bdf01a7b4fe1f386bef88b1966b9bc457545783c
1 /* GStreamer
2 *
3 * Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
4 * 2004 Wim Taymans <wim.taymans@gmail.com>
5 *
6 * gstbin.c: GstBin container object and support code
7 *
8 * This library is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Library General Public
10 * License as published by the Free Software Foundation; either
11 * version 2 of the License, or (at your option) any later version.
12 *
13 * This library is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Library General Public License for more details.
17 *
18 * You should have received a copy of the GNU Library General Public
19 * License along with this library; if not, write to the
20 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
21 * Boston, MA 02111-1307, USA.
22 *
23 * MT safe.
24 */
26 /**
27 * SECTION:gstbin
28 * @short_description: Base class and element that can contain other elements
29 *
30 * #GstBin is an element that can contain other #GstElement, allowing them to be
31 * managed as a group.
32 * Pads from the child elements can be ghosted to the bin, see #GstGhostPad.
33 * This makes the bin look like any other elements and enables creation of
34 * higher-level abstraction elements.
35 *
36 * A new #GstBin is created with gst_bin_new(). Use a #GstPipeline instead if you
37 * want to create a toplevel bin because a normal bin doesn't have a bus or
38 * handle clock distribution of its own.
39 *
40 * After the bin has been created you will typically add elements to it with
41 * gst_bin_add(). You can remove elements with gst_bin_remove().
42 *
43 * An element can be retrieved from a bin with gst_bin_get_by_name(), using the
44 * elements name. gst_bin_get_by_name_recurse_up() is mainly used for internal
45 * purposes and will query the parent bins when the element is not found in the
46 * current bin.
47 *
48 * An iterator of elements in a bin can be retrieved with
49 * gst_bin_iterate_elements(). Various other iterators exist to retrieve the
50 * elements in a bin.
51 *
52 * gst_object_unref() is used to drop your reference to the bin.
53 *
54 * The #GstBin::element-added signal is fired whenever a new element is added to
55 * the bin. Likewise the #GstBin::element-removed signal is fired whenever an
56 * element is removed from the bin.
57 *
58 * <refsect2><title>Notes</title>
59 * <para>
60 * A #GstBin internally intercepts every #GstMessage posted by its children and
61 * implements the following default behaviour for each of them:
62 * <variablelist>
63 * <varlistentry>
64 * <term>GST_MESSAGE_EOS</term>
65 * <listitem><para>This message is only posted by sinks in the PLAYING
66 * state. If all sinks posted the EOS message, this bin will post and EOS
67 * message upwards.</para></listitem>
68 * </varlistentry>
69 * <varlistentry>
70 * <term>GST_MESSAGE_SEGMENT_START</term>
71 * <listitem><para>just collected and never forwarded upwards.
72 * The messages are used to decide when all elements have completed playback
73 * of their segment.</para></listitem>
74 * </varlistentry>
75 * <varlistentry>
76 * <term>GST_MESSAGE_SEGMENT_DONE</term>
77 * <listitem><para> Is posted by #GstBin when all elements that posted
78 * a SEGMENT_START have posted a SEGMENT_DONE.</para></listitem>
79 * </varlistentry>
80 * <varlistentry>
81 * <term>GST_MESSAGE_DURATION</term>
82 * <listitem><para> Is posted by an element that detected a change
83 * in the stream duration. The default bin behaviour is to clear any
84 * cached duration values so that the next duration query will perform
85 * a full duration recalculation. The duration change is posted to the
86 * application so that it can refetch the new duration with a duration
87 * query. Note that these messages can be posted before the bin is
88 * prerolled, in which case the duration query might fail.
89 * </para></listitem>
90 * </varlistentry>
91 * <varlistentry>
92 * <term>GST_MESSAGE_CLOCK_LOST</term>
93 * <listitem><para> This message is posted by an element when it
94 * can no longer provide a clock. The default bin behaviour is to
95 * check if the lost clock was the one provided by the bin. If so and
96 * the bin is currently in the PLAYING state, the message is forwarded to
97 * the bin parent.
98 * This message is also generated when a clock provider is removed from
99 * the bin. If this message is received by the application, it should
100 * PAUSE the pipeline and set it back to PLAYING to force a new clock
101 * distribution.
102 * </para></listitem>
103 * </varlistentry>
104 * <varlistentry>
105 * <term>GST_MESSAGE_CLOCK_PROVIDE</term>
106 * <listitem><para> This message is generated when an element
107 * can provide a clock. This mostly happens when a new clock
108 * provider is added to the bin. The default behaviour of the bin is to
109 * mark the currently selected clock as dirty, which will perform a clock
110 * recalculation the next time the bin is asked to provide a clock.
111 * This message is never sent tot the application but is forwarded to
112 * the parent of the bin.
113 * </para></listitem>
114 * </varlistentry>
115 * <varlistentry>
116 * <term>OTHERS</term>
117 * <listitem><para> posted upwards.</para></listitem>
118 * </varlistentry>
119 * </variablelist>
120 *
121 *
122 * A #GstBin implements the following default behaviour for answering to a
123 * #GstQuery:
124 * <variablelist>
125 * <varlistentry>
126 * <term>GST_QUERY_DURATION</term>
127 * <listitem><para>If the query has been asked before with the same format
128 * and the bin is a toplevel bin (ie. has no parent),
129 * use the cached previous value. If no previous value was cached, the
130 * query is sent to all sink elements in the bin and the MAXIMUM of all
131 * values is returned. If the bin is a toplevel bin the value is cached.
132 * If no sinks are available in the bin, the query fails.
133 * </para></listitem>
134 * </varlistentry>
135 * <varlistentry>
136 * <term>GST_QUERY_POSITION</term>
137 * <listitem><para>The query is sent to all sink elements in the bin and the
138 * MAXIMUM of all values is returned. If no sinks are available in the bin,
139 * the query fails.
140 * </para></listitem>
141 * </varlistentry>
142 * <varlistentry>
143 * <term>OTHERS</term>
144 * <listitem><para>the query is forwarded to all sink elements, the result
145 * of the first sink that answers the query successfully is returned. If no
146 * sink is in the bin, the query fails.</para></listitem>
147 * </varlistentry>
148 * </variablelist>
149 *
150 * A #GstBin will by default forward any event sent to it to all sink elements.
151 * If all the sinks return TRUE, the bin will also return TRUE, else FALSE is
152 * returned. If no sinks are in the bin, the event handler will return TRUE.
153 *
154 * </para>
155 * </refsect2>
156 *
157 * Last reviewed on 2006-04-28 (0.10.6)
158 */
160 #include "gst_private.h"
162 #include "gstevent.h"
163 #include "gstbin.h"
164 #include "gstmarshal.h"
165 #include "gstxml.h"
166 #include "gstinfo.h"
167 #include "gsterror.h"
169 #include "gstindex.h"
170 #include "gstindexfactory.h"
171 #include "gstutils.h"
172 #include "gstchildproxy.h"
174 #ifdef GST_DISABLE_DEPRECATED
175 #if !defined(GST_DISABLE_LOADSAVE) && !defined(GST_REMOVE_DEPRECATED)
176 #undef GstXmlNodePtr
177 #define GstXmlNodePtr xmlNodePtr
178 #include <libxml/parser.h>
179 GstXmlNodePtr gst_object_save_thyself (GstObject * object,
180 GstXmlNodePtr parent);
181 void gst_object_restore_thyself (GstObject * object, GstXmlNodePtr parent);
182 GstElement *gst_xml_make_element (xmlNodePtr cur, GstObject * parent);
183 #endif
184 #endif
186 /* enable for DURATION caching.
187 * FIXME currently too many elements don't update
188 * their duration when it changes so we return inaccurate values. */
189 #undef DURATION_CACHING
191 /* latency is by default enabled now.
192 * live-preroll and no-live-preroll in the environment var GST_COMPAT
193 * to enables or disable it respectively.
