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
84 * <title>controlled properties</title>
86 * Controlled properties offers a lightweight way to adjust gobject
87 * properties over stream-time. It works by using time-stamped value pairs that
88 * are queued for element-properties. At run-time the elements continously pull
89 * values changes for the current stream-time.
91 * What needs to be changed in a #GstElement?
92 * Very little - it is just two steps to make a plugin controllable!
95 * mark gobject-properties paramspecs that make sense to be controlled,
96 * by GST_PARAM_CONTROLLABLE.
99 * when processing data (get, chain, loop function) at the beginning call
100 * gst_object_sync_values(element,timestamp).
101 * This will made the controller to update all gobject properties that are under
102 * control with the current values based on timestamp.
106 * What needs to be done in applications?
107 * Again its not a lot to change.
110 * first put some properties under control, by calling
111 * gst_object_control_properties (object, "prop1", "prop2",...);
114 * create a #GstControlSource.
115 * csource = gst_interpolation_control_source_new ();
116 * g_object_set (csource, "mode", GST_INTERPOLATION_MODE_LINEAR, NULL);
119 * Attach the #GstControlSource on the controller to a property.
120 * gst_object_add_control_binding (object, gst_direct_control_binding_new (objetct, "prop1", csource));
123 * Set the control values
124 * gst_timed_value_control_source_set ((GstTimedValueControlSource *)csource,0 * GST_SECOND, value1);
125 * gst_timed_value_control_source_set ((GstTimedValueControlSource *)csource,1 * GST_SECOND, value2);
128 * start your pipeline
134 * Last reviewed on 2005-11-09 (0.9.4)
137 #include "gst_private.h"
138 #include "glib-compat-private.h"
140 #include "gstobject.h"
141 #include "gstmarshal.h"
142 #include "gstclock.h"
143 #include "gstcontrolbinding.h"
144 #include "gstcontrolsource.h"
146 #include "gstparamspecs.h"
147 #include "gstutils.h"
149 #ifndef GST_DISABLE_TRACE
150 #include "gsttrace.h"
151 static GstAllocTrace *_gst_object_trace;
154 #define DEBUG_REFCOUNT
156 /* Object signals and args */
177 /* maps type name quark => count */
178 static GData *object_name_counts = NULL;
180 G_LOCK_DEFINE_STATIC (object_name_mutex);
182 static void gst_object_set_property (GObject * object, guint prop_id,
183 const GValue * value, GParamSpec * pspec);
184 static void gst_object_get_property (GObject * object, guint prop_id,
185 GValue * value, GParamSpec * pspec);
187 static void gst_object_dispatch_properties_changed (GObject * object,
188 guint n_pspecs, GParamSpec ** pspecs);
190 static void gst_object_dispose (GObject * object);
191 static void gst_object_finalize (GObject * object);
193 static gboolean gst_object_set_name_default (GstObject * object);
195 static guint gst_object_signals[LAST_SIGNAL] = { 0 };
197 static GParamSpec *properties[PROP_LAST];
199 G_DEFINE_ABSTRACT_TYPE (GstObject, gst_object, G_TYPE_INITIALLY_UNOWNED);
202 gst_object_class_init (GstObjectClass * klass)
204 GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
206 #ifndef GST_DISABLE_TRACE
208 _gst_alloc_trace_register (g_type_name (GST_TYPE_OBJECT), -2);
211 gobject_class->set_property = gst_object_set_property;
212 gobject_class->get_property = gst_object_get_property;
214 properties[PROP_NAME] =
215 g_param_spec_string ("name", "Name", "The name of the object", NULL,
216 G_PARAM_READWRITE | G_PARAM_CONSTRUCT | G_PARAM_STATIC_STRINGS);
218 properties[PROP_PARENT] =
219 g_param_spec_object ("parent", "Parent", "The parent of the object",
220 GST_TYPE_OBJECT, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS);
222 g_object_class_install_properties (gobject_class, PROP_LAST, properties);
225 * GstObject::deep-notify:
226 * @gstobject: a #GstObject
227 * @prop_object: the object that originated the signal
228 * @prop: the property that changed
230 * The deep notify signal is used to be notified of property changes. It is
231 * typically attached to the toplevel bin to receive notifications from all
232 * the elements contained in that bin.
