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GST-Tensordecoder-ov_ep/subprojects/gstreamer/gst/gstbin.c
Sebastian Dröge 79c4275ed4 bin: Don't check twice for adding a bin to itself or removing it from itself 
This is already covered by a `g_return_val_if_fail()` in the calling
function.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/1320>
2021-11-08 20:31:44 +00:00

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/* GStreamer
*
* Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
* 2004 Wim Taymans <wim.taymans@gmail.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., 51 Franklin St, Fifth Floor,
* Boston, MA 02110-1301, USA.
*/
/**
* SECTION:gstbin
* @title: GstBin
* @short_description: Base class and element that can contain other elements
*
* #GstBin is an element that can contain other #GstElement, allowing them to be
* managed as a group.
* Pads from the child elements can be ghosted to the bin, see #GstGhostPad.
* This makes the bin look like any other elements and enables creation of
* higher-level abstraction elements.
*
* A new #GstBin is created with gst_bin_new(). Use a #GstPipeline instead if you
* want to create a toplevel bin because a normal bin doesn't have a bus or
* handle clock distribution of its own.
*
* After the bin has been created you will typically add elements to it with
* gst_bin_add(). You can remove elements with gst_bin_remove().
*
* An element can be retrieved from a bin with gst_bin_get_by_name(), using the
* elements name. gst_bin_get_by_name_recurse_up() is mainly used for internal
* purposes and will query the parent bins when the element is not found in the
* current bin.
*
* An iterator of elements in a bin can be retrieved with
* gst_bin_iterate_elements(). Various other iterators exist to retrieve the
* elements in a bin.
*
* gst_object_unref() is used to drop your reference to the bin.
*
* The #GstBin::element-added signal is fired whenever a new element is added to
* the bin. Likewise the #GstBin::element-removed signal is fired whenever an
* element is removed from the bin.
*
* A #GstBin internally intercepts every #GstMessage posted by its children and
* implements the following default behaviour for each of them:
*
* * %GST_MESSAGE_EOS: This message is only posted by sinks in the PLAYING
* state. If all sinks posted the EOS message, this bin will post and EOS
* message upwards.
*
* * %GST_MESSAGE_SEGMENT_START: Just collected and never forwarded upwards.
* The messages are used to decide when all elements have completed playback
* of their segment.
*
* * %GST_MESSAGE_SEGMENT_DONE: Is posted by #GstBin when all elements that posted
* a SEGMENT_START have posted a SEGMENT_DONE.
*
* * %GST_MESSAGE_DURATION_CHANGED: Is posted by an element that detected a change
* in the stream duration. The duration change is posted to the
* application so that it can refetch the new duration with a duration
* query.
*
* Note that these messages can be posted before the bin is prerolled, in which
* case the duration query might fail.
*
* Note also that there might be a discrepancy (due to internal buffering/queueing)
* between the stream being currently displayed and the returned duration query.
*
* Applications might want to also query for duration (and changes) by
* listening to the %GST_MESSAGE_STREAM_START message, signaling the active start
* of a (new) stream.
*
* * %GST_MESSAGE_CLOCK_LOST: This message is posted by an element when it
* can no longer provide a clock.
*
* The default bin behaviour is to check if the lost clock was the one provided
* by the bin. If so and the bin is currently in the PLAYING state, the message
* is forwarded to the bin parent.
*
* This message is also generated when a clock provider is removed from
* the bin. If this message is received by the application, it should
* PAUSE the pipeline and set it back to PLAYING to force a new clock
* distribution.
*
* * %GST_MESSAGE_CLOCK_PROVIDE: This message is generated when an element
* can provide a clock. This mostly happens when a new clock
* provider is added to the bin.
*
* The default behaviour of the bin is to mark the currently selected clock as
* dirty, which will perform a clock recalculation the next time the bin is
* asked to provide a clock.
*
* This message is never sent to the application but is forwarded to
* the parent of the bin.
*
* * OTHERS: posted upwards.
*
* A #GstBin implements the following default behaviour for answering to a
* #GstQuery:
*
* * %GST_QUERY_DURATION: The bin will forward the query to all sink
* elements contained within and will return the maximum value.
* If no sinks are available in the bin, the query fails.
*
* * %GST_QUERY_POSITION: The query is sent to all sink elements in the bin and the
* MAXIMUM of all values is returned. If no sinks are available in the bin,
* the query fails.
*
* * OTHERS: the query is forwarded to all sink elements, the result
* of the first sink that answers the query successfully is returned. If no
* sink is in the bin, the query fails.
*
* A #GstBin will by default forward any event sent to it to all sink
* ( %GST_EVENT_TYPE_DOWNSTREAM ) or source ( %GST_EVENT_TYPE_UPSTREAM ) elements
* depending on the event type.
*
* If all the elements return %TRUE, the bin will also return %TRUE, else %FALSE
* is returned. If no elements of the required type are in the bin, the event
* handler will return %TRUE.
*/
#include "gst_private.h"
#include "gstevent.h"
#include "gstbin.h"
#include "gstinfo.h"
#include "gsterror.h"
#include "gstutils.h"
#include "gstchildproxy.h"
GST_DEBUG_CATEGORY_STATIC (bin_debug);
#define GST_CAT_DEFAULT bin_debug
/* a bin is toplevel if it has no parent or when it is configured to behave like
* a toplevel bin */
#define BIN_IS_TOPLEVEL(bin) ((GST_OBJECT_PARENT (bin) == NULL) || bin->priv->asynchandling)
struct _GstBinPrivate
{
gboolean asynchandling;
/* if we get an ASYNC_DONE message from ourselves, this means that the
* subclass will simulate ASYNC behaviour without having ASYNC children. When
* such an ASYNC_DONE message is posted while we are doing a state change, we
* have to process the message after finishing the state change even when no
* child returned GST_STATE_CHANGE_ASYNC. */
gboolean pending_async_done;
guint32 structure_cookie;
#if 0
/* cached index */
GstIndex *index;
#endif
/* forward messages from our children */
gboolean message_forward;
gboolean posted_eos;
gboolean posted_playing;
GstElementFlags suppressed_flags;
};
typedef struct
{
guint32 cookie;
GstState pending;
} BinContinueData;
static void gst_bin_dispose (GObject * object);
static void gst_bin_set_property (GObject * object, guint prop_id,
const GValue * value, GParamSpec * pspec);
static void gst_bin_get_property (GObject * object, guint prop_id,
GValue * value, GParamSpec * pspec);
static GstStateChangeReturn gst_bin_change_state_func (GstElement * element,
GstStateChange transition);
static gboolean gst_bin_post_message (GstElement * element, GstMessage * msg);
static GstStateChangeReturn gst_bin_get_state_func (GstElement * element,
GstState * state, GstState * pending, GstClockTime timeout);
static void bin_handle_async_done (GstBin * bin, GstStateChangeReturn ret,
gboolean flag_pending, GstClockTime running_time);
static void bin_handle_async_start (GstBin * bin);
static void bin_push_state_continue (GstBin * bin, BinContinueData * data);
static void bin_do_eos (GstBin * bin);
static gboolean gst_bin_add_func (GstBin * bin, GstElement * element);
static gboolean gst_bin_remove_func (GstBin * bin, GstElement * element);
static void gst_bin_deep_element_added_func (GstBin * bin, GstBin * sub_bin,
GstElement * element);
static void gst_bin_deep_element_removed_func (GstBin * bin, GstBin * sub_bin,
GstElement * element);
static void gst_bin_update_context (GstBin * bin, GstContext * context);
static void gst_bin_update_context_unlocked (GstBin * bin,
GstContext * context);
#if 0
static void gst_bin_set_index_func (GstElement * element, GstIndex * index);
static GstIndex *gst_bin_get_index_func (GstElement * element);
#endif
static GstClock *gst_bin_provide_clock_func (GstElement * element);
static gboolean gst_bin_set_clock_func (GstElement * element, GstClock * clock);
static void gst_bin_handle_message_func (GstBin * bin, GstMessage * message);
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);
static void gst_bin_set_context (GstElement * element, GstContext * context);
static gboolean gst_bin_do_latency_func (GstBin * bin);
static void bin_remove_messages (GstBin * bin, GstObject * src,
GstMessageType types);
static void gst_bin_continue_func (GstBin * bin, BinContinueData * data);
static gint bin_element_is_sink (GstElement * child, GstBin * bin);
static gint bin_element_is_src (GstElement * child, GstBin * bin);
static GstIterator *gst_bin_sort_iterator_new (GstBin * bin);
/* Bin signals and properties */
enum
{
ELEMENT_ADDED,
ELEMENT_REMOVED,
DO_LATENCY,
DEEP_ELEMENT_ADDED,
DEEP_ELEMENT_REMOVED,
LAST_SIGNAL
};
#define DEFAULT_ASYNC_HANDLING FALSE
#define DEFAULT_MESSAGE_FORWARD FALSE
enum
{
PROP_0,
PROP_ASYNC_HANDLING,
PROP_MESSAGE_FORWARD,
PROP_LAST
};
static void gst_bin_child_proxy_init (gpointer g_iface, gpointer iface_data);
static guint gst_bin_signals[LAST_SIGNAL] = { 0 };
#define _do_init \
{ \
static const GInterfaceInfo iface_info = { \
gst_bin_child_proxy_init, \
NULL, \
NULL}; \
\
g_type_add_interface_static (g_define_type_id, GST_TYPE_CHILD_PROXY, &iface_info); \
\
GST_DEBUG_CATEGORY_INIT (bin_debug, "bin", GST_DEBUG_BOLD, \
"debugging info for the 'bin' container element"); \
\
}
#define gst_bin_parent_class parent_class
G_DEFINE_TYPE_WITH_CODE (GstBin, gst_bin, GST_TYPE_ELEMENT,
G_ADD_PRIVATE (GstBin)
_do_init);
static GObject *
gst_bin_child_proxy_get_child_by_index (GstChildProxy * child_proxy,
guint index)
{
GstObject *res;
GstBin *bin;
bin = GST_BIN_CAST (child_proxy);
GST_OBJECT_LOCK (bin);
if ((res = g_list_nth_data (bin->children, index)))
gst_object_ref (res);
GST_OBJECT_UNLOCK (bin);
return (GObject *) res;
}
static guint
gst_bin_child_proxy_get_children_count (GstChildProxy * child_proxy)
{
guint num;
GstBin *bin;
bin = GST_BIN_CAST (child_proxy);
GST_OBJECT_LOCK (bin);
num = bin->numchildren;
GST_OBJECT_UNLOCK (bin);
return num;
}
static void
gst_bin_child_proxy_init (gpointer g_iface, gpointer iface_data)
{
GstChildProxyInterface *iface = g_iface;
iface->get_children_count = gst_bin_child_proxy_get_children_count;
iface->get_child_by_index = gst_bin_child_proxy_get_child_by_index;
}
static gboolean
_gst_boolean_accumulator (GSignalInvocationHint * ihint,
GValue * return_accu, const GValue * handler_return, gpointer dummy)
{
gboolean myboolean;
myboolean = g_value_get_boolean (handler_return);
g_value_set_boolean (return_accu, myboolean);
GST_DEBUG ("invocation %d, %d", ihint->run_type, myboolean);
/* stop emission */
return FALSE;
}
static void
gst_bin_class_init (GstBinClass * klass)
{
GObjectClass *gobject_class;
GstElementClass *gstelement_class;
gobject_class = (GObjectClass *) klass;
gstelement_class = (GstElementClass *) klass;
gobject_class->set_property = gst_bin_set_property;
gobject_class->get_property = gst_bin_get_property;
/**
* GstBin:async-handling:
*
* If set to %TRUE, the bin will handle asynchronous state changes.
* This should be used only if the bin subclass is modifying the state
* of its children on its own.
*/
g_object_class_install_property (gobject_class, PROP_ASYNC_HANDLING,
g_param_spec_boolean ("async-handling", "Async Handling",
"The bin will handle Asynchronous state changes",
DEFAULT_ASYNC_HANDLING, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
/**
* GstBin::element-added:
* @self: the #GstBin
* @element: the #GstElement that was added to the bin
*
* Will be emitted after the element was added to the bin.
*/
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, NULL, G_TYPE_NONE, 1, GST_TYPE_ELEMENT);
/**
* GstBin::element-removed:
* @self: the #GstBin
* @element: the #GstElement that was removed from the bin
*
* Will be emitted after the element was removed from the bin.
*/
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, NULL, G_TYPE_NONE, 1, GST_TYPE_ELEMENT);
/**
* GstBin::deep-element-added:
* @self: the #GstBin
* @sub_bin: the #GstBin the element was added to
* @element: the #GstElement that was added to @sub_bin
*
* Will be emitted after the element was added to @sub_bin.
*
* Since: 1.10
*/
gst_bin_signals[DEEP_ELEMENT_ADDED] =
g_signal_new ("deep-element-added", G_TYPE_FROM_CLASS (klass),
G_SIGNAL_RUN_FIRST, G_STRUCT_OFFSET (GstBinClass, deep_element_added),
NULL, NULL, NULL, G_TYPE_NONE, 2, GST_TYPE_BIN, GST_TYPE_ELEMENT);
/**
* GstBin::deep-element-removed:
* @self: the #GstBin
* @sub_bin: the #GstBin the element was removed from
* @element: the #GstElement that was removed from @sub_bin
*
* Will be emitted after the element was removed from @sub_bin.
*
* Since: 1.10
*/
gst_bin_signals[DEEP_ELEMENT_REMOVED] =
g_signal_new ("deep-element-removed", G_TYPE_FROM_CLASS (klass),
G_SIGNAL_RUN_FIRST, G_STRUCT_OFFSET (GstBinClass, deep_element_removed),
NULL, NULL, NULL, G_TYPE_NONE, 2, GST_TYPE_BIN, GST_TYPE_ELEMENT);
/**
* GstBin::do-latency:
* @self: the #GstBin
*
* Will be emitted when the bin needs to perform latency calculations. This
* signal is only emitted for toplevel bins or when #GstBin:async-handling is
* enabled.
*
* Only one signal handler is invoked. If no signals are connected, the
* default handler is invoked, which will query and distribute the lowest
* possible latency to all sinks.
*
* Connect to this signal if the default latency calculations are not
* sufficient, like when you need different latencies for different sinks in
* the same pipeline.
*/
gst_bin_signals[DO_LATENCY] =
g_signal_new ("do-latency", G_TYPE_FROM_CLASS (klass),
G_SIGNAL_RUN_LAST, G_STRUCT_OFFSET (GstBinClass, do_latency),
_gst_boolean_accumulator, NULL, NULL, G_TYPE_BOOLEAN, 0, G_TYPE_NONE);
/**
* GstBin:message-forward:
*
* Forward all children messages, even those that would normally be filtered by
* the bin. This can be interesting when one wants to be notified of the EOS
* state of individual elements, for example.
*
* The messages are converted to an ELEMENT message with the bin as the
* source. The structure of the message is named `GstBinForwarded` and contains
* a field named `message` that contains the original forwarded #GstMessage.
*/
g_object_class_install_property (gobject_class, PROP_MESSAGE_FORWARD,
g_param_spec_boolean ("message-forward", "Message Forward",
"Forwards all children messages",
DEFAULT_MESSAGE_FORWARD, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
gobject_class->dispose = gst_bin_dispose;
gst_element_class_set_static_metadata (gstelement_class, "Generic bin",
"Generic/Bin",
"Simple container object",
"Erik Walthinsen <omega@cse.ogi.edu>,"
"Wim Taymans <wim.taymans@gmail.com>");
gstelement_class->change_state =
GST_DEBUG_FUNCPTR (gst_bin_change_state_func);
gstelement_class->post_message = GST_DEBUG_FUNCPTR (gst_bin_post_message);
gstelement_class->get_state = GST_DEBUG_FUNCPTR (gst_bin_get_state_func);
#if 0
gstelement_class->get_index = GST_DEBUG_FUNCPTR (gst_bin_get_index_func);
gstelement_class->set_index = GST_DEBUG_FUNCPTR (gst_bin_set_index_func);
#endif
gstelement_class->provide_clock =
GST_DEBUG_FUNCPTR (gst_bin_provide_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);
gstelement_class->set_context = GST_DEBUG_FUNCPTR (gst_bin_set_context);
klass->add_element = GST_DEBUG_FUNCPTR (gst_bin_add_func);
klass->remove_element = GST_DEBUG_FUNCPTR (gst_bin_remove_func);
klass->handle_message = GST_DEBUG_FUNCPTR (gst_bin_handle_message_func);
klass->deep_element_added = gst_bin_deep_element_added_func;
klass->deep_element_removed = gst_bin_deep_element_removed_func;
klass->do_latency = GST_DEBUG_FUNCPTR (gst_bin_do_latency_func);
}
static void
gst_bin_init (GstBin * bin)
{
GstBus *bus;
bin->numchildren = 0;
bin->children = NULL;
bin->children_cookie = 0;
bin->messages = NULL;
bin->provided_clock = NULL;
bin->clock_dirty = FALSE;
/* Set up a bus for listening to child elements */
bus = g_object_new (GST_TYPE_BUS, "enable-async", FALSE, NULL);
gst_object_ref_sink (bus);
bin->child_bus = bus;
GST_DEBUG_OBJECT (bin, "using bus %" GST_PTR_FORMAT " to listen to children",
bus);
gst_bus_set_sync_handler (bus, (GstBusSyncHandler) bin_bus_handler, bin,
NULL);
bin->priv = gst_bin_get_instance_private (bin);
bin->priv->asynchandling = DEFAULT_ASYNC_HANDLING;
bin->priv->structure_cookie = 0;
bin->priv->message_forward = DEFAULT_MESSAGE_FORWARD;
}
static void
gst_bin_dispose (GObject * object)
{
GstBin *bin = GST_BIN_CAST (object);
GstBus **child_bus_p = &bin->child_bus;
GstClock **provided_clock_p = &bin->provided_clock;
GstElement **clock_provider_p = &bin->clock_provider;
GST_CAT_DEBUG_OBJECT (GST_CAT_REFCOUNTING, object, "%p dispose", object);
GST_OBJECT_LOCK (object);
gst_object_replace ((GstObject **) child_bus_p, NULL);
gst_object_replace ((GstObject **) provided_clock_p, NULL);
gst_object_replace ((GstObject **) clock_provider_p, NULL);
bin_remove_messages (bin, NULL, GST_MESSAGE_ANY);
GST_OBJECT_UNLOCK (object);
while (bin->children) {
gst_bin_remove (bin, GST_ELEMENT_CAST (bin->children->data));
}
if (G_UNLIKELY (bin->children != NULL)) {
g_critical ("could not remove elements from bin '%s'",
GST_STR_NULL (GST_OBJECT_NAME (object)));
}
G_OBJECT_CLASS (parent_class)->dispose (object);
}
/**
* gst_bin_new:
* @name: (allow-none): the name of the new bin
*
* Creates a new bin with the given name.
