gstreamer/gst/gstobject.c
Sebastian Dröge b8454d623d gstobject: Replace recursive gst_object_has_ancestor() with an iterative version
This is slightly more efficient because the compiler can't do tail
recursion here and has to keep all stack frames.

Not that efficiency is that important here but I already had
the iterative version somewhere else and both are easy to read.
2009-10-14 08:34:03 +02:00

1206 lines
34 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., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, 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
* #GObject. 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 function 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()).
*
* The most interesting difference between #GstObject and #GObject is the
* "floating" reference count. A #GObject is created with a reference count of
* 1, owned by the creator of the #GObject. (The owner of a reference is the
* code section that has the right to call gst_object_unref() in order to
* remove that reference.) A #GstObject is created with a reference count of 1
* also, but it isn't owned by anyone; Instead, the initial reference count
* of a #GstObject is "floating". The floating reference can be removed by
* anyone at any time, by calling gst_object_sink(). gst_object_sink() does
* nothing if an object is already sunk (has no floating reference).
*
* When you add a #GstElement to its parent container, the parent container will
* do this:
* <informalexample>
* <programlisting>
* gst_object_ref (GST_OBJECT (child_element));
* gst_object_sink (GST_OBJECT (child_element));
* </programlisting>
* </informalexample>
* This means that the container now owns a reference to the child element
* (since it called gst_object_ref()), and the child element has no floating
* reference.
*
* The purpose of the floating reference is to keep the child element alive
* until you add it to a parent container, which then manages the lifetime of
* the object itself:
* <informalexample>
* <programlisting>
* element = gst_element_factory_make (factoryname, name);
* // element has one floating reference to keep it alive
* gst_bin_add (GST_BIN (bin), element);
* // element has one non-floating reference owned by the container
* </programlisting>
* </informalexample>
*
* Another effect of this is, that calling gst_object_unref() on a bin object,
* will also destoy all the #GstElement objects in it. The same is true for
* calling gst_bin_remove().
*
* Special care has to be taken for all methods that gst_object_sink() an object
* since if the caller of those functions had a floating reference to the object,
* the object reference is now invalid.
*
* 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.
*
* Last reviewed on 2005-11-09 (0.9.4)
*/
#include "gst_private.h"
#include "gstobject.h"
#include "gstmarshal.h"
#include "gstinfo.h"
#include "gstutils.h"
#ifndef GST_DISABLE_TRACE
#include "gsttrace.h"
static GstAllocTrace *_gst_object_trace;
#endif
#define DEBUG_REFCOUNT
/* Object signals and args */
/* FIXME-0.11: have a read-only parent property instead of the two signals
* then we get notify::parent for free */
enum
{
PARENT_SET,
PARENT_UNSET,
#ifndef GST_DISABLE_LOADSAVE
OBJECT_SAVED,
#endif
DEEP_NOTIFY,
LAST_SIGNAL
};
enum
{
ARG_0,
ARG_NAME
/* FILL ME */
};
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);
typedef struct _GstSignalObject GstSignalObject;
typedef struct _GstSignalObjectClass GstSignalObjectClass;
static GType gst_signal_object_get_type (void);
static void gst_signal_object_class_init (GstSignalObjectClass * klass);
static void gst_signal_object_init (GstSignalObject * object);
#ifndef GST_DISABLE_LOADSAVE
static guint gst_signal_object_signals[SO_LAST_SIGNAL] = { 0 };
#endif
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);
#ifndef GST_DISABLE_LOADSAVE
static void gst_object_real_restore_thyself (GstObject * object,
xmlNodePtr self);
#endif
static GObjectClass *parent_class = NULL;
static guint gst_object_signals[LAST_SIGNAL] = { 0 };
G_DEFINE_ABSTRACT_TYPE (GstObject, gst_object, G_TYPE_OBJECT);
static void
gst_object_class_init (GstObjectClass * klass)
{
GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
parent_class = g_type_class_peek_parent (klass);
#ifndef GST_DISABLE_TRACE
_gst_object_trace = gst_alloc_trace_register (g_type_name (GST_TYPE_OBJECT));
#endif
gobject_class->set_property = GST_DEBUG_FUNCPTR (gst_object_set_property);
gobject_class->get_property = GST_DEBUG_FUNCPTR (gst_object_get_property);
g_object_class_install_property (gobject_class, ARG_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-set:
* @gstobject: a #GstObject
* @parent: the new parent
*
* Emitted when the parent of an object is set.