234 gst_object_signals[DEEP_NOTIFY] =
235 g_signal_new ("deep-notify", G_TYPE_FROM_CLASS (klass),
236 G_SIGNAL_RUN_FIRST | G_SIGNAL_NO_RECURSE | G_SIGNAL_DETAILED |
237 G_SIGNAL_NO_HOOKS, G_STRUCT_OFFSET (GstObjectClass, deep_notify), NULL,
238 NULL, gst_marshal_VOID__OBJECT_PARAM, G_TYPE_NONE, 2, GST_TYPE_OBJECT,
241 klass->path_string_separator = "/";
243 /* see the comments at gst_object_dispatch_properties_changed */
244 gobject_class->dispatch_properties_changed
245 = GST_DEBUG_FUNCPTR (gst_object_dispatch_properties_changed);
247 gobject_class->dispose = gst_object_dispose;
248 gobject_class->finalize = gst_object_finalize;
252 gst_object_init (GstObject * object)
254 g_mutex_init (&object->lock);
255 object->parent = NULL;
257 GST_CAT_TRACE_OBJECT (GST_CAT_REFCOUNTING, object, "%p new", object);
259 #ifndef GST_DISABLE_TRACE
260 _gst_alloc_trace_new (_gst_object_trace, object);
265 object->control_rate = 100 * GST_MSECOND;
266 object->last_sync = GST_CLOCK_TIME_NONE;
271 * @object: a #GstObject to reference
273 * Increments the reference count on @object. This function
274 * does not take the lock on @object because it relies on
275 * atomic refcounting.
277 * This object returns the input parameter to ease writing
279 * result = gst_object_ref (object->parent);
281 * Returns: (transfer full): A pointer to @object
284 gst_object_ref (gpointer object)
286 g_return_val_if_fail (object != NULL, NULL);
288 #ifdef DEBUG_REFCOUNT
289 GST_CAT_TRACE_OBJECT (GST_CAT_REFCOUNTING, object, "%p ref %d->%d", object,
290 ((GObject *) object)->ref_count, ((GObject *) object)->ref_count + 1);
292 g_object_ref (object);
299 * @object: a #GstObject to unreference
301 * Decrements the reference count on @object. If reference count hits
302 * zero, destroy @object. This function does not take the lock
303 * on @object as it relies on atomic refcounting.
305 * The unref method should never be called with the LOCK held since
306 * this might deadlock the dispose function.
309 gst_object_unref (gpointer object)
311 g_return_if_fail (object != NULL);
312 g_return_if_fail (((GObject *) object)->ref_count > 0);
314 #ifdef DEBUG_REFCOUNT
315 GST_CAT_TRACE_OBJECT (GST_CAT_REFCOUNTING, object, "%p unref %d->%d", object,
316 ((GObject *) object)->ref_count, ((GObject *) object)->ref_count - 1);
318 g_object_unref (object);
322 * gst_object_ref_sink: (skip)
323 * @object: a #GstObject to sink
325 * Increase the reference count of @object, and possibly remove the floating
326 * reference, if @object has a floating reference.
328 * In other words, if the object is floating, then this call "assumes ownership"
329 * of the floating reference, converting it to a normal reference by clearing
330 * the floating flag while leaving the reference count unchanged. If the object
331 * is not floating, then this call adds a new normal reference increasing the
332 * reference count by one.
335 gst_object_ref_sink (gpointer object)
337 g_return_val_if_fail (object != NULL, NULL);
339 #ifdef DEBUG_REFCOUNT
340 GST_CAT_TRACE_OBJECT (GST_CAT_REFCOUNTING, object, "%p ref_sink %d->%d",
341 object, ((GObject *) object)->ref_count,
342 ((GObject *) object)->ref_count + 1);
344 return g_object_ref_sink (object);
348 * gst_object_replace:
349 * @oldobj: (inout) (transfer full): pointer to a place of a #GstObject to
351 * @newobj: (transfer none): a new #GstObject
353 * Atomically modifies a pointer to point to a new object.
354 * The reference count of @oldobj is decreased and the reference count of
355 * @newobj is increased.
357 * Either @newobj and the value pointed to by @oldobj may be NULL.
