gstreamer/gst/gstbin.c
Andy Wingo c5e2202f20 gst/base/gstbasetransform.c: Debug changes.
Original commit message from CVS:
2005-08-17  Andy Wingo  <wingo@pobox.com>

* gst/base/gstbasetransform.c: Debug changes.

* gst/gstutils.h:
* gst/gstutils.c (gst_bin_watch_for_state_change): Add function to
ensure bins post state change messages. A bit of a hack but I can't
think of a way to avoid it.

* check/gst/gstbin.c (test_watch_for_state_change): Added test.
2005-08-17 16:33:27 +00:00

1743 lines
48 KiB
C

/* GStreamer
*
* Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
* 2004 Wim Taymans <wim@fluendo.com>
*
* gstbin.c: GstBin container object and support code
*
* 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.
*
* MT safe.
*/
#include "gst_private.h"
#include "gstevent.h"
#include "gstbin.h"
#include "gstmarshal.h"
#include "gstxml.h"
#include "gstinfo.h"
#include "gsterror.h"
#include "gstindex.h"
#include "gstutils.h"
GST_DEBUG_CATEGORY_STATIC (bin_debug);
#define GST_CAT_DEFAULT bin_debug
#define GST_LOG_BIN_CONTENTS(bin, text) GST_LOG_OBJECT ((bin), \
text ": %d elements: %u PLAYING, %u PAUSED, %u READY, %u NULL, own state: %s", \
(bin)->numchildren, (guint) (bin)->child_states[3], \
(guint) (bin)->child_states[2], (bin)->child_states[1], \
(bin)->child_states[0], gst_element_state_get_name (GST_STATE (bin)))
static GstElementDetails gst_bin_details = GST_ELEMENT_DETAILS ("Generic bin",
"Generic/Bin",
"Simple container object",
"Erik Walthinsen <omega@cse.ogi.edu>," "Wim Taymans <wim@fluendo.com>");
GType _gst_bin_type = 0;
static void gst_bin_dispose (GObject * object);
static GstElementStateReturn gst_bin_change_state (GstElement * element);
static GstElementStateReturn gst_bin_get_state (GstElement * element,
GstElementState * state, GstElementState * pending, GTimeVal * timeout);
static gboolean gst_bin_add_func (GstBin * bin, GstElement * element);
static gboolean gst_bin_remove_func (GstBin * bin, GstElement * element);
#ifndef GST_DISABLE_INDEX
static void gst_bin_set_index_func (GstElement * element, GstIndex * index);
#endif
static GstClock *gst_bin_get_clock_func (GstElement * element);
static void gst_bin_set_clock_func (GstElement * element, GstClock * clock);
static gboolean gst_bin_send_event (GstElement * element, GstEvent * event);
static GstBusSyncReply bin_bus_handler (GstBus * bus,
GstMessage * message, GstBin * bin);
static gboolean gst_bin_query (GstElement * element, GstQuery * query);
#ifndef GST_DISABLE_LOADSAVE
static xmlNodePtr gst_bin_save_thyself (GstObject * object, xmlNodePtr parent);
static void gst_bin_restore_thyself (GstObject * object, xmlNodePtr self);
#endif
static gint bin_element_is_sink (GstElement * child, GstBin * bin);
/* Bin signals and args */
enum
{
ELEMENT_ADDED,
ELEMENT_REMOVED,
LAST_SIGNAL
};
enum
{
ARG_0
/* FILL ME */
};
static void gst_bin_base_init (gpointer g_class);
static void gst_bin_class_init (GstBinClass * klass);
static void gst_bin_init (GstBin * bin);
static GstElementClass *parent_class = NULL;
static guint gst_bin_signals[LAST_SIGNAL] = { 0 };
/**
* gst_bin_get_type:
*
* Returns: the type of #GstBin
*/
GType
gst_bin_get_type (void)
{
if (!_gst_bin_type) {
static const GTypeInfo bin_info = {
sizeof (GstBinClass),
gst_bin_base_init,
NULL,
(GClassInitFunc) gst_bin_class_init,
NULL,
NULL,
sizeof (GstBin),
0,
(GInstanceInitFunc) gst_bin_init,
NULL
};
_gst_bin_type =
g_type_register_static (GST_TYPE_ELEMENT, "GstBin", &bin_info, 0);
GST_DEBUG_CATEGORY_INIT (bin_debug, "bin", GST_DEBUG_BOLD,
"debugging info for the 'bin' container element");
}
return _gst_bin_type;
}
static void
gst_bin_base_init (gpointer g_class)
{
GstElementClass *gstelement_class = GST_ELEMENT_CLASS (g_class);
gst_element_class_set_details (gstelement_class, &gst_bin_details);
}
static void
gst_bin_class_init (GstBinClass * klass)
{
GObjectClass *gobject_class;
GstObjectClass *gstobject_class;
GstElementClass *gstelement_class;
gobject_class = (GObjectClass *) klass;
gstobject_class = (GstObjectClass *) klass;
gstelement_class = (GstElementClass *) klass;
parent_class = g_type_class_ref (GST_TYPE_ELEMENT);
gst_bin_signals[ELEMENT_ADDED] =
g_signal_new ("element-added", G_TYPE_FROM_CLASS (klass),
G_SIGNAL_RUN_FIRST, G_STRUCT_OFFSET (GstBinClass, element_added), NULL,
NULL, gst_marshal_VOID__OBJECT, G_TYPE_NONE, 1, GST_TYPE_ELEMENT);
gst_bin_signals[ELEMENT_REMOVED] =
g_signal_new ("element-removed", G_TYPE_FROM_CLASS (klass),
G_SIGNAL_RUN_FIRST, G_STRUCT_OFFSET (GstBinClass, element_removed), NULL,
NULL, gst_marshal_VOID__OBJECT, G_TYPE_NONE, 1, GST_TYPE_ELEMENT);
gobject_class->dispose = GST_DEBUG_FUNCPTR (gst_bin_dispose);
#ifndef GST_DISABLE_LOADSAVE
gstobject_class->save_thyself = GST_DEBUG_FUNCPTR (gst_bin_save_thyself);
gstobject_class->restore_thyself =
GST_DEBUG_FUNCPTR (gst_bin_restore_thyself);
#endif
gstelement_class->change_state = GST_DEBUG_FUNCPTR (gst_bin_change_state);
gstelement_class->get_state = GST_DEBUG_FUNCPTR (gst_bin_get_state);
#ifndef GST_DISABLE_INDEX
gstelement_class->set_index = GST_DEBUG_FUNCPTR (gst_bin_set_index_func);
#endif
gstelement_class->get_clock = GST_DEBUG_FUNCPTR (gst_bin_get_clock_func);
gstelement_class->set_clock = GST_DEBUG_FUNCPTR (gst_bin_set_clock_func);
gstelement_class->send_event = GST_DEBUG_FUNCPTR (gst_bin_send_event);
gstelement_class->query = GST_DEBUG_FUNCPTR (gst_bin_query);
klass->add_element = GST_DEBUG_FUNCPTR (gst_bin_add_func);
klass->remove_element = GST_DEBUG_FUNCPTR (gst_bin_remove_func);
}
static void
gst_bin_init (GstBin * bin)
{
GstBus *bus;
bin->numchildren = 0;
bin->children = NULL;
bin->children_cookie = 0;
bin->eosed = NULL;
/* Set up a bus for listening to child elements,
* and one for sending messages up the hierarchy */
bus = g_object_new (gst_bus_get_type (), NULL);
bin->child_bus = bus;
gst_bus_set_sync_handler (bus, (GstBusSyncHandler) bin_bus_handler, bin);
bus = g_object_new (gst_bus_get_type (), NULL);
gst_element_set_bus (GST_ELEMENT (bin), bus);
/* set_bus refs the bus via gst_object_replace, we drop our ref */
gst_object_unref (bus);
}
/**
* gst_bin_new:
* @name: name of new bin
*
* Create a new bin with given name.
