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_set_control_source (object, "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
207 _gst_object_trace = gst_alloc_trace_register (g_type_name (GST_TYPE_OBJECT));
210 gobject_class->set_property = gst_object_set_property;
211 gobject_class->get_property = gst_object_get_property;
213 properties[PROP_NAME] =
214 g_param_spec_string ("name", "Name", "The name of the object", NULL,
215 G_PARAM_READWRITE | G_PARAM_CONSTRUCT | G_PARAM_STATIC_STRINGS);
216 g_object_class_install_property (gobject_class, PROP_NAME,
217 properties[PROP_NAME]);
219 properties[PROP_PARENT] =
220 g_param_spec_object ("parent", "Parent", "The parent of the object",
221 GST_TYPE_OBJECT, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS);
222 g_object_class_install_property (gobject_class, PROP_PARENT,
223 properties[PROP_PARENT]);
226 * GstObject::deep-notify:
227 * @gstobject: a #GstObject
228 * @prop_object: the object that originated the signal
229 * @prop: the property that changed
231 * The deep notify signal is used to be notified of property changes. It is
232 * typically attached to the toplevel bin to receive notifications from all
233 * the elements contained in that bin.
235 gst_object_signals[DEEP_NOTIFY] =
236 g_signal_new ("deep-notify", G_TYPE_FROM_CLASS (klass),
237 G_SIGNAL_RUN_FIRST | G_SIGNAL_NO_RECURSE | G_SIGNAL_DETAILED |
238 G_SIGNAL_NO_HOOKS, G_STRUCT_OFFSET (GstObjectClass, deep_notify), NULL,
239 NULL, gst_marshal_VOID__OBJECT_PARAM, G_TYPE_NONE, 2, GST_TYPE_OBJECT,
242 klass->path_string_separator = "/";
244 /* see the comments at gst_object_dispatch_properties_changed */
245 gobject_class->dispatch_properties_changed
246 = GST_DEBUG_FUNCPTR (gst_object_dispatch_properties_changed);
248 gobject_class->dispose = gst_object_dispose;
249 gobject_class->finalize = gst_object_finalize;
253 gst_object_init (GstObject * object)
255 g_mutex_init (&object->lock);
256 object->parent = NULL;
258 GST_CAT_TRACE_OBJECT (GST_CAT_REFCOUNTING, object, "%p new", object);
260 #ifndef GST_DISABLE_TRACE
261 gst_alloc_trace_new (_gst_object_trace, object);
266 object->control_rate = 100 * GST_MSECOND;
267 object->last_sync = GST_CLOCK_TIME_NONE;
272 * @object: a #GstObject to reference
274 * Increments the reference count on @object. This function
275 * does not take the lock on @object because it relies on
276 * atomic refcounting.
278 * This object returns the input parameter to ease writing
280 * result = gst_object_ref (object->parent);
282 * Returns: (transfer full): A pointer to @object
285 gst_object_ref (gpointer object)
287 g_return_val_if_fail (object != NULL, NULL);
289 #ifdef DEBUG_REFCOUNT
290 GST_CAT_TRACE_OBJECT (GST_CAT_REFCOUNTING, object, "%p ref %d->%d", object,
291 ((GObject *) object)->ref_count, ((GObject *) object)->ref_count + 1);
293 g_object_ref (object);
300 * @object: a #GstObject to unreference
302 * Decrements the reference count on @object. If reference count hits
303 * zero, destroy @object. This function does not take the lock
304 * on @object as it relies on atomic refcounting.
306 * The unref method should never be called with the LOCK held since
307 * this might deadlock the dispose function.
310 gst_object_unref (gpointer object)
312 g_return_if_fail (object != NULL);
313 g_return_if_fail (((GObject *) object)->ref_count > 0);
315 #ifdef DEBUG_REFCOUNT
316 GST_CAT_TRACE_OBJECT (GST_CAT_REFCOUNTING, object, "%p unref %d->%d", object,
317 ((GObject *) object)->ref_count, ((GObject *) object)->ref_count - 1);
319 g_object_unref (object);
323 * gst_object_ref_sink: (skip)
324 * @object: a #GstObject to sink
326 * Increase the reference count of @object, and possibly remove the floating
327 * reference, if @object has a floating reference.
329 * In other words, if the object is floating, then this call "assumes ownership"
330 * of the floating reference, converting it to a normal reference by clearing
331 * the floating flag while leaving the reference count unchanged. If the object
332 * is not floating, then this call adds a new normal reference increasing the
333 * reference count by one.