*
* Returns: (transfer floating): a new #GstBin
*/
GstElement *
gst_bin_new (const gchar * name)
{
return gst_element_factory_make ("bin", name);
}
static void
gst_bin_set_property (GObject * object, guint prop_id,
const GValue * value, GParamSpec * pspec)
{
GstBin *gstbin;
gstbin = GST_BIN_CAST (object);
switch (prop_id) {
case PROP_ASYNC_HANDLING:
GST_OBJECT_LOCK (gstbin);
gstbin->priv->asynchandling = g_value_get_boolean (value);
GST_OBJECT_UNLOCK (gstbin);
break;
case PROP_MESSAGE_FORWARD:
GST_OBJECT_LOCK (gstbin);
gstbin->priv->message_forward = g_value_get_boolean (value);
GST_OBJECT_UNLOCK (gstbin);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static void
gst_bin_get_property (GObject * object, guint prop_id,
GValue * value, GParamSpec * pspec)
{
GstBin *gstbin;
gstbin = GST_BIN_CAST (object);
switch (prop_id) {
case PROP_ASYNC_HANDLING:
GST_OBJECT_LOCK (gstbin);
g_value_set_boolean (value, gstbin->priv->asynchandling);
GST_OBJECT_UNLOCK (gstbin);
break;
case PROP_MESSAGE_FORWARD:
GST_OBJECT_LOCK (gstbin);
g_value_set_boolean (value, gstbin->priv->message_forward);
GST_OBJECT_UNLOCK (gstbin);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
#if 0
/* return the cached index */
static GstIndex *
gst_bin_get_index_func (GstElement * element)
{
GstBin *bin;
GstIndex *result;
bin = GST_BIN_CAST (element);
GST_OBJECT_LOCK (bin);
if ((result = bin->priv->index))
gst_object_ref (result);
GST_OBJECT_UNLOCK (bin);
return result;
}
/* set the index on all elements in this bin
*
* MT safe
*/
static void
gst_bin_set_index_func (GstElement * element, GstIndex * index)
{
GstBin *bin;
gboolean done;
GstIterator *it;
GstIndex *old;
GValue data = { 0, };
bin = GST_BIN_CAST (element);
GST_OBJECT_LOCK (bin);
old = bin->priv->index;
if (G_UNLIKELY (old == index))
goto was_set;
if (index)
gst_object_ref (index);
bin->priv->index = index;
GST_OBJECT_UNLOCK (bin);
if (old)
gst_object_unref (old);
it = gst_bin_iterate_elements (bin);
/* set the index on all elements in the bin */
done = FALSE;
while (!done) {
switch (gst_iterator_next (it, &data)) {
case GST_ITERATOR_OK:
{
GstElement *child = g_value_get_object (&data);
GST_DEBUG_OBJECT (bin, "setting index on '%s'",
GST_ELEMENT_NAME (child));
gst_element_set_index (child, index);
g_value_reset (&data);
break;
}
case GST_ITERATOR_RESYNC:
GST_DEBUG_OBJECT (bin, "iterator doing resync");
gst_iterator_resync (it);
break;
default:
case GST_ITERATOR_DONE:
GST_DEBUG_OBJECT (bin, "iterator done");
done = TRUE;
break;
}
}
g_value_unset (&data);
gst_iterator_free (it);
return;
was_set:
{
GST_DEBUG_OBJECT (bin, "index was already set");
GST_OBJECT_UNLOCK (bin);
return;
}
}
#endif
/* set the clock on all elements in this bin
*
* MT safe
*/
static gboolean
gst_bin_set_clock_func (GstElement * element, GstClock * clock)
{
GstBin *bin;
gboolean done;
GstIterator *it;
gboolean res = TRUE;
GValue data = { 0, };
bin = GST_BIN_CAST (element);
it = gst_bin_iterate_elements (bin);
done = FALSE;
while (!done) {
switch (gst_iterator_next (it, &data)) {
case GST_ITERATOR_OK:
{
GstElement *child = g_value_get_object (&data);
res &= gst_element_set_clock (child, clock);
g_value_reset (&data);
break;
}
case GST_ITERATOR_RESYNC:
GST_DEBUG_OBJECT (bin, "iterator doing resync");
gst_iterator_resync (it);
res = TRUE;
break;
default:
case GST_ITERATOR_DONE:
GST_DEBUG_OBJECT (bin, "iterator done");
done = TRUE;
break;
}
}
g_value_unset (&data);
gst_iterator_free (it);
if (res)
res = GST_ELEMENT_CLASS (parent_class)->set_clock (element, clock);
return res;
}
/* get the clock for this bin by asking all of the children in this bin
*
* The ref of the returned clock in increased so unref after usage.
*
* We loop the elements in state order and pick the last clock we can
* get. This makes sure we get a clock from the source.
*
* MT safe
*/
static GstClock *
gst_bin_provide_clock_func (GstElement * element)
{
GstClock *result = NULL;
GstElement *provider = NULL;
GstBin *bin;
GstIterator *it;
gboolean done;
GValue val = { 0, };
GstClock **provided_clock_p;
GstElement **clock_provider_p;
bin = GST_BIN_CAST (element);
GST_OBJECT_LOCK (bin);
if (!bin->clock_dirty)
goto not_dirty;
GST_DEBUG_OBJECT (bin, "finding new clock");
it = gst_bin_sort_iterator_new (bin);
GST_OBJECT_UNLOCK (bin);
done = FALSE;
while (!done) {
switch (gst_iterator_next (it, &val)) {
case GST_ITERATOR_OK:
{
GstElement *child = g_value_get_object (&val);
GstClock *clock;
clock = gst_element_provide_clock (child);
if (clock) {
GST_DEBUG_OBJECT (bin, "found candidate clock %p by element %s",
clock, GST_ELEMENT_NAME (child));
if (result) {
gst_object_unref (result);
gst_object_unref (provider);
}
result = clock;
provider = gst_object_ref (child);
}
g_value_reset (&val);
break;
}
case GST_ITERATOR_RESYNC:
gst_iterator_resync (it);
break;
default:
case GST_ITERATOR_DONE:
done = TRUE;
break;
}
}
g_value_unset (&val);
gst_iterator_free (it);
GST_OBJECT_LOCK (bin);
if (!bin->clock_dirty) {
if (provider)
gst_object_unref (provider);
if (result)
gst_object_unref (result);
result = NULL;
goto not_dirty;
}
provided_clock_p = &bin->provided_clock;
clock_provider_p = &bin->clock_provider;
gst_object_replace ((GstObject **) provided_clock_p, (GstObject *) result);
gst_object_replace ((GstObject **) clock_provider_p, (GstObject *) provider);
bin->clock_dirty = FALSE;
GST_DEBUG_OBJECT (bin,
"provided new clock %" GST_PTR_FORMAT " by provider %" GST_PTR_FORMAT,
result, provider);
/* Provider is not being returned to caller, just the result */
if (provider)
gst_object_unref (provider);
GST_OBJECT_UNLOCK (bin);
return result;
not_dirty:
{
if ((result = bin->provided_clock))
gst_object_ref (result);
GST_DEBUG_OBJECT (bin, "returning old clock %p", result);
GST_OBJECT_UNLOCK (bin);
return result;
}
}
/*
* functions for manipulating cached messages
*/
typedef struct
{
GstObject *src;
GstMessageType types;
} MessageFind;
/* check if a message is of given src and type */
static gint
message_check (GstMessage * message, MessageFind * target)
{
gboolean eq = TRUE;
if (target->src)
eq &= GST_MESSAGE_SRC (message) == target->src;
if (target->types)
eq &= (GST_MESSAGE_TYPE (message) & target->types) != 0;
GST_LOG ("looking at message %p: %d", message, eq);
return (eq ? 0 : 1);
}
static GList *
find_message (GstBin * bin, GstObject * src, GstMessageType types)
{
GList *result;
MessageFind find;
find.src = src;
find.types = types;
result = g_list_find_custom (bin->messages, &find,
(GCompareFunc) message_check);
if (result) {
GST_DEBUG_OBJECT (bin, "we found a message %p from %s matching types %08x",
result->data, GST_OBJECT_NAME (GST_MESSAGE_CAST (result->data)->src),
types);
} else {
GST_DEBUG_OBJECT (bin, "no message found matching types %08x", types);
#ifndef GST_DISABLE_GST_DEBUG
{
guint i;
for (i = 0; i < 32; i++)
if (types & (1U << i))
GST_DEBUG_OBJECT (bin, " %s", gst_message_type_get_name (1U << i));
}
#endif
}
return result;
}
/* with LOCK, returns TRUE if message had a valid SRC, takes ownership of
* the message.
*
* A message that is cached and has the same SRC and type is replaced
* by the given message.
*/
static gboolean
bin_replace_message (GstBin * bin, GstMessage * message, GstMessageType types)
{
GList *previous;
GstObject *src;
gboolean res = TRUE;
if ((src = GST_MESSAGE_SRC (message))) {
/* first find the previous message posted by this element */
if ((previous = find_message (bin, src, types))) {
GstMessage *previous_msg;
/* if we found a previous message, replace it */
previous_msg = previous->data;
previous->data = message;
GST_DEBUG_OBJECT (bin, "replace old message %s from %s with %s message",
GST_MESSAGE_TYPE_NAME (previous_msg), GST_ELEMENT_NAME (src),
GST_MESSAGE_TYPE_NAME (message));
gst_message_unref (previous_msg);
} else {
/* keep new message */
bin->messages = g_list_prepend (bin->messages, message);
GST_DEBUG_OBJECT (bin, "got new message %p, %s from %s",
message, GST_MESSAGE_TYPE_NAME (message), GST_ELEMENT_NAME (src));
}
} else {
GST_DEBUG_OBJECT (bin, "got message %s from (NULL), not processing",
GST_MESSAGE_TYPE_NAME (message));
res = FALSE;
gst_message_unref (message);
}
return res;
}
/* with LOCK. Remove all messages of given types */
static void
bin_remove_messages (GstBin * bin, GstObject * src, GstMessageType types)
{
MessageFind find;
GList *walk, *next;
find.src = src;
find.types = types;
for (walk = bin->messages; walk; walk = next) {
GstMessage *message = (GstMessage *) walk->data;
next = g_list_next (walk);
if (message_check (message, &find) == 0) {
GST_DEBUG_OBJECT (GST_MESSAGE_SRC (message),
"deleting message %p of type %s (types 0x%08x)", message,
GST_MESSAGE_TYPE_NAME (message), types);
bin->messages = g_list_delete_link (bin->messages, walk);
gst_message_unref (message);
} else {
GST_DEBUG_OBJECT (GST_MESSAGE_SRC (message),
"not deleting message %p of type 0x%08x", message,
GST_MESSAGE_TYPE (message));
}
}
}
/* Check if the bin is EOS. We do this by scanning all sinks and
* checking if they posted an EOS message.
*
* call with bin LOCK */
static gboolean
is_eos (GstBin * bin, guint32 * seqnum)
{
gboolean result;
gint n_eos = 0;
GList *walk, *msgs;
result = TRUE;
for (walk = bin->children; walk; walk = g_list_next (walk)) {
GstElement *element;
element = GST_ELEMENT_CAST (walk->data);
if (bin_element_is_sink (element, bin) == 0) {
/* check if element posted EOS */
if ((msgs =
find_message (bin, GST_OBJECT_CAST (element), GST_MESSAGE_EOS))) {
GST_DEBUG ("sink '%s' posted EOS", GST_ELEMENT_NAME (element));
*seqnum = gst_message_get_seqnum (GST_MESSAGE_CAST (msgs->data));
n_eos++;
} else {
GST_DEBUG ("sink '%s' did not post EOS yet",
GST_ELEMENT_NAME (element));
result = FALSE;
break;
}
}
}
/* FIXME: Some tests (e.g. elements/capsfilter) use
* pipelines with a dangling sinkpad but no sink element.
* These tests assume that no EOS message is ever
* posted on the bus so let's keep that behaviour.
* In valid pipelines this doesn't make a difference.
*/
return result && n_eos > 0;
}
/* Check if the bin is STREAM_START. We do this by scanning all sinks and
* checking if they posted an STREAM_START message.
*
* call with bin LOCK */
static gboolean
is_stream_start (GstBin * bin, guint32 * seqnum, gboolean * have_group_id,
guint * group_id)
{
gboolean result;
GList *walk, *msgs;
guint tmp_group_id;
gboolean first_stream_start = TRUE, first_group_id = TRUE;
gboolean same_group_id = TRUE;
*have_group_id = FALSE;
*group_id = 0;
result = FALSE;
for (walk = bin->children; walk; walk = g_list_next (walk)) {
GstElement *element;
element = GST_ELEMENT_CAST (walk->data);
if (bin_element_is_sink (element, bin) == 0) {
/* check if element posted STREAM_START */
if ((msgs =
find_message (bin, GST_OBJECT_CAST (element),
GST_MESSAGE_STREAM_START))) {
/* Only initialize to TRUE if we have any stream-start messages at
* all, otherwise it should be FALSE. */
if (first_stream_start) {
/* If any stream-start message do not contain a group id then we
* will set it to FALSE below */
*have_group_id = TRUE;
/* Similarly if any sinks did not post stream-start then we will
* set it to FALSE afterwards */
result = TRUE;
first_stream_start = FALSE;
}
GST_DEBUG ("sink '%s' posted STREAM_START", GST_ELEMENT_NAME (element));
*seqnum = gst_message_get_seqnum (GST_MESSAGE_CAST (msgs->data));
if (gst_message_parse_group_id (GST_MESSAGE_CAST (msgs->data),
&tmp_group_id)) {
if (first_group_id) {
first_group_id = FALSE;
*group_id = tmp_group_id;
} else {
if (tmp_group_id != *group_id)
same_group_id = FALSE;
}
} else {
*have_group_id = FALSE;
}
} else {
GST_DEBUG ("sink '%s' did not post STREAM_START yet",
GST_ELEMENT_NAME (element));
result = FALSE;
break;
}
}
}
/* If all have a group_id we only consider this stream started
* if all group ids were the same and all sinks posted a stream-start
* message */
if (*have_group_id)
return same_group_id && result;
/* otherwise consider this stream started after all sinks
* have reported stream-start for backward compatibility.