359 * Returns: TRUE if @newobj was different from @oldobj
362 gst_object_replace (GstObject ** oldobj, GstObject * newobj)
366 g_return_val_if_fail (oldobj != NULL, FALSE);
368 #ifdef DEBUG_REFCOUNT
369 GST_CAT_TRACE (GST_CAT_REFCOUNTING, "replace %p %s (%d) with %p %s (%d)",
370 *oldobj, *oldobj ? GST_STR_NULL (GST_OBJECT_NAME (*oldobj)) : "(NONE)",
371 *oldobj ? G_OBJECT (*oldobj)->ref_count : 0,
372 newobj, newobj ? GST_STR_NULL (GST_OBJECT_NAME (newobj)) : "(NONE)",
373 newobj ? G_OBJECT (newobj)->ref_count : 0);
376 oldptr = g_atomic_pointer_get ((gpointer *) oldobj);
378 if (G_UNLIKELY (oldptr == newobj))
382 g_object_ref (newobj);
384 while (G_UNLIKELY (!g_atomic_pointer_compare_and_exchange ((gpointer *)
385 oldobj, oldptr, newobj))) {
386 oldptr = g_atomic_pointer_get ((gpointer *) oldobj);
387 if (G_UNLIKELY (oldptr == newobj))
392 g_object_unref (oldptr);
394 return oldptr != newobj;
397 /* dispose is called when the object has to release all links
398 * to other objects */
400 gst_object_dispose (GObject * object)
402 GstObject *self = (GstObject *) object;
405 GST_CAT_TRACE_OBJECT (GST_CAT_REFCOUNTING, object, "dispose");
407 GST_OBJECT_LOCK (object);
408 if ((parent = GST_OBJECT_PARENT (object)))
410 GST_OBJECT_PARENT (object) = NULL;
411 GST_OBJECT_UNLOCK (object);
413 if (self->control_bindings) {
416 for (node = self->control_bindings; node; node = g_list_next (node)) {
417 g_object_unref (node->data);
419 g_list_free (self->control_bindings);
420 self->control_bindings = NULL;
423 ((GObjectClass *) gst_object_parent_class)->dispose (object);
430 g_critical ("\nTrying to dispose object \"%s\", but it still has a "
431 "parent \"%s\".\nYou need to let the parent manage the "
432 "object instead of unreffing the object directly.\n",
433 GST_OBJECT_NAME (object), GST_OBJECT_NAME (parent));
434 GST_OBJECT_UNLOCK (object);
435 /* ref the object again to revive it in this error case */
436 gst_object_ref (object);
441 /* finalize is called when the object has to free its resources */
443 gst_object_finalize (GObject * object)
445 GstObject *gstobject = GST_OBJECT_CAST (object);
447 GST_CAT_TRACE_OBJECT (GST_CAT_REFCOUNTING, object, "finalize");
449 g_signal_handlers_destroy (object);
451 g_free (gstobject->name);
452 g_mutex_clear (&gstobject->lock);
454 #ifndef GST_DISABLE_TRACE
455 _gst_alloc_trace_free (_gst_object_trace, object);
458 ((GObjectClass *) gst_object_parent_class)->finalize (object);
461 /* Changing a GObject property of a GstObject will result in "deep-notify"
462 * signals being emitted by the object itself, as well as in each parent
463 * object. This is so that an application can connect a listener to the
464 * top-level bin to catch property-change notifications for all contained
470 gst_object_dispatch_properties_changed (GObject * object,
471 guint n_pspecs, GParamSpec ** pspecs)
473 GstObject *gst_object, *parent, *old_parent;
475 #ifndef GST_DISABLE_GST_DEBUG
477 const gchar *debug_name;
480 /* do the standard dispatching */
482 gst_object_parent_class)->dispatch_properties_changed (object, n_pspecs,
485 gst_object = GST_OBJECT_CAST (object);
486 #ifndef GST_DISABLE_GST_DEBUG
487 if (G_UNLIKELY (_gst_debug_min >= GST_LEVEL_LOG)) {
488 name = gst_object_get_name (gst_object);
489 debug_name = GST_STR_NULL (name);
494 /* now let the parent dispatch those, too */
495 parent = gst_object_get_parent (gst_object);
497 for (i = 0; i < n_pspecs; i++) {
498 GST_CAT_LOG_OBJECT (GST_CAT_PROPERTIES, parent,
499 "deep notification from %s (%s)", debug_name, pspecs[i]->name);
501 g_signal_emit (parent, gst_object_signals[DEEP_NOTIFY],
502 g_quark_from_string (pspecs[i]->name), gst_object, pspecs[i]);
506 parent = gst_object_get_parent (old_parent);
507 gst_object_unref (old_parent);
509 #ifndef GST_DISABLE_GST_DEBUG
515 * gst_object_default_deep_notify:
516 * @object: the #GObject that signalled the notify.