336 gst_object_ref_sink (gpointer object)
338 g_return_val_if_fail (object != NULL, NULL);
340 #ifdef DEBUG_REFCOUNT
341 GST_CAT_TRACE_OBJECT (GST_CAT_REFCOUNTING, object, "%p ref_sink %d->%d",
342 object, ((GObject *) object)->ref_count,
343 ((GObject *) object)->ref_count + 1);
345 return g_object_ref_sink (object);
349 * gst_object_replace:
350 * @oldobj: (inout) (transfer full): pointer to a place of a #GstObject to
352 * @newobj: (transfer none): a new #GstObject
354 * Atomically modifies a pointer to point to a new object.
355 * The reference count of @oldobj is decreased and the reference count of
356 * @newobj is increased.
358 * Either @newobj and the value pointed to by @oldobj may be NULL.
360 * Returns: TRUE if @newobj was different from @oldobj
363 gst_object_replace (GstObject ** oldobj, GstObject * newobj)
367 g_return_val_if_fail (oldobj != NULL, FALSE);
369 #ifdef DEBUG_REFCOUNT
370 GST_CAT_TRACE (GST_CAT_REFCOUNTING, "replace %p %s (%d) with %p %s (%d)",
371 *oldobj, *oldobj ? GST_STR_NULL (GST_OBJECT_NAME (*oldobj)) : "(NONE)",
372 *oldobj ? G_OBJECT (*oldobj)->ref_count : 0,
373 newobj, newobj ? GST_STR_NULL (GST_OBJECT_NAME (newobj)) : "(NONE)",
374 newobj ? G_OBJECT (newobj)->ref_count : 0);
377 oldptr = g_atomic_pointer_get ((gpointer *) oldobj);
379 if (G_UNLIKELY (oldptr == newobj))
383 g_object_ref (newobj);
385 while (G_UNLIKELY (!g_atomic_pointer_compare_and_exchange ((gpointer *)
386 oldobj, oldptr, newobj))) {
387 oldptr = g_atomic_pointer_get ((gpointer *) oldobj);
388 if (G_UNLIKELY (oldptr == newobj))
393 g_object_unref (oldptr);
395 return oldptr != newobj;
398 /* dispose is called when the object has to release all links
399 * to other objects */
401 gst_object_dispose (GObject * object)
403 GstObject *self = (GstObject *) object;
406 GST_CAT_TRACE_OBJECT (GST_CAT_REFCOUNTING, object, "dispose");
408 GST_OBJECT_LOCK (object);
409 if ((parent = GST_OBJECT_PARENT (object)))
411 GST_OBJECT_PARENT (object) = NULL;
412 GST_OBJECT_UNLOCK (object);
414 if (self->control_bindings) {
417 for (node = self->control_bindings; node; node = g_list_next (node)) {
418 g_object_unref (node->data);
420 g_list_free (self->control_bindings);
421 self->control_bindings = NULL;
424 ((GObjectClass *) gst_object_parent_class)->dispose (object);
431 g_critical ("\nTrying to dispose object \"%s\", but it still has a "
432 "parent \"%s\".\nYou need to let the parent manage the "
433 "object instead of unreffing the object directly.\n",
434 GST_OBJECT_NAME (object), GST_OBJECT_NAME (parent));
435 GST_OBJECT_UNLOCK (object);
436 /* ref the object again to revive it in this error case */
437 gst_object_ref (object);
442 /* finalize is called when the object has to free its resources */
444 gst_object_finalize (GObject * object)
446 GstObject *gstobject = GST_OBJECT_CAST (object);
448 GST_CAT_TRACE_OBJECT (GST_CAT_REFCOUNTING, object, "finalize");
450 g_signal_handlers_destroy (object);
452 g_free (gstobject->name);
453 g_mutex_clear (&gstobject->lock);
455 #ifndef GST_DISABLE_TRACE
456 gst_alloc_trace_free (_gst_object_trace, object);
459 ((GObjectClass *) gst_object_parent_class)->finalize (object);
462 /* Changing a GObject property of a GstObject will result in "deep-notify"
463 * signals being emitted by the object itself, as well as in each parent
464 * object. This is so that an application can connect a listener to the
465 * top-level bin to catch property-change notifications for all contained
471 gst_object_dispatch_properties_changed (GObject * object,
472 guint n_pspecs, GParamSpec ** pspecs)
474 GstObject *gst_object, *parent, *old_parent;
476 #ifndef GST_DISABLE_GST_DEBUG
478 const gchar *debug_name;
481 /* do the standard dispatching */
483 gst_object_parent_class)->dispatch_properties_changed (object, n_pspecs,
486 gst_object = GST_OBJECT_CAST (object);
487 #ifndef GST_DISABLE_GST_DEBUG
488 if (G_UNLIKELY (_gst_debug_min >= GST_LEVEL_LOG)) {
489 name = gst_object_get_name (gst_object);
490 debug_name = GST_STR_NULL (name);
495 /* now let the parent dispatch those, too */
496 parent = gst_object_get_parent (gst_object);
498 for (i = 0; i < n_pspecs; i++) {
499 GST_CAT_LOG_OBJECT (GST_CAT_PROPERTIES, parent,
500 "deep notification from %s (%s)", debug_name, pspecs[i]->name);
502 g_signal_emit (parent, gst_object_signals[DEEP_NOTIFY],
503 g_quark_from_string (pspecs[i]->name), gst_object, pspecs[i]);
507 parent = gst_object_get_parent (old_parent);
508 gst_object_unref (old_parent);
510 #ifndef GST_DISABLE_GST_DEBUG
516 * gst_object_default_deep_notify:
517 * @object: the #GObject that signalled the notify.
