gstreamer/gst/gstobject.c
Tim-Philipp Müller 6eb6d9ec38 docs: remove outdated and pointless 'Last reviewed' lines from docs
They are very confusing for people, and more often than not
also just not very accurate. Seeing 'last reviewed: 2005' in
your docs is not very confidence-inspiring. Let's just remove
those comments.
2014-04-26 21:21:51 +01:00

1428 lines
41 KiB
C

/* GStreamer
* Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
* 2000 Wim Taymans <wtay@chello.be>
* 2005 Wim Taymans <wim@fluendo.com>
*
* gstobject.c: Fundamental class used for all of GStreamer
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
* Boston, MA 02110-1301, USA.
*/
/**
* SECTION:gstobject
* @short_description: Base class for the GStreamer object hierarchy
*
* #GstObject provides a root for the object hierarchy tree filed in by the
* GStreamer library. It is currently a thin wrapper on top of
* #GInitiallyUnowned. It is an abstract class that is not very usable on its own.
*
* #GstObject gives us basic refcounting, parenting functionality and locking.
* Most of the functions are just extended for special GStreamer needs and can be
* found under the same name in the base class of #GstObject which is #GObject
* (e.g. g_object_ref() becomes gst_object_ref()).
*
* Since #GstObject derives from #GInitiallyUnowned, it also inherits the
* floating reference. Be aware that functions such as gst_bin_add() and
* gst_element_add_pad() take ownership of the floating reference.
*
* In contrast to #GObject instances, #GstObject adds a name property. The functions
* gst_object_set_name() and gst_object_get_name() are used to set/get the name
* of the object.
*
* <refsect2>
* <title>controlled properties</title>
* <para>
* Controlled properties offers a lightweight way to adjust gobject properties
* over stream-time. It works by using time-stamped value pairs that are queued
* for element-properties. At run-time the elements continuously pull value
* changes for the current stream-time.
*
* What needs to be changed in a #GstElement?
* Very little - it is just two steps to make a plugin controllable!
* <orderedlist>
* <listitem><para>
* mark gobject-properties paramspecs that make sense to be controlled,
* by GST_PARAM_CONTROLLABLE.
* </para></listitem>
* <listitem><para>
* when processing data (get, chain, loop function) at the beginning call
* gst_object_sync_values(element,timestamp).
* This will make the controller to update all gobject properties that are under
* control with the current values based on timestamp.
* </para></listitem>
* </orderedlist>
*
* What needs to be done in applications?
* Again it's not a lot to change.
* <orderedlist>
* <listitem><para>
* create a #GstControlSource.
* csource = gst_interpolation_control_source_new ();
* g_object_set (csource, "mode", GST_INTERPOLATION_MODE_LINEAR, NULL);
* </para></listitem>
* <listitem><para>
* Attach the #GstControlSource on the controller to a property.
* gst_object_add_control_binding (object, gst_direct_control_binding_new (object, "prop1", csource));
* </para></listitem>
* <listitem><para>
* Set the control values
* gst_timed_value_control_source_set ((GstTimedValueControlSource *)csource,0 * GST_SECOND, value1);
* gst_timed_value_control_source_set ((GstTimedValueControlSource *)csource,1 * GST_SECOND, value2);
* </para></listitem>
* <listitem><para>
* start your pipeline
* </para></listitem>
* </orderedlist>
* </para>
* </refsect2>
*/
#include "gst_private.h"
#include "glib-compat-private.h"
#include "gstobject.h"
#include "gstclock.h"
#include "gstcontrolbinding.h"
#include "gstcontrolsource.h"
#include "gstinfo.h"
#include "gstparamspecs.h"
#include "gstutils.h"
#ifndef GST_DISABLE_TRACE
#include "gsttrace.h"
static GstAllocTrace *_gst_object_trace;
#endif
#define DEBUG_REFCOUNT
/* Object signals and args */
enum
{
DEEP_NOTIFY,
LAST_SIGNAL
};
enum
{
PROP_0,
PROP_NAME,
PROP_PARENT,
PROP_LAST
};
enum
{
SO_OBJECT_LOADED,
SO_LAST_SIGNAL
};
/* maps type name quark => count */
static GData *object_name_counts = NULL;
G_LOCK_DEFINE_STATIC (object_name_mutex);
static void gst_object_set_property (GObject * object, guint prop_id,
const GValue * value, GParamSpec * pspec);
static void gst_object_get_property (GObject * object, guint prop_id,
GValue * value, GParamSpec * pspec);
static void gst_object_dispatch_properties_changed (GObject * object,
guint n_pspecs, GParamSpec ** pspecs);
static void gst_object_dispose (GObject * object);
static void gst_object_finalize (GObject * object);
static gboolean gst_object_set_name_default (GstObject * object);
static guint gst_object_signals[LAST_SIGNAL] = { 0 };
static GParamSpec *properties[PROP_LAST];
G_DEFINE_ABSTRACT_TYPE (GstObject, gst_object, G_TYPE_INITIALLY_UNOWNED);
static void
gst_object_class_init (GstObjectClass * klass)
{
GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
#ifndef GST_DISABLE_TRACE
_gst_object_trace =
_gst_alloc_trace_register (g_type_name (GST_TYPE_OBJECT), -2);
#endif
gobject_class->set_property = gst_object_set_property;
gobject_class->get_property = gst_object_get_property;
properties[PROP_NAME] =
g_param_spec_string ("name", "Name", "The name of the object", NULL,
G_PARAM_READWRITE | G_PARAM_CONSTRUCT | G_PARAM_STATIC_STRINGS);
/**
* GstObject:parent:
*
* The parent of the object. Please note, that when changing the 'parent'
* property, we don't emit #GObject::notify and #GstObject::deep-notify
* signals due to locking issues. In some cases one can use
* #GstBin::element-added or #GstBin::element-removed signals on the parent to
* achieve a similar effect.