*/
gst_object_signals[PARENT_SET] =
g_signal_new ("parent-set", G_TYPE_FROM_CLASS (klass), G_SIGNAL_RUN_LAST,
G_STRUCT_OFFSET (GstObjectClass, parent_set), NULL, NULL,
g_cclosure_marshal_VOID__OBJECT, G_TYPE_NONE, 1, GST_TYPE_OBJECT);
/**
* GstObject::parent-unset:
* @gstobject: a #GstObject
* @parent: the old parent
*
* Emitted when the parent of an object is unset.
*/
gst_object_signals[PARENT_UNSET] =
g_signal_new ("parent-unset", G_TYPE_FROM_CLASS (klass),
G_SIGNAL_RUN_LAST, G_STRUCT_OFFSET (GstObjectClass, parent_unset), NULL,
NULL, g_cclosure_marshal_VOID__OBJECT, G_TYPE_NONE, 1, GST_TYPE_OBJECT);
#ifndef GST_DISABLE_LOADSAVE
/**
* GstObject::object-saved:
* @gstobject: a #GstObject
* @xml_node: the xmlNodePtr of the parent node
*
* Trigered whenever a new object is saved to XML. You can connect to this
* signal to insert custom XML tags into the core XML.
*/
/* FIXME This should be the GType of xmlNodePtr instead of G_TYPE_POINTER
* (if libxml would use GObject)
*/
gst_object_signals[OBJECT_SAVED] =
g_signal_new ("object-saved", G_TYPE_FROM_CLASS (klass),
G_SIGNAL_RUN_LAST, G_STRUCT_OFFSET (GstObjectClass, object_saved), NULL,
NULL, g_cclosure_marshal_VOID__POINTER, G_TYPE_NONE, 1, G_TYPE_POINTER);
klass->restore_thyself = gst_object_real_restore_thyself;
#endif
/**
* 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, gst_marshal_VOID__OBJECT_PARAM, G_TYPE_NONE, 2, GST_TYPE_OBJECT,
G_TYPE_PARAM);
klass->path_string_separator = "/";
klass->lock = g_new0 (GStaticRecMutex, 1);
g_static_rec_mutex_init (klass->lock);
klass->signal_object = g_object_new (gst_signal_object_get_type (), NULL);
/* 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)
{
object->lock = g_mutex_new ();
object->parent = NULL;
object->name = NULL;
GST_CAT_LOG_OBJECT (GST_CAT_REFCOUNTING, object, "%p new", object);
#ifndef GST_DISABLE_TRACE
gst_alloc_trace_new (_gst_object_trace, object);
#endif
object->flags = 0;
GST_OBJECT_FLAG_SET (object, GST_OBJECT_FLOATING);
}
/**
* gst_object_ref:
* @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: A pointer to @object
*/
gpointer
gst_object_ref (gpointer object)
{
g_return_val_if_fail (object != NULL, NULL);
#ifdef DEBUG_REFCOUNT
GST_CAT_LOG_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: 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_LOG_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:
* @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.
*
* MT safe. This function grabs and releases @object lock.