518 * @orig: a #GstObject that initiated the notify.
519 * @pspec: a #GParamSpec of the property.
520 * @excluded_props: (array zero-terminated=1) (element-type gchar*)
521 * (allow-none):a set of user-specified properties to exclude or
522 * NULL to show all changes.
524 * A default deep_notify signal callback for an object. The user data
525 * should contain a pointer to an array of strings that should be excluded
526 * from the notify. The default handler will print the new value of the property
529 * MT safe. This function grabs and releases @object's LOCK for getting its
533 gst_object_default_deep_notify (GObject * object, GstObject * orig,
534 GParamSpec * pspec, gchar ** excluded_props)
536 GValue value = { 0, }; /* the important thing is that value.type = 0 */
540 if (pspec->flags & G_PARAM_READABLE) {
541 /* let's not print these out for excluded properties... */
542 while (excluded_props != NULL && *excluded_props != NULL) {
543 if (strcmp (pspec->name, *excluded_props) == 0)
547 g_value_init (&value, pspec->value_type);
548 g_object_get_property (G_OBJECT (orig), pspec->name, &value);
550 /* FIXME: handle flags */
551 if (G_IS_PARAM_SPEC_ENUM (pspec)) {
552 GEnumValue *enum_value;
553 GEnumClass *klass = G_ENUM_CLASS (g_type_class_ref (pspec->value_type));
555 enum_value = g_enum_get_value (klass, g_value_get_enum (&value));
557 str = g_strdup_printf ("%s (%d)", enum_value->value_nick,
559 g_type_class_unref (klass);
561 str = g_strdup_value_contents (&value);
563 name = gst_object_get_path_string (orig);
564 g_print ("%s: %s = %s\n", name, pspec->name, str);
567 g_value_unset (&value);
569 name = gst_object_get_path_string (orig);
570 g_warning ("Parameter %s not readable in %s.", pspec->name, name);
576 gst_object_set_name_default (GstObject * object)
578 const gchar *type_name;
584 /* to ensure guaranteed uniqueness across threads, only one thread
585 * may ever assign a name */
586 G_LOCK (object_name_mutex);
588 if (!object_name_counts) {
589 g_datalist_init (&object_name_counts);
592 q = g_type_qname (G_OBJECT_TYPE (object));
593 count = GPOINTER_TO_INT (g_datalist_id_get_data (&object_name_counts, q));
594 g_datalist_id_set_data (&object_name_counts, q, GINT_TO_POINTER (count + 1));
596 G_UNLOCK (object_name_mutex);
598 /* GstFooSink -> foosink<N> */
599 type_name = g_quark_to_string (q);
600 if (strncmp (type_name, "Gst", 3) == 0)
602 name = g_strdup_printf ("%s%d", type_name, count);
604 for (i = 0; i < l; i++)
605 name[i] = g_ascii_tolower (name[i]);
607 GST_OBJECT_LOCK (object);
608 if (G_UNLIKELY (object->parent != NULL))
611 g_free (object->name);
614 GST_OBJECT_UNLOCK (object);
621 GST_WARNING ("parented objects can't be renamed");
622 GST_OBJECT_UNLOCK (object);
628 * gst_object_set_name:
629 * @object: a #GstObject
630 * @name: new name of object
632 * Sets the name of @object, or gives @object a guaranteed unique
633 * name (if @name is NULL).
634 * This function makes a copy of the provided name, so the caller
635 * retains ownership of the name it sent.
637 * Returns: TRUE if the name could be set. Since Objects that have
638 * a parent cannot be renamed, this function returns FALSE in those
641 * MT safe. This function grabs and releases @object's LOCK.