* FIXME 2.0: This should go away! */
return result;
}
static void
unlink_pads (const GValue * item, gpointer user_data)
{
GstPad *pad;
GstPad *peer;
pad = g_value_get_object (item);
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);
}
}
static void
bin_deep_iterator_foreach (const GValue * item, gpointer user_data)
{
GQueue *queue = user_data;
g_queue_push_tail (queue, g_value_dup_object (item));
}
static void
gst_bin_do_deep_add_remove (GstBin * bin, gint sig_id, const gchar * sig_name,
GstElement * element)
{
g_signal_emit (bin, sig_id, 0, bin, element);
/* When removing a bin, emit deep-element-* for everything in the bin too */
if (GST_IS_BIN (element)) {
GstIterator *it;
GstIteratorResult ires;
GQueue elements = G_QUEUE_INIT;
GST_LOG_OBJECT (bin, "Recursing into bin %" GST_PTR_FORMAT " for %s",
element, sig_name);
it = gst_bin_iterate_recurse (GST_BIN_CAST (element));
do {
ires = gst_iterator_foreach (it, bin_deep_iterator_foreach, &elements);
if (ires != GST_ITERATOR_DONE) {
g_queue_foreach (&elements, (GFunc) gst_object_unref, NULL);
g_queue_clear (&elements);
}
if (ires == GST_ITERATOR_RESYNC)
gst_iterator_resync (it);
} while (ires == GST_ITERATOR_RESYNC);
if (ires != GST_ITERATOR_ERROR) {
GstElement *e;
while ((e = g_queue_pop_head (&elements))) {
GstObject *parent = gst_object_get_parent (GST_OBJECT_CAST (e));
/* an element could have removed some of its internal elements
* meanwhile, so protect against that */
if (parent) {
GST_LOG_OBJECT (bin, "calling %s for element %" GST_PTR_FORMAT
" in bin %" GST_PTR_FORMAT, sig_name, e, parent);
g_signal_emit (bin, sig_id, 0, parent, e);
gst_object_unref (parent);
gst_object_unref (e);
}
}
}
gst_iterator_free (it);
}
}
/* vmethod that adds an element to a bin
*
* MT safe
*/
static gboolean
gst_bin_add_func (GstBin * bin, GstElement * element)
{
gchar *elem_name;
GstIterator *it;
gboolean is_sink, is_source, provides_clock, requires_clock;
GstMessage *clock_message = NULL, *async_message = NULL;
GstStateChangeReturn ret;
GList *l, *elem_contexts, *need_context_messages;
GST_DEBUG_OBJECT (bin, "element :%s", GST_ELEMENT_NAME (element));
/* get the element name to make sure it is unique in this bin. */
GST_OBJECT_LOCK (element);
elem_name = g_strdup (GST_ELEMENT_NAME (element));
is_sink = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_SINK);
is_source = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_SOURCE);
provides_clock =
GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_PROVIDE_CLOCK);
requires_clock =
GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_REQUIRE_CLOCK);
GST_OBJECT_UNLOCK (element);
GST_OBJECT_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 (is_sink && !(bin->priv->suppressed_flags & GST_ELEMENT_FLAG_SINK)) {
GST_CAT_DEBUG_OBJECT (GST_CAT_PARENTAGE, bin, "element \"%s\" was sink",
elem_name);
GST_OBJECT_FLAG_SET (bin, GST_ELEMENT_FLAG_SINK);
}
if (is_source && !(bin->priv->suppressed_flags & GST_ELEMENT_FLAG_SOURCE)) {
GST_CAT_DEBUG_OBJECT (GST_CAT_PARENTAGE, bin, "element \"%s\" was source",
elem_name);
GST_OBJECT_FLAG_SET (bin, GST_ELEMENT_FLAG_SOURCE);
}
if (provides_clock
&& !(bin->priv->suppressed_flags & GST_ELEMENT_FLAG_PROVIDE_CLOCK)) {
GST_DEBUG_OBJECT (bin, "element \"%s\" can provide a clock", elem_name);
clock_message =
gst_message_new_clock_provide (GST_OBJECT_CAST (element), NULL, TRUE);
GST_OBJECT_FLAG_SET (bin, GST_ELEMENT_FLAG_PROVIDE_CLOCK);
}
if (requires_clock
&& !(bin->priv->suppressed_flags & GST_ELEMENT_FLAG_REQUIRE_CLOCK)) {
GST_DEBUG_OBJECT (bin, "element \"%s\" requires a clock", elem_name);
GST_OBJECT_FLAG_SET (bin, GST_ELEMENT_FLAG_REQUIRE_CLOCK);
}
bin->children = g_list_prepend (bin->children, element);
bin->numchildren++;
bin->children_cookie++;
if (!GST_BIN_IS_NO_RESYNC (bin))
bin->priv->structure_cookie++;
/* distribute the bus */
gst_element_set_bus (element, bin->child_bus);
/* propagate the current base_time, start_time and clock */
gst_element_set_base_time (element, GST_ELEMENT_CAST (bin)->base_time);
gst_element_set_start_time (element, GST_ELEMENT_START_TIME (bin));
/* it's possible that the element did not accept the clock but
* that is not important right now. When the pipeline goes to PLAYING,
* a new clock will be selected */
gst_element_set_clock (element, GST_ELEMENT_CLOCK (bin));
/* get the element's list of contexts before propagating our own */
elem_contexts = gst_element_get_contexts (element);
for (l = GST_ELEMENT_CAST (bin)->contexts; l; l = l->next)
gst_element_set_context (element, l->data);
need_context_messages = NULL;
for (l = elem_contexts; l; l = l->next) {
GstContext *replacement, *context = l->data;
const gchar *context_type;
context_type = gst_context_get_context_type (context);
/* we already set this context above? */
replacement =
gst_element_get_context_unlocked (GST_ELEMENT (bin), context_type);
if (replacement) {
gst_context_unref (replacement);
} else {
GstMessage *msg;
GstStructure *s;
/* ask our parent for the context */
msg = gst_message_new_need_context (GST_OBJECT_CAST (bin), context_type);
s = (GstStructure *) gst_message_get_structure (msg);
gst_structure_set (s, "bin.old.context", GST_TYPE_CONTEXT, context, NULL);
need_context_messages = g_list_prepend (need_context_messages, msg);
}
}
#if 0
/* set the cached index on the children */
if (bin->priv->index)
gst_element_set_index (element, bin->priv->index);
#endif
ret = GST_STATE_RETURN (bin);
/* no need to update the state if we are in error */
if (ret == GST_STATE_CHANGE_FAILURE)
goto no_state_recalc;
/* update the bin state, the new element could have been an ASYNC or
* NO_PREROLL element */
ret = GST_STATE_RETURN (element);
GST_DEBUG_OBJECT (bin, "added %s element",
gst_element_state_change_return_get_name (ret));
switch (ret) {
case GST_STATE_CHANGE_ASYNC:
{
/* create message to track this aync element when it posts an async-done
* message */
async_message = gst_message_new_async_start (GST_OBJECT_CAST (element));
break;
}
case GST_STATE_CHANGE_NO_PREROLL:
/* ignore all async elements we might have and commit our state */
bin_handle_async_done (bin, ret, FALSE, GST_CLOCK_TIME_NONE);
break;
case GST_STATE_CHANGE_FAILURE:
break;
default:
break;
}
no_state_recalc:
GST_OBJECT_UNLOCK (bin);
for (l = need_context_messages; l; l = l->next) {
GstMessage *msg = l->data;
GstStructure *s;
const gchar *context_type;
GstContext *replacement, *context;
gst_message_parse_context_type (msg, &context_type);
GST_LOG_OBJECT (bin, "asking parent for context type: %s "
"from %" GST_PTR_FORMAT, context_type, element);
s = (GstStructure *) gst_message_get_structure (msg);
gst_structure_get (s, "bin.old.context", GST_TYPE_CONTEXT, &context, NULL);
gst_structure_remove_field (s, "bin.old.context");
/* Keep the msg around while we still need access to the context_type */
gst_element_post_message (GST_ELEMENT_CAST (bin), gst_message_ref (msg));
/* lock to avoid losing a potential write */
GST_OBJECT_LOCK (bin);
replacement =
gst_element_get_context_unlocked (GST_ELEMENT_CAST (bin), context_type);
gst_message_unref (msg);
if (replacement) {
/* we got the context set from GstElement::set_context */
gst_context_unref (replacement);
GST_OBJECT_UNLOCK (bin);
} else {
/* Propagate the element's context upwards */
GST_LOG_OBJECT (bin, "propagating existing context type: %s %p "
"from %" GST_PTR_FORMAT, context_type, context, element);
gst_bin_update_context_unlocked (bin, context);
msg =
gst_message_new_have_context (GST_OBJECT_CAST (bin),
gst_context_ref (context));
GST_OBJECT_UNLOCK (bin);
gst_element_post_message (GST_ELEMENT_CAST (bin), msg);
}
gst_context_unref (context);
}
g_list_free_full (elem_contexts, (GDestroyNotify) gst_context_unref);
g_list_free (need_context_messages);
/* post the messages on the bus of the element so that the bin can handle
* them */
if (clock_message)
gst_element_post_message (element, clock_message);
if (async_message)
gst_element_post_message (element, async_message);
/* unlink all linked pads */
it = gst_element_iterate_pads (element);
while (gst_iterator_foreach (it, (GstIteratorForeachFunction) unlink_pads,
NULL) == GST_ITERATOR_RESYNC)
gst_iterator_resync (it);
gst_iterator_free (it);
GST_CAT_DEBUG_OBJECT (GST_CAT_PARENTAGE, bin, "added element \"%s\"",
elem_name);
g_signal_emit (bin, gst_bin_signals[ELEMENT_ADDED], 0, element);
gst_child_proxy_child_added ((GstChildProxy *) bin, (GObject *) element,
elem_name);
gst_bin_do_deep_add_remove (bin, gst_bin_signals[DEEP_ELEMENT_ADDED],
"deep-element-added", element);
g_free (elem_name);
return TRUE;
/* ERROR handling here */
duplicate_name:
{
GST_OBJECT_UNLOCK (bin);
GST_WARNING_OBJECT (bin, "Name '%s' is not unique in bin, not adding",
elem_name);
g_free (elem_name);
gst_object_ref_sink (element);
gst_object_unref (element);
return FALSE;
}
had_parent:
{
GST_OBJECT_UNLOCK (bin);
GST_WARNING_OBJECT (bin, "Element '%s' already has parent", elem_name);
g_free (elem_name);
return FALSE;
}
}
/**
* gst_bin_set_suppressed_flags:
* @bin: a #GstBin
* @flags: the #GstElementFlags to suppress
*
* Suppresses the given flags on the bin. #GstElementFlags of a
* child element are propagated when it is added to the bin.
* When suppressed flags are set, those specified flags will
* not be propagated to the bin.
*
* Since: 1.10
*/
void
gst_bin_set_suppressed_flags (GstBin * bin, GstElementFlags flags)
{
g_return_if_fail (GST_IS_BIN (bin));
GST_OBJECT_LOCK (bin);
bin->priv->suppressed_flags = bin->priv->suppressed_flags | flags;
GST_OBJECT_UNLOCK (bin);
GST_DEBUG_OBJECT (bin, "Set suppressed flags(0x%x) to bin '%s'", flags,
GST_ELEMENT_NAME (bin));
}
/**
* gst_bin_get_suppressed_flags:
* @bin: a #GstBin
*
* Returns: the bin's suppressed #GstElementFlags.
*
* Since: 1.10
*/
GstElementFlags
gst_bin_get_suppressed_flags (GstBin * bin)
{
GstElementFlags res;
g_return_val_if_fail (GST_IS_BIN (bin), 0);
GST_OBJECT_LOCK (bin);
res = bin->priv->suppressed_flags;
GST_OBJECT_UNLOCK (bin);
return res;
}
/* signal vfunc, will be called when a new element was added */
static void
gst_bin_deep_element_added_func (GstBin * bin, GstBin * sub_bin,
GstElement * child)
{
GstBin *parent_bin;
parent_bin = (GstBin *) gst_object_get_parent (GST_OBJECT_CAST (bin));
if (parent_bin == NULL) {
GST_LOG_OBJECT (bin, "no parent, reached top-level");
return;
}
GST_LOG_OBJECT (parent_bin, "emitting deep-element-added for element "
"%" GST_PTR_FORMAT " which has just been added to %" GST_PTR_FORMAT,
child, sub_bin);
g_signal_emit (parent_bin, gst_bin_signals[DEEP_ELEMENT_ADDED], 0, sub_bin,
child);
gst_object_unref (parent_bin);
}
/* signal vfunc, will be called when an element was removed */
static void
gst_bin_deep_element_removed_func (GstBin * bin, GstBin * sub_bin,
GstElement * child)
{
GstBin *parent_bin;
parent_bin = (GstBin *) gst_object_get_parent (GST_OBJECT_CAST (bin));
if (parent_bin == NULL) {
GST_LOG_OBJECT (bin, "no parent, reached top-level");
return;
}
GST_LOG_OBJECT (parent_bin, "emitting deep-element-removed for element "
"%" GST_PTR_FORMAT " which has just been removed from %" GST_PTR_FORMAT,
child, sub_bin);
g_signal_emit (parent_bin, gst_bin_signals[DEEP_ELEMENT_REMOVED], 0, sub_bin,
child);
gst_object_unref (parent_bin);
}
/**
* gst_bin_add:
* @bin: a #GstBin
* @element: (transfer floating): the #GstElement to add
*
* 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.
*
* > When you add an element to an already-running pipeline, you will have to
* > take care to set the state of the newly-added element to the desired
* > state (usually PLAYING or PAUSED, same you set the pipeline to originally)
* > with gst_element_set_state(), or use gst_element_sync_state_with_parent().
* > The bin or pipeline will not take care of this for you.