*/
properties[PROP_PARENT] =
g_param_spec_object ("parent", "Parent", "The parent of the object",
GST_TYPE_OBJECT, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS);
g_object_class_install_properties (gobject_class, PROP_LAST, properties);
/**
* GstObject::deep-notify:
* @gstobject: a #GstObject
* @prop_object: the object that originated the signal
* @prop: the property that changed
*
* The deep notify signal is used to be notified of property changes. It is
* typically attached to the toplevel bin to receive notifications from all
* the elements contained in that bin.
*/
gst_object_signals[DEEP_NOTIFY] =
g_signal_new ("deep-notify", G_TYPE_FROM_CLASS (klass),
G_SIGNAL_RUN_FIRST | G_SIGNAL_NO_RECURSE | G_SIGNAL_DETAILED |
G_SIGNAL_NO_HOOKS, G_STRUCT_OFFSET (GstObjectClass, deep_notify), NULL,
NULL, g_cclosure_marshal_generic, G_TYPE_NONE, 2, GST_TYPE_OBJECT,
G_TYPE_PARAM);
klass->path_string_separator = "/";
/* see the comments at gst_object_dispatch_properties_changed */
gobject_class->dispatch_properties_changed
= GST_DEBUG_FUNCPTR (gst_object_dispatch_properties_changed);
gobject_class->dispose = gst_object_dispose;
gobject_class->finalize = gst_object_finalize;
}
static void
gst_object_init (GstObject * object)
{
g_mutex_init (&object->lock);
object->parent = NULL;
object->name = NULL;
GST_CAT_TRACE_OBJECT (GST_CAT_REFCOUNTING, object, "%p new", object);
#ifndef GST_DISABLE_TRACE
_gst_alloc_trace_new (_gst_object_trace, object);
#endif
object->flags = 0;
object->control_rate = 100 * GST_MSECOND;
object->last_sync = GST_CLOCK_TIME_NONE;
}
/**
* gst_object_ref:
* @object: (type Gst.Object): a #GstObject to reference
*
* Increments the reference count on @object. This function
* does not take the lock on @object because it relies on
* atomic refcounting.
*
* This object returns the input parameter to ease writing
* constructs like :
* result = gst_object_ref (object->parent);
*
* Returns: (transfer full) (type Gst.Object): A pointer to @object
*/
gpointer
gst_object_ref (gpointer object)
{
g_return_val_if_fail (object != NULL, NULL);
#ifdef DEBUG_REFCOUNT
GST_CAT_TRACE_OBJECT (GST_CAT_REFCOUNTING, object, "%p ref %d->%d", object,
((GObject *) object)->ref_count, ((GObject *) object)->ref_count + 1);
#endif
g_object_ref (object);
return object;
}
/**
* gst_object_unref:
* @object: (type Gst.Object): a #GstObject to unreference
*
* Decrements the reference count on @object. If reference count hits
* zero, destroy @object. This function does not take the lock
* on @object as it relies on atomic refcounting.
*
* The unref method should never be called with the LOCK held since
* this might deadlock the dispose function.
*/
void
gst_object_unref (gpointer object)
{
g_return_if_fail (object != NULL);
g_return_if_fail (((GObject *) object)->ref_count > 0);
#ifdef DEBUG_REFCOUNT
GST_CAT_TRACE_OBJECT (GST_CAT_REFCOUNTING, object, "%p unref %d->%d", object,
((GObject *) object)->ref_count, ((GObject *) object)->ref_count - 1);
#endif
g_object_unref (object);
}
/**
* gst_object_ref_sink: (skip)
* @object: a #GstObject to sink
*
* Increase the reference count of @object, and possibly remove the floating
* reference, if @object has a floating reference.
*
* In other words, if the object is floating, then this call "assumes ownership"
* of the floating reference, converting it to a normal reference by clearing
* the floating flag while leaving the reference count unchanged. If the object
* is not floating, then this call adds a new normal reference increasing the
* reference count by one.
*/
gpointer
gst_object_ref_sink (gpointer object)
{
g_return_val_if_fail (object != NULL, NULL);
#ifdef DEBUG_REFCOUNT
GST_CAT_TRACE_OBJECT (GST_CAT_REFCOUNTING, object, "%p ref_sink %d->%d",
object, ((GObject *) object)->ref_count,
((GObject *) object)->ref_count + 1);
#endif
return g_object_ref_sink (object);
}
/**
* gst_object_replace:
* @oldobj: (inout) (transfer full): pointer to a place of a #GstObject to
* replace
* @newobj: (transfer none): a new #GstObject
*
* Atomically modifies a pointer to point to a new object.
* The reference count of @oldobj is decreased and the reference count of
* @newobj is increased.
*
* Either @newobj and the value pointed to by @oldobj may be NULL.
