp: the time that should be processed
1339 * @interval: the time spacing between subsequent values
1340 * @n_values: the number of values
1341 * @values: array to put control-values in
1343 * Gets a number of values for the given controlled property starting at the
1344 * requested time. The array @values need to hold enough space for @n_values of
1345 * the same type as the objects property's type.
1347 * This function is useful if one wants to e.g. draw a graph of the control
1348 * curve or apply a control curve sample by sample.
1350 * The values are unboxed and ready to be used. The similar function
1351 * gst_object_get_g_value_array() returns the array as #GValues and is
1352 * better suites for bindings.
1354 * Returns: %TRUE if the given array could be filled, %FALSE otherwise
1357 gst_object_get_value_array (GstObject * object, const gchar * property_name,
1358 GstClockTime timestamp, GstClockTime interval, guint n_values,
1361 gboolean res = FALSE;
1362 GstControlBinding *binding;
1364 g_return_val_if_fail (GST_IS_OBJECT (object), FALSE);
1365 g_return_val_if_fail (property_name, FALSE);
1366 g_return_val_if_fail (GST_CLOCK_TIME_IS_VALID (timestamp), FALSE);
1367 g_return_val_if_fail (GST_CLOCK_TIME_IS_VALID (interval), FALSE);
1368 g_return_val_if_fail (values, FALSE);
1370 GST_OBJECT_LOCK (object);
1371 if ((binding = gst_object_find_control_binding (object, property_name))) {
1372 res = gst_control_binding_get_value_array (binding, timestamp, interval,
1375 GST_OBJECT_UNLOCK (object);
1380 * gst_object_get_g_value_array:
1381 * @object: the object that has controlled properties
1382 * @property_name: the name of the property to get
1383 * @timestamp: the time that should be processed
1384 * @interval: the time spacing between subsequent values
1385 * @n_values: the number of values
1386 * @values: (array length=n_values): array to put control-values in
1388 * Gets a number of #GValues for the given controlled property starting at the
1389 * requested time. The array @values need to hold enough space for @n_values of
1392 * This function is useful if one wants to e.g. draw a graph of the control
1393 * curve or apply a control curve sample by sample.
1395 * Returns: %TRUE if the given array could be filled, %FALSE otherwise
1398 gst_object_get_g_value_array (GstObject * object, const gchar * property_name,
1399 GstClockTime timestamp, GstClockTime interval, guint n_values,
1402 gboolean res = FALSE;
1403 GstControlBinding *binding;
1405 g_return_val_if_fail (GST_IS_OBJECT (object), FALSE);
1406 g_return_val_if_fail (property_name, FALSE);
1407 g_return_val_if_fail (GST_CLOCK_TIME_IS_VALID (timestamp), FALSE);
1408 g_return_val_if_fail (GST_CLOCK_TIME_IS_VALID (interval), FALSE);
1409 g_return_val_if_fail (values, FALSE);
1411 GST_OBJECT_LOCK (object);
1412 if ((binding = gst_object_find_control_binding (object, property_name))) {
1413 res = gst_control_binding_get_g_value_array (binding, timestamp, interval,
1416 GST_OBJECT_UNLOCK (object);
1422 * gst_object_get_control_rate:
1423 * @object: the object that has controlled properties
1425 * Obtain the control-rate for this @object. Audio processing #GstElement
1426 * objects will use this rate to sub-divide their processing loop and call
1427 * gst_object_sync_values() inbetween. The length of the processing segment
1428 * should be up to @control-rate nanoseconds.
1430 * If the @object is not under property control, this will return
1431 * %GST_CLOCK_TIME_NONE. This allows the element to avoid the sub-dividing.
1433 * The control-rate is not expected to change if the element is in
1434 * %GST_STATE_PAUSED or %GST_STATE_PLAYING.
1436 * Returns: the control rate in nanoseconds
1439 gst_object_get_control_rate (GstObject * object)
1441 g_return_val_if_fail (GST_IS_OBJECT (object), FALSE);
1443 return object->control_rate;
1447 * gst_object_set_control_rate:
1448 * @object: the object that has controlled properties
1449 * @control_rate: the new control-rate in nanoseconds.
1451 * Change the control-rate for this @object. Audio processing #GstElement
1452 * objects will use this rate to sub-divide their processing loop and call
1453 * gst_object_sync_values() inbetween. The length of the processing segment
1454 * should be up to @control-rate nanoseconds.
1456 * The control-rate should not change if the element is in %GST_STATE_PAUSED or
1457 * %GST_STATE_PLAYING.
1460 gst_object_set_control_rate (GstObject * object, GstClockTime control_rate)
1462 g_return_if_fail (GST_IS_OBJECT (object));
1464 object->control_rate = control_rate;