*
* Returns: %TRUE if the element could be added, %FALSE if
* 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);
g_return_val_if_fail (GST_ELEMENT_CAST (bin) != 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_STR_NULL (GST_ELEMENT_NAME (element)),
GST_STR_NULL (GST_ELEMENT_NAME (bin)));
GST_TRACER_BIN_ADD_PRE (bin, element);
result = bclass->add_element (bin, element);
GST_TRACER_BIN_ADD_POST (bin, element, result);
return result;
/* ERROR handling */
no_function:
{
GST_WARNING_OBJECT (bin, "adding elements to bin is not supported");
gst_object_ref_sink (element);
gst_object_unref (element);
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;
gboolean is_sink, is_source, provides_clock, requires_clock;
gboolean othersink, othersource, otherprovider, otherrequirer, found;
GstMessage *clock_message = NULL;
GstClock **provided_clock_p;
GstElement **clock_provider_p;
GList *walk, *next;
gboolean other_async, this_async, have_no_preroll, removed_eos;
GstStateChangeReturn ret;
GST_DEBUG_OBJECT (bin, "element :%s", GST_ELEMENT_NAME (element));
GST_OBJECT_LOCK (bin);
GST_OBJECT_LOCK (element);
elem_name = g_strdup (GST_ELEMENT_NAME (element));
if (GST_OBJECT_PARENT (element) != GST_OBJECT_CAST (bin))
goto not_in_bin;
/* remove the parent ref */
GST_OBJECT_PARENT (element) = NULL;
/* grab element name so we can print it */
is_sink = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_SINK);
is_source = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_SOURCE);
provides_clock =
GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_PROVIDE_CLOCK);
requires_clock =
GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_REQUIRE_CLOCK);
GST_OBJECT_UNLOCK (element);
found = FALSE;
othersink = FALSE;
othersource = FALSE;
otherprovider = FALSE;
otherrequirer = FALSE;
have_no_preroll = FALSE;
/* iterate the elements, we collect which ones are async and no_preroll. We
* also remove the element when we find it. */
for (walk = bin->children; walk; walk = next) {
GstElement *child = GST_ELEMENT_CAST (walk->data);
next = g_list_next (walk);
if (child == element) {
found = TRUE;
/* remove the element */
bin->children = g_list_delete_link (bin->children, walk);
} else {
gboolean child_sink, child_source, child_provider, child_requirer;
GST_OBJECT_LOCK (child);
child_sink = GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_FLAG_SINK);
child_source = GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_FLAG_SOURCE);
child_provider =
GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_FLAG_PROVIDE_CLOCK);
child_requirer =
GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_FLAG_REQUIRE_CLOCK);
/* when we remove a sink, check if there are other sinks. */
if (is_sink && !othersink && child_sink)
othersink = TRUE;
if (is_source && !othersource && child_source)
othersource = TRUE;
if (provides_clock && !otherprovider && child_provider)
otherprovider = TRUE;
if (requires_clock && !otherrequirer && child_requirer)
otherrequirer = TRUE;
/* check if we have NO_PREROLL children */
if (GST_STATE_RETURN (child) == GST_STATE_CHANGE_NO_PREROLL)
have_no_preroll = TRUE;
GST_OBJECT_UNLOCK (child);
}
}
/* the element must have been in the bin's list of children */
if (G_UNLIKELY (!found))
goto not_in_bin;
/* we now removed the element from the list of elements, increment the cookie
* so that others can detect a change in the children list. */
bin->numchildren--;
bin->children_cookie++;
if (!GST_BIN_IS_NO_RESYNC (bin))
bin->priv->structure_cookie++;
if (is_sink && !othersink
&& !(bin->priv->suppressed_flags & GST_ELEMENT_FLAG_SINK)) {
/* we're not a sink anymore */
GST_DEBUG_OBJECT (bin, "we removed the last sink");
GST_OBJECT_FLAG_UNSET (bin, GST_ELEMENT_FLAG_SINK);
}
if (is_source && !othersource
&& !(bin->priv->suppressed_flags & GST_ELEMENT_FLAG_SOURCE)) {
/* we're not a source anymore */
GST_DEBUG_OBJECT (bin, "we removed the last source");
GST_OBJECT_FLAG_UNSET (bin, GST_ELEMENT_FLAG_SOURCE);
}
if (provides_clock && !otherprovider
&& !(bin->priv->suppressed_flags & GST_ELEMENT_FLAG_PROVIDE_CLOCK)) {
/* we're not a clock provider anymore */
GST_DEBUG_OBJECT (bin, "we removed the last clock provider");
GST_OBJECT_FLAG_UNSET (bin, GST_ELEMENT_FLAG_PROVIDE_CLOCK);
}
if (requires_clock && !otherrequirer
&& !(bin->priv->suppressed_flags & GST_ELEMENT_FLAG_REQUIRE_CLOCK)) {
/* we're not a clock requirer anymore */
GST_DEBUG_OBJECT (bin, "we removed the last clock requirer");
GST_OBJECT_FLAG_UNSET (bin, GST_ELEMENT_FLAG_REQUIRE_CLOCK);
}
/* if the clock provider for this element is removed, we lost
* the clock as well, we need to inform the parent of this
* so that it can select a new clock */
if (bin->clock_provider == element) {
GST_DEBUG_OBJECT (bin, "element \"%s\" provided the clock", elem_name);
bin->clock_dirty = TRUE;
clock_message =
gst_message_new_clock_lost (GST_OBJECT_CAST (bin), bin->provided_clock);
provided_clock_p = &bin->provided_clock;
clock_provider_p = &bin->clock_provider;
gst_object_replace ((GstObject **) provided_clock_p, NULL);
gst_object_replace ((GstObject **) clock_provider_p, NULL);
}
/* remove messages for the element, if there was a pending ASYNC_START
* message we must see if removing the element caused the bin to lose its
* async state. */
this_async = FALSE;
other_async = FALSE;
/* If we remove an EOSed element, the bin might go EOS */
removed_eos = FALSE;
for (walk = bin->messages; walk; walk = next) {
GstMessage *message = (GstMessage *) walk->data;
GstElement *src = GST_ELEMENT_CAST (GST_MESSAGE_SRC (message));
gboolean remove;
next = g_list_next (walk);
remove = FALSE;
switch (GST_MESSAGE_TYPE (message)) {
case GST_MESSAGE_ASYNC_START:
if (src == element)
this_async = TRUE;
else
other_async = TRUE;
GST_DEBUG_OBJECT (src, "looking at message %p", message);
break;
case GST_MESSAGE_STRUCTURE_CHANGE:
{
GstElement *owner;
GST_DEBUG_OBJECT (src, "looking at structure change message %p",
message);
/* it's unlikely that this message is still in the list of messages
* because this would mean that a link/unlink is busy in another thread
* while we remove the element. We still have to remove the message
* because we might not receive the done message anymore when the element
* is removed from the bin. */
gst_message_parse_structure_change (message, NULL, &owner, NULL);
if (owner == element)
remove = TRUE;
break;
}
case GST_MESSAGE_EOS:
if (src == element)
removed_eos = TRUE;
break;
default:
break;
}
if (src == element)
remove = TRUE;
if (remove) {
/* delete all message types */
GST_DEBUG_OBJECT (src, "deleting message %p of element \"%s\"",
message, elem_name);
bin->messages = g_list_delete_link (bin->messages, walk);
gst_message_unref (message);
}
}
/* get last return */
ret = GST_STATE_RETURN (bin);
/* no need to update the state if we are in error */
if (ret == GST_STATE_CHANGE_FAILURE)
goto no_state_recalc;
if (!other_async && this_async) {
/* all other elements were not async and we removed the async one,
* handle the async-done case because we are not async anymore now. */
GST_DEBUG_OBJECT (bin,
"we removed the last async element, have no_preroll %d",
have_no_preroll);
/* the current state return of the bin depends on if there are no_preroll
* elements in the pipeline or not */
if (have_no_preroll)
ret = GST_STATE_CHANGE_NO_PREROLL;
else
ret = GST_STATE_CHANGE_SUCCESS;
bin_handle_async_done (bin, ret, FALSE, GST_CLOCK_TIME_NONE);
} else {
GST_DEBUG_OBJECT (bin,
"recalc state preroll: %d, other async: %d, this async %d",
have_no_preroll, other_async, this_async);
if (have_no_preroll) {
ret = GST_STATE_CHANGE_NO_PREROLL;
} else if (other_async) {
/* there are other async elements and we were not doing an async state
* change, change our pending state and go async */
if (GST_STATE_PENDING (bin) == GST_STATE_VOID_PENDING) {
GST_STATE_NEXT (bin) = GST_STATE (bin);
GST_STATE_PENDING (bin) = GST_STATE (bin);
}
ret = GST_STATE_CHANGE_ASYNC;
}
GST_STATE_RETURN (bin) = ret;
}
no_state_recalc:
/* clear bus */
gst_element_set_bus (element, NULL);
/* Clear the clock we provided to the element */
gst_element_set_clock (element, NULL);
GST_OBJECT_UNLOCK (bin);
/* If the element was a sink that had not posted EOS,
* it might have been the last one we were waiting for,
* so check if it's time to send EOS now */
if (is_sink && !removed_eos) {
GST_DEBUG_OBJECT (bin,
"Removing sink that had not EOSed. Re-checking overall EOS status");
bin_do_eos (bin);
}
if (clock_message)
gst_element_post_message (GST_ELEMENT_CAST (bin), clock_message);
/* unlink all linked pads */
it = gst_element_iterate_pads (element);
while (gst_iterator_foreach (it, (GstIteratorForeachFunction) unlink_pads,
NULL) == GST_ITERATOR_RESYNC)
gst_iterator_resync (it);
gst_iterator_free (it);
GST_CAT_INFO_OBJECT (GST_CAT_PARENTAGE, bin, "removed child \"%s\"",
elem_name);
g_signal_emit (bin, gst_bin_signals[ELEMENT_REMOVED], 0, element);
gst_child_proxy_child_removed ((GstChildProxy *) bin, (GObject *) element,
elem_name);
gst_bin_do_deep_add_remove (bin, gst_bin_signals[DEEP_ELEMENT_REMOVED],
"deep-element-removed", element);
g_free (elem_name);
/* element is really out of our control now */
gst_object_unref (element);
return TRUE;
/* ERROR handling */
not_in_bin:
{
GST_OBJECT_UNLOCK (element);
GST_OBJECT_UNLOCK (bin);
GST_WARNING_OBJECT (bin, "Element '%s' is not in bin", elem_name);
g_free (elem_name);
return FALSE;
}
}
/**
* gst_bin_remove:
* @bin: a #GstBin
* @element: (transfer none): the #GstElement to remove
*
* Removes the element from the 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.
*
* Returns: %TRUE if the element could be removed, %FALSE if
* 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);
g_return_val_if_fail (GST_ELEMENT_CAST (bin) != 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));
GST_TRACER_BIN_REMOVE_PRE (bin, element);
result = bclass->remove_element (bin, element);
GST_TRACER_BIN_REMOVE_POST (bin, result);
return result;
/* ERROR handling */
no_function:
{
GST_WARNING_OBJECT (bin, "Removing elements from bin is not supported");
return FALSE;
}
}
/**
* gst_bin_iterate_elements:
* @bin: a #GstBin
*
* Gets an iterator for the elements in this bin.
*
* Returns: (transfer full) (nullable): a #GstIterator of #GstElement
*/
GstIterator *
gst_bin_iterate_elements (GstBin * bin)
{
GstIterator *result;
g_return_val_if_fail (GST_IS_BIN (bin), NULL);
GST_OBJECT_LOCK (bin);
result = gst_iterator_new_list (GST_TYPE_ELEMENT,
GST_OBJECT_GET_LOCK (bin),
&bin->children_cookie, &bin->children, (GObject *) bin, NULL);
GST_OBJECT_UNLOCK (bin);
return result;
}
static GstIteratorItem
iterate_child_recurse (GstIterator * it, const GValue * item)
{
GstElement *child = g_value_get_object (item);
if (GST_IS_BIN (child)) {
GstIterator *other = gst_bin_iterate_recurse (GST_BIN_CAST (child));
gst_iterator_push (it, other);
}
return GST_ITERATOR_ITEM_PASS;
}
/**
* gst_bin_iterate_recurse:
* @bin: a #GstBin
*
* Gets an iterator for the elements in this bin.
* This iterator recurses into GstBin children.
*
* Returns: (transfer full) (nullable): a #GstIterator of #GstElement
*/
GstIterator *
gst_bin_iterate_recurse (GstBin * bin)
{
GstIterator *result;
g_return_val_if_fail (GST_IS_BIN (bin), NULL);
GST_OBJECT_LOCK (bin);
result = gst_iterator_new_list (GST_TYPE_ELEMENT,
GST_OBJECT_GET_LOCK (bin),
&bin->children_cookie,
&bin->children,
(GObject *) bin, (GstIteratorItemFunction) iterate_child_recurse);
GST_OBJECT_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 and flag safely. */
GST_OBJECT_LOCK (child);
is_sink = GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_FLAG_SINK);
GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin,
"child %s %s sink", GST_OBJECT_NAME (child), is_sink ? "is" : "is not");
GST_OBJECT_UNLOCK (child);
return is_sink ? 0 : 1;
}
static gint
sink_iterator_filter (const GValue * vchild, GValue * vbin)
{
GstBin *bin = g_value_get_object (vbin);
GstElement *child = g_value_get_object (vchild);
return (bin_element_is_sink (child, bin));
}
/**
* gst_bin_iterate_sinks:
* @bin: a #GstBin
*
* Gets an iterator for all elements in the bin that have the
* #GST_ELEMENT_FLAG_SINK flag set.
*
* Returns: (transfer full) (nullable): a #GstIterator of #GstElement
*/
GstIterator *
gst_bin_iterate_sinks (GstBin * bin)
{
GstIterator *children;
GstIterator *result;
GValue vbin = { 0, };
g_return_val_if_fail (GST_IS_BIN (bin), NULL);
g_value_init (&vbin, GST_TYPE_BIN);
g_value_set_object (&vbin, bin);
children = gst_bin_iterate_elements (bin);
result = gst_iterator_filter (children,
(GCompareFunc) sink_iterator_filter, &vbin);
g_value_unset (&vbin);
return result;
}
/* returns 0 when TRUE because this is a GCompareFunc */
/* MT safe */
static gint
bin_element_is_src (GstElement * child, GstBin * bin)
{
gboolean is_src;
/* we lock the child here for the remainder of the function to
* get its name and other info safely. */
GST_OBJECT_LOCK (child);
is_src = GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_FLAG_SOURCE);
GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin,
"child %s %s src", GST_OBJECT_NAME (child), is_src ? "is" : "is not");
GST_OBJECT_UNLOCK (child);
return is_src ? 0 : 1;
}
static gint
src_iterator_filter (const GValue * vchild, GValue * vbin)
{
GstBin *bin = g_value_get_object (vbin);
GstElement *child = g_value_get_object (vchild);
return (bin_element_is_src (child, bin));
}
/**
* gst_bin_iterate_sources:
* @bin: a #GstBin
*
* Gets an iterator for all elements in the bin that have the
* #GST_ELEMENT_FLAG_SOURCE flag set.
*
* Returns: (transfer full) (nullable): a #GstIterator of #GstElement
*/
GstIterator *
gst_bin_iterate_sources (GstBin * bin)
{
GstIterator *children;
GstIterator *result;
GValue vbin = { 0, };
g_return_val_if_fail (GST_IS_BIN (bin), NULL);
g_value_init (&vbin, GST_TYPE_BIN);
g_value_set_object (&vbin, bin);
children = gst_bin_iterate_elements (bin);
result = gst_iterator_filter (children,
(GCompareFunc) src_iterator_filter, &vbin);
g_value_unset (&vbin);
return result;
}
/*
* MT safe
*/
static GstStateChangeReturn
gst_bin_get_state_func (GstElement * element, GstState * state,
GstState * pending, GstClockTime timeout)
{
GstStateChangeReturn ret;
GST_CAT_INFO_OBJECT (GST_CAT_STATES, element, "getting state");
ret =
GST_ELEMENT_CLASS (parent_class)->get_state (element, state, pending,
timeout);
return ret;
}
/***********************************************
* Topologically sorted iterator
* see http://en.wikipedia.org/wiki/Topological_sorting
*
* For each element in the graph, an entry is kept in a HashTable
* with its number of srcpad connections (degree).
* We then change state of all elements without dependencies
* (degree 0) and decrement the degree of all elements connected
* on the sinkpads. When an element reaches degree 0, its state is
* changed next.
* When all elements are handled the algorithm stops.
*/
typedef struct _GstBinSortIterator
{
GstIterator it;
GQueue queue; /* elements queued for state change */
GstBin *bin; /* bin we iterate */
gint mode; /* adding or removing dependency */
GstElement *best; /* next element with least dependencies */
gint best_deg; /* best degree */
GHashTable *hash; /* hashtable with element dependencies */
gboolean dirty; /* we detected structure change */
} GstBinSortIterator;
static void
copy_to_queue (gpointer data, gpointer user_data)
{
GstElement *element = data;
GQueue *queue = user_data;
gst_object_ref (element);
g_queue_push_tail (queue, element);
}
static void
gst_bin_sort_iterator_copy (const GstBinSortIterator * it,
GstBinSortIterator * copy)
{
GHashTableIter iter;
gpointer key, value;
g_queue_init (&copy->queue);
g_queue_foreach ((GQueue *) & it->queue, copy_to_queue, &copy->queue);
copy->bin = gst_object_ref (it->bin);
if (it->best)
copy->best = gst_object_ref (it->best);
copy->hash = g_hash_table_new (NULL, NULL);
g_hash_table_iter_init (&iter, it->hash);
while (g_hash_table_iter_next (&iter, &key, &value))
g_hash_table_insert (copy->hash, key, value);
}
/* we add and subtract 1 to make sure we don't confuse NULL and 0 */
#define HASH_SET_DEGREE(bit, elem, deg) \
g_hash_table_replace (bit->hash, elem, GINT_TO_POINTER(deg+1))
#define HASH_GET_DEGREE(bit, elem) \
(GPOINTER_TO_INT(g_hash_table_lookup (bit->hash, elem))-1)
/* add element to queue of next elements in the iterator.
* We push at the tail to give higher priority elements a
* chance first */
static void
add_to_queue (GstBinSortIterator * bit, GstElement * element)
{
GST_DEBUG_OBJECT (bit->bin, "adding '%s' to queue",
GST_ELEMENT_NAME (element));
gst_object_ref (element);
g_queue_push_tail (&bit->queue, element);
HASH_SET_DEGREE (bit, element, -1);
}
static void
remove_from_queue (GstBinSortIterator * bit, GstElement * element)
{
GList *find;
if ((find = g_queue_find (&bit->queue, element))) {
GST_DEBUG_OBJECT (bit->bin, "removing '%s' from queue",
GST_ELEMENT_NAME (element));
g_queue_delete_link (&bit->queue, find);
gst_object_unref (element);
} else {
GST_DEBUG_OBJECT (bit->bin, "unable to remove '%s' from queue",
GST_ELEMENT_NAME (element));
}
}
/* clear the queue, unref all objects as we took a ref when
* we added them to the queue */
static void
clear_queue (GQueue * queue)
{
gpointer p;
while ((p = g_queue_pop_head (queue)))
gst_object_unref (p);
}
/* set all degrees to 0. Elements marked as a sink are
* added to the queue immediately. Since we only look at the SINK flag of the
* element, it is possible that we add non-sinks to the queue. These will be
* removed from the queue again when we can prove that it provides data for some
* other element. */
static void
reset_degree (GstElement * element, GstBinSortIterator * bit)
{
gboolean is_sink;
/* sinks are added right away */
GST_OBJECT_LOCK (element);
is_sink = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_SINK);
GST_OBJECT_UNLOCK (element);
if (is_sink) {
add_to_queue (bit, element);
} else {
/* others are marked with 0 and handled when sinks are done */
HASH_SET_DEGREE (bit, element, 0);
}
}
/* adjust the degree of all elements connected to the given
* element. If a degree of an element drops to 0, it is
* added to the queue of elements to schedule next.
*
* We have to make sure not to cross the bin boundary this element
* belongs to.