194 */
195 static gboolean enable_latency = TRUE;
197 GST_DEBUG_CATEGORY_STATIC (bin_debug);
198 #define GST_CAT_DEFAULT bin_debug
200 /* a bin is toplevel if it has no parent or when it is configured to behave like
201 * a toplevel bin */
202 #define BIN_IS_TOPLEVEL(bin) ((GST_OBJECT_PARENT (bin) == NULL) || bin->priv->asynchandling)
204 #define GST_BIN_GET_PRIVATE(obj) \
205 (G_TYPE_INSTANCE_GET_PRIVATE ((obj), GST_TYPE_BIN, GstBinPrivate))
207 struct _GstBinPrivate
208 {
209 gboolean asynchandling;
210 /* if we get an ASYNC_DONE message from ourselves, this means that the
211 * subclass will simulate ASYNC behaviour without having ASYNC children. When
212 * such an ASYNC_DONE message is posted while we are doing a state change, we
213 * have to process the message after finishing the state change even when no
214 * child returned GST_STATE_CHANGE_ASYNC. */
215 gboolean pending_async_done;
217 guint32 structure_cookie;
219 /* cached index */
220 GstIndex *index;
221 /* forward messages from our children */
222 gboolean message_forward;
224 gboolean posted_eos;
225 };
227 typedef struct
228 {
229 GstBin *bin;
230 guint32 cookie;
231 GstState pending;
232 } BinContinueData;
234 static void gst_bin_dispose (GObject * object);
236 static void gst_bin_set_property (GObject * object, guint prop_id,
237 const GValue * value, GParamSpec * pspec);
238 static void gst_bin_get_property (GObject * object, guint prop_id,
239 GValue * value, GParamSpec * pspec);
241 static GstStateChangeReturn gst_bin_change_state_func (GstElement * element,
242 GstStateChange transition);
243 static void gst_bin_state_changed (GstElement * element, GstState oldstate,
244 GstState newstate, GstState pending);
245 static GstStateChangeReturn gst_bin_get_state_func (GstElement * element,
246 GstState * state, GstState * pending, GstClockTime timeout);
247 static void bin_handle_async_done (GstBin * bin, GstStateChangeReturn ret,
248 gboolean flag_pending);
249 static void bin_handle_async_start (GstBin * bin, gboolean new_base_time);
250 static void bin_push_state_continue (BinContinueData * data);
251 static void bin_do_eos (GstBin * bin);
253 static gboolean gst_bin_add_func (GstBin * bin, GstElement * element);
254 static gboolean gst_bin_remove_func (GstBin * bin, GstElement * element);
256 static void gst_bin_set_index_func (GstElement * element, GstIndex * index);
257 static GstIndex *gst_bin_get_index_func (GstElement * element);
259 static GstClock *gst_bin_provide_clock_func (GstElement * element);
260 static gboolean gst_bin_set_clock_func (GstElement * element, GstClock * clock);
262 static void gst_bin_handle_message_func (GstBin * bin, GstMessage * message);
263 static gboolean gst_bin_send_event (GstElement * element, GstEvent * event);
264 static GstBusSyncReply bin_bus_handler (GstBus * bus,
265 GstMessage * message, GstBin * bin);
266 static gboolean gst_bin_query (GstElement * element, GstQuery * query);
268 static gboolean gst_bin_do_latency_func (GstBin * bin);
270 #if !defined(GST_DISABLE_LOADSAVE) && !defined(GST_REMOVE_DEPRECATED)
271 static xmlNodePtr gst_bin_save_thyself (GstObject * object, xmlNodePtr parent);
272 static void gst_bin_restore_thyself (GstObject * object, xmlNodePtr self);
273 #endif
275 static void bin_remove_messages (GstBin * bin, GstObject * src,
276 GstMessageType types);
277 static void gst_bin_continue_func (BinContinueData * data);
278 static gint bin_element_is_sink (GstElement * child, GstBin * bin);
279 static gint bin_element_is_src (GstElement * child, GstBin * bin);
281 static GstIterator *gst_bin_sort_iterator_new (GstBin * bin);
283 /* Bin signals and properties */
284 enum
285 {
286 ELEMENT_ADDED,
287 ELEMENT_REMOVED,
288 DO_LATENCY,
289 LAST_SIGNAL
290 };
292 #define DEFAULT_ASYNC_HANDLING FALSE
293 #define DEFAULT_MESSAGE_FORWARD FALSE
295 enum
296 {
297 PROP_0,
298 PROP_ASYNC_HANDLING,
299 PROP_MESSAGE_FORWARD,
300 PROP_LAST
301 };
303 static void gst_bin_child_proxy_init (gpointer g_iface, gpointer iface_data);
305 static guint gst_bin_signals[LAST_SIGNAL] = { 0 };
307 #define _do_init(type) \
308 { \
309 const gchar *compat; \
310 static const GInterfaceInfo iface_info = { \
311 gst_bin_child_proxy_init, \
312 NULL, \
313 NULL}; \
314 \
315 g_type_add_interface_static (type, GST_TYPE_CHILD_PROXY, &iface_info); \
316 \
317 GST_DEBUG_CATEGORY_INIT (bin_debug, "bin", GST_DEBUG_BOLD, \
318 "debugging info for the 'bin' container element"); \
319 \
320 /* compatibility stuff */ \
321 compat = g_getenv ("GST_COMPAT"); \
322 if (compat != NULL) { \
323 if (strstr (compat, "no-live-preroll")) \
324 enable_latency = FALSE; \
325 else if (strstr (compat, "live-preroll")) \
326 enable_latency = TRUE; \
327 } \
328 }
330 GST_BOILERPLATE_FULL (GstBin, gst_bin, GstElement, GST_TYPE_ELEMENT, _do_init);
332 static void
333 gst_bin_base_init (gpointer g_class)
334 {
335 GstElementClass *gstelement_class = GST_ELEMENT_CLASS (g_class);
337 gst_element_class_set_details_simple (gstelement_class, "Generic bin",
338 "Generic/Bin",
339 "Simple container object",
340 "Erik Walthinsen <omega@cse.ogi.edu>,"
341 "Wim Taymans <wim.taymans@gmail.com>");
342 }
344 static GstObject *
345 gst_bin_child_proxy_get_child_by_index (GstChildProxy * child_proxy,
346 guint index)
347 {
348 GstObject *res;
349 GstBin *bin;
351 bin = GST_BIN_CAST (child_proxy);
353 GST_OBJECT_LOCK (bin);
354 if ((res = g_list_nth_data (bin->children, index)))
355 gst_object_ref (res);
356 GST_OBJECT_UNLOCK (bin);
358 return res;
359 }
361 static guint
362 gst_bin_child_proxy_get_children_count (GstChildProxy * child_proxy)
363 {
364 guint num;
365 GstBin *bin;
367 bin = GST_BIN_CAST (child_proxy);
369 GST_OBJECT_LOCK (bin);
370 num = bin->numchildren;
371 GST_OBJECT_UNLOCK (bin);
373 return num;
374 }
376 static void
377 gst_bin_child_proxy_init (gpointer g_iface, gpointer iface_data)
378 {
379 GstChildProxyInterface *iface = g_iface;
381 iface->get_children_count = gst_bin_child_proxy_get_children_count;
382 iface->get_child_by_index = gst_bin_child_proxy_get_child_by_index;
383 }
385 static gboolean
386 _gst_boolean_accumulator (GSignalInvocationHint * ihint,
387 GValue * return_accu, const GValue * handler_return, gpointer dummy)
388 {
389 gboolean myboolean;
391 myboolean = g_value_get_boolean (handler_return);
392 if (!(ihint->run_type & G_SIGNAL_RUN_CLEANUP))
393 g_value_set_boolean (return_accu, myboolean);
395 GST_DEBUG ("invocation %d, %d", ihint->run_type, myboolean);
397 /* stop emission */
398 return FALSE;
399 }
401 static void
402 gst_bin_class_init (GstBinClass * klass)
403 {
404 GObjectClass *gobject_class;
405 GstObjectClass *gstobject_class;
406 GstElementClass *gstelement_class;
407 GError *err;
409 gobject_class = (GObjectClass *) klass;
410 gstobject_class = (GstObjectClass *) klass;
411 gstelement_class = (GstElementClass *) klass;
413 g_type_class_add_private (klass, sizeof (GstBinPrivate));
415 gobject_class->set_property = gst_bin_set_property;
416 gobject_class->get_property = gst_bin_get_property;
418 /**
419 * GstBin:async-handling
420 *
421 * If set to #TRUE, the bin will handle asynchronous state changes.
422 * This should be used only if the bin subclass is modifying the state
423 * of its children on its own.
424 *
425 * Since: 0.10.13
426 */
427 g_object_class_install_property (gobject_class, PROP_ASYNC_HANDLING,
428 g_param_spec_boolean ("async-handling", "Async Handling",
429 "The bin will handle Asynchronous state changes",
430 DEFAULT_ASYNC_HANDLING, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
432 /**
433 * GstBin::element-added:
434 * @bin: the #GstBin
435 * @element: the #GstElement that was added to the bin
436 *
437 * Will be emitted after the element was added to the bin.
438 */
439 gst_bin_signals[ELEMENT_ADDED] =
440 g_signal_new ("element-added", G_TYPE_FROM_CLASS (klass),
441 G_SIGNAL_RUN_FIRST, G_STRUCT_OFFSET (GstBinClass, element_added), NULL,
442 NULL, gst_marshal_VOID__OBJECT, G_TYPE_NONE, 1, GST_TYPE_ELEMENT);
443 /**
444 * GstBin::element-removed:
445 * @bin: the #GstBin
446 * @element: the #GstElement that was removed from the bin
447 *
448 * Will be emitted after the element was removed from the bin.
449 */
450 gst_bin_signals[ELEMENT_REMOVED] =
451 g_signal_new ("element-removed", G_TYPE_FROM_CLASS (klass),
452 G_SIGNAL_RUN_FIRST, G_STRUCT_OFFSET (GstBinClass, element_removed), NULL,
453 NULL, gst_marshal_VOID__OBJECT, G_TYPE_NONE, 1, GST_TYPE_ELEMENT);
454 /**
455 * GstBin::do-latency:
456 * @bin: the #GstBin
457 *
458 * Will be emitted when the bin needs to perform latency calculations. This
459 * signal is only emited for toplevel bins or when async-handling is
460 * enabled.
461 *
462 * Only one signal handler is invoked. If no signals are connected, the
463 * default handler is invoked, which will query and distribute the lowest
464 * possible latency to all sinks.
465 *
466 * Connect to this signal if the default latency calculations are not
467 * sufficient, like when you need different latencies for different sinks in
468 * the same pipeline.
469 *
470 * Since: 0.10.22
471 */
472 gst_bin_signals[DO_LATENCY] =
473 g_signal_new ("do-latency", G_TYPE_FROM_CLASS (klass),
474 G_SIGNAL_RUN_LAST, G_STRUCT_OFFSET (GstBinClass, do_latency),
475 _gst_boolean_accumulator, NULL, gst_marshal_BOOLEAN__VOID,
476 G_TYPE_BOOLEAN, 0, G_TYPE_NONE);
478 /**
479 * GstBin:message-forward
480 *
481 * Forward all children messages, even those that would normally be filtered by
482 * the bin. This can be interesting when one wants to be notified of the EOS
483 * state of individual elements, for example.