517 * @orig: a #GstObject that initiated the notify.
518 * @pspec: a #GParamSpec of the property.
519 * @excluded_props: (array zero-terminated=1) (element-type gchar*)
520 * (allow-none):a set of user-specified properties to exclude or
521 * NULL to show all changes.
523 * A default deep_notify signal callback for an object. The user data
524 * should contain a pointer to an array of strings that should be excluded
525 * from the notify. The default handler will print the new value of the property
528 * MT safe. This function grabs and releases @object's LOCK for getting its
532 gst_object_default_deep_notify (GObject * object, GstObject * orig,
533 GParamSpec * pspec, gchar ** excluded_props)
535 GValue value = { 0, }; /* the important thing is that value.type = 0 */
539 if (pspec->flags & G_PARAM_READABLE) {
540 /* let's not print these out for excluded properties... */
541 while (excluded_props != NULL && *excluded_props != NULL) {
542 if (strcmp (pspec->name, *excluded_props) == 0)
546 g_value_init (&value, pspec->value_type);
547 g_object_get_property (G_OBJECT (orig), pspec->name, &value);
549 /* FIXME: handle flags */
550 if (G_IS_PARAM_SPEC_ENUM (pspec)) {
551 GEnumValue *enum_value;
552 GEnumClass *klass = G_ENUM_CLASS (g_type_class_ref (pspec->value_type));
554 enum_value = g_enum_get_value (klass, g_value_get_enum (&value));
556 str = g_strdup_printf ("%s (%d)", enum_value->value_nick,
558 g_type_class_unref (klass);
560 str = g_strdup_value_contents (&value);
562 name = gst_object_get_path_string (orig);
563 g_print ("%s: %s = %s\n", name, pspec->name, str);
566 g_value_unset (&value);
568 name = gst_object_get_path_string (orig);
569 g_warning ("Parameter %s not readable in %s.", pspec->name, name);
575 gst_object_set_name_default (GstObject * object)
577 const gchar *type_name;
583 /* to ensure guaranteed uniqueness across threads, only one thread
584 * may ever assign a name */
585 G_LOCK (object_name_mutex);
587 if (!object_name_counts) {
588 g_datalist_init (&object_name_counts);
591 q = g_type_qname (G_OBJECT_TYPE (object));
592 count = GPOINTER_TO_INT (g_datalist_id_get_data (&object_name_counts, q));
593 g_datalist_id_set_data (&object_name_counts, q, GINT_TO_POINTER (count + 1));
595 G_UNLOCK (object_name_mutex);
597 /* GstFooSink -> foosink<N> */
598 type_name = g_quark_to_string (q);
599 if (strncmp (type_name, "Gst", 3) == 0)
601 name = g_strdup_printf ("%s%d", type_name, count);
603 for (i = 0; i < l; i++)
604 name[i] = g_ascii_tolower (name[i]);
606 GST_OBJECT_LOCK (object);
607 if (G_UNLIKELY (object->parent != NULL))
610 g_free (object->name);
613 GST_OBJECT_UNLOCK (object);
620 GST_WARNING ("parented objects can't be renamed");
621 GST_OBJECT_UNLOCK (object);
627 * gst_object_set_name:
628 * @object: a #GstObject
629 * @name: new name of object
631 * Sets the name of @object, or gives @object a guaranteed unique
632 * name (if @name is NULL).
633 * This function makes a copy of the provided name, so the caller
634 * retains ownership of the name it sent.
636 * Returns: TRUE if the name could be set. Since Objects that have
637 * a parent cannot be renamed, this function returns FALSE in those
640 * MT safe. This function grabs and releases @object's LOCK.