*/
static void
update_degree (GstElement * element, GstBinSortIterator * bit)
{
gboolean linked = FALSE;
GST_OBJECT_LOCK (element);
/* don't touch degree if element has no sinkpads */
if (element->numsinkpads != 0) {
/* loop over all sinkpads, decrement degree for all connected
* elements in this bin */
GList *pads;
for (pads = element->sinkpads; pads; pads = g_list_next (pads)) {
GstPad *pad, *peer;
pad = GST_PAD_CAST (pads->data);
/* we're iterating over the sinkpads, check if it's busy in a link/unlink */
if (G_UNLIKELY (find_message (bit->bin, GST_OBJECT_CAST (pad),
GST_MESSAGE_STRUCTURE_CHANGE))) {
/* mark the iterator as dirty because we won't be updating the degree
* of the peer parent now. This would result in the 'loop detected'
* later on because the peer parent element could become the best next
* element with a degree > 0. We will simply continue our state
* changes and we'll eventually resync when the unlink completed and
* the iterator cookie is updated. */
bit->dirty = TRUE;
continue;
}
if ((peer = gst_pad_get_peer (pad))) {
GstElement *peer_element;
if ((peer_element = gst_pad_get_parent_element (peer))) {
GST_OBJECT_LOCK (peer_element);
/* check that we don't go outside of this bin */
if (GST_OBJECT_CAST (peer_element)->parent ==
GST_OBJECT_CAST (bit->bin)) {
gint old_deg, new_deg;
old_deg = HASH_GET_DEGREE (bit, peer_element);
/* check to see if we added an element as sink that was not really a
* sink because it was connected to some other element. */
if (old_deg == -1) {
remove_from_queue (bit, peer_element);
old_deg = 0;
}
new_deg = old_deg + bit->mode;
GST_DEBUG_OBJECT (bit->bin,
"change element %s, degree %d->%d, linked to %s",
GST_ELEMENT_NAME (peer_element), old_deg, new_deg,
GST_ELEMENT_NAME (element));
/* update degree, it is possible that an element was in 0 and
* reaches -1 here. This would mean that the element had no sinkpads
* but became linked while the state change was happening. We will
* resync on this with the structure change message. */
if (new_deg == 0) {
/* degree hit 0, add to queue */
add_to_queue (bit, peer_element);
} else {
HASH_SET_DEGREE (bit, peer_element, new_deg);
}
linked = TRUE;
}
GST_OBJECT_UNLOCK (peer_element);
gst_object_unref (peer_element);
}
gst_object_unref (peer);
}
}
}
if (!linked) {
GST_DEBUG_OBJECT (bit->bin, "element %s not linked on any sinkpads",
GST_ELEMENT_NAME (element));
}
GST_OBJECT_UNLOCK (element);
}
/* find the next best element not handled yet. This is the one
* with the lowest non-negative degree */
static void
find_element (GstElement * element, GstBinSortIterator * bit)
{
gint degree;
/* element is already handled */
if ((degree = HASH_GET_DEGREE (bit, element)) < 0)
return;
/* first element or element with smaller degree */
if (bit->best == NULL || bit->best_deg > degree) {
bit->best = element;
bit->best_deg = degree;
} else if (bit->best_deg == degree
&& GST_OBJECT_FLAG_IS_SET (bit->best, GST_ELEMENT_FLAG_SOURCE)
&& !GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_FLAG_SOURCE)) {
/* If two elements have the same degree, we want to ensure we
* return non-source elements first. */
bit->best = element;
}
}
/* get next element in iterator. */
static GstIteratorResult
gst_bin_sort_iterator_next (GstBinSortIterator * bit, GValue * result)
{
GstElement *best;
GstBin *bin = bit->bin;
/* empty queue, we have to find a next best element */
if (g_queue_is_empty (&bit->queue)) {
bit->best = NULL;
bit->best_deg = G_MAXINT;
g_list_foreach (bin->children, (GFunc) find_element, bit);
if ((best = bit->best)) {
/* when we detected an unlink, don't warn because our degrees might be
* screwed up. We will resync later */
if (bit->best_deg != 0 && !bit->dirty) {
/* we don't fail on this one yet */
GST_WARNING_OBJECT (bin, "loop dected in graph");
g_warning ("loop detected in the graph of bin '%s'!!",
GST_ELEMENT_NAME (bin));
}
/* best unhandled element, schedule as next element */
GST_DEBUG_OBJECT (bin, "queue empty, next best: %s",
GST_ELEMENT_NAME (best));
HASH_SET_DEGREE (bit, best, -1);
g_value_set_object (result, best);
} else {
GST_DEBUG_OBJECT (bin, "queue empty, elements exhausted");
/* no more unhandled elements, we are done */
return GST_ITERATOR_DONE;
}
} else {
/* everything added to the queue got reffed */
best = g_queue_pop_head (&bit->queue);
g_value_set_object (result, best);
gst_object_unref (best);
}
GST_DEBUG_OBJECT (bin, "queue head gives %s", GST_ELEMENT_NAME (best));
/* update degrees of linked elements */
update_degree (best, bit);
return GST_ITERATOR_OK;
}
/* clear queues, recalculate the degrees and restart. */
static void
gst_bin_sort_iterator_resync (GstBinSortIterator * bit)
{
GstBin *bin = bit->bin;
GST_DEBUG_OBJECT (bin, "resync");
bit->dirty = FALSE;
clear_queue (&bit->queue);
/* reset degrees */
g_list_foreach (bin->children, (GFunc) reset_degree, bit);
/* calc degrees, incrementing */
bit->mode = 1;
g_list_foreach (bin->children, (GFunc) update_degree, bit);
/* for the rest of the function we decrement the degrees */
bit->mode = -1;
}
/* clear queues, unref bin and free iterator. */
static void
gst_bin_sort_iterator_free (GstBinSortIterator * bit)
{
GstBin *bin = bit->bin;
GST_DEBUG_OBJECT (bin, "free");
clear_queue (&bit->queue);
g_hash_table_destroy (bit->hash);
gst_object_unref (bin);
}
/* should be called with the bin LOCK held */
static GstIterator *
gst_bin_sort_iterator_new (GstBin * bin)
{
GstBinSortIterator *result;
/* we don't need an ItemFunction because we ref the items in the _next
* method already */
result = (GstBinSortIterator *)
gst_iterator_new (sizeof (GstBinSortIterator),
GST_TYPE_ELEMENT,
GST_OBJECT_GET_LOCK (bin),
&bin->priv->structure_cookie,
(GstIteratorCopyFunction) gst_bin_sort_iterator_copy,
(GstIteratorNextFunction) gst_bin_sort_iterator_next,
(GstIteratorItemFunction) NULL,
(GstIteratorResyncFunction) gst_bin_sort_iterator_resync,
(GstIteratorFreeFunction) gst_bin_sort_iterator_free);
g_queue_init (&result->queue);
result->hash = g_hash_table_new (NULL, NULL);
gst_object_ref (bin);
result->bin = bin;
gst_bin_sort_iterator_resync (result);
return (GstIterator *) result;
}
/**
* gst_bin_iterate_sorted:
* @bin: a #GstBin
*
* Gets an iterator for the elements in this bin in topologically
* sorted order. This means that the elements are returned from
* the most downstream elements (sinks) to the sources.
*
* This function is used internally to perform the state changes
* of the bin elements and for clock selection.
*
* Returns: (transfer full) (nullable): a #GstIterator of #GstElement
*/
GstIterator *
gst_bin_iterate_sorted (GstBin * bin)
{
GstIterator *result;
g_return_val_if_fail (GST_IS_BIN (bin), NULL);
GST_OBJECT_LOCK (bin);
result = gst_bin_sort_iterator_new (bin);
GST_OBJECT_UNLOCK (bin);
return result;
}
static GstStateChangeReturn
gst_bin_element_set_state (GstBin * bin, GstElement * element,
GstClockTime base_time, GstClockTime start_time, GstState current,
GstState next)
{
GstStateChangeReturn ret;
GstState child_current, child_pending;
gboolean locked;
GList *found;
GST_STATE_LOCK (element);
GST_OBJECT_LOCK (element);
/* set base_time and start time on child */
GST_ELEMENT_START_TIME (element) = start_time;
element->base_time = base_time;
/* peel off the locked flag */
locked = GST_ELEMENT_IS_LOCKED_STATE (element);
/* Get the previous set_state result to preserve NO_PREROLL and ASYNC */
ret = GST_STATE_RETURN (element);
child_current = GST_STATE (element);
child_pending = GST_STATE_PENDING (element);
GST_OBJECT_UNLOCK (element);
/* skip locked elements */
if (G_UNLIKELY (locked))
goto locked;
/* if the element was no preroll, just start changing the state regardless
* if it had async elements (in the case of a bin) because they won't preroll
* anyway. */
if (G_UNLIKELY (ret == GST_STATE_CHANGE_NO_PREROLL)) {
GST_DEBUG_OBJECT (element, "element is NO_PREROLL, ignore async elements");
goto no_preroll;
}
GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
"current %s pending %s, desired next %s",
gst_element_state_get_name (child_current),
gst_element_state_get_name (child_pending),
gst_element_state_get_name (next));
/* always recurse into bins so that we can set the base time */
if (GST_IS_BIN (element))
goto do_state;
/* Try not to change the state of elements that are already in the state we're
* going to */
if (child_current == next && child_pending == GST_STATE_VOID_PENDING) {
/* child is already at the requested state, return previous return. Note that
* if the child has a pending state to next, we will still call the
* set_state function */
goto unneeded;
} else if (next > current) {
/* upward state change */
if (child_pending == GST_STATE_VOID_PENDING) {
/* .. and the child is not busy doing anything */
if (child_current > next) {
/* .. and is already past the requested state, assume it got there
* without error */
ret = GST_STATE_CHANGE_SUCCESS;
goto unneeded;
}
} else if (child_pending > child_current) {
/* .. and the child is busy going upwards */
if (child_current >= next) {
/* .. and is already past the requested state, assume it got there
* without error */
ret = GST_STATE_CHANGE_SUCCESS;
goto unneeded;
}
} else {
/* .. and the child is busy going downwards */
if (child_current > next) {
/* .. and is already past the requested state, assume it got there
* without error */
ret = GST_STATE_CHANGE_SUCCESS;
goto unneeded;
}
}
} else if (next < current) {
/* downward state change */
if (child_pending == GST_STATE_VOID_PENDING) {
/* .. and the child is not busy doing anything */
if (child_current < next) {
/* .. and is already past the requested state, assume it got there
* without error */
ret = GST_STATE_CHANGE_SUCCESS;
goto unneeded;
}
} else if (child_pending < child_current) {
/* .. and the child is busy going downwards */
if (child_current <= next) {
/* .. and is already past the requested state, assume it got there
* without error */
ret = GST_STATE_CHANGE_SUCCESS;
goto unneeded;
}
} else {
/* .. and the child is busy going upwards */
if (child_current < next) {
/* .. and is already past the requested state, assume it got there
* without error */
ret = GST_STATE_CHANGE_SUCCESS;
goto unneeded;
}
}
}
do_state:
GST_OBJECT_LOCK (bin);
/* the element was busy with an upwards async state change, we must wait for
* an ASYNC_DONE message before we attempt to change the state. */
if ((found =
find_message (bin, GST_OBJECT_CAST (element),
GST_MESSAGE_ASYNC_START))) {
#ifndef GST_DISABLE_GST_DEBUG
GstMessage *message = GST_MESSAGE_CAST (found->data);
GST_DEBUG_OBJECT (element, "element message %p, %s async busy",
message, GST_ELEMENT_NAME (GST_MESSAGE_SRC (message)));
#endif
/* only wait for upward state changes */
if (next > current) {
/* We found an async element check if we can force its state to change or
* if we have to wait for it to preroll. */
goto was_busy;
}
}
GST_OBJECT_UNLOCK (bin);
no_preroll:
GST_DEBUG_OBJECT (bin,
"setting element %s to %s, base_time %" GST_TIME_FORMAT,
GST_ELEMENT_NAME (element), gst_element_state_get_name (next),
GST_TIME_ARGS (base_time));
/* change state */
ret = gst_element_set_state (element, next);
GST_STATE_UNLOCK (element);
return ret;
locked:
{
GST_DEBUG_OBJECT (element,
"element is locked, return previous return %s",
gst_element_state_change_return_get_name (ret));
GST_STATE_UNLOCK (element);
return ret;
}
unneeded:
{
GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
"skipping transition from %s to %s",
gst_element_state_get_name (child_current),
gst_element_state_get_name (next));
GST_STATE_UNLOCK (element);
return ret;
}
was_busy:
{
GST_DEBUG_OBJECT (element, "element was busy, delaying state change");
GST_OBJECT_UNLOCK (bin);
GST_STATE_UNLOCK (element);
return GST_STATE_CHANGE_ASYNC;
}
}
/* gst_iterator_fold functions for pads_activate
* Stop the iterator if activating one pad failed, but only if that pad
* has not been removed from the element. */
static gboolean
activate_pads (const GValue * vpad, GValue * ret, gboolean * active)
{
GstPad *pad = g_value_get_object (vpad);
gboolean cont = TRUE;
if (!gst_pad_set_active (pad, *active)) {
if (GST_PAD_PARENT (pad) != NULL) {
cont = FALSE;
g_value_set_boolean (ret, FALSE);
}
}
return cont;
}
/* returns false on error or early cutout of the fold, true if all
* pads in @iter were (de)activated successfully. */
static gboolean
iterator_activate_fold_with_resync (GstIterator * iter, gpointer user_data)
{
GstIteratorResult ires;
GValue ret = { 0 };
/* no need to unset this later, it's just a boolean */
g_value_init (&ret, G_TYPE_BOOLEAN);
g_value_set_boolean (&ret, TRUE);
while (1) {
ires = gst_iterator_fold (iter, (GstIteratorFoldFunction) activate_pads,
&ret, user_data);
switch (ires) {
case GST_ITERATOR_RESYNC:
/* need to reset the result again */
g_value_set_boolean (&ret, TRUE);
gst_iterator_resync (iter);
break;
case GST_ITERATOR_DONE:
/* all pads iterated, return collected value */
goto done;
default:
/* iterator returned _ERROR or premature end with _OK,
* mark an error and exit */
g_value_set_boolean (&ret, FALSE);
goto done;
}
}
done:
/* return collected value */
return g_value_get_boolean (&ret);
}
/* is called with STATE_LOCK
*/
static gboolean
gst_bin_src_pads_activate (GstBin * bin, gboolean active)
{
GstIterator *iter;
gboolean fold_ok;
GST_DEBUG_OBJECT (bin, "%s pads", active ? "activate" : "deactivate");
iter = gst_element_iterate_src_pads ((GstElement *) bin);
fold_ok = iterator_activate_fold_with_resync (iter, &active);
gst_iterator_free (iter);
if (G_UNLIKELY (!fold_ok))
goto failed;
GST_DEBUG_OBJECT (bin, "pad %sactivation successful", active ? "" : "de");
return TRUE;
/* ERRORS */
failed:
{
GST_DEBUG_OBJECT (bin, "pad %sactivation failed", active ? "" : "de");
return FALSE;
}
}
/**
* gst_bin_recalculate_latency:
* @bin: a #GstBin
*
* Queries @bin for the current latency and reconfigures this latency on all the
* elements using a LATENCY event.
*
* This method is typically called on the pipeline when a #GST_MESSAGE_LATENCY
* is posted on the bus.
*
* This function simply emits the #GstBin::do-latency signal so any custom latency
* calculations will be performed.
*
* Returns: %TRUE if the latency could be queried and reconfigured.
*/
gboolean
gst_bin_recalculate_latency (GstBin * bin)
{
gboolean res;
g_signal_emit (bin, gst_bin_signals[DO_LATENCY], 0, &res);
GST_DEBUG_OBJECT (bin, "latency returned %d", res);
return res;
}
static gboolean
gst_bin_do_latency_func (GstBin * bin)
{
GstQuery *query;
GstElement *element;
GstClockTime min_latency, max_latency;
gboolean res;
g_return_val_if_fail (GST_IS_BIN (bin), FALSE);
element = GST_ELEMENT_CAST (bin);
GST_DEBUG_OBJECT (element, "querying latency");
query = gst_query_new_latency ();
if ((res = gst_element_query (element, query))) {
gboolean live;
gst_query_parse_latency (query, &live, &min_latency, &max_latency);
GST_DEBUG_OBJECT (element,
"got min latency %" GST_TIME_FORMAT ", max latency %"
GST_TIME_FORMAT ", live %d", GST_TIME_ARGS (min_latency),
GST_TIME_ARGS (max_latency), live);
if (max_latency < min_latency) {
/* this is an impossible situation, some parts of the pipeline might not
* work correctly. We post a warning for now. */
GST_ELEMENT_WARNING (element, CORE, CLOCK, (NULL),
("Impossible to configure latency: max %" GST_TIME_FORMAT " < min %"
GST_TIME_FORMAT ". Add queues or other buffering elements.",
GST_TIME_ARGS (max_latency), GST_TIME_ARGS (min_latency)));
}
/* configure latency on elements */
res = gst_element_send_event (element, gst_event_new_latency (min_latency));
if (res) {
GST_INFO_OBJECT (element, "configured latency of %" GST_TIME_FORMAT,
GST_TIME_ARGS (min_latency));
} else {
GST_WARNING_OBJECT (element,
"did not really configure latency of %" GST_TIME_FORMAT,
GST_TIME_ARGS (min_latency));
}
} else {
/* this is not a real problem, we just don't configure any latency. */
GST_WARNING_OBJECT (element, "failed to query latency");
}
gst_query_unref (query);
return res;
}
static gboolean
gst_bin_post_message (GstElement * element, GstMessage * msg)
{
GstElementClass *pklass = (GstElementClass *) parent_class;
gboolean ret;
ret = pklass->post_message (element, gst_message_ref (msg));
if (GST_MESSAGE_TYPE (msg) == GST_MESSAGE_STATE_CHANGED &&
GST_MESSAGE_SRC (msg) == GST_OBJECT_CAST (element)) {
GstState newstate, pending;
gst_message_parse_state_changed (msg, NULL, &newstate, &pending);
if (newstate == GST_STATE_PLAYING && pending == GST_STATE_VOID_PENDING) {
GST_BIN_CAST (element)->priv->posted_playing = TRUE;
bin_do_eos (GST_BIN_CAST (element));
} else {
GST_BIN_CAST (element)->priv->posted_playing = FALSE;
}
}
gst_message_unref (msg);
return ret;
}
static void
reset_state (const GValue * data, gpointer user_data)
{
GstElement *e = g_value_get_object (data);
GstState state = GPOINTER_TO_INT (user_data);
if (gst_element_set_state (e, state) == GST_STATE_CHANGE_FAILURE)
GST_WARNING_OBJECT (e, "Failed to switch back down to %s",
gst_element_state_get_name (state));
}
static GstStateChangeReturn
gst_bin_change_state_func (GstElement * element, GstStateChange transition)
{
GstBin *bin;
GstStateChangeReturn ret;
GstState current, next;
gboolean have_async;
gboolean have_no_preroll;
GstClockTime base_time, start_time;
GstIterator *it;
gboolean done;
GValue data = { 0, };
/* we don't need to take the STATE_LOCK, it is already taken */
current = (GstState) GST_STATE_TRANSITION_CURRENT (transition);
next = (GstState) GST_STATE_TRANSITION_NEXT (transition);
GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element,
"changing state of children from %s to %s",
gst_element_state_get_name (current), gst_element_state_get_name (next));
bin = GST_BIN_CAST (element);
switch (next) {
case GST_STATE_PLAYING:
{
gboolean toplevel, asynchandling;
GST_OBJECT_LOCK (bin);
toplevel = BIN_IS_TOPLEVEL (bin);
asynchandling = bin->priv->asynchandling;
GST_OBJECT_UNLOCK (bin);
if (toplevel)
gst_bin_recalculate_latency (bin);
if (asynchandling)
gst_element_post_message (element,
gst_message_new_latency (GST_OBJECT_CAST (element)));
break;
}
case GST_STATE_PAUSED:
/* Clear EOS list on next PAUSED */
GST_OBJECT_LOCK (bin);
GST_DEBUG_OBJECT (element, "clearing EOS elements");
bin_remove_messages (bin, NULL, GST_MESSAGE_EOS);
bin->priv->posted_eos = FALSE;
if (current == GST_STATE_READY)
bin_remove_messages (bin, NULL, GST_MESSAGE_STREAM_START);
GST_OBJECT_UNLOCK (bin);
if (current == GST_STATE_READY)
if (!(gst_bin_src_pads_activate (bin, TRUE)))
goto activate_failure;
break;
case GST_STATE_READY:
/* Clear message list on next READY */
GST_OBJECT_LOCK (bin);
GST_DEBUG_OBJECT (element, "clearing all cached messages");
bin_remove_messages (bin, NULL, GST_MESSAGE_ANY);
GST_OBJECT_UNLOCK (bin);
/* We might not have reached PAUSED yet due to async errors,
* make sure to always deactivate the pads nonetheless */
if (!(gst_bin_src_pads_activate (bin, FALSE)))
goto activate_failure;
break;
case GST_STATE_NULL:
/* Clear message list on next NULL */
GST_OBJECT_LOCK (bin);
GST_DEBUG_OBJECT (element, "clearing all cached messages");
bin_remove_messages (bin, NULL, GST_MESSAGE_ANY);
GST_OBJECT_UNLOCK (bin);
if (current == GST_STATE_READY) {
if (!(gst_bin_src_pads_activate (bin, FALSE)))
goto activate_failure;
}
break;
default:
break;
}
/* this flag is used to make the async state changes return immediately. We
* don't want them to interfere with this state change */
GST_OBJECT_LOCK (bin);
bin->polling = TRUE;
GST_OBJECT_UNLOCK (bin);
/* iterate in state change order */
it = gst_bin_iterate_sorted (bin);
/* mark if we've seen an ASYNC element in the bin when we did a state change.