484 *
485 * The messages are converted to an ELEMENT message with the bin as the
486 * source. The structure of the message is named 'GstBinForwarded' and contains
487 * a field named 'message' of type GST_TYPE_MESSAGE that contains the original
488 * forwarded message.
489 *
490 * Since: 0.10.31
491 */
492 g_object_class_install_property (gobject_class, PROP_MESSAGE_FORWARD,
493 g_param_spec_boolean ("message-forward", "Message Forward",
494 "Forwards all children messages",
495 DEFAULT_MESSAGE_FORWARD, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
497 gobject_class->dispose = gst_bin_dispose;
499 #if !defined(GST_DISABLE_LOADSAVE) && !defined(GST_REMOVE_DEPRECATED)
500 gstobject_class->save_thyself =
501 ((gpointer (*)(GstObject * object,
502 gpointer self)) * GST_DEBUG_FUNCPTR (gst_bin_save_thyself));
503 gstobject_class->restore_thyself =
504 ((void (*)(GstObject * object,
505 gpointer self)) *GST_DEBUG_FUNCPTR (gst_bin_restore_thyself));
506 #endif
508 gstelement_class->change_state =
509 GST_DEBUG_FUNCPTR (gst_bin_change_state_func);
510 gstelement_class->state_changed = GST_DEBUG_FUNCPTR (gst_bin_state_changed);
511 gstelement_class->get_state = GST_DEBUG_FUNCPTR (gst_bin_get_state_func);
512 gstelement_class->get_index = GST_DEBUG_FUNCPTR (gst_bin_get_index_func);
513 gstelement_class->set_index = GST_DEBUG_FUNCPTR (gst_bin_set_index_func);
514 gstelement_class->provide_clock =
515 GST_DEBUG_FUNCPTR (gst_bin_provide_clock_func);
516 gstelement_class->set_clock = GST_DEBUG_FUNCPTR (gst_bin_set_clock_func);
518 gstelement_class->send_event = GST_DEBUG_FUNCPTR (gst_bin_send_event);
519 gstelement_class->query = GST_DEBUG_FUNCPTR (gst_bin_query);
521 klass->add_element = GST_DEBUG_FUNCPTR (gst_bin_add_func);
522 klass->remove_element = GST_DEBUG_FUNCPTR (gst_bin_remove_func);
523 klass->handle_message = GST_DEBUG_FUNCPTR (gst_bin_handle_message_func);
525 klass->do_latency = GST_DEBUG_FUNCPTR (gst_bin_do_latency_func);
527 GST_DEBUG ("creating bin thread pool");
528 err = NULL;
529 klass->pool =
530 g_thread_pool_new ((GFunc) gst_bin_continue_func, NULL, -1, FALSE, &err);
531 if (err != NULL) {
532 g_critical ("could alloc threadpool %s", err->message);
533 }
534 }
536 static void
537 gst_bin_init (GstBin * bin, GstBinClass * klass)
538 {
539 GstBus *bus;
541 bin->numchildren = 0;
542 bin->children = NULL;
543 bin->children_cookie = 0;
544 bin->messages = NULL;
545 bin->provided_clock = NULL;
546 bin->clock_dirty = FALSE;
548 /* Set up a bus for listening to child elements */
549 bus = gst_bus_new ();
550 bin->child_bus = bus;
551 GST_DEBUG_OBJECT (bin, "using bus %" GST_PTR_FORMAT " to listen to children",
552 bus);
553 gst_bus_set_sync_handler (bus, (GstBusSyncHandler) bin_bus_handler, bin);
555 bin->priv = GST_BIN_GET_PRIVATE (bin);
556 bin->priv->asynchandling = DEFAULT_ASYNC_HANDLING;
557 bin->priv->structure_cookie = 0;
558 bin->priv->message_forward = DEFAULT_MESSAGE_FORWARD;
559 }
561 static void
562 gst_bin_dispose (GObject * object)
563 {
564 GstBin *bin = GST_BIN_CAST (object);
565 GstBus **child_bus_p = &bin->child_bus;
566 GstClock **provided_clock_p = &bin->provided_clock;
567 GstElement **clock_provider_p = &bin->clock_provider;
568 GstIndex **index_p = &bin->priv->index;
570 GST_CAT_DEBUG_OBJECT (GST_CAT_REFCOUNTING, object, "dispose");
572 GST_OBJECT_LOCK (object);
573 gst_object_replace ((GstObject **) child_bus_p, NULL);
574 gst_object_replace ((GstObject **) provided_clock_p, NULL);
575 gst_object_replace ((GstObject **) clock_provider_p, NULL);
576 gst_object_replace ((GstObject **) index_p, NULL);
577 bin_remove_messages (bin, NULL, GST_MESSAGE_ANY);
578 GST_OBJECT_UNLOCK (object);
580 while (bin->children) {
581 gst_bin_remove (bin, GST_ELEMENT_CAST (bin->children->data));
582 }
583 if (G_UNLIKELY (bin->children != NULL)) {
584 g_critical ("could not remove elements from bin '%s'",
585 GST_STR_NULL (GST_OBJECT_NAME (object)));
586 }
588 G_OBJECT_CLASS (parent_class)->dispose (object);
589 }
591 /**
592 * gst_bin_new:
593 * @name: the name of the new bin
594 *
595 * Creates a new bin with the given name.
596 *
597 * Returns: (transfer full): a new #GstBin
598 */
599 GstElement *
600 gst_bin_new (const gchar * name)
601 {
602 return gst_element_factory_make ("bin", name);
603 }
605 static void
606 gst_bin_set_property (GObject * object, guint prop_id,
607 const GValue * value, GParamSpec * pspec)
608 {
609 GstBin *gstbin;
611 gstbin = GST_BIN_CAST (object);
613 switch (prop_id) {
614 case PROP_ASYNC_HANDLING:
615 GST_OBJECT_LOCK (gstbin);
616 gstbin->priv->asynchandling = g_value_get_boolean (value);
617 GST_OBJECT_UNLOCK (gstbin);
618 break;
619 case PROP_MESSAGE_FORWARD:
620 GST_OBJECT_LOCK (gstbin);
621 gstbin->priv->message_forward = g_value_get_boolean (value);
622 GST_OBJECT_UNLOCK (gstbin);
623 break;
624 default:
625 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
626 break;
627 }
628 }
630 static void
631 gst_bin_get_property (GObject * object, guint prop_id,
632 GValue * value, GParamSpec * pspec)
633 {
634 GstBin *gstbin;
636 gstbin = GST_BIN_CAST (object);
638 switch (prop_id) {
639 case PROP_ASYNC_HANDLING:
640 GST_OBJECT_LOCK (gstbin);
641 g_value_set_boolean (value, gstbin->priv->asynchandling);
642 GST_OBJECT_UNLOCK (gstbin);
643 break;
644 case PROP_MESSAGE_FORWARD:
645 GST_OBJECT_LOCK (gstbin);
646 g_value_set_boolean (value, gstbin->priv->message_forward);
647 GST_OBJECT_UNLOCK (gstbin);
648 break;
649 default:
650 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
651 break;
652 }
653 }
655 /* return the cached index */
656 static GstIndex *
657 gst_bin_get_index_func (GstElement * element)
658 {
659 GstBin *bin;
660 GstIndex *result;
662 bin = GST_BIN_CAST (element);
664 GST_OBJECT_LOCK (bin);
665 if ((result = bin->priv->index))
666 gst_object_ref (result);
667 GST_OBJECT_UNLOCK (bin);
669 return result;
670 }
672 /* set the index on all elements in this bin
673 *
674 * MT safe
675 */
676 static void
677 gst_bin_set_index_func (GstElement * element, GstIndex * index)
678 {
679 GstBin *bin;
680 gboolean done;
681 GstIterator *it;
682 GstIndex *old;
684 bin = GST_BIN_CAST (element);
686 GST_OBJECT_LOCK (bin);
687 old = bin->priv->index;
688 if (G_UNLIKELY (old == index))
689 goto was_set;
690 if (index)
691 gst_object_ref (index);
692 bin->priv->index = index;
693 GST_OBJECT_UNLOCK (bin);
695 if (old)
696 gst_object_unref (old);
698 it = gst_bin_iterate_elements (bin);
700 /* set the index on all elements in the bin */
701 done = FALSE;
702 while (!done) {
703 gpointer data;
705 switch (gst_iterator_next (it, &data)) {
706 case GST_ITERATOR_OK:
707 {
708 GstElement *child = GST_ELEMENT_CAST (data);
710 GST_DEBUG_OBJECT (bin, "setting index on '%s'",
711 GST_ELEMENT_NAME (child));
712 gst_element_set_index (child, index);
714 gst_object_unref (child);
715 break;
716 }
717 case GST_ITERATOR_RESYNC:
718 GST_DEBUG_OBJECT (bin, "iterator doing resync");
719 gst_iterator_resync (it);
720 break;
721 default:
722 case GST_ITERATOR_DONE:
723 GST_DEBUG_OBJECT (bin, "iterator done");
724 done = TRUE;
725 break;
726 }
727 }
728 gst_iterator_free (it);
729 return;
731 was_set:
732 {
733 GST_DEBUG_OBJECT (bin, "index was already set");
734 GST_OBJECT_UNLOCK (bin);
735 return;
736 }
737 }
739 /* set the clock on all elements in this bin
740 *
741 * MT safe
742 */
743 static gboolean
744 gst_bin_set_clock_func (GstElement * element, GstClock * clock)
745 {
746 GstBin *bin;
747 gboolean done;
748 GstIterator *it;
749 gboolean res = TRUE;
751 bin = GST_BIN_CAST (element);
753 it = gst_bin_iterate_elements (bin);
755 done = FALSE;
756 while (!done) {
757 gpointer data;
759 switch (gst_iterator_next (it, &data)) {
760 case GST_ITERATOR_OK:
761 {
762 GstElement *child = GST_ELEMENT_CAST (data);
764 res &= gst_element_set_clock (child, clock);
766 gst_object_unref (child);
767 break;
768 }
769 case GST_ITERATOR_RESYNC:
770 GST_DEBUG_OBJECT (bin, "iterator doing resync");
771 gst_iterator_resync (it);
772 res = TRUE;
773 break;
774 default:
775 case GST_ITERATOR_DONE:
776 GST_DEBUG_OBJECT (bin, "iterator done");
777 done = TRUE;
778 break;
779 }
780 }
781 gst_iterator_free (it);
783 return res;
784 }
786 /* get the clock for this bin by asking all of the children in this bin
787 *
788 * The ref of the returned clock in increased so unref after usage.