644 gst_object_set_name (GstObject * object, const gchar * name)
648 g_return_val_if_fail (GST_IS_OBJECT (object), FALSE);
650 GST_OBJECT_LOCK (object);
652 /* parented objects cannot be renamed */
653 if (G_UNLIKELY (object->parent != NULL))
657 g_free (object->name);
658 object->name = g_strdup (name);
659 GST_OBJECT_UNLOCK (object);
662 GST_OBJECT_UNLOCK (object);
663 result = gst_object_set_name_default (object);
665 /* FIXME-0.11: this misses a g_object_notify (object, "name"); unless called
666 * from gst_object_set_property.
667 * Ideally remove such custom setters (or make it static).
674 GST_WARNING ("parented objects can't be renamed");
675 GST_OBJECT_UNLOCK (object);
681 * gst_object_get_name:
682 * @object: a #GstObject
684 * Returns a copy of the name of @object.
685 * Caller should g_free() the return value after usage.
686 * For a nameless object, this returns NULL, which you can safely g_free()
689 * Free-function: g_free
691 * Returns: (transfer full): the name of @object. g_free() after usage.
693 * MT safe. This function grabs and releases @object's LOCK.
696 gst_object_get_name (GstObject * object)
698 gchar *result = NULL;
700 g_return_val_if_fail (GST_IS_OBJECT (object), NULL);
702 GST_OBJECT_LOCK (object);
703 result = g_strdup (object->name);
704 GST_OBJECT_UNLOCK (object);
710 * gst_object_set_parent:
711 * @object: a #GstObject
712 * @parent: new parent of object
714 * Sets the parent of @object to @parent. The object's reference count will
715 * be incremented, and any floating reference will be removed (see gst_object_ref_sink()).
717 * Returns: TRUE if @parent could be set or FALSE when @object
718 * already had a parent or @object and @parent are the same.
720 * MT safe. Grabs and releases @object's LOCK.
723 gst_object_set_parent (GstObject * object, GstObject * parent)
725 g_return_val_if_fail (GST_IS_OBJECT (object), FALSE);
726 g_return_val_if_fail (GST_IS_OBJECT (parent), FALSE);
727 g_return_val_if_fail (object != parent, FALSE);
729 GST_CAT_DEBUG_OBJECT (GST_CAT_REFCOUNTING, object,
730 "set parent (ref and sink)");
732 GST_OBJECT_LOCK (object);
733 if (G_UNLIKELY (object->parent != NULL))
736 object->parent = parent;
737 gst_object_ref_sink (object);
738 GST_OBJECT_UNLOCK (object);
740 /* FIXME, this does not work, the deep notify takes the lock from the parent
741 * object and deadlocks when the parent holds its lock when calling this
742 * function (like _element_add_pad()) */
743 /* g_object_notify_by_pspec ((GObject *)object, properties[PROP_PARENT]); */
750 GST_CAT_DEBUG_OBJECT (GST_CAT_REFCOUNTING, object,
751 "set parent failed, object already had a parent");
752 GST_OBJECT_UNLOCK (object);
758 * gst_object_get_parent:
759 * @object: a #GstObject
761 * Returns the parent of @object. This function increases the refcount
762 * of the parent object so you should gst_object_unref() it after usage.
764 * Returns: (transfer full): parent of @object, this can be NULL if @object
765 * has no parent. unref after usage.
767 * MT safe. Grabs and releases @object's LOCK.
770 gst_object_get_parent (GstObject * object)
772 GstObject *result = NULL;
774 g_return_val_if_fail (GST_IS_OBJECT (object), NULL);
776 GST_OBJECT_LOCK (object);
777 result = object->parent;
778 if (G_LIKELY (result))
779 gst_object_ref (result);
780 GST_OBJECT_UNLOCK (object);
786 * gst_object_unparent:
787 * @object: a #GstObject to unparent
789 * Clear the parent of @object, removing the associated reference.
790 * This function decreases the refcount of @object.
792 * MT safe. Grabs and releases @object's lock.
795 gst_object_unparent (GstObject * object)
799 g_return_if_fail (GST_IS_OBJECT (object));
801 GST_OBJECT_LOCK (object);
802 parent = object->parent;
804 if (G_LIKELY (parent != NULL)) {
805 GST_CAT_TRACE_OBJECT (GST_CAT_REFCOUNTING, object, "unparent");
806 object->parent = NULL;
807 GST_OBJECT_UNLOCK (object);
809 /* g_object_notify_by_pspec ((GObject *)object, properties[PROP_PARENT]); */
811 gst_object_unref (object);
813 GST_OBJECT_UNLOCK (object);
818 * gst_object_has_ancestor:
819 * @object: a #GstObject to check
820 * @ancestor: a #GstObject to check as ancestor
822 * Check if @object has an ancestor @ancestor somewhere up in
823 * the hierarchy. One can e.g. check if a #GstElement is inside a #GstPipeline.