643 gst_object_set_name (GstObject * object, const gchar * name)
647 g_return_val_if_fail (GST_IS_OBJECT (object), FALSE);
649 GST_OBJECT_LOCK (object);
651 /* parented objects cannot be renamed */
652 if (G_UNLIKELY (object->parent != NULL))
656 g_free (object->name);
657 object->name = g_strdup (name);
658 GST_OBJECT_UNLOCK (object);
661 GST_OBJECT_UNLOCK (object);
662 result = gst_object_set_name_default (object);
664 /* FIXME-0.11: this misses a g_object_notify (object, "name"); unless called
665 * from gst_object_set_property.
666 * Ideally remove such custom setters (or make it static).
673 GST_WARNING ("parented objects can't be renamed");
674 GST_OBJECT_UNLOCK (object);
680 * gst_object_get_name:
681 * @object: a #GstObject
683 * Returns a copy of the name of @object.
684 * Caller should g_free() the return value after usage.
685 * For a nameless object, this returns NULL, which you can safely g_free()
688 * Free-function: g_free
690 * Returns: (transfer full): the name of @object. g_free() after usage.
692 * MT safe. This function grabs and releases @object's LOCK.
695 gst_object_get_name (GstObject * object)
697 gchar *result = NULL;
699 g_return_val_if_fail (GST_IS_OBJECT (object), NULL);
701 GST_OBJECT_LOCK (object);
702 result = g_strdup (object->name);
703 GST_OBJECT_UNLOCK (object);
709 * gst_object_set_parent:
710 * @object: a #GstObject
711 * @parent: new parent of object
713 * Sets the parent of @object to @parent. The object's reference count will
714 * be incremented, and any floating reference will be removed (see gst_object_ref_sink()).
716 * Returns: TRUE if @parent could be set or FALSE when @object
717 * already had a parent or @object and @parent are the same.
719 * MT safe. Grabs and releases @object's LOCK.
722 gst_object_set_parent (GstObject * object, GstObject * parent)
724 g_return_val_if_fail (GST_IS_OBJECT (object), FALSE);
725 g_return_val_if_fail (GST_IS_OBJECT (parent), FALSE);
726 g_return_val_if_fail (object != parent, FALSE);
728 GST_CAT_DEBUG_OBJECT (GST_CAT_REFCOUNTING, object,
729 "set parent (ref and sink)");
731 GST_OBJECT_LOCK (object);
732 if (G_UNLIKELY (object->parent != NULL))
735 object->parent = parent;
736 gst_object_ref_sink (object);
737 GST_OBJECT_UNLOCK (object);
739 /* FIXME, this does not work, the deep notify takes the lock from the parent
740 * object and deadlocks when the parent holds its lock when calling this
741 * function (like _element_add_pad()) */
742 /* g_object_notify_by_pspec ((GObject *)object, properties[PROP_PARENT]); */
749 GST_CAT_DEBUG_OBJECT (GST_CAT_REFCOUNTING, object,
750 "set parent failed, object already had a parent");
751 GST_OBJECT_UNLOCK (object);
757 * gst_object_get_parent:
758 * @object: a #GstObject
760 * Returns the parent of @object. This function increases the refcount
761 * of the parent object so you should gst_object_unref() it after usage.
763 * Returns: (transfer full): parent of @object, this can be NULL if @object
764 * has no parent. unref after usage.
766 * MT safe. Grabs and releases @object's LOCK.
769 gst_object_get_parent (GstObject * object)
771 GstObject *result = NULL;
773 g_return_val_if_fail (GST_IS_OBJECT (object), NULL);
775 GST_OBJECT_LOCK (object);
776 result = object->parent;
777 if (G_LIKELY (result))
778 gst_object_ref (result);
779 GST_OBJECT_UNLOCK (object);
785 * gst_object_unparent:
786 * @object: a #GstObject to unparent
788 * Clear the parent of @object, removing the associated reference.
789 * This function decreases the refcount of @object.
791 * MT safe. Grabs and releases @object's lock.