789 *
790 * We loop the elements in state order and pick the last clock we can
791 * get. This makes sure we get a clock from the source.
792 *
793 * MT safe
794 */
795 static GstClock *
796 gst_bin_provide_clock_func (GstElement * element)
797 {
798 GstClock *result = NULL;
799 GstElement *provider = NULL;
800 GstBin *bin;
801 GstIterator *it;
802 gpointer val;
803 GstClock **provided_clock_p;
804 GstElement **clock_provider_p;
806 bin = GST_BIN_CAST (element);
808 GST_OBJECT_LOCK (bin);
809 if (!bin->clock_dirty)
810 goto not_dirty;
812 GST_DEBUG_OBJECT (bin, "finding new clock");
814 it = gst_bin_sort_iterator_new (bin);
816 while (it->next (it, &val) == GST_ITERATOR_OK) {
817 GstElement *child = GST_ELEMENT_CAST (val);
818 GstClock *clock;
820 clock = gst_element_provide_clock (child);
821 if (clock) {
822 GST_DEBUG_OBJECT (bin, "found candidate clock %p by element %s",
823 clock, GST_ELEMENT_NAME (child));
824 if (result) {
825 gst_object_unref (result);
826 gst_object_unref (provider);
827 }
828 result = clock;
829 provider = child;
830 } else {
831 gst_object_unref (child);
832 }
833 }
835 provided_clock_p = &bin->provided_clock;
836 clock_provider_p = &bin->clock_provider;
837 gst_object_replace ((GstObject **) provided_clock_p, (GstObject *) result);
838 gst_object_replace ((GstObject **) clock_provider_p, (GstObject *) provider);
839 bin->clock_dirty = FALSE;
840 GST_DEBUG_OBJECT (bin,
841 "provided new clock %" GST_PTR_FORMAT " by provider %" GST_PTR_FORMAT,
842 result, provider);
843 /* Provider is not being returned to caller, just the result */
844 if (provider)
845 gst_object_unref (provider);
846 GST_OBJECT_UNLOCK (bin);
848 gst_iterator_free (it);
850 return result;
852 not_dirty:
853 {
854 if ((result = bin->provided_clock))
855 gst_object_ref (result);
856 GST_DEBUG_OBJECT (bin, "returning old clock %p", result);
857 GST_OBJECT_UNLOCK (bin);
859 return result;
860 }
861 }
863 /*
864 * functions for manipulating cached messages
865 */
866 typedef struct
867 {
868 GstObject *src;
869 GstMessageType types;
870 } MessageFind;
872 /* check if a message is of given src and type */
873 static gint
874 message_check (GstMessage * message, MessageFind * target)
875 {
876 gboolean eq = TRUE;
878 if (target->src)
879 eq &= GST_MESSAGE_SRC (message) == target->src;
880 if (target->types)
881 eq &= (GST_MESSAGE_TYPE (message) & target->types) != 0;
882 GST_LOG ("looking at message %p: %d", message, eq);
884 return (eq ? 0 : 1);
885 }
887 static GList *
888 find_message (GstBin * bin, GstObject * src, GstMessageType types)
889 {
890 GList *result;
891 MessageFind find;
893 find.src = src;
894 find.types = types;
896 result = g_list_find_custom (bin->messages, &find,
897 (GCompareFunc) message_check);
899 if (result) {
900 GST_DEBUG_OBJECT (bin, "we found a message %p from %s matching types %08x",
901 result->data, GST_OBJECT_NAME (GST_MESSAGE_CAST (result->data)->src),
902 types);
903 } else {
904 GST_DEBUG_OBJECT (bin, "no message found matching types %08x", types);
905 #ifndef GST_DISABLE_GST_DEBUG
906 {
907 guint i;
909 for (i = 0; i < 32; i++)
910 if (types & (1 << i))
911 GST_DEBUG_OBJECT (bin, " %s", gst_message_type_get_name (1 << i));
912 }
913 #endif
914 }
916 return result;
917 }
919 /* with LOCK, returns TRUE if message had a valid SRC, takes ownership of
920 * the message.
921 *
922 * A message that is cached and has the same SRC and type is replaced
923 * by the given message.
924 */
925 static gboolean
926 bin_replace_message (GstBin * bin, GstMessage * message, GstMessageType types)
927 {
928 GList *previous;
929 GstObject *src;
930 gboolean res = TRUE;
932 if ((src = GST_MESSAGE_SRC (message))) {
933 /* first find the previous message posted by this element */
934 if ((previous = find_message (bin, src, types))) {
935 GstMessage *previous_msg;
937 /* if we found a previous message, replace it */
938 previous_msg = previous->data;
939 previous->data = message;
941 GST_DEBUG_OBJECT (bin, "replace old message %s from %s with %s message",
942 GST_MESSAGE_TYPE_NAME (previous_msg), GST_ELEMENT_NAME (src),
943 GST_MESSAGE_TYPE_NAME (message));
945 gst_message_unref (previous_msg);
946 } else {
947 /* keep new message */
948 bin->messages = g_list_prepend (bin->messages, message);
950 GST_DEBUG_OBJECT (bin, "got new message %p, %s from %s",
951 message, GST_MESSAGE_TYPE_NAME (message), GST_ELEMENT_NAME (src));
952 }
953 } else {
954 GST_DEBUG_OBJECT (bin, "got message %s from (NULL), not processing",
955 GST_MESSAGE_TYPE_NAME (message));
956 res = FALSE;
957 gst_message_unref (message);
958 }
959 return res;
960 }
962 /* with LOCK. Remove all messages of given types */
963 static void
964 bin_remove_messages (GstBin * bin, GstObject * src, GstMessageType types)
965 {
966 MessageFind find;
967 GList *walk, *next;
969 find.src = src;
970 find.types = types;
972 for (walk = bin->messages; walk; walk = next) {
973 GstMessage *message = (GstMessage *) walk->data;
975 next = g_list_next (walk);
977 if (message_check (message, &find) == 0) {
978 GST_DEBUG_OBJECT (GST_MESSAGE_SRC (message),
979 "deleting message %p of types 0x%08x", message, types);
980 bin->messages = g_list_delete_link (bin->messages, walk);
981 gst_message_unref (message);
982 } else {
983 GST_DEBUG_OBJECT (GST_MESSAGE_SRC (message),
984 "not deleting message %p of type 0x%08x", message,
985 GST_MESSAGE_TYPE (message));
986 }
987 }
988 }
991 /* Check if the bin is EOS. We do this by scanning all sinks and
992 * checking if they posted an EOS message.
993 *
994 * call with bin LOCK */
995 static gboolean
996 is_eos (GstBin * bin, guint32 * seqnum)
997 {
998 gboolean result;
999 gint n_eos = 0;
1000 GList *walk, *msgs;
1002 result = TRUE;
1003 for (walk = bin->children; walk; walk = g_list_next (walk)) {
1004 GstElement *element;
1006 element = GST_ELEMENT_CAST (walk->data);
1007 if (bin_element_is_sink (element, bin) == 0) {
1008 /* check if element posted EOS */
1009 if ((msgs =
1010 find_message (bin, GST_OBJECT_CAST (element), GST_MESSAGE_EOS))) {
1011 GST_DEBUG ("sink '%s' posted EOS", GST_ELEMENT_NAME (element));
1012 *seqnum = gst_message_get_seqnum (GST_MESSAGE_CAST (msgs->data));
1013 n_eos++;
1014 } else {
1015 GST_DEBUG ("sink '%s' did not post EOS yet",
1016 GST_ELEMENT_NAME (element));
1017 result = FALSE;
1018 break;
1019 }
1020 }
1021 }
1022 /* FIXME: Some tests (e.g. elements/capsfilter) use
1023 * pipelines with a dangling sinkpad but no sink element.
1024 * These tests assume that no EOS message is ever
1025 * posted on the bus so let's keep that behaviour.
1026 * In valid pipelines this doesn't make a difference.