825 * Returns: TRUE if @ancestor is an ancestor of @object.
827 * MT safe. Grabs and releases @object's locks.
830 gst_object_has_ancestor (GstObject * object, GstObject * ancestor)
832 GstObject *parent, *tmp;
834 if (!ancestor || !object)
837 parent = gst_object_ref (object);
839 if (parent == ancestor) {
840 gst_object_unref (parent);
844 tmp = gst_object_get_parent (parent);
845 gst_object_unref (parent);
853 * gst_object_check_uniqueness:
854 * @list: (transfer none) (element-type Gst.Object): a list of #GstObject to
856 * @name: the name to search for
858 * Checks to see if there is any object named @name in @list. This function
859 * does not do any locking of any kind. You might want to protect the
860 * provided list with the lock of the owner of the list. This function
861 * will lock each #GstObject in the list to compare the name, so be
862 * carefull when passing a list with a locked object.
864 * Returns: TRUE if a #GstObject named @name does not appear in @list,
867 * MT safe. Grabs and releases the LOCK of each object in the list.
870 gst_object_check_uniqueness (GList * list, const gchar * name)
872 gboolean result = TRUE;
874 g_return_val_if_fail (name != NULL, FALSE);
876 for (; list; list = g_list_next (list)) {
880 child = GST_OBJECT_CAST (list->data);
882 GST_OBJECT_LOCK (child);
883 eq = strcmp (GST_OBJECT_NAME (child), name) == 0;
884 GST_OBJECT_UNLOCK (child);
886 if (G_UNLIKELY (eq)) {
896 gst_object_set_property (GObject * object, guint prop_id,
897 const GValue * value, GParamSpec * pspec)
899 GstObject *gstobject;
901 gstobject = GST_OBJECT_CAST (object);
905 gst_object_set_name (gstobject, g_value_get_string (value));
908 gst_object_set_parent (gstobject, g_value_get_object (value));
911 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
917 gst_object_get_property (GObject * object, guint prop_id,
918 GValue * value, GParamSpec * pspec)
920 GstObject *gstobject;
922 gstobject = GST_OBJECT_CAST (object);
926 g_value_take_string (value, gst_object_get_name (gstobject));
929 g_value_take_object (value, gst_object_get_parent (gstobject));
932 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
938 * gst_object_get_path_string:
939 * @object: a #GstObject
941 * Generates a string describing the path of @object in
942 * the object hierarchy. Only useful (or used) for debugging.
944 * Free-function: g_free
946 * Returns: (transfer full): a string describing the path of @object. You must
947 * g_free() the string after usage.
949 * MT safe. Grabs and releases the #GstObject's LOCK for all objects
953 gst_object_get_path_string (GstObject * object)
958 gchar *prevpath, *path;
959 const gchar *typename;
961 const gchar *separator;
963 /* ref object before adding to list */
964 gst_object_ref (object);
965 parentage = g_slist_prepend (NULL, object);
967 path = g_strdup ("");
969 /* first walk the object hierarchy to build a list of the parents,
970 * be carefull here with refcounting. */
972 if (GST_IS_OBJECT (object)) {
973 parent = gst_object_get_parent (object);
974 /* add parents to list, refcount remains increased while
975 * we handle the object */
977 parentage = g_slist_prepend (parentage, parent);
982 } while (object != NULL);
984 /* then walk the parent list and print them out. we need to
985 * decrease the refcounting on each element after we handled
987 for (parents = parentage; parents; parents = g_slist_next (parents)) {
988 if (G_IS_OBJECT (parents->data)) {
989 typename = G_OBJECT_TYPE_NAME (parents->data);
993 if (GST_IS_OBJECT (parents->data)) {
994 GstObject *item = GST_OBJECT_CAST (parents->data);
995 GstObjectClass *oclass = GST_OBJECT_GET_CLASS (item);
996 gchar *objname = gst_object_get_name (item);
998 component = g_strdup_printf ("%s:%s", typename, objname);
999 separator = oclass->path_string_separator;
1001 gst_object_unref (item);
1005 component = g_strdup_printf ("%s:%p", typename, parents->data);
1007 component = g_strdup_printf ("%p", parents->data);
1013 path = g_strjoin (separator, prevpath, component, NULL);
1018 g_slist_free (parentage);
1023 /* controller helper functions */
1026 * gst_object_find_control_binding:
1027 * @self: the gobject to search for a property in
1028 * @name: the gobject property name to look for
1030 * Searches the list of properties under control.