*
* Returns: new bin
*/
GstElement *
gst_bin_new (const gchar * name)
{
return gst_element_factory_make ("bin", name);
}
/* set the index on all elements in this bin
*
* MT safe
*/
#ifndef GST_DISABLE_INDEX
static void
gst_bin_set_index_func (GstElement * element, GstIndex * index)
{
GstBin *bin;
GList *children;
bin = GST_BIN (element);
GST_LOCK (bin);
for (children = bin->children; children; children = g_list_next (children)) {
GstElement *child = GST_ELEMENT (children->data);
gst_element_set_index (child, index);
}
GST_UNLOCK (bin);
}
#endif
/* set the clock on all elements in this bin
*
* MT safe
*/
static void
gst_bin_set_clock_func (GstElement * element, GstClock * clock)
{
GList *children;
GstBin *bin;
bin = GST_BIN (element);
GST_LOCK (bin);
for (children = bin->children; children; children = g_list_next (children)) {
GstElement *child = GST_ELEMENT (children->data);
gst_element_set_clock (child, clock);
}
GST_UNLOCK (bin);
}
/* get the clock for this bin by asking all of the children in this bin
*
* MT safe
*/
static GstClock *
gst_bin_get_clock_func (GstElement * element)
{
GstClock *result = NULL;
GstBin *bin;
GList *children;
bin = GST_BIN (element);
GST_LOCK (bin);
for (children = bin->children; children; children = g_list_next (children)) {
GstElement *child = GST_ELEMENT (children->data);
result = gst_element_get_clock (child);
if (result)
break;
}
GST_UNLOCK (bin);
return result;
}
static gboolean
is_eos (GstBin * bin)
{
GstIterator *sinks;
gboolean result = TRUE;
gboolean done = FALSE;
sinks = gst_bin_iterate_sinks (bin);
while (!done) {
gpointer data;
switch (gst_iterator_next (sinks, &data)) {
case GST_ITERATOR_OK:
{
GstElement *element = GST_ELEMENT (data);
GList *eosed;
gchar *name;
name = gst_element_get_name (element);
eosed = g_list_find (bin->eosed, element);
if (!eosed) {
GST_DEBUG ("element %s did not post EOS yet", name);
result = FALSE;
done = TRUE;
} else {
GST_DEBUG ("element %s posted EOS", name);
}
g_free (name);
gst_object_unref (element);
break;
}
case GST_ITERATOR_RESYNC:
result = TRUE;
gst_iterator_resync (sinks);
break;
case GST_ITERATOR_DONE:
done = TRUE;
break;
default:
g_assert_not_reached ();
break;
}
}
gst_iterator_free (sinks);
return result;
}
static void
unlink_pads (GstPad * pad)
{
GstPad *peer;
if ((peer = gst_pad_get_peer (pad))) {
if (gst_pad_get_direction (pad) == GST_PAD_SRC)
gst_pad_unlink (pad, peer);
else
gst_pad_unlink (peer, pad);
gst_object_unref (peer);
}
gst_object_unref (pad);
}
/* add an element to this bin
*
* MT safe
*/
static gboolean
gst_bin_add_func (GstBin * bin, GstElement * element)
{
gchar *elem_name;
GstIterator *it;
/* we obviously can't add ourself to ourself */
if (G_UNLIKELY (GST_ELEMENT_CAST (element) == GST_ELEMENT_CAST (bin)))
goto adding_itself;
/* get the element name to make sure it is unique in this bin. */
GST_LOCK (element);
elem_name = g_strdup (GST_ELEMENT_NAME (element));
GST_UNLOCK (element);
GST_LOCK (bin);
/* then check to see if the element's name is already taken in the bin,
* we can safely take the lock here. This check is probably bogus because
* you can safely change the element name after this check and before setting
* the object parent. The window is very small though... */
if (G_UNLIKELY (!gst_object_check_uniqueness (bin->children, elem_name)))
goto duplicate_name;
/* set the element's parent and add the element to the bin's list of children */
if (G_UNLIKELY (!gst_object_set_parent (GST_OBJECT_CAST (element),
GST_OBJECT_CAST (bin))))
goto had_parent;
/* if we add a sink we become a sink */
if (GST_FLAG_IS_SET (element, GST_ELEMENT_IS_SINK))
GST_FLAG_SET (bin, GST_ELEMENT_IS_SINK);
bin->children = g_list_prepend (bin->children, element);
bin->numchildren++;
bin->children_cookie++;
/* distribute the bus */
gst_element_set_bus (element, bin->child_bus);
/* propagate the current base time and clock */
gst_element_set_base_time (element, GST_ELEMENT (bin)->base_time);
gst_element_set_clock (element, GST_ELEMENT_CLOCK (bin));
GST_UNLOCK (bin);
/* unlink all linked pads */
it = gst_element_iterate_pads (element);
gst_iterator_foreach (it, (GFunc) unlink_pads, element);
gst_iterator_free (it);
GST_CAT_DEBUG_OBJECT (GST_CAT_PARENTAGE, bin, "added element \"%s\"",
elem_name);
g_free (elem_name);
g_signal_emit (G_OBJECT (bin), gst_bin_signals[ELEMENT_ADDED], 0, element);
return TRUE;
/* ERROR handling here */
adding_itself:
{
GST_LOCK (bin);
g_warning ("Cannot add bin %s to itself", GST_ELEMENT_NAME (bin));
GST_UNLOCK (bin);
return FALSE;
}
duplicate_name:
{
g_warning ("Name %s is not unique in bin %s, not adding",
elem_name, GST_ELEMENT_NAME (bin));
GST_UNLOCK (bin);
g_free (elem_name);
return FALSE;
}
had_parent:
{
g_warning ("Element %s already has parent", elem_name);
GST_UNLOCK (bin);
g_free (elem_name);
return FALSE;
}
}
/**
* gst_bin_add:
* @bin: #GstBin to add element to
* @element: #GstElement to add to bin
*
* Adds the given element to the bin. Sets the element's parent, and thus
* takes ownership of the element. An element can only be added to one bin.