*
* Since: 0.10.24
*/
void
gst_object_ref_sink (gpointer object)
{
g_return_if_fail (GST_IS_OBJECT (object));
GST_OBJECT_LOCK (object);
if (G_LIKELY (GST_OBJECT_IS_FLOATING (object))) {
GST_CAT_LOG_OBJECT (GST_CAT_REFCOUNTING, object, "unsetting floating flag");
GST_OBJECT_FLAG_UNSET (object, GST_OBJECT_FLOATING);
GST_OBJECT_UNLOCK (object);
} else {
GST_OBJECT_UNLOCK (object);
gst_object_ref (object);
}
}
/**
* gst_object_sink:
* @object: a #GstObject to sink
*
* If @object was floating, the #GST_OBJECT_FLOATING flag is removed
* and @object is unreffed. When @object was not floating,
* this function does nothing.
*
* Any newly created object has a refcount of 1 and is floating.
* This function should be used when creating a new object to
* symbolically 'take ownership' of @object. This done by first doing a
* gst_object_ref() to keep a reference to @object and then gst_object_sink()
* to remove and unref any floating references to @object.
* Use gst_object_set_parent() to have this done for you.
*
* MT safe. This function grabs and releases @object lock.
*/
void
gst_object_sink (gpointer object)
{
g_return_if_fail (GST_IS_OBJECT (object));
GST_CAT_LOG_OBJECT (GST_CAT_REFCOUNTING, object, "sink");
GST_OBJECT_LOCK (object);
if (G_LIKELY (GST_OBJECT_IS_FLOATING (object))) {
GST_CAT_LOG_OBJECT (GST_CAT_REFCOUNTING, object, "clear floating flag");
GST_OBJECT_FLAG_UNSET (object, GST_OBJECT_FLOATING);
GST_OBJECT_UNLOCK (object);
gst_object_unref (object);
} else {
GST_OBJECT_UNLOCK (object);
}
}
/**
* gst_object_replace:
* @oldobj: pointer to a place of a #GstObject to replace
* @newobj: a new #GstObject
*
* Unrefs the #GstObject pointed to by @oldobj, refs @newobj and
* puts @newobj in *@oldobj. Be carefull when calling this
* function, it does not take any locks. You might want to lock
* the object owning @oldobj pointer before calling this
* function.
*
* Make sure not to LOCK @oldobj because it might be unreffed
* which could cause a deadlock when it is disposed.
*/
void
gst_object_replace (GstObject ** oldobj, GstObject * newobj)
{
g_return_if_fail (oldobj != NULL);
g_return_if_fail (*oldobj == NULL || GST_IS_OBJECT (*oldobj));
g_return_if_fail (newobj == NULL || GST_IS_OBJECT (newobj));
#ifdef DEBUG_REFCOUNT
GST_CAT_LOG (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
if (G_LIKELY (*oldobj != newobj)) {
if (newobj)
gst_object_ref (newobj);
if (*oldobj)
gst_object_unref (*oldobj);
*oldobj = newobj;
}
}
/* dispose is called when the object has to release all links
* to other objects */
static void
gst_object_dispose (GObject * object)
{
GstObject *parent;
GST_CAT_LOG_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);
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 (object);
GST_CAT_LOG_OBJECT (GST_CAT_REFCOUNTING, object, "finalize");
g_signal_handlers_destroy (object);
g_free (gstobject->name);
g_mutex_free (gstobject->lock);
#ifndef GST_DISABLE_TRACE
gst_alloc_trace_free (_gst_object_trace, object);
#endif
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.
*
* This function is not MT safe in glib < 2.8 so we need to lock it with a
* classwide mutex in that case.
*
* MT safe.