*
* Returns: TRUE if @newobj was different from @oldobj
*/
gboolean
gst_object_replace (GstObject ** oldobj, GstObject * newobj)
{
GstObject *oldptr;
g_return_val_if_fail (oldobj != NULL, FALSE);
#ifdef DEBUG_REFCOUNT
GST_CAT_TRACE (GST_CAT_REFCOUNTING, "replace %p %s (%d) with %p %s (%d)",
*oldobj, *oldobj ? GST_STR_NULL (GST_OBJECT_NAME (*oldobj)) : "(NONE)",
*oldobj ? G_OBJECT (*oldobj)->ref_count : 0,
newobj, newobj ? GST_STR_NULL (GST_OBJECT_NAME (newobj)) : "(NONE)",
newobj ? G_OBJECT (newobj)->ref_count : 0);
#endif
oldptr = g_atomic_pointer_get ((gpointer *) oldobj);
if (G_UNLIKELY (oldptr == newobj))
return FALSE;
if (newobj)
gst_object_ref (newobj);
while (G_UNLIKELY (!g_atomic_pointer_compare_and_exchange ((gpointer *)
oldobj, oldptr, newobj))) {
oldptr = g_atomic_pointer_get ((gpointer *) oldobj);
if (G_UNLIKELY (oldptr == newobj))
break;
}
if (oldptr)
gst_object_unref (oldptr);
return oldptr != newobj;
}
/* dispose is called when the object has to release all links
* to other objects */
static void
gst_object_dispose (GObject * object)
{
GstObject *self = (GstObject *) object;
GstObject *parent;
GST_CAT_TRACE_OBJECT (GST_CAT_REFCOUNTING, object, "dispose");
GST_OBJECT_LOCK (object);
if ((parent = GST_OBJECT_PARENT (object)))
goto have_parent;
GST_OBJECT_PARENT (object) = NULL;
GST_OBJECT_UNLOCK (object);
if (self->control_bindings) {
GList *node;
for (node = self->control_bindings; node; node = g_list_next (node)) {
gst_object_unparent (node->data);
}
g_list_free (self->control_bindings);
self->control_bindings = NULL;
}
((GObjectClass *) gst_object_parent_class)->dispose (object);
return;
/* ERRORS */
have_parent:
{
g_critical ("\nTrying to dispose object \"%s\", but it still has a "
"parent \"%s\".\nYou need to let the parent manage the "
"object instead of unreffing the object directly.\n",
GST_OBJECT_NAME (object), GST_OBJECT_NAME (parent));
GST_OBJECT_UNLOCK (object);
/* ref the object again to revive it in this error case */
gst_object_ref (object);
return;
}
}
/* finalize is called when the object has to free its resources */
static void
gst_object_finalize (GObject * object)
{
GstObject *gstobject = GST_OBJECT_CAST (object);
GST_CAT_TRACE_OBJECT (GST_CAT_REFCOUNTING, object, "finalize");
g_signal_handlers_destroy (object);
g_free (gstobject->name);
g_mutex_clear (&gstobject->lock);
#ifndef GST_DISABLE_TRACE
_gst_alloc_trace_free (_gst_object_trace, object);
#endif
((GObjectClass *) gst_object_parent_class)->finalize (object);
}
/* Changing a GObject property of a GstObject will result in "deep-notify"
* signals being emitted by the object itself, as well as in each parent
* object. This is so that an application can connect a listener to the
* top-level bin to catch property-change notifications for all contained
* elements.
*
* MT safe.
*/
static void
gst_object_dispatch_properties_changed (GObject * object,
guint n_pspecs, GParamSpec ** pspecs)
{
GstObject *gst_object, *parent, *old_parent;
guint i;
#ifndef GST_DISABLE_GST_DEBUG
gchar *name = NULL;
const gchar *debug_name;
#endif
/* do the standard dispatching */
((GObjectClass *)
gst_object_parent_class)->dispatch_properties_changed (object, n_pspecs,
pspecs);
gst_object = GST_OBJECT_CAST (object);
#ifndef GST_DISABLE_GST_DEBUG
if (G_UNLIKELY (_gst_debug_min >= GST_LEVEL_LOG)) {
name = gst_object_get_name (gst_object);
debug_name = GST_STR_NULL (name);
} else
debug_name = "";
#endif
/* now let the parent dispatch those, too */
parent = gst_object_get_parent (gst_object);
while (parent) {
for (i = 0; i < n_pspecs; i++) {
GST_CAT_LOG_OBJECT (GST_CAT_PROPERTIES, parent,
"deep notification from %s (%s)", debug_name, pspecs[i]->name);
g_signal_emit (parent, gst_object_signals[DEEP_NOTIFY],
g_quark_from_string (pspecs[i]->name), gst_object, pspecs[i]);
}
old_parent = parent;
parent = gst_object_get_parent (old_parent);
gst_object_unref (old_parent);
}
#ifndef GST_DISABLE_GST_DEBUG
g_free (name);
#endif
}
/**
* gst_object_default_deep_notify:
* @object: the #GObject that signalled the notify.
* @orig: a #GstObject that initiated the notify.
* @pspec: a #GParamSpec of the property.
* @excluded_props: (array zero-terminated=1) (element-type gchar*) (allow-none):
* a set of user-specified properties to exclude or NULL to show
* all changes.
*
* A default deep_notify signal callback for an object. The user data
* should contain a pointer to an array of strings that should be excluded
* from the notify. The default handler will print the new value of the property
* using g_print.
*
* MT safe. This function grabs and releases @object's LOCK for getting its
* path string.