*
* If the element's pads are linked to other pads, the pads will be unlinked
* before the element is added to the bin.
*
* MT safe.
*
* Returns: TRUE if the element could be added, FALSE on wrong parameters or
* the bin does not want to accept the element.
*/
gboolean
gst_bin_add (GstBin * bin, GstElement * element)
{
GstBinClass *bclass;
gboolean result;
g_return_val_if_fail (GST_IS_BIN (bin), FALSE);
g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
bclass = GST_BIN_GET_CLASS (bin);
if (G_UNLIKELY (bclass->add_element == NULL))
goto no_function;
GST_CAT_DEBUG (GST_CAT_PARENTAGE, "adding element %s to bin %s",
GST_ELEMENT_NAME (element), GST_ELEMENT_NAME (bin));
result = bclass->add_element (bin, element);
return result;
/* ERROR handling */
no_function:
{
g_warning ("adding elements to bin %s is not supported",
GST_ELEMENT_NAME (bin));
return FALSE;
}
}
/* remove an element from the bin
*
* MT safe
*/
static gboolean
gst_bin_remove_func (GstBin * bin, GstElement * element)
{
gchar *elem_name;
GstIterator *it;
/* grab element name so we can print it */
GST_LOCK (element);
elem_name = g_strdup (GST_ELEMENT_NAME (element));
GST_UNLOCK (element);
GST_LOCK (bin);
/* the element must be in the bin's list of children */
if (G_UNLIKELY (g_list_find (bin->children, element) == NULL))
goto not_in_bin;
/* now remove the element from the list of elements */
bin->children = g_list_remove (bin->children, element);
bin->numchildren--;
bin->children_cookie++;
/* check if we removed a sink */
if (GST_FLAG_IS_SET (element, GST_ELEMENT_IS_SINK)) {
GList *other_sink;
/* check if we removed the last sink */
other_sink = g_list_find_custom (bin->children,
bin, (GCompareFunc) bin_element_is_sink);
if (!other_sink) {
/* yups, we're not a sink anymore */
GST_FLAG_UNSET (bin, GST_ELEMENT_IS_SINK);
}
}
GST_UNLOCK (bin);
GST_CAT_INFO_OBJECT (GST_CAT_PARENTAGE, bin, "removed child \"%s\"",
elem_name);
g_free (elem_name);
/* unlink all linked pads */
it = gst_element_iterate_pads (element);
gst_iterator_foreach (it, (GFunc) unlink_pads, element);
gst_iterator_free (it);
gst_element_set_bus (element, NULL);
/* unlock any waiters for the state change. It is possible that
* we are waiting for an ASYNC state change on this element. The
* element cannot be added to another bin yet as it is not yet
* unparented. */
GST_STATE_LOCK (element);
GST_STATE_BROADCAST (element);
GST_STATE_UNLOCK (element);
/* we ref here because after the _unparent() the element can be disposed
* and we still need it to fire a signal. */
gst_object_ref (element);
gst_object_unparent (GST_OBJECT_CAST (element));
g_signal_emit (G_OBJECT (bin), gst_bin_signals[ELEMENT_REMOVED], 0, element);
/* element is really out of our control now */
gst_object_unref (element);
return TRUE;
/* ERROR handling */
not_in_bin:
{
g_warning ("Element %s is not in bin %s", elem_name,
GST_ELEMENT_NAME (bin));
GST_UNLOCK (bin);
g_free (elem_name);
return FALSE;
}
}
/**
* gst_bin_remove:
* @bin: #GstBin to remove element from
* @element: #GstElement to remove
*
* Remove the element from its associated bin, unparenting it as well.
* Unparenting the element means that the element will be dereferenced,
* so if the bin holds the only reference to the element, the element
* will be freed in the process of removing it from the bin. If you
* want the element to still exist after removing, you need to call
* #gst_object_ref before removing it from the bin.
*
* If the element's pads are linked to other pads, the pads will be unlinked
* before the element is removed from the bin.
*
* MT safe.
*
* Returns: TRUE if the element could be removed, FALSE on wrong parameters or
* the bin does not want to remove the element.
*/
gboolean
gst_bin_remove (GstBin * bin, GstElement * element)
{
GstBinClass *bclass;
gboolean result;
g_return_val_if_fail (GST_IS_BIN (bin), FALSE);
g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
bclass = GST_BIN_GET_CLASS (bin);
if (G_UNLIKELY (bclass->remove_element == NULL))
goto no_function;
GST_CAT_DEBUG (GST_CAT_PARENTAGE, "removing element %s from bin %s",
GST_ELEMENT_NAME (element), GST_ELEMENT_NAME (bin));
result = bclass->remove_element (bin, element);
return result;
/* ERROR handling */
no_function:
{
g_warning ("removing elements from bin %s is not supported",
GST_ELEMENT_NAME (bin));
return FALSE;
}
}
static GstIteratorItem
iterate_child (GstIterator * it, GstElement * child)
{
gst_object_ref (child);
return GST_ITERATOR_ITEM_PASS;
}
/**
* gst_bin_iterate_elements:
* @bin: #Gstbin to iterate the elements of
*
* Get an iterator for the elements in this bin.