*/
static void
gst_object_dispatch_properties_changed (GObject * object,
guint n_pspecs, GParamSpec ** pspecs)
{
GstObject *gst_object, *parent, *old_parent;
guint i;
gchar *name, *debug_name;
/* do the standard dispatching */
parent_class->dispatch_properties_changed (object, n_pspecs, pspecs);
gst_object = GST_OBJECT_CAST (object);
name = gst_object_get_name (gst_object);
debug_name = GST_STR_NULL (name);
/* 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);
}
g_free (name);
}
/**
* 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: 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, G_PARAM_SPEC_VALUE_TYPE (pspec));
g_object_get_property (G_OBJECT (orig), pspec->name, &value);
/* FIXME: handle flags */
if (G_IS_PARAM_SPEC_ENUM (pspec)) {
GEnumValue *enum_value;
GEnumClass *klass = G_ENUM_CLASS (g_type_class_ref (pspec->value_type));
enum_value = g_enum_get_value (klass, g_value_get_enum (&value));
str = g_strdup_printf ("%s (%d)", enum_value->value_nick,
enum_value->value);
g_type_class_unref (klass);
} else {
str = g_strdup_value_contents (&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, *tmp;
gboolean result;
GQuark q;
/* 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 -> foosinkN */
type_name = g_quark_to_string (q);
if (strncmp (type_name, "Gst", 3) == 0)
type_name += 3;
tmp = g_strdup_printf ("%s%d", type_name, count);
name = g_ascii_strdown (tmp, -1);
g_free (tmp);
result = gst_object_set_name (object, name);
g_free (name);
return result;
}
/**
* 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);
}
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.
*
* Returns: 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_name_prefix:
* @object: a #GstObject
* @name_prefix: new name prefix of @object
*
* Sets the name prefix of @object to @name_prefix.
* This function makes a copy of the provided name prefix, so the caller
* retains ownership of the name prefix it sent.
*
* MT safe. This function grabs and releases @object's LOCK.
*/
void
gst_object_set_name_prefix (GstObject * object, const gchar * name_prefix)
{
g_return_if_fail (GST_IS_OBJECT (object));
GST_OBJECT_LOCK (object);
g_free (object->name_prefix);
object->name_prefix = g_strdup (name_prefix); /* NULL gives NULL */
GST_OBJECT_UNLOCK (object);
}
/**
* gst_object_get_name_prefix:
* @object: a #GstObject
*
* Returns a copy of the name prefix of @object.
* Caller should g_free() the return value after usage.
* For a prefixless object, this returns NULL, which you can safely g_free()
* as well.
*
* Returns: the name prefix of @object. g_free() after usage.
*
* MT safe. This function grabs and releases @object's LOCK.
*/
gchar *
gst_object_get_name_prefix (GstObject * object)
{
gchar *result = NULL;
g_return_val_if_fail (GST_IS_OBJECT (object), NULL);
GST_OBJECT_LOCK (object);
result = g_strdup (object->name_prefix);
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_sink()).
*
* This function causes the parent-set signal to be emitted when the parent
* was successfully set.
*
* 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;
/* sink object, we don't call our own function because we don't
* need to release/acquire the lock needlessly or touch the refcount
* in the floating case. */
object->parent = parent;
if (G_LIKELY (GST_OBJECT_IS_FLOATING (object))) {
GST_CAT_LOG_OBJECT (GST_CAT_REFCOUNTING, object, "unsetting floating flag");
GST_OBJECT_FLAG_UNSET (object, GST_OBJECT_FLOATING);
GST_OBJECT_UNLOCK (object);
} else {
GST_OBJECT_UNLOCK (object);
gst_object_ref (object);
}
g_signal_emit (object, gst_object_signals[PARENT_SET], 0, 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: 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_LOG_OBJECT (GST_CAT_REFCOUNTING, object, "unparent");
object->parent = NULL;
GST_OBJECT_UNLOCK (object);
g_signal_emit (object, gst_object_signals[PARENT_UNSET], 0, 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.
*
* 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: 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
* carefull 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 (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;
}
#ifndef GST_DISABLE_LOADSAVE
/**
* gst_object_save_thyself:
* @object: a #GstObject to save
* @parent: The parent XML node to save @object into
*
* Saves @object into the parent XML node.