* Note how we don't reset this value when a resync happens, the reason being
* that the async element posted ASYNC_START and we want to post ASYNC_DONE
* even after a resync when the async element is gone */
have_async = FALSE;
restart:
/* take base_time */
base_time = gst_element_get_base_time (element);
start_time = gst_element_get_start_time (element);
have_no_preroll = FALSE;
done = FALSE;
while (!done) {
switch (gst_iterator_next (it, &data)) {
case GST_ITERATOR_OK:
{
GstElement *child;
child = g_value_get_object (&data);
/* set state and base_time now */
ret = gst_bin_element_set_state (bin, child, base_time, start_time,
current, next);
switch (ret) {
case GST_STATE_CHANGE_SUCCESS:
GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
"child '%s' changed state to %d(%s) successfully",
GST_ELEMENT_NAME (child), next,
gst_element_state_get_name (next));
break;
case GST_STATE_CHANGE_ASYNC:
{
GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
"child '%s' is changing state asynchronously to %s",
GST_ELEMENT_NAME (child), gst_element_state_get_name (next));
have_async = TRUE;
break;
}
case GST_STATE_CHANGE_FAILURE:{
GstObject *parent;
GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
"child '%s' failed to go to state %d(%s)",
GST_ELEMENT_NAME (child),
next, gst_element_state_get_name (next));
/* Only fail if the child is still inside
* this bin. It might've been removed already
* because of the error by the bin subclass
* to ignore the error. */
parent = gst_object_get_parent (GST_OBJECT_CAST (child));
if (parent == GST_OBJECT_CAST (element)) {
/* element is still in bin, really error now */
gst_object_unref (parent);
goto undo;
}
/* child removed from bin, let the resync code redo the state
* change */
GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
"child '%s' was removed from the bin",
GST_ELEMENT_NAME (child));
if (parent)
gst_object_unref (parent);
break;
}
case GST_STATE_CHANGE_NO_PREROLL:
GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
"child '%s' changed state to %d(%s) successfully without preroll",
GST_ELEMENT_NAME (child), next,
gst_element_state_get_name (next));
have_no_preroll = TRUE;
break;
default:
g_assert_not_reached ();
break;
}
g_value_reset (&data);
break;
}
case GST_ITERATOR_RESYNC:
GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element, "iterator doing resync");
gst_iterator_resync (it);
goto restart;
default:
case GST_ITERATOR_DONE:
GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element, "iterator done");
done = TRUE;
break;
}
}
ret = GST_ELEMENT_CLASS (parent_class)->change_state (element, transition);
if (G_UNLIKELY (ret == GST_STATE_CHANGE_FAILURE))
goto done;
if (have_no_preroll) {
GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin,
"we have NO_PREROLL elements %s -> NO_PREROLL",
gst_element_state_change_return_get_name (ret));
ret = GST_STATE_CHANGE_NO_PREROLL;
} else if (have_async) {
GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin,
"we have ASYNC elements %s -> ASYNC",
gst_element_state_change_return_get_name (ret));
ret = GST_STATE_CHANGE_ASYNC;
}
done:
g_value_unset (&data);
gst_iterator_free (it);
GST_OBJECT_LOCK (bin);
bin->polling = FALSE;
/* it's possible that we did not get ASYNC from the children while the bin is
* simulating ASYNC behaviour by posting an ASYNC_DONE message on the bus with
* itself as the source. In that case we still want to check if the state
* change completed. */
if (ret != GST_STATE_CHANGE_ASYNC && !bin->priv->pending_async_done) {
/* no element returned ASYNC and there are no pending async_done messages,
* we can just complete. */
GST_DEBUG_OBJECT (bin, "no async elements");
goto state_end;
}
/* when we get here an ASYNC element was found */
if (GST_STATE_TARGET (bin) <= GST_STATE_READY) {
/* we ignore ASYNC state changes when we go to READY or NULL */
GST_DEBUG_OBJECT (bin, "target state %s <= READY",
gst_element_state_get_name (GST_STATE_TARGET (bin)));
goto state_end;
}
GST_DEBUG_OBJECT (bin, "check async elements");
/* check if all elements managed to commit their state already */
if (!find_message (bin, NULL, GST_MESSAGE_ASYNC_START)) {
/* nothing found, remove all old ASYNC_DONE messages. This can happen when
* all the elements committed their state while we were doing the state
* change. We will still return ASYNC for consistency but we commit the
* state already so that a _get_state() will return immediately. */
bin_remove_messages (bin, NULL, GST_MESSAGE_ASYNC_DONE);
GST_DEBUG_OBJECT (bin, "async elements committed");
bin_handle_async_done (bin, GST_STATE_CHANGE_SUCCESS, FALSE,
GST_CLOCK_TIME_NONE);
}
state_end:
bin->priv->pending_async_done = FALSE;
GST_OBJECT_UNLOCK (bin);
GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element,
"done changing bin's state from %s to %s, now in %s, ret %s",
gst_element_state_get_name (current),
gst_element_state_get_name (next),
gst_element_state_get_name (GST_STATE (element)),
gst_element_state_change_return_get_name (ret));
return ret;
/* ERRORS */
activate_failure:
{
GST_CAT_WARNING_OBJECT (GST_CAT_STATES, element,
"failure (de)activating src pads");
return GST_STATE_CHANGE_FAILURE;
}
undo:
{
if (current < next) {
GstIterator *it = gst_bin_iterate_sorted (GST_BIN (element));
GstIteratorResult ret;
GST_DEBUG_OBJECT (element,
"Bin failed to change state, switching children back to %s",
gst_element_state_get_name (current));
while (TRUE) {
ret =
gst_iterator_foreach (it, &reset_state, GINT_TO_POINTER (current));
if (ret != GST_ITERATOR_RESYNC)
break;
gst_iterator_resync (it);
}
gst_iterator_free (it);
}
goto done;
}
}
/*
* This function is a utility event handler. It will send the event to all sinks
* or sources and appropriate ghost pads depending on the event-direction.
*
* Applications are free to override this behaviour and implement their own
* 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_CAST (element);
GstIterator *iter;
gboolean res = TRUE;
gboolean done = FALSE;
GValue data = { 0, };
if (GST_EVENT_IS_DOWNSTREAM (event)) {
iter = gst_bin_iterate_sources (bin);
GST_DEBUG_OBJECT (bin, "Sending %s event to src children",
GST_EVENT_TYPE_NAME (event));
} else {
iter = gst_bin_iterate_sinks (bin);
GST_DEBUG_OBJECT (bin, "Sending %s event to sink children",
GST_EVENT_TYPE_NAME (event));
}
while (!done) {
switch (gst_iterator_next (iter, &data)) {
case GST_ITERATOR_OK:
{
GstElement *child = g_value_get_object (&data);
gst_event_ref (event);
res &= gst_element_send_event (child, event);
GST_LOG_OBJECT (child, "After handling %s event: %d",
GST_EVENT_TYPE_NAME (event), res);
g_value_reset (&data);
break;
}
case GST_ITERATOR_RESYNC:
gst_iterator_resync (iter);
res = TRUE;
break;
case GST_ITERATOR_DONE:
done = TRUE;
break;
case GST_ITERATOR_ERROR:
g_assert_not_reached ();
break;
}
}
g_value_unset (&data);
gst_iterator_free (iter);
if (GST_EVENT_IS_DOWNSTREAM (event)) {
iter = gst_element_iterate_sink_pads (GST_ELEMENT (bin));
GST_DEBUG_OBJECT (bin, "Sending %s event to sink pads",
GST_EVENT_TYPE_NAME (event));
} else {
iter = gst_element_iterate_src_pads (GST_ELEMENT (bin));
GST_DEBUG_OBJECT (bin, "Sending %s event to src pads",
GST_EVENT_TYPE_NAME (event));
}
done = FALSE;
while (!done) {
switch (gst_iterator_next (iter, &data)) {
case GST_ITERATOR_OK:
{
GstPad *pad = g_value_get_object (&data);
gst_event_ref (event);
res &= gst_pad_send_event (pad, event);
GST_LOG_OBJECT (pad, "After handling %s event: %d",
GST_EVENT_TYPE_NAME (event), res);
break;
}
case GST_ITERATOR_RESYNC:
gst_iterator_resync (iter);
res = TRUE;
break;
case GST_ITERATOR_DONE:
done = TRUE;
break;
case GST_ITERATOR_ERROR:
g_assert_not_reached ();
break;
}
}
g_value_unset (&data);
gst_iterator_free (iter);
gst_event_unref (event);
return res;
}
/* this is the function called by the threadpool. When async elements commit
* their state, this function will attempt to bring the bin to the next state.
*/
static void
gst_bin_continue_func (GstBin * bin, BinContinueData * data)
{
GstState current, next, pending;
GstStateChange transition;
pending = data->pending;
GST_DEBUG_OBJECT (bin, "waiting for state lock");
GST_STATE_LOCK (bin);
GST_DEBUG_OBJECT (bin, "doing state continue");
GST_OBJECT_LOCK (bin);
/* if a new state change happened after this thread was scheduled, we return
* immediately. */
if (data->cookie != GST_ELEMENT_CAST (bin)->state_cookie)
goto interrupted;
current = GST_STATE (bin);
next = GST_STATE_GET_NEXT (current, pending);
transition = (GstStateChange) GST_STATE_TRANSITION (current, next);
GST_STATE_NEXT (bin) = next;
GST_STATE_PENDING (bin) = pending;
/* mark busy */
GST_STATE_RETURN (bin) = GST_STATE_CHANGE_ASYNC;
GST_OBJECT_UNLOCK (bin);
GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
"continue state change %s to %s, final %s",
gst_element_state_get_name (current),
gst_element_state_get_name (next), gst_element_state_get_name (pending));
gst_element_change_state (GST_ELEMENT_CAST (bin), transition);
GST_STATE_UNLOCK (bin);
GST_DEBUG_OBJECT (bin, "state continue done");
return;
interrupted:
{
GST_OBJECT_UNLOCK (bin);
GST_STATE_UNLOCK (bin);
GST_DEBUG_OBJECT (bin, "state continue aborted due to intervening change");
return;
}
}
static GstBusSyncReply
bin_bus_handler (GstBus * bus, GstMessage * message, GstBin * bin)
{
GstBinClass *bclass;
bclass = GST_BIN_GET_CLASS (bin);
if (bclass->handle_message)
bclass->handle_message (bin, message);
else
gst_message_unref (message);
return GST_BUS_DROP;
}
static void
free_bin_continue_data (BinContinueData * data)
{
g_slice_free (BinContinueData, data);
}
static void
bin_push_state_continue (GstBin * bin, BinContinueData * data)
{
GST_DEBUG_OBJECT (bin, "pushing continue on thread pool");
gst_element_call_async (GST_ELEMENT_CAST (bin),
(GstElementCallAsyncFunc) gst_bin_continue_func, data,
(GDestroyNotify) free_bin_continue_data);
}
/* an element started an async state change, if we were not busy with a state
* change, we perform a lost state.
* This function is called with the OBJECT lock.
*/
static void
bin_handle_async_start (GstBin * bin)
{
GstState old_state, new_state;
gboolean toplevel;
GstMessage *amessage = NULL;
if (GST_STATE_RETURN (bin) == GST_STATE_CHANGE_FAILURE)
goto had_error;
/* get our toplevel state */
toplevel = BIN_IS_TOPLEVEL (bin);
/* prepare an ASYNC_START message, we always post the start message even if we
* are busy with a state change or when we are NO_PREROLL. */
if (!toplevel)
/* non toplevel bin, prepare async-start for the parent */
amessage = gst_message_new_async_start (GST_OBJECT_CAST (bin));
if (bin->polling || GST_STATE_PENDING (bin) != GST_STATE_VOID_PENDING)
goto was_busy;
/* async starts are ignored when we are NO_PREROLL */
if (GST_STATE_RETURN (bin) == GST_STATE_CHANGE_NO_PREROLL)
goto was_no_preroll;
old_state = GST_STATE (bin);
/* when we PLAYING we go back to PAUSED, when preroll happens, we go back to
* PLAYING after optionally redistributing the base_time. */
if (old_state > GST_STATE_PAUSED)
new_state = GST_STATE_PAUSED;
else
new_state = old_state;
GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin,
"lost state of %s, new %s", gst_element_state_get_name (old_state),
gst_element_state_get_name (new_state));
GST_STATE (bin) = new_state;
GST_STATE_NEXT (bin) = new_state;
GST_STATE_PENDING (bin) = new_state;
GST_STATE_RETURN (bin) = GST_STATE_CHANGE_ASYNC;
GST_OBJECT_UNLOCK (bin);
/* post message */
_priv_gst_element_state_changed (GST_ELEMENT_CAST (bin), new_state, new_state,
new_state);
post_start:
if (amessage) {
/* post our ASYNC_START. */
GST_DEBUG_OBJECT (bin, "posting ASYNC_START to parent");
gst_element_post_message (GST_ELEMENT_CAST (bin), amessage);
}
GST_OBJECT_LOCK (bin);
return;
had_error:
{
GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "we had an error");
return;
}
was_busy:
{
GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "state change busy");
GST_OBJECT_UNLOCK (bin);
goto post_start;
}
was_no_preroll:
{
GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "ignoring, we are NO_PREROLL");
GST_OBJECT_UNLOCK (bin);
goto post_start;
}
}
/* this function is called when there are no more async elements in the bin. We
* post a state changed message and an ASYNC_DONE message.
* This function is called with the OBJECT lock.