*/
void
gst_object_default_deep_notify (GObject * object, GstObject * orig,
GParamSpec * pspec, gchar ** excluded_props)
{
GValue value = { 0, }; /* the important thing is that value.type = 0 */
gchar *str = NULL;
gchar *name = NULL;
if (pspec->flags & G_PARAM_READABLE) {
/* let's not print these out for excluded properties... */
while (excluded_props != NULL && *excluded_props != NULL) {
if (strcmp (pspec->name, *excluded_props) == 0)
return;
excluded_props++;
}
g_value_init (&value, pspec->value_type);
g_object_get_property (G_OBJECT (orig), pspec->name, &value);
if (G_VALUE_HOLDS_STRING (&value))
str = g_value_dup_string (&value);
else
str = gst_value_serialize (&value);
name = gst_object_get_path_string (orig);
g_print ("%s: %s = %s\n", name, pspec->name, str);
g_free (name);
g_free (str);
g_value_unset (&value);
} else {
name = gst_object_get_path_string (orig);
g_warning ("Parameter %s not readable in %s.", pspec->name, name);
g_free (name);
}
}
static gboolean
gst_object_set_name_default (GstObject * object)
{
const gchar *type_name;
gint count;
gchar *name;
GQuark q;
guint i, l;
/* to ensure guaranteed uniqueness across threads, only one thread
* may ever assign a name */
G_LOCK (object_name_mutex);
if (!object_name_counts) {
g_datalist_init (&object_name_counts);
}
q = g_type_qname (G_OBJECT_TYPE (object));
count = GPOINTER_TO_INT (g_datalist_id_get_data (&object_name_counts, q));
g_datalist_id_set_data (&object_name_counts, q, GINT_TO_POINTER (count + 1));
G_UNLOCK (object_name_mutex);
/* GstFooSink -> foosink<N> */
type_name = g_quark_to_string (q);
if (strncmp (type_name, "Gst", 3) == 0)
type_name += 3;
/* give the 20th "queue" element and the first "queue2" different names */
l = strlen (type_name);
if (l > 0 && g_ascii_isdigit (type_name[l - 1])) {
name = g_strdup_printf ("%s-%d", type_name, count);
} else {
name = g_strdup_printf ("%s%d", type_name, count);
}
l = strlen (name);
for (i = 0; i < l; i++)
name[i] = g_ascii_tolower (name[i]);
GST_OBJECT_LOCK (object);
if (G_UNLIKELY (object->parent != NULL))
goto had_parent;
g_free (object->name);
object->name = name;
GST_OBJECT_UNLOCK (object);
return TRUE;
had_parent:
{
g_free (name);
GST_WARNING ("parented objects can't be renamed");
GST_OBJECT_UNLOCK (object);
return FALSE;
}
}
/**
* gst_object_set_name:
* @object: a #GstObject
* @name: new name of object
*
* Sets the name of @object, or gives @object a guaranteed unique
* name (if @name is NULL).
* This function makes a copy of the provided name, so the caller
* retains ownership of the name it sent.
*
* Returns: TRUE if the name could be set. Since Objects that have
* a parent cannot be renamed, this function returns FALSE in those
* cases.
*
* MT safe. This function grabs and releases @object's LOCK.
*/
gboolean
gst_object_set_name (GstObject * object, const gchar * name)
{
gboolean result;
g_return_val_if_fail (GST_IS_OBJECT (object), FALSE);
GST_OBJECT_LOCK (object);
/* parented objects cannot be renamed */
if (G_UNLIKELY (object->parent != NULL))
goto had_parent;
if (name != NULL) {
g_free (object->name);
object->name = g_strdup (name);
GST_OBJECT_UNLOCK (object);
result = TRUE;
} else {
GST_OBJECT_UNLOCK (object);
result = gst_object_set_name_default (object);
}
/* FIXME-0.11: this misses a g_object_notify (object, "name"); unless called
* from gst_object_set_property.
* Ideally remove such custom setters (or make it static).
*/
return result;
/* error */
had_parent:
{
GST_WARNING ("parented objects can't be renamed");
GST_OBJECT_UNLOCK (object);
return FALSE;
}
}
/**
* gst_object_get_name:
* @object: a #GstObject
*
* Returns a copy of the name of @object.
* Caller should g_free() the return value after usage.
* For a nameless object, this returns NULL, which you can safely g_free()
* as well.
*
* Free-function: g_free
*
* Returns: (transfer full): the name of @object. g_free() after usage.
*
* MT safe. This function grabs and releases @object's LOCK.
*/
gchar *
gst_object_get_name (GstObject * object)
{
gchar *result = NULL;
g_return_val_if_fail (GST_IS_OBJECT (object), NULL);
GST_OBJECT_LOCK (object);
result = g_strdup (object->name);
GST_OBJECT_UNLOCK (object);
return result;
}
/**
* gst_object_set_parent:
* @object: a #GstObject
* @parent: new parent of object
*
* Sets the parent of @object to @parent. The object's reference count will
* be incremented, and any floating reference will be removed (see gst_object_ref_sink()).
*
* Returns: TRUE if @parent could be set or FALSE when @object
* already had a parent or @object and @parent are the same.
*
* MT safe. Grabs and releases @object's LOCK.