*
* Returns: the new xmlNodePtr with the saved object
*/
xmlNodePtr
gst_object_save_thyself (GstObject * object, xmlNodePtr parent)
{
GstObjectClass *oclass;
g_return_val_if_fail (GST_IS_OBJECT (object), parent);
g_return_val_if_fail (parent != NULL, parent);
oclass = GST_OBJECT_GET_CLASS (object);
if (oclass->save_thyself)
oclass->save_thyself (object, parent);
g_signal_emit (object, gst_object_signals[OBJECT_SAVED], 0, parent);
return parent;
}
/**
* gst_object_restore_thyself:
* @object: a #GstObject to load into
* @self: The XML node to load @object from
*
* Restores @object with the data from the parent XML node.
*/
void
gst_object_restore_thyself (GstObject * object, xmlNodePtr self)
{
GstObjectClass *oclass;
g_return_if_fail (GST_IS_OBJECT (object));
g_return_if_fail (self != NULL);
oclass = GST_OBJECT_GET_CLASS (object);
if (oclass->restore_thyself)
oclass->restore_thyself (object, self);
}
static void
gst_object_real_restore_thyself (GstObject * object, xmlNodePtr self)
{
g_return_if_fail (GST_IS_OBJECT (object));
g_return_if_fail (self != NULL);
gst_class_signal_emit_by_name (object, "object_loaded", self);
}
#endif /* GST_DISABLE_LOADSAVE */
static void
gst_object_set_property (GObject * object, guint prop_id,
const GValue * value, GParamSpec * pspec)
{
GstObject *gstobject;
gstobject = GST_OBJECT (object);
switch (prop_id) {
case ARG_NAME:
gst_object_set_name (gstobject, g_value_get_string (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 (object);
switch (prop_id) {
case ARG_NAME:
g_value_take_string (value, gst_object_get_name (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.
*
* Returns: 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;
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 carefull 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;
}
struct _GstSignalObject
{
GObject object;
};
struct _GstSignalObjectClass
{
GObjectClass parent_class;
/* signals */
#ifndef GST_DISABLE_LOADSAVE
void (*object_loaded) (GstSignalObject * object, GstObject * new,
xmlNodePtr self);
#endif
};
G_DEFINE_TYPE (GstSignalObject, gst_signal_object, G_TYPE_OBJECT);
static void
gst_signal_object_class_init (GstSignalObjectClass * klass)
{
parent_class = g_type_class_peek_parent (klass);
#ifndef GST_DISABLE_LOADSAVE
gst_signal_object_signals[SO_OBJECT_LOADED] =
g_signal_new ("object-loaded", G_TYPE_FROM_CLASS (klass),
G_SIGNAL_RUN_LAST, G_STRUCT_OFFSET (GstSignalObjectClass, object_loaded),
NULL, NULL, gst_marshal_VOID__OBJECT_POINTER, G_TYPE_NONE, 2,
G_TYPE_OBJECT, G_TYPE_POINTER);
#endif
}
static void
gst_signal_object_init (GstSignalObject * object)
{
}
/**
* gst_class_signal_connect
* @klass: a #GstObjectClass to attach the signal to
* @name: the name of the signal to attach to
* @func: the signal function
* @func_data: a pointer to user data
*
* Connect to a class signal.
*
* Returns: the signal id.
*/
guint
gst_class_signal_connect (GstObjectClass * klass,
const gchar * name, gpointer func, gpointer func_data)
{
/* [0.11] func parameter needs to be changed to a GCallback *
* doing so now would be an API break. */
return g_signal_connect (klass->signal_object, name, G_CALLBACK (func),
func_data);
}
#ifndef GST_DISABLE_LOADSAVE
/**
* gst_class_signal_emit_by_name:
* @object: a #GstObject that emits the signal
* @name: the name of the signal to emit
* @self: data for the signal
*
* emits the named class signal.
*/
void
gst_class_signal_emit_by_name (GstObject * object,
const gchar * name, xmlNodePtr self)
{
GstObjectClass *oclass;
oclass = GST_OBJECT_GET_CLASS (object);
g_signal_emit_by_name (oclass->signal_object, name, object, self);
}
#endif /* GST_DISABLE_LOADSAVE */