* Each element will have its refcount increased, so unref
* after use.
*
* MT safe.
*
* Returns: a #GstIterator of #GstElements. gst_iterator_free after
* use. returns NULL when passing bad parameters.
*/
GstIterator *
gst_bin_iterate_elements (GstBin * bin)
{
GstIterator *result;
g_return_val_if_fail (GST_IS_BIN (bin), NULL);
GST_LOCK (bin);
/* add ref because the iterator refs the bin. When the iterator
* is freed it will unref the bin again using the provided dispose
* function. */
gst_object_ref (bin);
result = gst_iterator_new_list (GST_GET_LOCK (bin),
&bin->children_cookie,
&bin->children,
bin,
(GstIteratorItemFunction) iterate_child,
(GstIteratorDisposeFunction) gst_object_unref);
GST_UNLOCK (bin);
return result;
}
static GstIteratorItem
iterate_child_recurse (GstIterator * it, GstElement * child)
{
gst_object_ref (child);
if (GST_IS_BIN (child)) {
GstIterator *other = gst_bin_iterate_recurse (GST_BIN (child));
gst_iterator_push (it, other);
}
return GST_ITERATOR_ITEM_PASS;
}
/**
* gst_bin_iterate_recurse:
* @bin: #Gstbin to iterate the elements of
*
* Get an iterator for the elements in this bin.
* Each element will have its refcount increased, so unref
* after use. This iterator recurses into GstBin children.
*
* MT safe.
*
* Returns: a #GstIterator of #GstElements. gst_iterator_free after
* use. returns NULL when passing bad parameters.
*/
GstIterator *
gst_bin_iterate_recurse (GstBin * bin)
{
GstIterator *result;
g_return_val_if_fail (GST_IS_BIN (bin), NULL);
GST_LOCK (bin);
/* add ref because the iterator refs the bin. When the iterator
* is freed it will unref the bin again using the provided dispose
* function. */
gst_object_ref (bin);
result = gst_iterator_new_list (GST_GET_LOCK (bin),
&bin->children_cookie,
&bin->children,
bin,
(GstIteratorItemFunction) iterate_child_recurse,
(GstIteratorDisposeFunction) gst_object_unref);
GST_UNLOCK (bin);
return result;
}
/* returns 0 when TRUE because this is a GCompareFunc */
/* MT safe */
static gint
bin_element_is_sink (GstElement * child, GstBin * bin)
{
gboolean is_sink;
/* we lock the child here for the remainder of the function to
* get its name safely. */
GST_LOCK (child);
is_sink = GST_FLAG_IS_SET (child, GST_ELEMENT_IS_SINK);
GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin,
"child %s %s sink", GST_OBJECT_NAME (child), is_sink ? "is" : "is not");
GST_UNLOCK (child);
return is_sink ? 0 : 1;
}
/* check if object has the given ancestor somewhere up in
* the hierarchy
*/
static gboolean
has_ancestor (GstObject * object, GstObject * ancestor)
{
GstObject *parent;
gboolean result = FALSE;
if (object == NULL)
return FALSE;
if (object == ancestor)
return TRUE;
parent = gst_object_get_parent (object);
result = has_ancestor (parent, ancestor);
if (parent)
gst_object_unref (parent);
return result;
}
/* returns 0 when TRUE because this is a GCompareFunc.
* This function returns elements that have no connected srcpads and
* are therefore not reachable from a real sink. */
/* MT safe */
static gint
bin_element_is_semi_sink (GstElement * child, GstBin * bin)
{
int ret = 1;
/* we lock the child here for the remainder of the function to
* get its pads and name safely. */
GST_LOCK (child);
/* check if this is a sink element, these are the elements
* without (linked) source pads. */
if (child->numsrcpads == 0) {
/* shortcut */
GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin,
"adding child %s as sink", GST_OBJECT_NAME (child));
ret = 0;
} else {
/* loop over all pads, try to figure out if this element
* is a semi sink because it has no linked source pads */
GList *pads;
gboolean connected_src = FALSE;
for (pads = child->srcpads; pads; pads = g_list_next (pads)) {
GstPad *peer;
if ((peer = gst_pad_get_peer (GST_PAD_CAST (pads->data)))) {
connected_src =
has_ancestor (GST_OBJECT_CAST (peer), GST_OBJECT_CAST (bin));
gst_object_unref (peer);
if (connected_src) {
break;
}
}
}
if (connected_src) {
GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin,
"not adding child %s as sink: linked source pads",
GST_OBJECT_NAME (child));
} else {
GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin,
"adding child %s as sink since it has unlinked source pads in this bin",
GST_OBJECT_NAME (child));
ret = 0;
}
}
GST_UNLOCK (child);
return ret;
}
static gint
sink_iterator_filter (GstElement * child, GstBin * bin)
{
if (bin_element_is_sink (child, bin) == 0) {
/* returns 0 because this is a GCompareFunc */
return 0;
} else {
/* child carries a ref from gst_bin_iterate_elements -- drop if not passing
through */
gst_object_unref ((GstObject *) child);
return 1;
}
}
/**
* gst_bin_iterate_sinks:
* @bin: #Gstbin to iterate on
*
* Get an iterator for the sink elements in this bin.
* Each element will have its refcount increased, so unref
* after use.
*
* The sink elements are those without any linked srcpads.
*
* MT safe.
*
* Returns: a #GstIterator of #GstElements. gst_iterator_free after use.
*/
GstIterator *
gst_bin_iterate_sinks (GstBin * bin)
{
GstIterator *children;
GstIterator *result;
g_return_val_if_fail (GST_IS_BIN (bin), NULL);
children = gst_bin_iterate_elements (bin);
result = gst_iterator_filter (children,
(GCompareFunc) sink_iterator_filter, bin);
return result;
}
/* 2 phases:
* 1) check state of all children with 0 timeout to find ERROR and
* NO_PREROLL elements. return if found.
* 2) perform full blocking wait with requested timeout.
*
* 2) cannot be performed when 1) returns results as the sinks might
* not be able to complete the state change making 2) block forever.