*/
gboolean
gst_object_set_parent (GstObject * object, GstObject * parent)
{
g_return_val_if_fail (GST_IS_OBJECT (object), FALSE);
g_return_val_if_fail (GST_IS_OBJECT (parent), FALSE);
g_return_val_if_fail (object != parent, FALSE);
GST_CAT_DEBUG_OBJECT (GST_CAT_REFCOUNTING, object,
"set parent (ref and sink)");
GST_OBJECT_LOCK (object);
if (G_UNLIKELY (object->parent != NULL))
goto had_parent;
object->parent = parent;
gst_object_ref_sink (object);
GST_OBJECT_UNLOCK (object);
/* FIXME-2.0: this does not work, the deep notify takes the lock from the
* parent object and deadlocks when the parent holds its lock when calling
* this function (like _element_add_pad()), we need to use a GRecMutex
* for locking the parent instead.
*/
/* g_object_notify_by_pspec ((GObject *)object, properties[PROP_PARENT]); */
return TRUE;
/* ERROR handling */
had_parent:
{
GST_CAT_DEBUG_OBJECT (GST_CAT_REFCOUNTING, object,
"set parent failed, object already had a parent");
GST_OBJECT_UNLOCK (object);
return FALSE;
}
}
/**
* gst_object_get_parent:
* @object: a #GstObject
*
* Returns the parent of @object. This function increases the refcount
* of the parent object so you should gst_object_unref() it after usage.
*
* Returns: (transfer full): parent of @object, this can be NULL if @object
* has no parent. unref after usage.
*
* MT safe. Grabs and releases @object's LOCK.
*/
GstObject *
gst_object_get_parent (GstObject * object)
{
GstObject *result = NULL;
g_return_val_if_fail (GST_IS_OBJECT (object), NULL);
GST_OBJECT_LOCK (object);
result = object->parent;
if (G_LIKELY (result))
gst_object_ref (result);
GST_OBJECT_UNLOCK (object);
return result;
}
/**
* gst_object_unparent:
* @object: a #GstObject to unparent
*
* Clear the parent of @object, removing the associated reference.
* This function decreases the refcount of @object.
*
* MT safe. Grabs and releases @object's lock.
*/
void
gst_object_unparent (GstObject * object)
{
GstObject *parent;
g_return_if_fail (GST_IS_OBJECT (object));
GST_OBJECT_LOCK (object);
parent = object->parent;
if (G_LIKELY (parent != NULL)) {
GST_CAT_TRACE_OBJECT (GST_CAT_REFCOUNTING, object, "unparent");
object->parent = NULL;
GST_OBJECT_UNLOCK (object);
/* g_object_notify_by_pspec ((GObject *)object, properties[PROP_PARENT]); */
gst_object_unref (object);
} else {
GST_OBJECT_UNLOCK (object);
}
}
/**
* gst_object_has_ancestor:
* @object: a #GstObject to check
* @ancestor: a #GstObject to check as ancestor
*
* Check if @object has an ancestor @ancestor somewhere up in
* the hierarchy. One can e.g. check if a #GstElement is inside a #GstPipeline.
*
* Returns: TRUE if @ancestor is an ancestor of @object.
*
* MT safe. Grabs and releases @object's locks.
*/
gboolean
gst_object_has_ancestor (GstObject * object, GstObject * ancestor)
{
GstObject *parent, *tmp;
if (!ancestor || !object)
return FALSE;
parent = gst_object_ref (object);
do {
if (parent == ancestor) {
gst_object_unref (parent);
return TRUE;
}
tmp = gst_object_get_parent (parent);
gst_object_unref (parent);
parent = tmp;
} while (parent);
return FALSE;
}
/**
* gst_object_check_uniqueness:
* @list: (transfer none) (element-type Gst.Object): a list of #GstObject to
* check through
* @name: the name to search for
*
* Checks to see if there is any object named @name in @list. This function
* does not do any locking of any kind. You might want to protect the
* provided list with the lock of the owner of the list. This function
* will lock each #GstObject in the list to compare the name, so be
* careful when passing a list with a locked object.
*
* Returns: TRUE if a #GstObject named @name does not appear in @list,
* FALSE if it does.
*
* MT safe. Grabs and releases the LOCK of each object in the list.
*/
gboolean
gst_object_check_uniqueness (GList * list, const gchar * name)
{
gboolean result = TRUE;
g_return_val_if_fail (name != NULL, FALSE);
for (; list; list = g_list_next (list)) {
GstObject *child;
gboolean eq;
child = GST_OBJECT_CAST (list->data);
GST_OBJECT_LOCK (child);
eq = strcmp (GST_OBJECT_NAME (child), name) == 0;
GST_OBJECT_UNLOCK (child);
if (G_UNLIKELY (eq)) {
result = FALSE;
break;
}
}
return result;
}
static void
gst_object_set_property (GObject * object, guint prop_id,
const GValue * value, GParamSpec * pspec)
{
GstObject *gstobject;
gstobject = GST_OBJECT_CAST (object);
switch (prop_id) {
case PROP_NAME:
gst_object_set_name (gstobject, g_value_get_string (value));
break;
case PROP_PARENT:
gst_object_set_parent (gstobject, g_value_get_object (value));
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static void
gst_object_get_property (GObject * object, guint prop_id,
GValue * value, GParamSpec * pspec)
{
GstObject *gstobject;
gstobject = GST_OBJECT_CAST (object);
switch (prop_id) {
case PROP_NAME:
g_value_take_string (value, gst_object_get_name (gstobject));
break;
case PROP_PARENT:
g_value_take_object (value, gst_object_get_parent (gstobject));
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
/**
* gst_object_get_path_string:
* @object: a #GstObject
*
* Generates a string describing the path of @object in
* the object hierarchy. Only useful (or used) for debugging.