1027 */
1028 return result && n_eos > 0;
1029 }
1031 static void
1032 unlink_pads (GstPad * pad)
1033 {
1034 GstPad *peer;
1036 if ((peer = gst_pad_get_peer (pad))) {
1037 if (gst_pad_get_direction (pad) == GST_PAD_SRC)
1038 gst_pad_unlink (pad, peer);
1039 else
1040 gst_pad_unlink (peer, pad);
1041 gst_object_unref (peer);
1042 }
1043 gst_object_unref (pad);
1044 }
1046 /* vmethod that adds an element to a bin
1047 *
1048 * MT safe
1049 */
1050 static gboolean
1051 gst_bin_add_func (GstBin * bin, GstElement * element)
1052 {
1053 gchar *elem_name;
1054 GstIterator *it;
1055 gboolean is_sink, is_source;
1056 GstMessage *clock_message = NULL, *async_message = NULL;
1057 GstStateChangeReturn ret;
1059 GST_DEBUG_OBJECT (bin, "element :%s", GST_ELEMENT_NAME (element));
1061 /* we obviously can't add ourself to ourself */
1062 if (G_UNLIKELY (GST_ELEMENT_CAST (element) == GST_ELEMENT_CAST (bin)))
1063 goto adding_itself;
1065 /* get the element name to make sure it is unique in this bin. */
1066 GST_OBJECT_LOCK (element);
1067 elem_name = g_strdup (GST_ELEMENT_NAME (element));
1068 is_sink = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_IS_SINK);
1069 is_source = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_IS_SOURCE);
1070 GST_OBJECT_UNLOCK (element);
1072 GST_OBJECT_LOCK (bin);
1074 /* then check to see if the element's name is already taken in the bin,
1075 * we can safely take the lock here. This check is probably bogus because
1076 * you can safely change the element name after this check and before setting
1077 * the object parent. The window is very small though... */
1078 if (G_UNLIKELY (!gst_object_check_uniqueness (bin->children, elem_name)))
1079 goto duplicate_name;
1081 /* set the element's parent and add the element to the bin's list of children */
1082 if (G_UNLIKELY (!gst_object_set_parent (GST_OBJECT_CAST (element),
1083 GST_OBJECT_CAST (bin))))
1084 goto had_parent;
1086 /* if we add a sink we become a sink */
1087 if (is_sink) {
1088 GST_CAT_DEBUG_OBJECT (GST_CAT_PARENTAGE, bin, "element \"%s\" was sink",
1089 elem_name);
1090 GST_OBJECT_FLAG_SET (bin, GST_ELEMENT_IS_SINK);
1091 }
1092 if (is_source) {
1093 GST_CAT_DEBUG_OBJECT (GST_CAT_PARENTAGE, bin, "element \"%s\" was source",
1094 elem_name);
1095 GST_OBJECT_FLAG_SET (bin, GST_ELEMENT_IS_SOURCE);
1096 }
1097 if (gst_element_provides_clock (element)) {
1098 GST_DEBUG_OBJECT (bin, "element \"%s\" can provide a clock", elem_name);
1099 clock_message =
1100 gst_message_new_clock_provide (GST_OBJECT_CAST (element), NULL, TRUE);
1101 }
1103 bin->children = g_list_prepend (bin->children, element);
1104 bin->numchildren++;
1105 bin->children_cookie++;
1106 bin->priv->structure_cookie++;
1108 /* distribute the bus */
1109 gst_element_set_bus (element, bin->child_bus);
1111 /* propagate the current base_time, start_time and clock */
1112 gst_element_set_base_time (element, GST_ELEMENT_CAST (bin)->base_time);
1113 gst_element_set_start_time (element, GST_ELEMENT_START_TIME (bin));
1114 /* it's possible that the element did not accept the clock but
1115 * that is not important right now. When the pipeline goes to PLAYING,
1116 * a new clock will be selected */
1117 gst_element_set_clock (element, GST_ELEMENT_CLOCK (bin));
1118 /* set the cached index on the children */
1119 if (bin->priv->index)
1120 gst_element_set_index (element, bin->priv->index);
1122 ret = GST_STATE_RETURN (bin);
1123 /* no need to update the state if we are in error */
1124 if (ret == GST_STATE_CHANGE_FAILURE)
1125 goto no_state_recalc;
1127 /* update the bin state, the new element could have been an ASYNC or
1128 * NO_PREROLL element */
1129 ret = GST_STATE_RETURN (element);
1130 GST_DEBUG_OBJECT (bin, "added %s element",
1131 gst_element_state_change_return_get_name (ret));
1133 switch (ret) {
1134 case GST_STATE_CHANGE_ASYNC:
1135 {
1136 /* create message to track this aync element when it posts an async-done
1137 * message */
1138 async_message =
1139 gst_message_new_async_start (GST_OBJECT_CAST (element), FALSE);
1140 break;
1141 }
1142 case GST_STATE_CHANGE_NO_PREROLL:
1143 /* ignore all async elements we might have and commit our state */
1144 bin_handle_async_done (bin, ret, FALSE);
1145 break;
1146 case GST_STATE_CHANGE_FAILURE:
1147 break;
1148 default:
1149 break;
1150 }
1152 no_state_recalc:
1153 GST_OBJECT_UNLOCK (bin);
1155 /* post the messages on the bus of the element so that the bin can handle
1156 * them */
1157 if (clock_message)
1158 gst_element_post_message (GST_ELEMENT_CAST (element), clock_message);
1160 if (async_message)
1161 gst_element_post_message (GST_ELEMENT_CAST (element), async_message);
1163 /* unlink all linked pads */
1164 it = gst_element_iterate_pads (element);
1165 gst_iterator_foreach (it, (GFunc) unlink_pads, element);
1166 gst_iterator_free (it);
1168 GST_CAT_DEBUG_OBJECT (GST_CAT_PARENTAGE, bin, "added element \"%s\"",
1169 elem_name);
1170 g_free (elem_name);
1172 g_signal_emit (bin, gst_bin_signals[ELEMENT_ADDED], 0, element);
1173 gst_child_proxy_child_added ((GstObject *) bin, (GstObject *) element);
1175 return TRUE;
1177 /* ERROR handling here */
1178 adding_itself:
1179 {
1180 GST_OBJECT_LOCK (bin);
1181 g_warning ("Cannot add bin '%s' to itself", GST_ELEMENT_NAME (bin));
1182 GST_OBJECT_UNLOCK (bin);
1183 return FALSE;
1184 }
1185 duplicate_name:
1186 {
1187 g_warning ("Name '%s' is not unique in bin '%s', not adding",
1188 elem_name, GST_ELEMENT_NAME (bin));
1189 GST_OBJECT_UNLOCK (bin);
1190 g_free (elem_name);
1191 return FALSE;
1192 }
1193 had_parent:
1194 {
1195 g_warning ("Element '%s' already has parent", elem_name);
1196 GST_OBJECT_UNLOCK (bin);
1197 g_free (elem_name);
1198 return FALSE;
1199 }
1200 }
1202 /**
1203 * gst_bin_add:
1204 * @bin: a #GstBin
1205 * @element: (transfer full): the #GstElement to add
1206 *
1207 * Adds the given element to the bin. Sets the element's parent, and thus
1208 * takes ownership of the element. An element can only be added to one bin.
1209 *
1210 * If the element's pads are linked to other pads, the pads will be unlinked
1211 * before the element is added to the bin.
1212 *
1213 * <note>
1214 * When you add an element to an already-running pipeline, you will have to
1215 * take care to set the state of the newly-added element to the desired
1216 * state (usually PLAYING or PAUSED, same you set the pipeline to originally)
1217 * with gst_element_set_state(), or use gst_element_sync_state_with_parent().
1218 * The bin or pipeline will not take care of this for you.
1219 * </note>
1220 *
1221 * MT safe.
1222 *
1223 * Returns: TRUE if the element could be added, FALSE if
1224 * the bin does not want to accept the element.