*
* MT safe
*/
static GstElementStateReturn
gst_bin_get_state (GstElement * element, GstElementState * state,
GstElementState * pending, GTimeVal * timeout)
{
GstBin *bin = GST_BIN (element);
GstElementStateReturn ret = GST_STATE_SUCCESS;
GList *children;
guint32 children_cookie;
gboolean have_no_preroll;
GST_CAT_INFO_OBJECT (GST_CAT_STATES, element, "getting state");
/* lock bin, no element can be added or removed between going into
* the quick scan and the blocking wait. */
GST_LOCK (bin);
restart:
have_no_preroll = FALSE;
/* first we need to poll with a non zero timeout to make sure we don't block
* on the sinks when we have NO_PREROLL elements. This is why we do
* a quick check if there are still NO_PREROLL elements. We also
* catch the error elements this way. */
{
GTimeVal tv;
gboolean have_async = FALSE;
GST_CAT_INFO_OBJECT (GST_CAT_STATES, element, "checking for NO_PREROLL");
/* use 0 timeout so we don't block on the sinks */
GST_TIME_TO_TIMEVAL (0, tv);
children = bin->children;
children_cookie = bin->children_cookie;
while (children) {
GstElement *child = GST_ELEMENT_CAST (children->data);
gst_object_ref (child);
/* now we release the lock to enter a non blocking wait. We
* release the lock anyway since we can. */
GST_UNLOCK (bin);
ret = gst_element_get_state (child, NULL, NULL, &tv);
gst_object_unref (child);
/* now grab the lock to iterate to the next child */
GST_LOCK (bin);
if (G_UNLIKELY (children_cookie != bin->children_cookie)) {
/* child added/removed during state change, restart. We need
* to restart with the quick check as a no-preroll element could
* have been added here and we don't want to block on sinks then.*/
goto restart;
}
switch (ret) {
/* report FAILURE immediatly */
case GST_STATE_FAILURE:
goto done;
case GST_STATE_NO_PREROLL:
/* we have to continue scanning as there might be
* ERRORS too */
have_no_preroll = TRUE;
break;
case GST_STATE_ASYNC:
have_async = TRUE;
break;
default:
break;
}
children = g_list_next (children);
}
/* if we get here, we have no FAILURES, check for any NO_PREROLL
* elements then. */
if (have_no_preroll) {
ret = GST_STATE_NO_PREROLL;
goto done;
}
/* if we get here, no NO_PREROLL elements are in the pipeline */
GST_CAT_INFO_OBJECT (GST_CAT_STATES, element, "no NO_PREROLL elements");
/* if no ASYNC elements exist we don't even have to poll with a
* timeout again */
if (!have_async) {
ret = GST_STATE_SUCCESS;
goto done;
}
}
/* next we poll all children for their state to see if one of them
* is still busy with its state change. We did not release the bin lock
* yet so the elements are the same as the ones from the quick scan. */
children = bin->children;
children_cookie = bin->children_cookie;
while (children) {
GstElement *child = GST_ELEMENT_CAST (children->data);
gst_object_ref (child);
/* now we release the lock to enter the potentialy blocking wait */
GST_UNLOCK (bin);
/* ret is ASYNC if some child is still performing the state change
* ater the timeout. */
ret = gst_element_get_state (child, NULL, NULL, timeout);
gst_object_unref (child);
/* now grab the lock to iterate to the next child */
GST_LOCK (bin);
if (G_UNLIKELY (children_cookie != bin->children_cookie)) {
/* child added/removed during state change, restart. We need
* to restart with the quick check as a no-preroll element could
* have been added here and we don't want to block on sinks then.*/
goto restart;
}
switch (ret) {
case GST_STATE_SUCCESS:
break;
case GST_STATE_FAILURE:
case GST_STATE_NO_PREROLL:
/* report FAILURE and NO_PREROLL immediatly */
goto done;
case GST_STATE_ASYNC:
goto done;
default:
g_assert_not_reached ();
}
children = g_list_next (children);
}
/* if we got here, all elements can do preroll */
have_no_preroll = FALSE;
done:
GST_UNLOCK (bin);
/* now we can take the state lock, it is possible that new elements
* are added now and we still report the old state. No problem though as
* the return is still consistent, the effect is as if the element was
* added after this function completed. */
GST_STATE_LOCK (bin);
switch (ret) {
case GST_STATE_SUCCESS:
/* we can commit the state */
gst_element_commit_state (element);
break;
case GST_STATE_FAILURE:
/* some element failed, abort the state change */
gst_element_abort_state (element);
break;
default:
/* other cases are just passed along */
break;
}
/* and report the state if needed */
if (state)
*state = GST_STATE (element);
if (pending)
*pending = GST_STATE_PENDING (element);
GST_STATE_NO_PREROLL (element) = have_no_preroll;
GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
"state current: %s, pending: %s, error: %d, no_preroll: %d, result: %d",
gst_element_state_get_name (GST_STATE (element)),
gst_element_state_get_name (GST_STATE_PENDING (element)),
GST_STATE_ERROR (element), GST_STATE_NO_PREROLL (element), ret);
GST_STATE_UNLOCK (bin);
return ret;
}
static void
append_child (gpointer child, GQueue * queue)
{
g_queue_push_tail (queue, child);
}
/**
* gst_bin_iterate_state_order:
* @bin: #Gstbin to iterate on
*
* Get an iterator for the elements in this bin in the order
* in which a state change should be performed on them. This
* means that first the sinks and then the other elements will
* be returned.
* Each element will have its refcount increased, so unref
* after use.
*
* Not implemented yet.
*
* MT safe.
*
* Returns: a #GstIterator of #GstElements. gst_iterator_free after use.
*/
GstIterator *
gst_bin_iterate_state_order (GstBin * bin)
{
GstIterator *result;
g_return_val_if_fail (GST_IS_BIN (bin), NULL);
result = NULL;
return result;
}
static void
clear_queue (GQueue * queue, gboolean unref)
{
gpointer p;
while ((p = g_queue_pop_head (queue)))
if (unref)
gst_object_unref (p);
}
static void
remove_all_from_queue (GQueue * queue, gpointer elem, gboolean unref)
{
gpointer p;
while ((p = g_queue_find (queue, elem))) {
if (unref)
gst_object_unref (elem);
g_queue_delete_link (queue, p);
}
}
/* this function is called with the STATE_LOCK held. It works
* as follows:
*
* 1) put all sink elements on the queue.
* 2) put all semisink elements on the queue.