1032 * Returns: a #GstControlBinding or %NULL if the property is not being
1035 static GstControlBinding *
1036 gst_object_find_control_binding (GstObject * self, const gchar * name)
1038 GstControlBinding *binding;
1041 for (node = self->control_bindings; node; node = g_list_next (node)) {
1042 binding = node->data;
1043 /* FIXME: eventually use GQuark to speed it up */
1044 if (!strcmp (binding->name, name)) {
1045 GST_DEBUG_OBJECT (self, "found control binding for property '%s'", name);
1049 GST_DEBUG_OBJECT (self, "controller does not manage property '%s'", name);
1054 /* controller functions */
1057 * gst_object_suggest_next_sync:
1058 * @object: the object that has controlled properties
1060 * Returns a suggestion for timestamps where buffers should be split
1061 * to get best controller results.
1063 * Returns: Returns the suggested timestamp or %GST_CLOCK_TIME_NONE
1064 * if no control-rate was set.
1067 gst_object_suggest_next_sync (GstObject * object)
1071 g_return_val_if_fail (GST_IS_OBJECT (object), GST_CLOCK_TIME_NONE);
1072 g_return_val_if_fail (object->control_rate != GST_CLOCK_TIME_NONE,
1073 GST_CLOCK_TIME_NONE);
1075 GST_OBJECT_LOCK (object);
1077 /* TODO: Implement more logic, depending on interpolation mode and control
1079 * FIXME: we need playback direction
1081 ret = object->last_sync + object->control_rate;
1083 GST_OBJECT_UNLOCK (object);
1089 * gst_object_sync_values:
1090 * @object: the object that has controlled properties
1091 * @timestamp: the time that should be processed
1093 * Sets the properties of the object, according to the #GstControlSources that
1094 * (maybe) handle them and for the given timestamp.
1096 * If this function fails, it is most likely the application developers fault.
1097 * Most probably the control sources are not setup correctly.
1099 * Returns: %TRUE if the controller values could be applied to the object
1100 * properties, %FALSE otherwise
1103 gst_object_sync_values (GstObject * object, GstClockTime timestamp)
1106 gboolean ret = TRUE;
1108 g_return_val_if_fail (GST_IS_OBJECT (object), FALSE);
1109 g_return_val_if_fail (GST_CLOCK_TIME_IS_VALID (timestamp), FALSE);
1111 GST_LOG_OBJECT (object, "sync_values");
1112 if (!object->control_bindings)
1115 /* FIXME: this deadlocks */
1116 /* GST_OBJECT_LOCK (object); */
1117 g_object_freeze_notify ((GObject *) object);
1118 for (node = object->control_bindings; node; node = g_list_next (node)) {
1119 ret &= gst_control_binding_sync_values ((GstControlBinding *) node->data,
1120 object, timestamp, object->last_sync);
1122 object->last_sync = timestamp;
1123 g_object_thaw_notify ((GObject *) object);
1124 /* GST_OBJECT_UNLOCK (object); */
1131 * gst_object_has_active_control_bindings:
1132 * @object: the object that has controlled properties
1134 * Check if the @object has an active controlled properties.
1136 * Returns: %TRUE if the object has active controlled properties
1139 gst_object_has_active_control_bindings (GstObject * object)
1141 gboolean res = FALSE;
1144 g_return_val_if_fail (GST_IS_OBJECT (object), FALSE);
1146 GST_OBJECT_LOCK (object);
1147 for (node = object->control_bindings; node; node = g_list_next (node)) {
1148 res |= !gst_control_binding_is_disabled ((GstControlBinding *) node->data);
1150 GST_OBJECT_UNLOCK (object);
1155 * gst_object_set_control_bindings_disabled:
1156 * @object: the object that has controlled properties
1157 * @disabled: boolean that specifies whether to disable the controller
1160 * This function is used to disable all controlled properties of the @object for
1161 * some time, i.e. gst_object_sync_values() will do nothing.
1164 gst_object_set_control_bindings_disabled (GstObject * object, gboolean disabled)
1168 g_return_if_fail (GST_IS_OBJECT (object));
1170 GST_OBJECT_LOCK (object);
1171 for (node = object->control_bindings; node; node = g_list_next (node)) {
1172 gst_control_binding_set_disabled ((GstControlBinding *) node->data,
1175 GST_OBJECT_UNLOCK (object);
1179 * gst_object_set_control_binding_disabled:
1180 * @object: the object that has controlled properties
1181 * @property_name: property to disable
1182 * @disabled: boolean that specifies whether to disable the controller
1185 * This function is used to disable the #GstController on a property for
1186 * some time, i.e. gst_controller_sync_values() will do nothing for the
1190 gst_object_set_control_binding_disabled (GstObject * object,
1191 const gchar * property_name, gboolean disabled)
1193 GstControlBinding *binding;
1195 g_return_if_fail (GST_IS_OBJECT (object));
1196 g_return_if_fail (property_name);
1198 GST_OBJECT_LOCK (object);
1199 if ((binding = gst_object_find_control_binding (object, property_name))) {
1200 gst_control_binding_set_disabled (binding, disabled);
1202 GST_OBJECT_UNLOCK (object);
1207 * gst_object_set_control_binding:
1208 * @object: the controller object
1209 * @binding: the #GstControlBinding that should be used for the property
1211 * Sets the #GstControlBinding. If there already was a #GstControlBinding
1212 * for this property it will be replaced. Use %NULL for @binding to unset it.