*
* Free-function: g_free
*
* Returns: (transfer full): a string describing the path of @object. You must
* g_free() the string after usage.
*
* MT safe. Grabs and releases the #GstObject's LOCK for all objects
* in the hierarchy.
*/
gchar *
gst_object_get_path_string (GstObject * object)
{
GSList *parentage;
GSList *parents;
void *parent;
gchar *prevpath, *path;
const gchar *typename;
gchar *component;
const gchar *separator;
/* ref object before adding to list */
gst_object_ref (object);
parentage = g_slist_prepend (NULL, object);
path = g_strdup ("");
/* first walk the object hierarchy to build a list of the parents,
* be careful here with refcounting. */
do {
if (GST_IS_OBJECT (object)) {
parent = gst_object_get_parent (object);
/* add parents to list, refcount remains increased while
* we handle the object */
if (parent)
parentage = g_slist_prepend (parentage, parent);
} else {
break;
}
object = parent;
} while (object != NULL);
/* then walk the parent list and print them out. we need to
* decrease the refcounting on each element after we handled
* it. */
for (parents = parentage; parents; parents = g_slist_next (parents)) {
if (G_IS_OBJECT (parents->data)) {
typename = G_OBJECT_TYPE_NAME (parents->data);
} else {
typename = NULL;
}
if (GST_IS_OBJECT (parents->data)) {
GstObject *item = GST_OBJECT_CAST (parents->data);
GstObjectClass *oclass = GST_OBJECT_GET_CLASS (item);
gchar *objname = gst_object_get_name (item);
component = g_strdup_printf ("%s:%s", typename, objname);
separator = oclass->path_string_separator;
/* and unref now */
gst_object_unref (item);
g_free (objname);
} else {
if (typename) {
component = g_strdup_printf ("%s:%p", typename, parents->data);
} else {
component = g_strdup_printf ("%p", parents->data);
}
separator = "/";
}
prevpath = path;
path = g_strjoin (separator, prevpath, component, NULL);
g_free (prevpath);
g_free (component);
}
g_slist_free (parentage);
return path;
}
/* controller helper functions */
/*
* gst_object_find_control_binding:
* @self: the gobject to search for a property in
* @name: the gobject property name to look for
*
* Searches the list of properties under control.
*
* Returns: a #GstControlBinding or %NULL if the property is not being
* controlled.
*/
static GstControlBinding *
gst_object_find_control_binding (GstObject * self, const gchar * name)
{
GstControlBinding *binding;
GList *node;
for (node = self->control_bindings; node; node = g_list_next (node)) {
binding = node->data;
/* FIXME: eventually use GQuark to speed it up */
if (!strcmp (binding->name, name)) {
GST_DEBUG_OBJECT (self, "found control binding for property '%s'", name);
return binding;
}
}
GST_DEBUG_OBJECT (self, "controller does not manage property '%s'", name);
return NULL;
}
/* controller functions */
/**
* gst_object_suggest_next_sync:
* @object: the object that has controlled properties
*
* Returns a suggestion for timestamps where buffers should be split
* to get best controller results.
*
* Returns: Returns the suggested timestamp or %GST_CLOCK_TIME_NONE
* if no control-rate was set.
*/
GstClockTime
gst_object_suggest_next_sync (GstObject * object)
{
GstClockTime ret;
g_return_val_if_fail (GST_IS_OBJECT (object), GST_CLOCK_TIME_NONE);
g_return_val_if_fail (object->control_rate != GST_CLOCK_TIME_NONE,
GST_CLOCK_TIME_NONE);
GST_OBJECT_LOCK (object);
/* TODO: Implement more logic, depending on interpolation mode and control
* points
* FIXME: we need playback direction
*/
ret = object->last_sync + object->control_rate;
GST_OBJECT_UNLOCK (object);
return ret;
}
/**
* gst_object_sync_values:
* @object: the object that has controlled properties
* @timestamp: the time that should be processed
*
* Sets the properties of the object, according to the #GstControlSources that
* (maybe) handle them and for the given timestamp.
*
* If this function fails, it is most likely the application developers fault.
* Most probably the control sources are not setup correctly.
*
* Returns: %TRUE if the controller values could be applied to the object
* properties, %FALSE otherwise
*/
gboolean
gst_object_sync_values (GstObject * object, GstClockTime timestamp)
{
GList *node;
gboolean ret = TRUE;
g_return_val_if_fail (GST_IS_OBJECT (object), FALSE);
g_return_val_if_fail (GST_CLOCK_TIME_IS_VALID (timestamp), FALSE);
GST_LOG_OBJECT (object, "sync_values");
if (!object->control_bindings)
return TRUE;
/* FIXME: this deadlocks */
/* GST_OBJECT_LOCK (object); */
g_object_freeze_notify ((GObject *) object);
for (node = object->control_bindings; node; node = g_list_next (node)) {
ret &= gst_control_binding_sync_values ((GstControlBinding *) node->data,
object, timestamp, object->last_sync);
}
object->last_sync = timestamp;
g_object_thaw_notify ((GObject *) object);
/* GST_OBJECT_UNLOCK (object); */
return ret;
}
/**
* gst_object_has_active_control_bindings:
* @object: the object that has controlled properties
*
* Check if the @object has an active controlled properties.