* 3) change state of elements in queue, put linked elements to queue.
* 4) while queue not empty goto 3)
*
* This will effectively change the state of all elements in the bin
* from the sinks to the sources. We have to change the states this
* way so that when a source element pushes data, the downstream element
* is in the right state to receive the data.
*
* MT safe.
*/
/* FIXME, make me more elegant, want to use a topological sort algorithm
* based on indegrees (or outdegrees in our case) */
static GstElementStateReturn
gst_bin_change_state (GstElement * element)
{
GstBin *bin;
GstElementStateReturn ret;
GstElementState old_state, pending;
gboolean have_async = FALSE;
gboolean have_no_preroll = FALSE;
GList *children;
guint32 children_cookie;
GQueue *elem_queue; /* list of elements waiting for a state change */
GQueue *semi_queue; /* list of elements with no connected srcpads */
GQueue *temp; /* queue of leftovers */
GstClockTime base_time;
bin = GST_BIN (element);
/* we don't need to take the STATE_LOCK, it is already taken */
old_state = GST_STATE (element);
pending = GST_STATE_PENDING (element);
GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element,
"changing state of children from %s to %s",
gst_element_state_get_name (old_state),
gst_element_state_get_name (pending));
if (pending == GST_STATE_VOID_PENDING)
return GST_STATE_SUCCESS;
/* Clear eosed element list on READY-> PAUSED */
if (GST_STATE_TRANSITION (element) == GST_STATE_READY_TO_PAUSED) {
g_list_free (bin->eosed);
bin->eosed = NULL;
}
/* all elements added to these queues should have their refcount
* incremented */
elem_queue = g_queue_new ();
semi_queue = g_queue_new ();
temp = g_queue_new ();
/* first step, find all sink elements, these are the elements
* without (linked) source pads. */
GST_LOCK (bin);
restart:
/* take base time */
base_time = element->base_time;
/* make sure queues are empty, they could be filled when
* restarting. */
clear_queue (elem_queue, TRUE);
clear_queue (semi_queue, TRUE);
clear_queue (temp, TRUE);
children = bin->children;
children_cookie = bin->children_cookie;
while (children) {
GstElement *child = GST_ELEMENT_CAST (children->data);
gst_object_ref (child);
GST_UNLOCK (bin);
if (bin_element_is_sink (child, bin) == 0) {
g_queue_push_tail (elem_queue, child);
} else if (bin_element_is_semi_sink (child, bin) == 0) {
g_queue_push_tail (semi_queue, child);
} else {
g_queue_push_tail (temp, child);
}
GST_LOCK (bin);
if (G_UNLIKELY (children_cookie != bin->children_cookie)) {
GST_INFO_OBJECT (bin, "bin->children_cookie changed, restarting");
/* restart will unref the children in the queues so that we don't
* leak refcounts. */
goto restart;
}
children = g_list_next (children);
}
GST_UNLOCK (bin);
/* after this point new elements can be added/removed from the
* bin. We operate on the snapshot taken above. Applications
* should serialize their add/remove and set_state. */
/* now change state for semi sink elements first so add them in
* front of the other elements */
g_queue_foreach (temp, (GFunc) append_child, semi_queue);
clear_queue (temp, FALSE);
/* if we don't have real sinks, we continue with the other elements */
if (g_queue_is_empty (elem_queue) && !g_queue_is_empty (semi_queue)) {
GQueue *q = elem_queue;
/* we swap the queues as oposed to copy them over */
elem_queue = semi_queue;
semi_queue = q;
}
/* second step, change state of elements in the queue */
while (!g_queue_is_empty (elem_queue)) {
GstElement *qelement;
GList *pads;
gboolean locked;
/* take element */
qelement = g_queue_pop_head (elem_queue);
/* we don't need any duplicates in the other queue anymore */
remove_all_from_queue (semi_queue, qelement, TRUE);
/* queue all elements connected to the sinkpads of this element */
GST_LOCK (qelement);
pads = qelement->sinkpads;
while (pads) {
GstPad *pad = GST_PAD_CAST (pads->data);
GstPad *peer;
GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element,
"found sinkpad %s:%s", GST_DEBUG_PAD_NAME (pad));
peer = gst_pad_get_peer (pad);
if (peer) {
GstObject *peer_parent;
/* get parent */
peer_parent = gst_object_get_parent (GST_OBJECT (peer));
/* if we have an element parent, follow it */
if (peer_parent && GST_IS_ELEMENT (peer_parent)) {
GstObject *parent;
/* see if this element is in the bin we are currently handling */
parent = gst_object_get_parent (peer_parent);
if (parent) {
if (parent == GST_OBJECT_CAST (bin)) {
GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element,
"adding element %s to queue", GST_ELEMENT_NAME (peer_parent));
/* make sure we don't have duplicates */
remove_all_from_queue (semi_queue, peer_parent, TRUE);
remove_all_from_queue (elem_queue, peer_parent, TRUE);
/* was reffed before pushing on the queue by the
* gst_object_get_parent() call we used to get the element. */
g_queue_push_tail (elem_queue, peer_parent);
/* so that we don't unref it */
peer_parent = NULL;
} else {
GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element,
"not adding element %s to queue, it is in another bin",
GST_ELEMENT_NAME (peer_parent));
}
gst_object_unref (parent);
}
}
if (peer_parent)
gst_object_unref (peer_parent);
gst_object_unref (peer);
} else {
GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element,
"pad %s:%s does not have a peer", GST_DEBUG_PAD_NAME (pad));
}
pads = g_list_next (pads);
}
/* peel off the locked flag and release the element lock */
locked = GST_FLAG_IS_SET (qelement, GST_ELEMENT_LOCKED_STATE);
GST_UNLOCK (qelement);
/* skip locked elements */
if (G_UNLIKELY (locked))
goto next_element;
/* set base time on element */
gst_element_set_base_time (qelement, base_time);
/* then change state */
ret = gst_element_set_state (qelement, pending);
/* the set state could have cause elements to be added/removed,
* we support that. */
GST_LOCK (bin);