1225 */
1226 gboolean
1227 gst_bin_add (GstBin * bin, GstElement * element)
1228 {
1229 GstBinClass *bclass;
1230 gboolean result;
1232 g_return_val_if_fail (GST_IS_BIN (bin), FALSE);
1233 g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
1235 bclass = GST_BIN_GET_CLASS (bin);
1237 if (G_UNLIKELY (bclass->add_element == NULL))
1238 goto no_function;
1240 GST_CAT_DEBUG (GST_CAT_PARENTAGE, "adding element %s to bin %s",
1241 GST_STR_NULL (GST_ELEMENT_NAME (element)),
1242 GST_STR_NULL (GST_ELEMENT_NAME (bin)));
1244 result = bclass->add_element (bin, element);
1246 return result;
1248 /* ERROR handling */
1249 no_function:
1250 {
1251 g_warning ("adding elements to bin '%s' is not supported",
1252 GST_ELEMENT_NAME (bin));
1253 return FALSE;
1254 }
1255 }
1257 /* remove an element from the bin
1258 *
1259 * MT safe
1260 */
1261 static gboolean
1262 gst_bin_remove_func (GstBin * bin, GstElement * element)
1263 {
1264 gchar *elem_name;
1265 GstIterator *it;
1266 gboolean is_sink, is_source, othersink, othersource, found;
1267 GstMessage *clock_message = NULL;
1268 GstClock **provided_clock_p;
1269 GstElement **clock_provider_p;
1270 GList *walk, *next;
1271 gboolean other_async, this_async, have_no_preroll;
1272 GstStateChangeReturn ret;
1274 GST_DEBUG_OBJECT (bin, "element :%s", GST_ELEMENT_NAME (element));
1276 GST_OBJECT_LOCK (element);
1277 /* Check if the element is already being removed and immediately
1278 * return */
1279 if (G_UNLIKELY (GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_UNPARENTING)))
1280 goto already_removing;
1282 GST_OBJECT_FLAG_SET (element, GST_ELEMENT_UNPARENTING);
1283 /* grab element name so we can print it */
1284 elem_name = g_strdup (GST_ELEMENT_NAME (element));
1285 is_sink = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_IS_SINK);
1286 is_source = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_IS_SOURCE);
1287 GST_OBJECT_UNLOCK (element);
1289 /* unlink all linked pads */
1290 it = gst_element_iterate_pads (element);
1291 gst_iterator_foreach (it, (GFunc) unlink_pads, element);
1292 gst_iterator_free (it);
1294 GST_OBJECT_LOCK (bin);
1295 found = FALSE;
1296 othersink = FALSE;
1297 othersource = FALSE;
1298 have_no_preroll = FALSE;
1299 /* iterate the elements, we collect which ones are async and no_preroll. We
1300 * also remove the element when we find it. */
1301 for (walk = bin->children; walk; walk = next) {
1302 GstElement *child = GST_ELEMENT_CAST (walk->data);
1304 next = g_list_next (walk);
1306 if (child == element) {
1307 found = TRUE;
1308 /* remove the element */
1309 bin->children = g_list_delete_link (bin->children, walk);
1310 } else {
1311 gboolean child_sink, child_source;
1313 GST_OBJECT_LOCK (child);
1314 child_sink = GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_IS_SINK);
1315 child_source = GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_IS_SOURCE);
1316 /* when we remove a sink, check if there are other sinks. */
1317 if (is_sink && !othersink && child_sink)
1318 othersink = TRUE;
1319 if (is_source && !othersource && child_source)
1320 othersource = TRUE;
1321 /* check if we have NO_PREROLL children */
1322 if (GST_STATE_RETURN (child) == GST_STATE_CHANGE_NO_PREROLL)
1323 have_no_preroll = TRUE;
1324 GST_OBJECT_UNLOCK (child);
1325 }
1326 }
1328 /* the element must have been in the bin's list of children */
1329 if (G_UNLIKELY (!found))
1330 goto not_in_bin;
1332 /* we now removed the element from the list of elements, increment the cookie
1333 * so that others can detect a change in the children list. */
1334 bin->numchildren--;
1335 bin->children_cookie++;
1336 bin->priv->structure_cookie++;
1338 if (is_sink && !othersink) {
1339 /* we're not a sink anymore */
1340 GST_DEBUG_OBJECT (bin, "we removed the last sink");
1341 GST_OBJECT_FLAG_UNSET (bin, GST_ELEMENT_IS_SINK);
1342 }
1343 if (is_source && !othersource) {
1344 /* we're not a source anymore */
1345 GST_DEBUG_OBJECT (bin, "we removed the last source");
1346 GST_OBJECT_FLAG_UNSET (bin, GST_ELEMENT_IS_SOURCE);
1347 }
1350 /* if the clock provider for this element is removed, we lost
1351 * the clock as well, we need to inform the parent of this
1352 * so that it can select a new clock */
1353 if (bin->clock_provider == element) {
1354 GST_DEBUG_OBJECT (bin, "element \"%s\" provided the clock", elem_name);
1355 bin->clock_dirty = TRUE;
1356 clock_message =
1357 gst_message_new_clock_lost (GST_OBJECT_CAST (bin), bin->provided_clock);
1358 provided_clock_p = &bin->provided_clock;
1359 clock_provider_p = &bin->clock_provider;
1360 gst_object_replace ((GstObject **) provided_clock_p, NULL);
1361 gst_object_replace ((GstObject **) clock_provider_p, NULL);
1362 }
1364 /* remove messages for the element, if there was a pending ASYNC_START
1365 * message we must see if removing the element caused the bin to lose its
1366 * async state. */
1367 this_async = FALSE;
1368 other_async = FALSE;
1369 for (walk = bin->messages; walk; walk = next) {
1370 GstMessage *message = (GstMessage *) walk->data;
1371 GstElement *src = GST_ELEMENT_CAST (GST_MESSAGE_SRC (message));
1372 gboolean remove;
1374 next = g_list_next (walk);
1375 remove = FALSE;
1377 switch (GST_MESSAGE_TYPE (message)) {
1378 case GST_MESSAGE_ASYNC_START:
1379 if (src == element)
1380 this_async = TRUE;
1381 else
1382 other_async = TRUE;
1384 GST_DEBUG_OBJECT (src, "looking at message %p", message);
1385 break;
1386 case GST_MESSAGE_STRUCTURE_CHANGE:
1387 {
1388 GstElement *owner;
1390 GST_DEBUG_OBJECT (src, "looking at structure change message %p",
1391 message);
1392 /* it's unlikely that this message is still in the list of messages
1393 * because this would mean that a link/unlink is busy in another thread
1394 * while we remove the element. We still have to remove the message
1395 * because we might not receive the done message anymore when the element
1396 * is removed from the bin. */
1397 gst_message_parse_structure_change (message, NULL, &owner, NULL);
1398 if (owner == element)
1399 remove = TRUE;
1400 break;
1401 }
1402 default:
1403 break;
1404 }
1405 if (src == element)
1406 remove = TRUE;
1408 if (remove) {
1409 /* delete all message types */
1410 GST_DEBUG_OBJECT (src, "deleting message %p of element \"%s\"",
1411 message, elem_name);
1412 bin->messages = g_list_delete_link (bin->messages, walk);
1413 gst_message_unref (message);
1414 }
1415 }
1417 /* get last return */
1418 ret = GST_STATE_RETURN (bin);
1420 /* no need to update the state if we are in error */
1421 if (ret == GST_STATE_CHANGE_FAILURE)
1422 goto no_state_recalc;
1424 if (!other_async && this_async) {
1425 /* all other elements were not async and we removed the async one,
1426 * handle the async-done case because we are not async anymore now. */
1427 GST_DEBUG_OBJECT (bin,
1428 "we removed the last async element, have no_preroll %d",
1429 have_no_preroll);
1431 /* the current state return of the bin depends on if there are no_preroll
1432 * elements in the pipeline or not */
1433 if (have_no_preroll)
1434 ret = GST_STATE_CHANGE_NO_PREROLL;
1435 else
1436 ret = GST_STATE_CHANGE_SUCCESS;
1438 bin_handle_async_done (bin, ret, FALSE);
1439 } else {
1440 GST_DEBUG_OBJECT (bin,
1441 "recalc state preroll: %d, other async: %d, this async %d",
1442 have_no_preroll, other_async, this_async);
1444 if (have_no_preroll) {
1445 ret = GST_STATE_CHANGE_NO_PREROLL;
1446 } else if (other_async) {
1447 /* there are other async elements and we were not doing an async state
1448 * change, change our pending state and go async */
1449 if (GST_STATE_PENDING (bin) == GST_STATE_VOID_PENDING) {
1450 GST_STATE_NEXT (bin) = GST_STATE (bin);
1451 GST_STATE_PENDING (bin) = GST_STATE (bin);
1452 }
1453 ret = GST_STATE_CHANGE_ASYNC;
1454 }
1455 GST_STATE_RETURN (bin) = ret;
1456 }
1457 no_state_recalc:
1458 GST_OBJECT_UNLOCK (bin);
1460 if (clock_message)
1461 gst_element_post_message (GST_ELEMENT_CAST (bin), clock_message);
1463 GST_CAT_INFO_OBJECT (GST_CAT_PARENTAGE, bin, "removed child \"%s\"",
1464 elem_name);
1465 g_free (elem_name);
1467 gst_element_set_bus (element, NULL);
1469 /* Clear the clock we provided to the element */
1470 gst_element_set_clock (element, NULL);
1472 /* we ref here because after the _unparent() the element can be disposed
1473 * and we still need it to reset the UNPARENTING flag and fire a signal. */
1474 gst_object_ref (element);
1475 gst_object_unparent (GST_OBJECT_CAST (element));
1477 GST_OBJECT_LOCK (element);
1478 GST_OBJECT_FLAG_UNSET (element, GST_ELEMENT_UNPARENTING);
1479 GST_OBJECT_UNLOCK (element);
1481 g_signal_emit (bin, gst_bin_signals[ELEMENT_REMOVED], 0, element);
1482 gst_child_proxy_child_removed ((GstObject *) bin, (GstObject *) element);
1484 /* element is really out of our control now */
1485 gst_object_unref (element);
1487 return TRUE;
1489 /* ERROR handling */
1490 not_in_bin:
1491 {
1492 g_warning ("Element '%s' is not in bin '%s'", elem_name,
1493 GST_ELEMENT_NAME (bin));
1494 GST_OBJECT_UNLOCK (bin);
1495 g_free (elem_name);
1496 return FALSE;
1497 }
1498 already_removing:
1499 {
1500 GST_CAT_INFO_OBJECT (GST_CAT_PARENTAGE, bin, "already removing child");
1501 GST_OBJECT_UNLOCK (element);
1502 return FALSE;
1503 }
1504 }
1506 /**
1507 * gst_bin_remove:
1508 * @bin: a #GstBin
1509 * @element: (transfer none): the #GstElement to remove
1510 *
1511 * Removes the element from the bin, unparenting it as well.
1512 * Unparenting the element means that the element will be dereferenced,
1513 * so if the bin holds the only reference to the element, the element
1514 * will be freed in the process of removing it from the bin. If you
1515 * want the element to still exist after removing, you need to call
1516 * gst_object_ref() before removing it from the bin.
1517 *
1518 * If the element's pads are linked to other pads, the pads will be unlinked
1519 * before the element is removed from the bin.
1520 *
1521 * MT safe.
1522 *
1523 * Returns: TRUE if the element could be removed, FALSE if
1524 * the bin does not want to remove the element.