*
* Returns: %TRUE if the object has active controlled properties
*/
gboolean
gst_object_has_active_control_bindings (GstObject * object)
{
gboolean res = FALSE;
GList *node;
g_return_val_if_fail (GST_IS_OBJECT (object), FALSE);
GST_OBJECT_LOCK (object);
for (node = object->control_bindings; node; node = g_list_next (node)) {
res |= !gst_control_binding_is_disabled ((GstControlBinding *) node->data);
}
GST_OBJECT_UNLOCK (object);
return res;
}
/**
* gst_object_set_control_bindings_disabled:
* @object: the object that has controlled properties
* @disabled: boolean that specifies whether to disable the controller
* or not.
*
* This function is used to disable all controlled properties of the @object for
* some time, i.e. gst_object_sync_values() will do nothing.
*/
void
gst_object_set_control_bindings_disabled (GstObject * object, gboolean disabled)
{
GList *node;
g_return_if_fail (GST_IS_OBJECT (object));
GST_OBJECT_LOCK (object);
for (node = object->control_bindings; node; node = g_list_next (node)) {
gst_control_binding_set_disabled ((GstControlBinding *) node->data,
disabled);
}
GST_OBJECT_UNLOCK (object);
}
/**
* gst_object_set_control_binding_disabled:
* @object: the object that has controlled properties
* @property_name: property to disable
* @disabled: boolean that specifies whether to disable the controller
* or not.
*
* This function is used to disable the control bindings on a property for
* some time, i.e. gst_object_sync_values() will do nothing for the
* property.
*/
void
gst_object_set_control_binding_disabled (GstObject * object,
const gchar * property_name, gboolean disabled)
{
GstControlBinding *binding;
g_return_if_fail (GST_IS_OBJECT (object));
g_return_if_fail (property_name);
GST_OBJECT_LOCK (object);
if ((binding = gst_object_find_control_binding (object, property_name))) {
gst_control_binding_set_disabled (binding, disabled);
}
GST_OBJECT_UNLOCK (object);
}
/**
* gst_object_add_control_binding:
* @object: the controller object
* @binding: (transfer full): the #GstControlBinding that should be used
*
* Attach the #GstControlBinding to the object. If there already was a
* #GstControlBinding for this property it will be replaced.
*
* The @object will take ownership of the @binding.
*
* Returns: %FALSE if the given @binding has not been setup for this object or
* has been setup for a non suitable property, %TRUE otherwise.
*/
gboolean
gst_object_add_control_binding (GstObject * object, GstControlBinding * binding)
{
GstControlBinding *old;
g_return_val_if_fail (GST_IS_OBJECT (object), FALSE);
g_return_val_if_fail (GST_IS_CONTROL_BINDING (binding), FALSE);
g_return_val_if_fail (binding->pspec, FALSE);
GST_OBJECT_LOCK (object);
if ((old = gst_object_find_control_binding (object, binding->name))) {
GST_DEBUG_OBJECT (object, "controlled property %s removed", old->name);
object->control_bindings = g_list_remove (object->control_bindings, old);
gst_object_unparent (GST_OBJECT_CAST (old));
}
object->control_bindings = g_list_prepend (object->control_bindings, binding);
gst_object_set_parent (GST_OBJECT_CAST (binding), object);
GST_DEBUG_OBJECT (object, "controlled property %s added", binding->name);
GST_OBJECT_UNLOCK (object);
return TRUE;
}
/**
* gst_object_get_control_binding:
* @object: the object
* @property_name: name of the property
*
* Gets the corresponding #GstControlBinding for the property. This should be
* unreferenced again after use.
*
* Returns: (transfer full): the #GstControlBinding for @property_name or %NULL if
* the property is not controlled.
*/
GstControlBinding *
gst_object_get_control_binding (GstObject * object, const gchar * property_name)
{
GstControlBinding *binding;
g_return_val_if_fail (GST_IS_OBJECT (object), NULL);
g_return_val_if_fail (property_name, NULL);
GST_OBJECT_LOCK (object);
if ((binding = gst_object_find_control_binding (object, property_name))) {
gst_object_ref (binding);
}
GST_OBJECT_UNLOCK (object);
return binding;
}
/**
* gst_object_remove_control_binding:
* @object: the object
* @binding: the binding
*
* Removes the corresponding #GstControlBinding. If it was the
* last ref of the binding, it will be disposed.
*
* Returns: %TRUE if the binding could be removed.
*/
gboolean
gst_object_remove_control_binding (GstObject * object,
GstControlBinding * binding)
{
GList *node;
gboolean ret = FALSE;
g_return_val_if_fail (GST_IS_OBJECT (object), FALSE);
g_return_val_if_fail (GST_IS_CONTROL_BINDING (binding), FALSE);
GST_OBJECT_LOCK (object);
if ((node = g_list_find (object->control_bindings, binding))) {
GST_DEBUG_OBJECT (object, "controlled property %s removed", binding->name);
object->control_bindings =
g_list_delete_link (object->control_bindings, node);
gst_object_unparent (GST_OBJECT_CAST (binding));
ret = TRUE;
}
GST_OBJECT_UNLOCK (object);
return ret;
}
/**
* gst_object_get_value:
* @object: the object that has controlled properties
* @property_name: the name of the property to get
* @timestamp: the time the control-change should be read from
*
* Gets the value for the given controlled property at the requested time.