1214 * Returns: %FALSE if the given property isn't handled by the controller or
1215 * %TRUE if everything worked as expected.
1218 gst_object_set_control_binding (GstObject * object, GstControlBinding * binding)
1220 GstControlBinding *old;
1221 gboolean ret = FALSE;
1223 g_return_val_if_fail (GST_IS_OBJECT (object), FALSE);
1224 g_return_val_if_fail ((!binding || GST_IS_CONTROL_BINDING (binding)), FALSE);
1226 GST_OBJECT_LOCK (object);
1227 if ((old = gst_object_find_control_binding (object, binding->name))) {
1228 object->control_bindings = g_list_remove (object->control_bindings, old);
1229 g_object_unref (old);
1230 GST_DEBUG_OBJECT (object, "controlled property %s removed", binding->name);
1234 object->control_bindings =
1235 g_list_prepend (object->control_bindings, g_object_ref (binding));
1236 GST_DEBUG_OBJECT (object, "controlled property %s added", binding->name);
1239 GST_OBJECT_UNLOCK (object);
1245 * gst_object_get_control_binding:
1246 * @object: the object
1247 * @property_name: name of the property
1249 * Gets the corresponding #GstControlBinding for the property. This should be
1250 * unreferenced again after use.
1252 * Returns: (transfer full): the #GstControlBinding for @property_name or %NULL if
1253 * the property is not controlled.
1256 gst_object_get_control_binding (GstObject * object, const gchar * property_name)
1258 GstControlBinding *binding;
1260 g_return_val_if_fail (GST_IS_OBJECT (object), NULL);
1261 g_return_val_if_fail (property_name, NULL);
1263 GST_OBJECT_LOCK (object);
1264 if ((binding = gst_object_find_control_binding (object, property_name))) {
1265 g_object_ref (binding);
1267 GST_OBJECT_UNLOCK (object);
1273 * gst_object_set_control_source:
1274 * @object: the controller object
1275 * @property_name: name of the property for which the #GstControlSource should be set
1276 * @csource: the #GstControlSource that should be used for the property
1278 * Sets the #GstControlSource for @property_name. If there already was a #GstControlSource
1279 * for this property it will be unreferenced.
1281 * This is a convenience function for gst_object_set_control_binding().
1283 * Returns: %FALSE if the given property isn't handled by the controller or the new #GstControlSource
1284 * couldn't be bound to the property, %TRUE if everything worked as expected.
1287 gst_object_set_control_source (GstObject * object, const gchar * property_name,
1288 GstControlSource * csource)
1290 GstControlBinding *binding;
1291 gboolean ret = FALSE;
1293 g_return_val_if_fail (GST_IS_OBJECT (object), FALSE);
1294 g_return_val_if_fail (property_name, FALSE);
1295 g_return_val_if_fail ((!csource || GST_IS_CONTROL_SOURCE (csource)), FALSE);
1297 GST_OBJECT_LOCK (object);
1298 if ((binding = gst_object_find_control_binding (object, property_name))) {
1299 object->control_bindings =
1300 g_list_remove (object->control_bindings, binding);
1301 g_object_unref (binding);
1302 GST_DEBUG_OBJECT (object, "controlled property %s removed", property_name);
1306 if ((binding = gst_control_binding_new (object, property_name, csource))) {
1307 object->control_bindings =
1308 g_list_prepend (object->control_bindings, binding);
1309 GST_DEBUG_OBJECT (object, "controlled property %s added", property_name);
1315 GST_OBJECT_UNLOCK (object);
1321 * gst_object_get_control_source:
1322 * @object: the object
1323 * @property_name: name of the property
1325 * Gets the corresponding #GstControlSource for the property. This should be
1326 * unreferenced again after use.
1328 * This is a convenience function for gst_object_get_control_binding().
1330 * Returns: (transfer full): the #GstControlSource for @property_name or %NULL if
1331 * the property is not controlled.