*/
static void
bin_handle_async_done (GstBin * bin, GstStateChangeReturn ret,
gboolean flag_pending, GstClockTime running_time)
{
GstState current, pending, target;
GstStateChangeReturn old_ret;
GstState old_state, old_next;
gboolean toplevel, state_changed = FALSE;
GstMessage *amessage = NULL;
BinContinueData *cont = NULL;
if (GST_STATE_RETURN (bin) == GST_STATE_CHANGE_FAILURE)
goto had_error;
pending = GST_STATE_PENDING (bin);
if (bin->polling)
goto was_busy;
/* check if there is something to commit */
if (pending == GST_STATE_VOID_PENDING)
goto nothing_pending;
old_ret = GST_STATE_RETURN (bin);
GST_STATE_RETURN (bin) = ret;
/* move to the next target state */
target = GST_STATE_TARGET (bin);
pending = GST_STATE_PENDING (bin) = target;
amessage = gst_message_new_async_done (GST_OBJECT_CAST (bin), running_time);
old_state = GST_STATE (bin);
/* this is the state we should go to next */
old_next = GST_STATE_NEXT (bin);
if (old_next != GST_STATE_PLAYING) {
GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
"committing state from %s to %s, old pending %s",
gst_element_state_get_name (old_state),
gst_element_state_get_name (old_next),
gst_element_state_get_name (pending));
/* update current state */
current = GST_STATE (bin) = old_next;
} else {
GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
"setting state from %s to %s, pending %s",
gst_element_state_get_name (old_state),
gst_element_state_get_name (old_state),
gst_element_state_get_name (pending));
current = old_state;
}
/* get our toplevel state */
toplevel = BIN_IS_TOPLEVEL (bin);
/* see if we reached the final state. If we are not toplevel, we also have to
* stop here, the parent will continue our state. */
if ((pending == current) || !toplevel) {
GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
"completed state change, pending VOID");
/* mark VOID pending */
pending = GST_STATE_VOID_PENDING;
GST_STATE_PENDING (bin) = pending;
GST_STATE_NEXT (bin) = GST_STATE_VOID_PENDING;
} else {
GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
"continue state change, pending %s",
gst_element_state_get_name (pending));
cont = g_slice_new (BinContinueData);
/* cookie to detect concurrent state change */
cont->cookie = GST_ELEMENT_CAST (bin)->state_cookie;
/* pending target state */
cont->pending = pending;
/* mark busy */
GST_STATE_RETURN (bin) = GST_STATE_CHANGE_ASYNC;
GST_STATE_NEXT (bin) = GST_STATE_GET_NEXT (old_state, pending);
}
if (old_next != GST_STATE_PLAYING) {
if (old_state != old_next || old_ret == GST_STATE_CHANGE_ASYNC) {
state_changed = TRUE;
}
}
GST_OBJECT_UNLOCK (bin);
if (state_changed) {
_priv_gst_element_state_changed (GST_ELEMENT_CAST (bin), old_state,
old_next, pending);
}
if (amessage) {
/* post our combined ASYNC_DONE when all is ASYNC_DONE. */
GST_DEBUG_OBJECT (bin, "posting ASYNC_DONE to parent");
gst_element_post_message (GST_ELEMENT_CAST (bin), amessage);
}
GST_OBJECT_LOCK (bin);
if (cont) {
/* toplevel, start continue state */
GST_DEBUG_OBJECT (bin, "all async-done, starting state continue");
bin_push_state_continue (bin, cont);
} else {
GST_DEBUG_OBJECT (bin, "state change complete");
GST_STATE_BROADCAST (bin);
}
return;
had_error:
{
GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "we had an error");
return;
}
was_busy:
{
GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "state change busy");
/* if we were busy with a state change and we are requested to flag a
* pending async done, we do so here */
if (flag_pending)
bin->priv->pending_async_done = TRUE;
return;
}
nothing_pending:
{
GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin, "nothing pending");
return;
}
}
static void
bin_do_eos (GstBin * bin)
{
guint32 seqnum = GST_SEQNUM_INVALID;
gboolean eos;
GST_OBJECT_LOCK (bin);
/* If all sinks are EOS, we're in PLAYING and no state change is pending
* (or we're doing playing to playing and no one else will trigger posting
* EOS for us) we forward the EOS message to the parent bin or application
*/
eos = GST_STATE (bin) == GST_STATE_PLAYING
&& (GST_STATE_PENDING (bin) == GST_STATE_VOID_PENDING ||
GST_STATE_PENDING (bin) == GST_STATE_PLAYING)
&& bin->priv->posted_playing && is_eos (bin, &seqnum);
GST_OBJECT_UNLOCK (bin);
if (eos
&& g_atomic_int_compare_and_exchange (&bin->priv->posted_eos, FALSE,
TRUE)) {
GstMessage *tmessage;
/* Clear out any further messages, and reset posted_eos so we can
detect any new EOS that happens (eg, after a seek). Since all
sinks have now posted an EOS, there will be no further EOS events
seen unless there is a new logical EOS */
GST_OBJECT_LOCK (bin);
bin_remove_messages (bin, NULL, GST_MESSAGE_EOS);
bin->priv->posted_eos = FALSE;
GST_OBJECT_UNLOCK (bin);
tmessage = gst_message_new_eos (GST_OBJECT_CAST (bin));
if (seqnum != GST_SEQNUM_INVALID)
gst_message_set_seqnum (tmessage, seqnum);
GST_DEBUG_OBJECT (bin,
"all sinks posted EOS, posting seqnum #%" G_GUINT32_FORMAT, seqnum);
gst_element_post_message (GST_ELEMENT_CAST (bin), tmessage);
} else {
GST_LOG_OBJECT (bin, "Not forwarding EOS due to in progress state change, "
" or already posted, or waiting for more EOS");
}
}
static void
bin_do_stream_start (GstBin * bin)
{
guint32 seqnum = GST_SEQNUM_INVALID;
gboolean stream_start;
gboolean have_group_id = FALSE;
guint group_id = 0;
GST_OBJECT_LOCK (bin);
/* If all sinks are STREAM_START we forward the STREAM_START message
* to the parent bin or application
*/
stream_start = is_stream_start (bin, &seqnum, &have_group_id, &group_id);
GST_OBJECT_UNLOCK (bin);
if (stream_start) {
GstMessage *tmessage;
GST_OBJECT_LOCK (bin);
bin_remove_messages (bin, NULL, GST_MESSAGE_STREAM_START);
GST_OBJECT_UNLOCK (bin);
tmessage = gst_message_new_stream_start (GST_OBJECT_CAST (bin));
if (seqnum != GST_SEQNUM_INVALID)
gst_message_set_seqnum (tmessage, seqnum);
if (have_group_id)
gst_message_set_group_id (tmessage, group_id);
GST_DEBUG_OBJECT (bin,
"all sinks posted STREAM_START, posting seqnum #%" G_GUINT32_FORMAT,
seqnum);
gst_element_post_message (GST_ELEMENT_CAST (bin), tmessage);
}
}
/* must be called without the object lock as it posts messages */
static void
bin_do_message_forward (GstBin * bin, GstMessage * message)
{
if (bin->priv->message_forward) {
GstMessage *forwarded;
GST_DEBUG_OBJECT (bin, "pass %s message upward",
GST_MESSAGE_TYPE_NAME (message));
/* we need to convert these messages to element messages so that our parent
* bin can easily ignore them and so that the application can easily
* distinguish between the internally forwarded and the real messages. */
forwarded = gst_message_new_element (GST_OBJECT_CAST (bin),
gst_structure_new ("GstBinForwarded",
"message", GST_TYPE_MESSAGE, message, NULL));
gst_element_post_message (GST_ELEMENT_CAST (bin), forwarded);
}
}
static void
gst_bin_update_context (GstBin * bin, GstContext * context)
{
GST_OBJECT_LOCK (bin);
gst_bin_update_context_unlocked (bin, context);
GST_OBJECT_UNLOCK (bin);
}
static void
gst_bin_update_context_unlocked (GstBin * bin, GstContext * context)
{
const gchar *context_type;
GList *l, **contexts;
contexts = &GST_ELEMENT_CAST (bin)->contexts;
context_type = gst_context_get_context_type (context);
GST_DEBUG_OBJECT (bin, "set context %p %" GST_PTR_FORMAT, context,
gst_context_get_structure (context));
for (l = *contexts; l; l = l->next) {
GstContext *tmp = l->data;
const gchar *tmp_type = gst_context_get_context_type (tmp);
/* Always store newest context but never replace
* a persistent one by a non-persistent one */
if (strcmp (context_type, tmp_type) == 0 &&
(gst_context_is_persistent (context) ||
!gst_context_is_persistent (tmp))) {
gst_context_replace ((GstContext **) & l->data, context);
break;
}
}
/* Not found? Add */
if (l == NULL) {
*contexts = g_list_prepend (*contexts, gst_context_ref (context));
}
}
/* handle child messages:
*
* This method is called synchronously when a child posts a message on
* the internal bus.
*
* GST_MESSAGE_EOS: This message is only posted by sinks
* in the PLAYING state. If all sinks posted the EOS message, post
* one upwards.
*
* GST_MESSAGE_STATE_DIRTY: Deprecated
*
* GST_MESSAGE_SEGMENT_START: just collect, never forward upwards. If an
* element posts segment_start twice, only the last message is kept.
*
* GST_MESSAGE_SEGMENT_DONE: replace SEGMENT_START message from same poster
* with the segment_done message. If there are no more segment_start
* messages, post segment_done message upwards.
*
* GST_MESSAGE_CLOCK_LOST: This message is posted by an element when it
* can no longer provide a clock. The default bin behaviour is to
* check if the lost clock was the one provided by the bin. If so and
* we are currently in the PLAYING state, we forward the message to
* our parent.
* This message is also generated when we remove a clock provider from
* a bin. If this message is received by the application, it should
* PAUSE the pipeline and set it back to PLAYING to force a new clock
* and a new base_time distribution.
*
* GST_MESSAGE_CLOCK_PROVIDE: This message is generated when an element
* can provide a clock. This mostly happens when we add a new clock
* provider to the bin. The default behaviour of the bin is to mark the
* currently selected clock as dirty, which will perform a clock
* recalculation the next time we are asked to provide a clock.
* This message is never sent to the application but is forwarded to
* the parent.
*
* GST_MESSAGE_ASYNC_START: Create an internal ELEMENT message that stores
* the state of the element and the fact that the element will need a
* new base_time. This message is not forwarded to the application.
*
* GST_MESSAGE_ASYNC_DONE: Find the internal ELEMENT message we kept for the
* element when it posted ASYNC_START. If all elements are done, post a
* ASYNC_DONE message to the parent.
*
* OTHER: post upwards.
*/
static void
gst_bin_handle_message_func (GstBin * bin, GstMessage * message)
{
GstObject *src;
GstMessageType type;
GstMessage *tmessage;
guint32 seqnum;
src = GST_MESSAGE_SRC (message);
type = GST_MESSAGE_TYPE (message);
GST_DEBUG_OBJECT (bin, "[msg %p] handling child %s message of type %s",
message, src ? GST_ELEMENT_NAME (src) : "(NULL)",
GST_MESSAGE_TYPE_NAME (message));
switch (type) {
case GST_MESSAGE_ERROR:
{
GST_OBJECT_LOCK (bin);
/* flag error */
GST_DEBUG_OBJECT (bin, "got ERROR message, unlocking state change");
GST_STATE_RETURN (bin) = GST_STATE_CHANGE_FAILURE;
GST_STATE_BROADCAST (bin);
GST_OBJECT_UNLOCK (bin);
goto forward;
}
case GST_MESSAGE_EOS:
{
/* collect all eos messages from the children */
bin_do_message_forward (bin, message);
GST_OBJECT_LOCK (bin);
/* ref message for future use */
bin_replace_message (bin, message, GST_MESSAGE_EOS);
GST_OBJECT_UNLOCK (bin);
bin_do_eos (bin);
break;
}
case GST_MESSAGE_STREAM_START:
{
/* collect all stream_start messages from the children */
GST_OBJECT_LOCK (bin);
/* ref message for future use */
bin_replace_message (bin, message, GST_MESSAGE_STREAM_START);
GST_OBJECT_UNLOCK (bin);
bin_do_stream_start (bin);
break;
}
case GST_MESSAGE_STATE_DIRTY:
{
GST_WARNING_OBJECT (bin, "received deprecated STATE_DIRTY message");
/* free message */
gst_message_unref (message);
break;
}
case GST_MESSAGE_SEGMENT_START:{
gboolean post = FALSE;
GstFormat format;
gint64 position;
gst_message_parse_segment_start (message, &format, &position);
seqnum = gst_message_get_seqnum (message);
bin_do_message_forward (bin, message);
GST_OBJECT_LOCK (bin);
/* if this is the first segment-start, post to parent but not to the
* application */
if (!find_message (bin, NULL, GST_MESSAGE_SEGMENT_START) &&
(GST_OBJECT_PARENT (bin) != NULL)) {
post = TRUE;
}
/* replace any previous segment_start message from this source
* with the new segment start message */
bin_replace_message (bin, message, GST_MESSAGE_SEGMENT_START);
GST_OBJECT_UNLOCK (bin);
if (post) {
tmessage = gst_message_new_segment_start (GST_OBJECT_CAST (bin),
format, position);
gst_message_set_seqnum (tmessage, seqnum);
/* post segment start with initial format and position. */
GST_DEBUG_OBJECT (bin, "posting SEGMENT_START (%u) bus message: %p",
seqnum, message);
gst_element_post_message (GST_ELEMENT_CAST (bin), tmessage);
}
break;
}
case GST_MESSAGE_SEGMENT_DONE:
{
gboolean post = FALSE;
GstFormat format;
gint64 position;
gst_message_parse_segment_done (message, &format, &position);
seqnum = gst_message_get_seqnum (message);
bin_do_message_forward (bin, message);
GST_OBJECT_LOCK (bin);
bin_replace_message (bin, message, GST_MESSAGE_SEGMENT_START);
/* if there are no more segment_start messages, everybody posted
* a segment_done and we can post one on the bus. */
/* we don't care who still has a pending segment start */
if (!find_message (bin, NULL, GST_MESSAGE_SEGMENT_START)) {
/* nothing found */
post = TRUE;
/* remove all old segment_done messages */
bin_remove_messages (bin, NULL, GST_MESSAGE_SEGMENT_DONE);
}
GST_OBJECT_UNLOCK (bin);
if (post) {
tmessage = gst_message_new_segment_done (GST_OBJECT_CAST (bin),
format, position);
gst_message_set_seqnum (tmessage, seqnum);
/* post segment done with latest format and position. */
GST_DEBUG_OBJECT (bin, "posting SEGMENT_DONE (%u) bus message: %p",
seqnum, message);
gst_element_post_message (GST_ELEMENT_CAST (bin), tmessage);
}
break;
}
case GST_MESSAGE_CLOCK_LOST:
{
GstClock **provided_clock_p;
GstElement **clock_provider_p;
gboolean playing, toplevel, provided, forward;
GstClock *clock;
gst_message_parse_clock_lost (message, &clock);
GST_OBJECT_LOCK (bin);
bin->clock_dirty = TRUE;
/* if we lost the clock that we provided, post to parent but
* only if we are not a top-level bin or PLAYING.
* The reason for this is that applications should be able
* to PAUSE/PLAY if they receive this message without worrying
* about the state of the pipeline. */
provided = (clock == bin->provided_clock);
playing = (GST_STATE (bin) == GST_STATE_PLAYING);
toplevel = GST_OBJECT_PARENT (bin) == NULL;
forward = provided && (playing || !toplevel);
if (provided) {
GST_DEBUG_OBJECT (bin,
"Lost clock %" GST_PTR_FORMAT " provided by %" GST_PTR_FORMAT,
bin->provided_clock, bin->clock_provider);
provided_clock_p = &bin->provided_clock;
clock_provider_p = &bin->clock_provider;
gst_object_replace ((GstObject **) provided_clock_p, NULL);
gst_object_replace ((GstObject **) clock_provider_p, NULL);
}
GST_DEBUG_OBJECT (bin, "provided %d, playing %d, forward %d",
provided, playing, forward);
GST_OBJECT_UNLOCK (bin);
if (forward)
goto forward;
/* free message */
gst_message_unref (message);
break;
}
case GST_MESSAGE_CLOCK_PROVIDE:
{
gboolean forward;
GST_OBJECT_LOCK (bin);
bin->clock_dirty = TRUE;
/* a new clock is available, post to parent but not
* to the application */
forward = GST_OBJECT_PARENT (bin) != NULL;
GST_OBJECT_UNLOCK (bin);
if (forward)
goto forward;
/* free message */
gst_message_unref (message);
break;
}
case GST_MESSAGE_ASYNC_START:
{
GstState target;
GST_DEBUG_OBJECT (bin, "ASYNC_START message %p, %s", message,
src ? GST_OBJECT_NAME (src) : "(NULL)");
bin_do_message_forward (bin, message);
GST_OBJECT_LOCK (bin);
/* we ignore the message if we are going to <= READY */
if ((target = GST_STATE_TARGET (bin)) <= GST_STATE_READY)
goto ignore_start_message;
/* takes ownership of the message */
bin_replace_message (bin, message, GST_MESSAGE_ASYNC_START);
bin_handle_async_start (bin);
GST_OBJECT_UNLOCK (bin);
break;
ignore_start_message:
{
GST_DEBUG_OBJECT (bin, "ignoring message, target %s",
gst_element_state_get_name (target));
GST_OBJECT_UNLOCK (bin);
gst_message_unref (message);
break;
}
}
case GST_MESSAGE_ASYNC_DONE:
{
GstClockTime running_time;
GstState target;
GST_DEBUG_OBJECT (bin, "ASYNC_DONE message %p, %s", message,
src ? GST_OBJECT_NAME (src) : "(NULL)");
gst_message_parse_async_done (message, &running_time);
bin_do_message_forward (bin, message);
GST_OBJECT_LOCK (bin);
/* ignore messages if we are shutting down */
if ((target = GST_STATE_TARGET (bin)) <= GST_STATE_READY)
goto ignore_done_message;
bin_replace_message (bin, message, GST_MESSAGE_ASYNC_START);
/* if there are no more ASYNC_START messages, everybody posted
* a ASYNC_DONE and we can post one on the bus. When checking, we
* don't care who still has a pending ASYNC_START */
if (!find_message (bin, NULL, GST_MESSAGE_ASYNC_START)) {
/* nothing found, remove all old ASYNC_DONE messages */
bin_remove_messages (bin, NULL, GST_MESSAGE_ASYNC_DONE);
GST_DEBUG_OBJECT (bin, "async elements committed");
/* when we get an async done message when a state change was busy, we
* need to set the pending_done flag so that at the end of the state
* change we can see if we need to verify pending async elements, hence
* the TRUE argument here. */
bin_handle_async_done (bin, GST_STATE_CHANGE_SUCCESS, TRUE,
running_time);
} else {
GST_DEBUG_OBJECT (bin, "there are more async elements pending");
}
GST_OBJECT_UNLOCK (bin);
break;
ignore_done_message:
{
GST_DEBUG_OBJECT (bin, "ignoring message, target %s",
gst_element_state_get_name (target));
GST_OBJECT_UNLOCK (bin);
gst_message_unref (message);
break;
}
}
case GST_MESSAGE_STRUCTURE_CHANGE:
{
gboolean busy;
gst_message_parse_structure_change (message, NULL, NULL, &busy);
GST_OBJECT_LOCK (bin);
if (busy) {
/* while the pad is busy, avoid following it when doing state changes.