794 gst_object_unparent (GstObject * object)
798 g_return_if_fail (GST_IS_OBJECT (object));
800 GST_OBJECT_LOCK (object);
801 parent = object->parent;
803 if (G_LIKELY (parent != NULL)) {
804 GST_CAT_TRACE_OBJECT (GST_CAT_REFCOUNTING, object, "unparent");
805 object->parent = NULL;
806 GST_OBJECT_UNLOCK (object);
808 /* g_object_notify_by_pspec ((GObject *)object, properties[PROP_PARENT]); */
810 gst_object_unref (object);
812 GST_OBJECT_UNLOCK (object);
817 * gst_object_has_ancestor:
818 * @object: a #GstObject to check
819 * @ancestor: a #GstObject to check as ancestor
821 * Check if @object has an ancestor @ancestor somewhere up in
822 * the hierarchy. One can e.g. check if a #GstElement is inside a #GstPipeline.
824 * Returns: TRUE if @ancestor is an ancestor of @object.
826 * MT safe. Grabs and releases @object's locks.
829 gst_object_has_ancestor (GstObject * object, GstObject * ancestor)
831 GstObject *parent, *tmp;
833 if (!ancestor || !object)
836 parent = gst_object_ref (object);
838 if (parent == ancestor) {
839 gst_object_unref (parent);
843 tmp = gst_object_get_parent (parent);
844 gst_object_unref (parent);
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 * carefull 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 carefull 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: a #GstControlBinding or %NULL if the property is not being
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 an 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 #GstController on a property for
1185 * some time, i.e. gst_controller_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 full): the #GstControlBinding that should be used
1210 * Sets the #GstControlBinding. If there already was a #GstControlBinding
1211 * for this property it will be replaced.
1212 * The @object will take ownership of the @binding.
1214 * Returns: %FALSE if the given @binding has not been setup for this object or
1218 gst_object_add_control_binding (GstObject * object, GstControlBinding * binding)
1220 GstControlBinding *old;
1222 g_return_val_if_fail (GST_IS_OBJECT (object), FALSE);
1223 g_return_val_if_fail (GST_IS_CONTROL_BINDING (binding), FALSE);
1224 //g_return_val_if_fail (g_type_is_a (binding->pspec->owner_type,
1225 // G_OBJECT_TYPE (object)), FALSE);
1227 GST_OBJECT_LOCK (object);
1228 if ((old = gst_object_find_control_binding (object, binding->name))) {
1229 GST_DEBUG_OBJECT (object, "controlled property %s removed", old->name);
1230 object->control_bindings = g_list_remove (object->control_bindings, old);
1231 gst_object_unparent (GST_OBJECT_CAST (old));
1233 object->control_bindings = g_list_prepend (object->control_bindings, binding);
1234 gst_object_set_parent (GST_OBJECT_CAST (binding), object);
1235 GST_DEBUG_OBJECT (object, "controlled property %s added", binding->name);
1236 GST_OBJECT_UNLOCK (object);
1242 * gst_object_get_control_binding:
1243 * @object: the object
1244 * @property_name: name of the property
1246 * Gets the corresponding #GstControlBinding for the property. This should be
1247 * unreferenced again after use.
1249 * Returns: (transfer full): the #GstControlBinding for @property_name or %NULL if
1250 * the property is not controlled.
1253 gst_object_get_control_binding (GstObject * object, const gchar * property_name)
1255 GstControlBinding *binding;
1257 g_return_val_if_fail (GST_IS_OBJECT (object), NULL);
1258 g_return_val_if_fail (property_name, NULL);
1260 GST_OBJECT_LOCK (object);
1261 if ((binding = gst_object_find_control_binding (object, property_name))) {
1262 g_object_ref (binding);
1264 GST_OBJECT_UNLOCK (object);
1270 * gst_object_remove_control_binding:
1271 * @object: the object
1272 * @binding: the binding
1274 * Removes the corresponding #GstControlBinding. If it was the
1275 * last ref of the binding, it will be disposed.
1277 * Returns: %TRUE if the binding could be removed.
1280 gst_object_remove_control_binding (GstObject * object,
1281 GstControlBinding * binding)
1284 gboolean ret = FALSE;
1286 g_return_val_if_fail (GST_IS_OBJECT (object), FALSE);
1287 g_return_val_if_fail (GST_IS_CONTROL_BINDING (binding), FALSE);
1289 GST_OBJECT_LOCK (object);
1290 if ((node = g_list_find (object->control_bindings, binding))) {
1291 GST_DEBUG_OBJECT (object, "controlled property %s removed", binding->name);
1292 object->control_bindings =
1293 g_list_delete_link (object->control_bindings, node);
1294 gst_object_unparent (GST_OBJECT_CAST (binding));
1297 GST_OBJECT_UNLOCK (object);
1303 * gst_object_get_value:
1304 * @object: the object that has controlled properties
1305 * @property_name: the name of the property to get
1306 * @timestamp: the time the control-change should be read from
1308 * Gets the value for the given controlled property at the requested time.