1334 gst_object_get_control_source (GstObject * object, const gchar * property_name)
1336 GstControlBinding *binding;
1337 GstControlSource *ret = NULL;
1339 g_return_val_if_fail (GST_IS_OBJECT (object), NULL);
1340 g_return_val_if_fail (property_name, NULL);
1342 GST_OBJECT_LOCK (object);
1343 if ((binding = gst_object_find_control_binding (object, property_name))) {
1344 ret = gst_control_binding_get_control_source (binding);
1346 GST_OBJECT_UNLOCK (object);
1353 * gst_object_get_value:
1354 * @object: the object that has controlled properties
1355 * @property_name: the name of the property to get
1356 * @timestamp: the time the control-change should be read from
1358 * Gets the value for the given controlled property at the requested time.
1360 * Returns: the GValue of the property at the given time, or %NULL if the
1361 * property isn't controlled.
1364 gst_object_get_value (GstObject * object, const gchar * property_name,
1365 GstClockTime timestamp)
1367 GstControlBinding *binding;
1370 g_return_val_if_fail (GST_IS_OBJECT (object), NULL);
1371 g_return_val_if_fail (property_name, NULL);
1372 g_return_val_if_fail (GST_CLOCK_TIME_IS_VALID (timestamp), NULL);
1374 GST_OBJECT_LOCK (object);
1375 if ((binding = gst_object_find_control_binding (object, property_name))) {
1376 val = gst_control_binding_get_value (binding, timestamp);
1378 GST_OBJECT_UNLOCK (object);
1384 * gst_object_get_value_array:
1385 * @object: the object that has controlled properties
1386 * @property_name: the name of the property to get
1387 * @timestamp: the time that should be processed
1388 * @interval: the time spacing between subsequent values
1389 * @n_values: the number of values
1390 * @values: array to put control-values in
1392 * Gets a number of values for the given controllered property starting at the
1393 * requested time. The array @values need to hold enough space for @n_values of
1394 * the same type as the objects property's type.
1396 * This function is useful if one wants to e.g. draw a graph of the control
1397 * curve or apply a control curve sample by sample.
1399 * Returns: %TRUE if the given array could be filled, %FALSE otherwise
1402 gst_object_get_value_array (GstObject * object, const gchar * property_name,
1403 GstClockTime timestamp, GstClockTime interval, guint n_values,
1406 gboolean res = FALSE;
1407 GstControlBinding *binding;
1409 g_return_val_if_fail (GST_IS_OBJECT (object), FALSE);
1410 g_return_val_if_fail (property_name, FALSE);
1411 g_return_val_if_fail (GST_CLOCK_TIME_IS_VALID (timestamp), FALSE);
1412 g_return_val_if_fail (GST_CLOCK_TIME_IS_VALID (interval), FALSE);
1413 g_return_val_if_fail (values, FALSE);
1415 GST_OBJECT_LOCK (object);
1416 if ((binding = gst_object_find_control_binding (object, property_name))) {
1417 res = gst_control_binding_get_value_array (binding, timestamp, interval,
1420 GST_OBJECT_UNLOCK (object);
1426 * gst_object_get_control_rate:
1427 * @object: the object that has controlled properties
1429 * Obtain the control-rate for this @object. Audio processing #GstElement
1430 * objects will use this rate to sub-divide their processing loop and call
1431 * gst_object_sync_values() inbetween. The length of the processing segment
1432 * should be up to @control-rate nanoseconds.
1434 * If the @object is not under property control, this will return
1435 * %GST_CLOCK_TIME_NONE. This allows the element to avoid the sub-dividing.
1437 * The control-rate is not expected to change if the element is in
1438 * %GST_STATE_PAUSED or %GST_STATE_PLAYING.
1440 * Returns: the control rate in nanoseconds
1443 gst_object_get_control_rate (GstObject * object)
1445 g_return_val_if_fail (GST_IS_OBJECT (object), FALSE);
1447 return object->control_rate;
1451 * gst_object_set_control_rate:
1452 * @object: the object that has controlled properties
1453 * @control_rate: the new control-rate in nanoseconds.
1455 * Change the control-rate for this @object. Audio processing #GstElement
1456 * objects will use this rate to sub-divide their processing loop and call
1457 * gst_object_sync_values() inbetween. The length of the processing segment
1458 * should be up to @control-rate nanoseconds.
1460 * The control-rate should not change if the element is in %GST_STATE_PAUSED or
1461 * %GST_STATE_PLAYING.
1464 gst_object_set_control_rate (GstObject * object, GstClockTime control_rate)
1466 g_return_if_fail (GST_IS_OBJECT (object));
1468 object->control_rate = control_rate;