* Don't update the cookie yet, we will do that after the structure
* change finished and we are ready to inspect the new updated
* structure. */
bin_replace_message (bin, message, GST_MESSAGE_STRUCTURE_CHANGE);
message = NULL;
} else {
/* a pad link/unlink ended, signal the state change iterator that we
* need to resync by updating the structure_cookie. */
bin_remove_messages (bin, GST_MESSAGE_SRC (message),
GST_MESSAGE_STRUCTURE_CHANGE);
if (!GST_BIN_IS_NO_RESYNC (bin))
bin->priv->structure_cookie++;
}
GST_OBJECT_UNLOCK (bin);
if (message)
gst_message_unref (message);
break;
}
case GST_MESSAGE_NEED_CONTEXT:{
const gchar *context_type;
GList *l, *contexts;
gst_message_parse_context_type (message, &context_type);
if (src) {
GST_OBJECT_LOCK (bin);
contexts = GST_ELEMENT_CAST (bin)->contexts;
GST_LOG_OBJECT (bin, "got need-context message type: %s", context_type);
for (l = contexts; l; l = l->next) {
GstContext *tmp = l->data;
const gchar *tmp_type = gst_context_get_context_type (tmp);
if (strcmp (context_type, tmp_type) == 0) {
gst_element_set_context (GST_ELEMENT (src), l->data);
break;
}
}
GST_OBJECT_UNLOCK (bin);
/* Forward if we couldn't answer the message */
if (l == NULL) {
goto forward;
} else {
gst_message_unref (message);
}
} else {
g_warning
("Got need-context message in bin '%s' without source element, dropping",
GST_ELEMENT_NAME (bin));
gst_message_unref (message);
}
break;
}
case GST_MESSAGE_HAVE_CONTEXT:{
GstContext *context;
gst_message_parse_have_context (message, &context);
gst_bin_update_context (bin, context);
gst_context_unref (context);
goto forward;
break;
}
default:
goto forward;
}
return;
forward:
{
/* Send all other messages upward */
GST_DEBUG_OBJECT (bin, "posting message upward");
gst_element_post_message (GST_ELEMENT_CAST (bin), message);
return;
}
}
/* generic struct passed to all query fold methods */
typedef struct
{
GstQuery *query;
gint64 min;
gint64 max;
gboolean live;
} QueryFold;
typedef void (*QueryInitFunction) (GstBin * bin, QueryFold * fold);
typedef void (*QueryDoneFunction) (GstBin * bin, QueryFold * fold);
/* for duration/position we collect all durations/positions and take
* the MAX of all valid results */
static void
bin_query_min_max_init (GstBin * bin, QueryFold * fold)
{
fold->min = 0;
fold->max = -1;
fold->live = FALSE;
}
static gboolean
bin_query_duration_fold (const GValue * vitem, GValue * ret, QueryFold * fold)
{
gboolean res = FALSE;
GstObject *item = g_value_get_object (vitem);
if (GST_IS_PAD (item))
res = gst_pad_query (GST_PAD (item), fold->query);
else
res = gst_element_query (GST_ELEMENT (item), fold->query);
if (res) {
gint64 duration;
g_value_set_boolean (ret, TRUE);
gst_query_parse_duration (fold->query, NULL, &duration);
GST_DEBUG_OBJECT (item, "got duration %" G_GINT64_FORMAT, duration);
if (duration == -1) {
/* duration query succeeded, but duration is unknown */
fold->max = -1;
return FALSE;
}
if (duration > fold->max)
fold->max = duration;
}
return TRUE;
}
static void
bin_query_duration_done (GstBin * bin, QueryFold * fold)
{
GstFormat format;
gst_query_parse_duration (fold->query, &format, NULL);
/* store max in query result */
gst_query_set_duration (fold->query, format, fold->max);
GST_DEBUG_OBJECT (bin, "max duration %" G_GINT64_FORMAT, fold->max);
}
static gboolean
bin_query_position_fold (const GValue * vitem, GValue * ret, QueryFold * fold)
{
gboolean res = FALSE;
GstObject *item = g_value_get_object (vitem);
if (GST_IS_PAD (item))
res = gst_pad_query (GST_PAD (item), fold->query);
else
res = gst_element_query (GST_ELEMENT (item), fold->query);
if (res) {
gint64 position;
g_value_set_boolean (ret, TRUE);
gst_query_parse_position (fold->query, NULL, &position);
GST_DEBUG_OBJECT (item, "got position %" G_GINT64_FORMAT, position);
if (position > fold->max)
fold->max = position;
}
return TRUE;
}
static void
bin_query_position_done (GstBin * bin, QueryFold * fold)
{
GstFormat format;
gst_query_parse_position (fold->query, &format, NULL);
/* store max in query result */
gst_query_set_position (fold->query, format, fold->max);
GST_DEBUG_OBJECT (bin, "max position %" G_GINT64_FORMAT, fold->max);
}
static gboolean
bin_query_latency_fold (const GValue * vitem, GValue * ret, QueryFold * fold)
{
gboolean res = FALSE;
GstObject *item = g_value_get_object (vitem);
if (GST_IS_PAD (item))
res = gst_pad_query (GST_PAD (item), fold->query);
else
res = gst_element_query (GST_ELEMENT (item), fold->query);
if (res) {
GstClockTime min, max;
gboolean live;
gst_query_parse_latency (fold->query, &live, &min, &max);
GST_DEBUG_OBJECT (item,
"got latency min %" GST_TIME_FORMAT ", max %" GST_TIME_FORMAT
", live %d", GST_TIME_ARGS (min), GST_TIME_ARGS (max), live);
/* for the combined latency we collect the MAX of all min latencies and
* the MIN of all max latencies */
if (live) {
if (min > fold->min)
fold->min = min;
if (fold->max == -1)
fold->max = max;
else if (max < fold->max)
fold->max = max;
if (!fold->live)
fold->live = live;
}
} else {
g_value_set_boolean (ret, FALSE);
GST_DEBUG_OBJECT (item, "failed query");
}
return TRUE;
}
static void
bin_query_latency_done (GstBin * bin, QueryFold * fold)
{
/* store max in query result */
gst_query_set_latency (fold->query, fold->live, fold->min, fold->max);
GST_DEBUG_OBJECT (bin,
"latency min %" GST_TIME_FORMAT ", max %" GST_TIME_FORMAT
", live %d", GST_TIME_ARGS (fold->min), GST_TIME_ARGS (fold->max),
fold->live);
}
/* generic fold, return first valid result */
static gboolean
bin_query_generic_fold (const GValue * vitem, GValue * ret, QueryFold * fold)
{
gboolean res = FALSE;
GstObject *item = g_value_get_object (vitem);
if (GST_IS_PAD (item))
res = gst_pad_query (GST_PAD (item), fold->query);
else
res = gst_element_query (GST_ELEMENT (item), fold->query);
if (res) {
g_value_set_boolean (ret, TRUE);
GST_DEBUG_OBJECT (item, "answered query %p", fold->query);
}
/* and stop as soon as we have a valid result */
return !res;
}
/* Perform a query iteration for the given bin. The query is stored in
* QueryFold and iter should be either a GstPad iterator or a
* GstElement iterator. */
static gboolean
bin_iterate_fold (GstBin * bin, GstIterator * iter, QueryInitFunction fold_init,
QueryDoneFunction fold_done, GstIteratorFoldFunction fold_func,
QueryFold * fold_data, gboolean default_return)
{
gboolean res = default_return;
GValue ret = { 0 };
/* set the result of the query to FALSE initially */
g_value_init (&ret, G_TYPE_BOOLEAN);
g_value_set_boolean (&ret, res);
while (TRUE) {
GstIteratorResult ires;
ires = gst_iterator_fold (iter, fold_func, &ret, fold_data);
switch (ires) {
case GST_ITERATOR_RESYNC:
gst_iterator_resync (iter);
if (fold_init)
fold_init (bin, fold_data);
g_value_set_boolean (&ret, res);
break;
case GST_ITERATOR_OK:
case GST_ITERATOR_DONE:
res = g_value_get_boolean (&ret);
if (fold_done != NULL && res)
fold_done (bin, fold_data);
goto done;
default:
res = FALSE;
goto done;
}
}
done:
return res;
}
static gboolean
gst_bin_query (GstElement * element, GstQuery * query)
{
GstBin *bin = GST_BIN_CAST (element);
GstIterator *iter;
gboolean default_return = FALSE;
gboolean res = FALSE;
gboolean src_pads_query_result = FALSE;
GstIteratorFoldFunction fold_func;
QueryInitFunction fold_init = NULL;
QueryDoneFunction fold_done = NULL;
QueryFold fold_data;
switch (GST_QUERY_TYPE (query)) {
case GST_QUERY_DURATION:
{
/* iterate and collect durations */
fold_func = (GstIteratorFoldFunction) bin_query_duration_fold;
fold_init = bin_query_min_max_init;
fold_done = bin_query_duration_done;
break;
}
case GST_QUERY_POSITION:
{
fold_func = (GstIteratorFoldFunction) bin_query_position_fold;
fold_init = bin_query_min_max_init;
fold_done = bin_query_position_done;
break;
}
case GST_QUERY_LATENCY:
{
fold_func = (GstIteratorFoldFunction) bin_query_latency_fold;
fold_init = bin_query_min_max_init;
fold_done = bin_query_latency_done;
default_return = TRUE;
break;
}
default:
fold_func = (GstIteratorFoldFunction) bin_query_generic_fold;
break;
}
fold_data.query = query;
iter = gst_bin_iterate_sinks (bin);
GST_DEBUG_OBJECT (bin, "Sending query %p (type %s) to sink children",
query, GST_QUERY_TYPE_NAME (query));
if (fold_init)
fold_init (bin, &fold_data);
res =
bin_iterate_fold (bin, iter, fold_init, fold_done, fold_func, &fold_data,
default_return);
gst_iterator_free (iter);
if (!res) {
/* Query the source pads of the element */
iter = gst_element_iterate_src_pads (element);
src_pads_query_result =
bin_iterate_fold (bin, iter, fold_init, fold_done, fold_func,
&fold_data, default_return);
gst_iterator_free (iter);
if (src_pads_query_result)
res = TRUE;
}
GST_DEBUG_OBJECT (bin, "query %p result %d", query, res);
return res;
}
static void
set_context (const GValue * item, gpointer user_data)
{
GstElement *element = g_value_get_object (item);
gst_element_set_context (element, user_data);
}
static void
gst_bin_set_context (GstElement * element, GstContext * context)
{
GstBin *bin;
GstIterator *children;
g_return_if_fail (GST_IS_BIN (element));
bin = GST_BIN (element);
GST_ELEMENT_CLASS (parent_class)->set_context (element, context);
children = gst_bin_iterate_elements (bin);
while (gst_iterator_foreach (children, set_context,
context) == GST_ITERATOR_RESYNC)
gst_iterator_resync (children);
gst_iterator_free (children);
}
static gint
compare_name (const GValue * velement, const gchar * name)
{
gint eq;
GstElement *element = g_value_get_object (velement);
GST_OBJECT_LOCK (element);
eq = strcmp (GST_ELEMENT_NAME (element), name);
GST_OBJECT_UNLOCK (element);
return eq;
}
/**
* gst_bin_get_by_name:
* @bin: a #GstBin
* @name: the element name to search for
*
* Gets the element with the given name from a bin. This
* function recurses into child bins.
*
* Returns: (transfer full) (nullable): the #GstElement with the given
* name
*/
GstElement *
gst_bin_get_by_name (GstBin * bin, const gchar * name)
{
GstIterator *children;
GValue result = { 0, };
GstElement *element;
gboolean found;
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);
found = gst_iterator_find_custom (children,
(GCompareFunc) compare_name, &result, (gpointer) name);
gst_iterator_free (children);
if (found) {
element = g_value_dup_object (&result);
g_value_unset (&result);
} else {
element = NULL;
}
return element;
}
/**
* gst_bin_get_by_name_recurse_up:
* @bin: a #GstBin
* @name: the element name to search for
*
* Gets the element with the given name from this bin. If the
* element is not found, a recursion is performed on the parent bin.
*
* Returns: (transfer full) (nullable): the #GstElement with the given
* name
*/
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 (const GValue * velement, GValue * interface)
{
GstElement *element = g_value_get_object (velement);
GType interface_type = (GType) g_value_get_pointer (interface);
gint ret;
if (G_TYPE_CHECK_INSTANCE_TYPE (element, interface_type)) {
ret = 0;
} else {
ret = 1;
}
return ret;
}
/**
* gst_bin_get_by_interface:
* @bin: a #GstBin
* @iface: the #GType of an interface
*
* Looks for an 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(). This function recurses into child bins.
*
* Returns: (transfer full) (nullable): A #GstElement inside the bin
* implementing the interface
*/
GstElement *
gst_bin_get_by_interface (GstBin * bin, GType iface)
{
GstIterator *children;
GValue result = { 0, };
GstElement *element;
gboolean found;
GValue viface = { 0, };
g_return_val_if_fail (GST_IS_BIN (bin), NULL);
g_return_val_if_fail (G_TYPE_IS_INTERFACE (iface), NULL);
g_value_init (&viface, G_TYPE_POINTER);
g_value_set_pointer (&viface, (gpointer) iface);
children = gst_bin_iterate_recurse (bin);
found = gst_iterator_find_custom (children, (GCompareFunc) compare_interface,
&result, &viface);
gst_iterator_free (children);
if (found) {
element = g_value_dup_object (&result);
g_value_unset (&result);
} else {
element = NULL;
}
g_value_unset (&viface);
return element;
}
/**
* gst_bin_iterate_all_by_interface:
* @bin: a #GstBin
* @iface: the #GType of an 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 inside child bins. The iterator will yield a series
* of #GstElement.
*
* Returns: (transfer full) (nullable): a #GstIterator of #GstElement
* for all elements in the bin implementing the given interface
*/
GstIterator *
gst_bin_iterate_all_by_interface (GstBin * bin, GType iface)
{
GstIterator *children;
GstIterator *result;
GValue viface = { 0, };
g_return_val_if_fail (GST_IS_BIN (bin), NULL);
g_return_val_if_fail (G_TYPE_IS_INTERFACE (iface), NULL);
g_value_init (&viface, G_TYPE_POINTER);
g_value_set_pointer (&viface, (gpointer) iface);
children = gst_bin_iterate_recurse (bin);
result = gst_iterator_filter (children, (GCompareFunc) compare_interface,
&viface);
g_value_unset (&viface);
return result;
}
static gint
compare_factory_names (const GValue * velement, GValue * factory_name_val)
{
GstElement *element = g_value_get_object (velement);
GstElementFactory *factory = gst_element_get_factory (element);
const gchar *factory_name = g_value_get_string (factory_name_val);
if (factory == NULL)
return -1;
return g_strcmp0 (GST_OBJECT_NAME (factory), factory_name);
}
/**
* gst_bin_iterate_all_by_element_factory_name:
* @bin: a #GstBin
* @factory_name: (not nullable): the name of the #GstElementFactory
*
* Looks for all elements inside the bin with the given element factory name.
* The function recurses inside child bins. The iterator will yield a series of
* #GstElement.
*
* Returns: (transfer full) (nullable): a #GstIterator of #GstElement
* for all elements in the bin with the given element factory name
*
* Since: 1.18
*/
GstIterator *
gst_bin_iterate_all_by_element_factory_name (GstBin * bin,
const gchar * factory_name)
{
GstIterator *children;
GstIterator *result;
GValue factory_name_val = G_VALUE_INIT;
g_return_val_if_fail (GST_IS_BIN (bin), NULL);
g_return_val_if_fail (factory_name && *factory_name, NULL);
g_value_init (&factory_name_val, G_TYPE_STRING);
g_value_set_string (&factory_name_val, factory_name);
children = gst_bin_iterate_recurse (bin);
result = gst_iterator_filter (children, (GCompareFunc) compare_factory_names,
&factory_name_val);
g_value_unset (&factory_name_val);
return result;
}
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