1525 */
1526 gboolean
1527 gst_bin_remove (GstBin * bin, GstElement * element)
1528 {
1529 GstBinClass *bclass;
1530 gboolean result;
1532 g_return_val_if_fail (GST_IS_BIN (bin), FALSE);
1533 g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
1535 bclass = GST_BIN_GET_CLASS (bin);
1537 if (G_UNLIKELY (bclass->remove_element == NULL))
1538 goto no_function;
1540 GST_CAT_DEBUG (GST_CAT_PARENTAGE, "removing element %s from bin %s",
1541 GST_ELEMENT_NAME (element), GST_ELEMENT_NAME (bin));
1543 result = bclass->remove_element (bin, element);
1545 return result;
1547 /* ERROR handling */
1548 no_function:
1549 {
1550 g_warning ("removing elements from bin '%s' is not supported",
1551 GST_ELEMENT_NAME (bin));
1552 return FALSE;
1553 }
1554 }
1556 static GstIteratorItem
1557 iterate_child (GstIterator * it, GstElement * child)
1558 {
1559 gst_object_ref (child);
1560 return GST_ITERATOR_ITEM_PASS;
1561 }
1563 /**
1564 * gst_bin_iterate_elements:
1565 * @bin: a #GstBin
1566 *
1567 * Gets an iterator for the elements in this bin.
1568 *
1569 * Each element yielded by the iterator will have its refcount increased, so
1570 * unref after use.
1571 *
1572 * MT safe. Caller owns returned value.
1573 *
1574 * Returns: (transfer full): a #GstIterator of #GstElement, or NULL
1575 */
1576 GstIterator *
1577 gst_bin_iterate_elements (GstBin * bin)
1578 {
1579 GstIterator *result;
1581 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
1583 GST_OBJECT_LOCK (bin);
1584 /* add ref because the iterator refs the bin. When the iterator
1585 * is freed it will unref the bin again using the provided dispose
1586 * function. */
1587 gst_object_ref (bin);
1588 result = gst_iterator_new_list (GST_TYPE_ELEMENT,
1589 GST_OBJECT_GET_LOCK (bin),
1590 &bin->children_cookie,
1591 &bin->children,
1592 bin,
1593 (GstIteratorItemFunction) iterate_child,
1594 (GstIteratorDisposeFunction) gst_object_unref);
1595 GST_OBJECT_UNLOCK (bin);
1597 return result;
1598 }
1600 static GstIteratorItem
1601 iterate_child_recurse (GstIterator * it, GstElement * child)
1602 {
1603 gst_object_ref (child);
1604 if (GST_IS_BIN (child)) {
1605 GstIterator *other = gst_bin_iterate_recurse (GST_BIN_CAST (child));
1607 gst_iterator_push (it, other);
1608 }
1609 return GST_ITERATOR_ITEM_PASS;
1610 }
1612 /**
1613 * gst_bin_iterate_recurse:
1614 * @bin: a #GstBin
1615 *
1616 * Gets an iterator for the elements in this bin.
1617 * This iterator recurses into GstBin children.
1618 *
1619 * Each element yielded by the iterator will have its refcount increased, so
1620 * unref after use.
1621 *
1622 * MT safe. Caller owns returned value.
1623 *
1624 * Returns: (transfer full): a #GstIterator of #GstElement, or NULL
1625 */
1626 GstIterator *
1627 gst_bin_iterate_recurse (GstBin * bin)
1628 {
1629 GstIterator *result;
1631 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
1633 GST_OBJECT_LOCK (bin);
1634 /* add ref because the iterator refs the bin. When the iterator
1635 * is freed it will unref the bin again using the provided dispose
1636 * function. */
1637 gst_object_ref (bin);
1638 result = gst_iterator_new_list (GST_TYPE_ELEMENT,
1639 GST_OBJECT_GET_LOCK (bin),
1640 &bin->children_cookie,
1641 &bin->children,
1642 bin,
1643 (GstIteratorItemFunction) iterate_child_recurse,
1644 (GstIteratorDisposeFunction) gst_object_unref);
1645 GST_OBJECT_UNLOCK (bin);
1647 return result;
1648 }
1650 /* returns 0 when TRUE because this is a GCompareFunc */
1651 /* MT safe */
1652 static gint
1653 bin_element_is_sink (GstElement * child, GstBin * bin)
1654 {
1655 gboolean is_sink;
1657 /* we lock the child here for the remainder of the function to
1658 * get its name and flag safely. */
1659 GST_OBJECT_LOCK (child);
1660 is_sink = GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_IS_SINK);
1662 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin,
1663 "child %s %s sink", GST_OBJECT_NAME (child), is_sink ? "is" : "is not");
1665 GST_OBJECT_UNLOCK (child);
1666 return is_sink ? 0 : 1;
1667 }
1669 static gint
1670 sink_iterator_filter (GstElement * child, GstBin * bin)
1671 {
1672 if (bin_element_is_sink (child, bin) == 0) {
1673 /* returns 0 because this is a GCompareFunc */
1674 return 0;
1675 } else {
1676 /* child carries a ref from gst_bin_iterate_elements -- drop if not passing
1677 through */
1678 gst_object_unref (child);
1679 return 1;
1680 }
1681 }
1683 /**
1684 * gst_bin_iterate_sinks:
1685 * @bin: a #GstBin
1686 *
1687 * Gets an iterator for all elements in the bin that have the
1688 * #GST_ELEMENT_IS_SINK flag set.
1689 *
1690 * Each element yielded by the iterator will have its refcount increased, so
1691 * unref after use.
1692 *
1693 * MT safe. Caller owns returned value.
1694 *
1695 * Returns: (transfer full): a #GstIterator of #GstElement, or NULL
1696 */
1697 GstIterator *
1698 gst_bin_iterate_sinks (GstBin * bin)
1699 {
1700 GstIterator *children;
1701 GstIterator *result;
1703 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
1705 children = gst_bin_iterate_elements (bin);
1706 result = gst_iterator_filter (children,
1707 (GCompareFunc) sink_iterator_filter, bin);
1709 return result;
1710 }
1712 /* returns 0 when TRUE because this is a GCompareFunc */
1713 /* MT safe */
1714 static gint
1715 bin_element_is_src (GstElement * child, GstBin * bin)
1716 {
1717 gboolean is_src;
1719 /* we lock the child here for the remainder of the function to
1720 * get its name and other info safely. */
1721 GST_OBJECT_LOCK (child);
1722 is_src = GST_OBJECT_FLAG_IS_SET (child, GST_ELEMENT_IS_SOURCE);
1724 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin,
1725 "child %s %s src", GST_OBJECT_NAME (child), is_src ? "is" : "is not");
1727 GST_OBJECT_UNLOCK (child);
1728 return is_src ? 0 : 1;
1729 }
1731 static gint
1732 src_iterator_filter (GstElement * child, GstBin * bin)
1733 {
1734 if (bin_element_is_src (child, bin) == 0) {
1735 /* returns 0 because this is a GCompareFunc */
1736 return 0;
1737 } else {
1738 /* child carries a ref from gst_bin_iterate_elements -- drop if not passing
1739 through */
1740 gst_object_unref (child);
1741 return 1;
1742 }
1743 }
1745 /**
1746 * gst_bin_iterate_sources:
1747 * @bin: a #GstBin
1748 *
1749 * Gets an iterator for all elements in the bin that have the
1750 * #GST_ELEMENT_IS_SOURCE flag set.
1751 *
1752 * Each element yielded by the iterator will have its refcount increased, so
1753 * unref after use.
1754 *
1755 * MT safe. Caller owns returned value.
1756 *
1757 * Returns: (transfer full): a #GstIterator of #GstElement, or NULL
1758 */
1759 GstIterator *
1760 gst_bin_iterate_sources (GstBin * bin)
1761 {
1762 GstIterator *children;
1763 GstIterator *result;
1765 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
1767 children = gst_bin_iterate_elements (bin);
1768 result = gst_iterator_filter (children,
1769 (GCompareFunc) src_iterator_filter, bin);
1771 return result;
1772 }
1774 /*
1775 * MT safe
1776 */
1777 static GstStateChangeReturn
1778 gst_bin_get_state_func (GstElement * element, GstState * state,
1779 GstState * pending, GstClockTime timeout)
1780 {
1781 GstStateChangeReturn ret;
1783 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element, "getting state");
1785 ret = parent_class->get_state (element, state, pending, timeout);
1787 return ret;
1788 }
1790 /***********************************************
1791 * Topologically sorted iterator
1792 * see http://en.wikipedia.org/wiki/Topological_sorting
1793 *
1794 * For each element in the graph, an entry is kept in a HashTable
1795 * with its number of srcpad connections (degree).
1796 * We then change state of all elements without dependencies
1797 * (degree 0) and decrement the degree of all elements connected
1798 * on the sinkpads. When an element reaches degree 0, its state is
1799 * changed next.
1800 * When all elements are handled the algorithm stops.
1801 */
1802 typedef struct _GstBinSortIterator
1803 {
1804 GstIterator it;
1805 GQueue *queue; /* elements queued for state change */
1806 GstBin *bin; /* bin we iterate */
1807 gint mode; /* adding or removing dependency */
1808 GstElement *best; /* next element with least dependencies */
1809 gint best_deg; /* best degree */
1810 GHashTable *hash; /* hashtable with element dependencies */
1811 gboolean dirty; /* we detected structure change */
1812 } GstBinSortIterator;
1814 /* we add and subtract 1 to make sure we don't confuse NULL and 0 */
1815 #define HASH_SET_DEGREE(bit, elem, deg) \
1816 g_hash_table_replace (bit->hash, elem, GINT_TO_POINTER(deg+1))
1817 #define HASH_GET_DEGREE(bit, elem) \
1818 (GPOINTER_TO_INT(g_hash_table_lookup (bit->hash, elem))-1)
1820 /* add element to queue of next elements in the iterator.