if (G_UNLIKELY (children_cookie != bin->children_cookie)) {
gst_object_unref (qelement);
goto restart;
}
GST_UNLOCK (bin);
switch (ret) {
case GST_STATE_SUCCESS:
GST_CAT_DEBUG (GST_CAT_STATES,
"child '%s' changed state to %d(%s) successfully",
GST_ELEMENT_NAME (qelement), pending,
gst_element_state_get_name (pending));
break;
case GST_STATE_ASYNC:
GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
"child '%s' is changing state asynchronously",
GST_ELEMENT_NAME (qelement));
have_async = TRUE;
break;
case GST_STATE_FAILURE:
GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
"child '%s' failed to go to state %d(%s)",
GST_ELEMENT_NAME (qelement),
pending, gst_element_state_get_name (pending));
ret = GST_STATE_FAILURE;
/* release refcount of element we popped off the queue */
gst_object_unref (qelement);
goto exit;
case GST_STATE_NO_PREROLL:
GST_CAT_DEBUG (GST_CAT_STATES,
"child '%s' changed state to %d(%s) successfully without preroll",
GST_ELEMENT_NAME (qelement), pending,
gst_element_state_get_name (pending));
have_no_preroll = TRUE;
break;
default:
g_assert_not_reached ();
break;
}
next_element:
gst_object_unref (qelement);
/* if queue is empty now, continue with a non-sink */
if (g_queue_is_empty (elem_queue)) {
GstElement *non_sink;
GST_DEBUG ("sinks and upstream elements exhausted");
non_sink = g_queue_pop_head (semi_queue);
if (non_sink) {
GST_DEBUG ("found lefover non-sink %s", GST_OBJECT_NAME (non_sink));
g_queue_push_tail (elem_queue, non_sink);
}
}
}
if (have_no_preroll) {
ret = GST_STATE_NO_PREROLL;
} else if (have_async) {
ret = GST_STATE_ASYNC;
} else {
ret = parent_class->change_state (element);
}
GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element,
"done changing bin's state from %s to %s, now in %s, ret %d",
gst_element_state_get_name (old_state),
gst_element_state_get_name (pending),
gst_element_state_get_name (GST_STATE (element)), ret);
exit:
/* release refcounts in queue, should normally be empty unless we
* had an error. */
clear_queue (elem_queue, TRUE);
clear_queue (semi_queue, TRUE);
g_queue_free (elem_queue);
g_queue_free (semi_queue);
g_queue_free (temp);
return ret;
}
static void
gst_bin_dispose (GObject * object)
{
GstBin *bin = GST_BIN (object);
GST_CAT_DEBUG_OBJECT (GST_CAT_REFCOUNTING, object, "dispose");
/* ref to not hit 0 again */
gst_object_ref (object);
g_list_free (bin->eosed);
bin->eosed = NULL;
gst_object_unref (bin->child_bus);
bin->child_bus = NULL;
gst_element_set_bus (GST_ELEMENT (bin), NULL);
while (bin->children) {
gst_bin_remove (bin, GST_ELEMENT (bin->children->data));
}
GST_CAT_DEBUG_OBJECT (GST_CAT_REFCOUNTING, object, "dispose no children");
g_assert (bin->children == NULL);
g_assert (bin->numchildren == 0);
G_OBJECT_CLASS (parent_class)->dispose (object);
}
/*
* This function is a utility event handler for seek events.
* It will send the event to all sinks.
* Applications are free to override this behaviour and
* implement their own seek handler, but this will work for
* pretty much all cases in practice.
*/
static gboolean
gst_bin_send_event (GstElement * element, GstEvent * event)
{
GstBin *bin = GST_BIN (element);
GstIterator *iter;
gboolean res = TRUE;
gboolean done = FALSE;
iter = gst_bin_iterate_sinks (bin);
GST_DEBUG_OBJECT (bin, "Sending event to sink children");
while (!done) {
gpointer data;
switch (gst_iterator_next (iter, &data)) {
case GST_ITERATOR_OK:
{
GstElement *sink;
gst_event_ref (event);
sink = GST_ELEMENT_CAST (data);
res &= gst_element_send_event (sink, event);
gst_object_unref (sink);
break;
}
case GST_ITERATOR_RESYNC:
gst_iterator_resync (iter);
res = TRUE;
break;
default:
case GST_ITERATOR_DONE:
done = TRUE;
break;
}
}
gst_iterator_free (iter);
gst_event_unref (event);
return res;
}
static GstBusSyncReply
bin_bus_handler (GstBus * bus, GstMessage * message, GstBin * bin)
{
GST_DEBUG_OBJECT (bin, "[msg %p] handling child message of type %d",
message, GST_MESSAGE_TYPE (message));
switch (GST_MESSAGE_TYPE (message)) {
case GST_MESSAGE_EOS:{
gchar *name = gst_object_get_name (GST_MESSAGE_SRC (message));
GST_DEBUG_OBJECT (bin, "got EOS message from %s", name);
g_free (name);
/* collect all eos messages from the children */
GST_LOCK (bin->child_bus);
bin->eosed = g_list_prepend (bin->eosed, GST_MESSAGE_SRC (message));
GST_UNLOCK (bin->child_bus);
/* if we are completely EOS, we forward an EOS message */
if (is_eos (bin)) {
GST_DEBUG_OBJECT (bin, "all sinks posted EOS");
gst_element_post_message (GST_ELEMENT (bin),
gst_message_new_eos (GST_OBJECT (bin)));
}
/* we drop all EOS messages */
gst_message_unref (message);
break;
}
default:
/* Send all other messages upward */
GST_DEBUG_OBJECT (bin, "posting message upward");
gst_element_post_message (GST_ELEMENT (bin), message);
break;
}
return GST_BUS_DROP;
}
static gboolean
gst_bin_query (GstElement * element, GstQuery * query)
{
GstBin *bin = GST_BIN (element);
GstIterator *iter;
gboolean res = FALSE, done = FALSE;
iter = gst_bin_iterate_sinks (bin);
GST_DEBUG_OBJECT (bin, "Sending event to sink children");
while (!(res || done)) {
gpointer data;
switch (gst_iterator_next (iter, &data)) {
case GST_ITERATOR_OK:
{
GstElement *sink;
sink = GST_ELEMENT_CAST (data);
res = gst_element_query (sink, query);
gst_object_unref (sink);
break;
}
case GST_ITERATOR_RESYNC:
gst_iterator_resync (iter);
break;
default:
case GST_ITERATOR_DONE:
done = TRUE;
break;
}
}
gst_iterator_free (iter);
return res;
}
static gint
compare_name (GstElement * element, const gchar * name)
{
gint eq;
GST_LOCK (element);
eq = strcmp (GST_ELEMENT_NAME (element), name);
GST_UNLOCK (element);
if (eq != 0) {
gst_object_unref (element);
}
return eq;
}
/**
* gst_bin_get_by_name:
* @bin: #Gstbin to search
* @name: the element name to search for
*
* Get the element with the given name from this bin. This
* function recurses into subbins.