*
* Returns: the GValue of the property at the given time, or %NULL if the
* property isn't controlled.
*/
GValue *
gst_object_get_value (GstObject * object, const gchar * property_name,
GstClockTime timestamp)
{
GstControlBinding *binding;
GValue *val = NULL;
g_return_val_if_fail (GST_IS_OBJECT (object), NULL);
g_return_val_if_fail (property_name, NULL);
g_return_val_if_fail (GST_CLOCK_TIME_IS_VALID (timestamp), NULL);
GST_OBJECT_LOCK (object);
if ((binding = gst_object_find_control_binding (object, property_name))) {
val = gst_control_binding_get_value (binding, timestamp);
}
GST_OBJECT_UNLOCK (object);
return val;
}
/**
* gst_object_get_value_array:
* @object: the object that has controlled properties
* @property_name: the name of the property to get
* @timestamp: the time that should be processed
* @interval: the time spacing between subsequent values
* @n_values: the number of values
* @values: array to put control-values in
*
* Gets a number of values for the given controlled property starting at the
* requested time. The array @values need to hold enough space for @n_values of
* the same type as the objects property's type.
*
* This function is useful if one wants to e.g. draw a graph of the control
* curve or apply a control curve sample by sample.
*
* The values are unboxed and ready to be used. The similar function
* gst_object_get_g_value_array() returns the array as #GValues and is
* better suites for bindings.
*
* Returns: %TRUE if the given array could be filled, %FALSE otherwise
*/
gboolean
gst_object_get_value_array (GstObject * object, const gchar * property_name,
GstClockTime timestamp, GstClockTime interval, guint n_values,
gpointer values)
{
gboolean res = FALSE;
GstControlBinding *binding;
g_return_val_if_fail (GST_IS_OBJECT (object), FALSE);
g_return_val_if_fail (property_name, FALSE);
g_return_val_if_fail (GST_CLOCK_TIME_IS_VALID (timestamp), FALSE);
g_return_val_if_fail (GST_CLOCK_TIME_IS_VALID (interval), FALSE);
g_return_val_if_fail (values, FALSE);
GST_OBJECT_LOCK (object);
if ((binding = gst_object_find_control_binding (object, property_name))) {
res = gst_control_binding_get_value_array (binding, timestamp, interval,
n_values, values);
}
GST_OBJECT_UNLOCK (object);
return res;
}
/**
* gst_object_get_g_value_array:
* @object: the object that has controlled properties
* @property_name: the name of the property to get
* @timestamp: the time that should be processed
* @interval: the time spacing between subsequent values
* @n_values: the number of values
* @values: array to put control-values in
*
* Gets a number of #GValues for the given controlled property starting at the
* requested time. The array @values need to hold enough space for @n_values of
* #GValue.
*
* This function is useful if one wants to e.g. draw a graph of the control
* curve or apply a control curve sample by sample.
*
* Returns: %TRUE if the given array could be filled, %FALSE otherwise
*/
gboolean
gst_object_get_g_value_array (GstObject * object, const gchar * property_name,
GstClockTime timestamp, GstClockTime interval, guint n_values,
GValue * values)
{
gboolean res = FALSE;
GstControlBinding *binding;
g_return_val_if_fail (GST_IS_OBJECT (object), FALSE);
g_return_val_if_fail (property_name, FALSE);
g_return_val_if_fail (GST_CLOCK_TIME_IS_VALID (timestamp), FALSE);
g_return_val_if_fail (GST_CLOCK_TIME_IS_VALID (interval), FALSE);
g_return_val_if_fail (values, FALSE);
GST_OBJECT_LOCK (object);
if ((binding = gst_object_find_control_binding (object, property_name))) {
res = gst_control_binding_get_g_value_array (binding, timestamp, interval,
n_values, values);
}
GST_OBJECT_UNLOCK (object);
return res;
}
/**
* gst_object_get_control_rate:
* @object: the object that has controlled properties
*
* Obtain the control-rate for this @object. Audio processing #GstElement
* objects will use this rate to sub-divide their processing loop and call
* gst_object_sync_values() inbetween. The length of the processing segment
* should be up to @control-rate nanoseconds.
*
* If the @object is not under property control, this will return
* %GST_CLOCK_TIME_NONE. This allows the element to avoid the sub-dividing.
*
* The control-rate is not expected to change if the element is in
* %GST_STATE_PAUSED or %GST_STATE_PLAYING.
*
* Returns: the control rate in nanoseconds
*/
GstClockTime
gst_object_get_control_rate (GstObject * object)
{
g_return_val_if_fail (GST_IS_OBJECT (object), FALSE);
return object->control_rate;
}
/**
* gst_object_set_control_rate:
* @object: the object that has controlled properties
* @control_rate: the new control-rate in nanoseconds.
*
* Change the control-rate for this @object. Audio processing #GstElement
* objects will use this rate to sub-divide their processing loop and call
* gst_object_sync_values() inbetween. The length of the processing segment
* should be up to @control-rate nanoseconds.
*
* The control-rate should not change if the element is in %GST_STATE_PAUSED or
* %GST_STATE_PLAYING.
*/
void
gst_object_set_control_rate (GstObject * object, GstClockTime control_rate)
{
g_return_if_fail (GST_IS_OBJECT (object));
object->control_rate = control_rate;
}