1310 * Returns: the GValue of the property at the given time, or %NULL if the
1311 * property isn't controlled.
1314 gst_object_get_value (GstObject * object, const gchar * property_name,
1315 GstClockTime timestamp)
1317 GstControlBinding *binding;
1320 g_return_val_if_fail (GST_IS_OBJECT (object), NULL);
1321 g_return_val_if_fail (property_name, NULL);
1322 g_return_val_if_fail (GST_CLOCK_TIME_IS_VALID (timestamp), NULL);
1324 GST_OBJECT_LOCK (object);
1325 if ((binding = gst_object_find_control_binding (object, property_name))) {
1326 val = gst_control_binding_get_value (binding, timestamp);
1328 GST_OBJECT_UNLOCK (object);
1334 * gst_object_get_value_array:
1335 * @object: the object that has controlled properties
1336 * @property_name: the name of the property to get
1337 * @timestamp: the time that should be processed
1338 * @interval: the time spacing between subsequent values
1339 * @n_values: the number of values
1340 * @values: array to put control-values in
1342 * Gets a number of values for the given controllered property starting at the
1343 * requested time. The array @values need to hold enough space for @n_values of
1344 * the same type as the objects property's type.
1346 * This function is useful if one wants to e.g. draw a graph of the control
1347 * curve or apply a control curve sample by sample.
1349 * Returns: %TRUE if the given array could be filled, %FALSE otherwise
1352 gst_object_get_value_array (GstObject * object, const gchar * property_name,
1353 GstClockTime timestamp, GstClockTime interval, guint n_values,
1356 gboolean res = FALSE;
1357 GstControlBinding *binding;
1359 g_return_val_if_fail (GST_IS_OBJECT (object), FALSE);
1360 g_return_val_if_fail (property_name, FALSE);
1361 g_return_val_if_fail (GST_CLOCK_TIME_IS_VALID (timestamp), FALSE);
1362 g_return_val_if_fail (GST_CLOCK_TIME_IS_VALID (interval), FALSE);
1363 g_return_val_if_fail (values, FALSE);
1365 GST_OBJECT_LOCK (object);
1366 if ((binding = gst_object_find_control_binding (object, property_name))) {
1367 res = gst_control_binding_get_value_array (binding, timestamp, interval,
1370 GST_OBJECT_UNLOCK (object);
1376 * gst_object_get_control_rate:
1377 * @object: the object that has controlled properties
1379 * Obtain the control-rate for this @object. Audio processing #GstElement
1380 * objects will use this rate to sub-divide their processing loop and call
1381 * gst_object_sync_values() inbetween. The length of the processing segment
1382 * should be up to @control-rate nanoseconds.
1384 * If the @object is not under property control, this will return
1385 * %GST_CLOCK_TIME_NONE. This allows the element to avoid the sub-dividing.
1387 * The control-rate is not expected to change if the element is in
1388 * %GST_STATE_PAUSED or %GST_STATE_PLAYING.
1390 * Returns: the control rate in nanoseconds
1393 gst_object_get_control_rate (GstObject * object)
1395 g_return_val_if_fail (GST_IS_OBJECT (object), FALSE);
1397 return object->control_rate;
1401 * gst_object_set_control_rate:
1402 * @object: the object that has controlled properties
1403 * @control_rate: the new control-rate in nanoseconds.
1405 * Change the control-rate for this @object. Audio processing #GstElement
1406 * objects will use this rate to sub-divide their processing loop and call
1407 * gst_object_sync_values() inbetween. The length of the processing segment
1408 * should be up to @control-rate nanoseconds.
1410 * The control-rate should not change if the element is in %GST_STATE_PAUSED or
1411 * %GST_STATE_PLAYING.
1414 gst_object_set_control_rate (GstObject * object, GstClockTime control_rate)
1416 g_return_if_fail (GST_IS_OBJECT (object));
1418 object->control_rate = control_rate;