*
* MT safe.
*
* Returns: the element with the given name. Returns NULL if the
* element is not found or when bad parameters were given. Unref after
* use.
*/
GstElement *
gst_bin_get_by_name (GstBin * bin, const gchar * name)
{
GstIterator *children;
GstIterator *result;
g_return_val_if_fail (GST_IS_BIN (bin), NULL);
GST_CAT_INFO (GST_CAT_PARENTAGE, "[%s]: looking up child element %s",
GST_ELEMENT_NAME (bin), name);
children = gst_bin_iterate_recurse (bin);
result = gst_iterator_find_custom (children,
(GCompareFunc) compare_name, (gpointer) name);
gst_iterator_free (children);
return GST_ELEMENT_CAST (result);
}
/**
* gst_bin_get_by_name_recurse_up:
* @bin: #Gstbin to search
* @name: the element name to search for
*
* MT safe.
*
* Get the element with the given name from this bin. If the
* element is not found, a recursion is performed on the parent bin.
*
* Returns: the element with the given name or NULL when the element
* was not found or bad parameters were given. Unref after use.
*/
GstElement *
gst_bin_get_by_name_recurse_up (GstBin * bin, const gchar * name)
{
GstElement *result;
g_return_val_if_fail (GST_IS_BIN (bin), NULL);
g_return_val_if_fail (name != NULL, NULL);
result = gst_bin_get_by_name (bin, name);
if (!result) {
GstObject *parent;
parent = gst_object_get_parent (GST_OBJECT_CAST (bin));
if (parent) {
if (GST_IS_BIN (parent)) {
result = gst_bin_get_by_name_recurse_up (GST_BIN_CAST (parent), name);
}
gst_object_unref (parent);
}
}
return result;
}
static gint
compare_interface (GstElement * element, gpointer interface)
{
gint ret;
if (G_TYPE_CHECK_INSTANCE_TYPE (element, GPOINTER_TO_INT (interface))) {
ret = 0;
} else {
/* we did not find the element, need to release the ref
* added by the iterator */
gst_object_unref (element);
ret = 1;
}
return ret;
}
/**
* gst_bin_get_by_interface:
* @bin: bin to find element in
* @interface: interface to be implemented by interface
*
* Looks for the first element inside the bin that implements the given
* interface. If such an element is found, it returns the element. You can
* cast this element to the given interface afterwards.
* If you want all elements that implement the interface, use
* gst_bin_iterate_all_by_interface(). The function recurses inside bins.
*
* MT safe.
*
* Returns: An #GstElement inside the bin implementing the interface.
* Unref after use.
*/
GstElement *
gst_bin_get_by_interface (GstBin * bin, GType interface)
{
GstIterator *children;
GstIterator *result;
g_return_val_if_fail (GST_IS_BIN (bin), NULL);
children = gst_bin_iterate_recurse (bin);
result = gst_iterator_find_custom (children, (GCompareFunc) compare_interface,
GINT_TO_POINTER (interface));
gst_iterator_free (children);
return GST_ELEMENT_CAST (result);
}
/**
* gst_bin_get_all_by_interface:
* @bin: bin to find elements in
* @interface: interface to be implemented by interface
*
* Looks for all elements inside the bin that implements the given
* interface. You can safely cast all returned elements to the given interface.
* The function recurses bins inside bins. The iterator will return a series
* of #GstElement that should be unreffed after use.
*
* MT safe.
*
* Returns: A #GstIterator for the elements inside the bin implementing the
* given interface.
*/
GstIterator *
gst_bin_iterate_all_by_interface (GstBin * bin, GType interface)
{
GstIterator *children;
GstIterator *result;
g_return_val_if_fail (GST_IS_BIN (bin), NULL);
children = gst_bin_iterate_recurse (bin);
result = gst_iterator_filter (children, (GCompareFunc) compare_interface,
GINT_TO_POINTER (interface));
return result;
}
#ifndef GST_DISABLE_LOADSAVE
static xmlNodePtr
gst_bin_save_thyself (GstObject * object, xmlNodePtr parent)
{
GstBin *bin = GST_BIN (object);
xmlNodePtr childlist, elementnode;
GList *children;
GstElement *child;
if (GST_OBJECT_CLASS (parent_class)->save_thyself)
GST_OBJECT_CLASS (parent_class)->save_thyself (GST_OBJECT (bin), parent);
childlist = xmlNewChild (parent, NULL, (xmlChar *) "children", NULL);
GST_CAT_INFO (GST_CAT_XML, "[%s]: saving %d children",
GST_ELEMENT_NAME (bin), bin->numchildren);
children = bin->children;
while (children) {
child = GST_ELEMENT (children->data);
elementnode = xmlNewChild (childlist, NULL, (xmlChar *) "element", NULL);
gst_object_save_thyself (GST_OBJECT (child), elementnode);
children = g_list_next (children);
}
return childlist;
}
static void
gst_bin_restore_thyself (GstObject * object, xmlNodePtr self)
{
GstBin *bin = GST_BIN (object);
xmlNodePtr field = self->xmlChildrenNode;
xmlNodePtr childlist;
while (field) {
if (!strcmp ((char *) field->name, "children")) {
GST_CAT_INFO (GST_CAT_XML, "[%s]: loading children",
GST_ELEMENT_NAME (object));
childlist = field->xmlChildrenNode;
while (childlist) {
if (!strcmp ((char *) childlist->name, "element")) {
GstElement *element =
gst_xml_make_element (childlist, GST_OBJECT (bin));
/* it had to be parented to find the pads, now we ref and unparent so
* we can add it to the bin */
gst_object_ref (element);
gst_object_unparent (GST_OBJECT (element));
gst_bin_add (bin, element);
}
childlist = childlist->next;
}
}
field = field->next;
}
if (GST_OBJECT_CLASS (parent_class)->restore_thyself)
(GST_OBJECT_CLASS (parent_class)->restore_thyself) (object, self);
}
#endif /* GST_DISABLE_LOADSAVE */