1821 * We push at the tail to give higher priority elements a
1822 * chance first */
1823 static void
1824 add_to_queue (GstBinSortIterator * bit, GstElement * element)
1825 {
1826 GST_DEBUG_OBJECT (bit->bin, "adding '%s' to queue",
1827 GST_ELEMENT_NAME (element));
1828 gst_object_ref (element);
1829 g_queue_push_tail (bit->queue, element);
1830 HASH_SET_DEGREE (bit, element, -1);
1831 }
1833 static void
1834 remove_from_queue (GstBinSortIterator * bit, GstElement * element)
1835 {
1836 GList *find;
1838 if ((find = g_queue_find (bit->queue, element))) {
1839 GST_DEBUG_OBJECT (bit->bin, "removing '%s' from queue",
1840 GST_ELEMENT_NAME (element));
1842 g_queue_delete_link (bit->queue, find);
1843 gst_object_unref (element);
1844 } else {
1845 GST_DEBUG_OBJECT (bit->bin, "unable to remove '%s' from queue",
1846 GST_ELEMENT_NAME (element));
1847 }
1848 }
1850 /* clear the queue, unref all objects as we took a ref when
1851 * we added them to the queue */
1852 static void
1853 clear_queue (GQueue * queue)
1854 {
1855 gpointer p;
1857 while ((p = g_queue_pop_head (queue)))
1858 gst_object_unref (p);
1859 }
1861 /* set all degrees to 0. Elements marked as a sink are
1862 * added to the queue immediately. Since we only look at the SINK flag of the
1863 * element, it is possible that we add non-sinks to the queue. These will be
1864 * removed from the queue again when we can prove that it provides data for some
1865 * other element. */
1866 static void
1867 reset_degree (GstElement * element, GstBinSortIterator * bit)
1868 {
1869 gboolean is_sink;
1871 /* sinks are added right away */
1872 GST_OBJECT_LOCK (element);
1873 is_sink = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_IS_SINK);
1874 GST_OBJECT_UNLOCK (element);
1876 if (is_sink) {
1877 add_to_queue (bit, element);
1878 } else {
1879 /* others are marked with 0 and handled when sinks are done */
1880 HASH_SET_DEGREE (bit, element, 0);
1881 }
1882 }
1884 /* adjust the degree of all elements connected to the given
1885 * element. If a degree of an element drops to 0, it is
1886 * added to the queue of elements to schedule next.
1887 *
1888 * We have to make sure not to cross the bin boundary this element
1889 * belongs to.
1890 */
1891 static void
1892 update_degree (GstElement * element, GstBinSortIterator * bit)
1893 {
1894 gboolean linked = FALSE;
1896 GST_OBJECT_LOCK (element);
1897 /* don't touch degree if element has no sinkpads */
1898 if (element->numsinkpads != 0) {
1899 /* loop over all sinkpads, decrement degree for all connected
1900 * elements in this bin */
1901 GList *pads;
1903 for (pads = element->sinkpads; pads; pads = g_list_next (pads)) {
1904 GstPad *pad, *peer;
1906 pad = GST_PAD_CAST (pads->data);
1908 /* we're iterating over the sinkpads, check if it's busy in a link/unlink */
1909 if (G_UNLIKELY (find_message (bit->bin, GST_OBJECT_CAST (pad),
1910 GST_MESSAGE_STRUCTURE_CHANGE))) {
1911 /* mark the iterator as dirty because we won't be updating the degree
1912 * of the peer parent now. This would result in the 'loop detected'
1913 * later on because the peer parent element could become the best next
1914 * element with a degree > 0. We will simply continue our state
1915 * changes and we'll eventually resync when the unlink completed and
1916 * the iterator cookie is updated. */
1917 bit->dirty = TRUE;
1918 continue;
1919 }
1921 if ((peer = gst_pad_get_peer (pad))) {
1922 GstElement *peer_element;
1924 if ((peer_element = gst_pad_get_parent_element (peer))) {
1925 GST_OBJECT_LOCK (peer_element);
1926 /* check that we don't go outside of this bin */
1927 if (GST_OBJECT_CAST (peer_element)->parent ==
1928 GST_OBJECT_CAST (bit->bin)) {
1929 gint old_deg, new_deg;
1931 old_deg = HASH_GET_DEGREE (bit, peer_element);
1933 /* check to see if we added an element as sink that was not really a
1934 * sink because it was connected to some other element. */
1935 if (old_deg == -1) {
1936 remove_from_queue (bit, peer_element);
1937 old_deg = 0;
1938 }
1939 new_deg = old_deg + bit->mode;
1941 GST_DEBUG_OBJECT (bit->bin,
1942 "change element %s, degree %d->%d, linked to %s",
1943 GST_ELEMENT_NAME (peer_element), old_deg, new_deg,
1944 GST_ELEMENT_NAME (element));
1946 /* update degree, it is possible that an element was in 0 and
1947 * reaches -1 here. This would mean that the element had no sinkpads
1948 * but became linked while the state change was happening. We will
1949 * resync on this with the structure change message. */
1950 if (new_deg == 0) {
1951 /* degree hit 0, add to queue */
1952 add_to_queue (bit, peer_element);
1953 } else {
1954 HASH_SET_DEGREE (bit, peer_element, new_deg);
1955 }
1956 linked = TRUE;
1957 }
1958 GST_OBJECT_UNLOCK (peer_element);
1959 gst_object_unref (peer_element);
1960 }
1961 gst_object_unref (peer);
1962 }
1963 }
1964 }
1965 if (!linked) {
1966 GST_DEBUG_OBJECT (bit->bin, "element %s not linked on any sinkpads",
1967 GST_ELEMENT_NAME (element));
1968 }
1969 GST_OBJECT_UNLOCK (element);
1970 }
1972 /* find the next best element not handled yet. This is the one
1973 * with the lowest non-negative degree */
1974 static void
1975 find_element (GstElement * element, GstBinSortIterator * bit)
1976 {
1977 gint degree;
1979 /* element is already handled */
1980 if ((degree = HASH_GET_DEGREE (bit, element)) < 0)
1981 return;
1983 /* first element or element with smaller degree */
1984 if (bit->best == NULL || bit->best_deg > degree) {
1985 bit->best = element;
1986 bit->best_deg = degree;
1987 }
1988 }
1990 /* get next element in iterator. the returned element has the
1991 * refcount increased */
1992 static GstIteratorResult
1993 gst_bin_sort_iterator_next (GstBinSortIterator * bit, gpointer * result)
1994 {
1995 GstBin *bin = bit->bin;
1997 /* empty queue, we have to find a next best element */
1998 if (g_queue_is_empty (bit->queue)) {
1999 GstElement *best;
2001 bit->best = NULL;
2002 bit->best_deg = G_MAXINT;
2003 g_list_foreach (bin->children, (GFunc) find_element, bit);
2004 if ((best = bit->best)) {
2005 /* when we detected an unlink, don't warn because our degrees might be
2006 * screwed up. We will resync later */
2007 if (bit->best_deg != 0 && !bit->dirty) {
2008 /* we don't fail on this one yet */
2009 GST_WARNING_OBJECT (bin, "loop dected in graph");
2010 g_warning ("loop detected in the graph of bin '%s'!!",
2011 GST_ELEMENT_NAME (bin));
2012 }
2013 /* best unhandled element, schedule as next element */
2014 GST_DEBUG_OBJECT (bin, "queue empty, next best: %s",
2015 GST_ELEMENT_NAME (best));
2016 gst_object_ref (best);
2017 HASH_SET_DEGREE (bit, best, -1);
2018 *result = best;
2019 } else {
2020 GST_DEBUG_OBJECT (bin, "queue empty, elements exhausted");
2021 /* no more unhandled elements, we are done */
2022 return GST_ITERATOR_DONE;
2023 }
2024 } else {
2025 /* everything added to the queue got reffed */
2026 *result = g_queue_pop_head (bit->queue);
2027 }
2029 GST_DEBUG_OBJECT (bin, "queue head gives %s", GST_ELEMENT_NAME (*result));
2030 /* update degrees of linked elements */
2031 update_degree (GST_ELEMENT_CAST (*result), bit);
2033 return GST_ITERATOR_OK;
2034 }
2036 /* clear queues, recalculate the degrees and restart. */
2037 static void
2038 gst_bin_sort_iterator_resync (GstBinSortIterator * bit)
2039 {
2040 GstBin *bin = bit->bin;
2042 GST_DEBUG_OBJECT (bin, "resync");
2043 bit->dirty = FALSE;
2044 clear_queue (bit->queue);
2045 /* reset degrees */
2046 g_list_foreach (bin->children, (GFunc) reset_degree, bit);
2047 /* calc degrees, incrementing */
2048 bit->mode = 1;
2049 g_list_foreach (bin->children, (GFunc) update_degree, bit);
2050 /* for the rest of the function we decrement the degrees */
2051 bit->mode = -1;
2052 }
2054 /* clear queues, unref bin and free iterator. */
2055 static void
2056 gst_bin_sort_iterator_free (GstBinSortIterator * bit)
2057 {
2058 GstBin *bin = bit->bin;
2060 GST_DEBUG_OBJECT (bin, "free");
2061 clear_queue (bit->queue);
2062 g_queue_free (bit->queue);
2063 g_hash_table_destroy (bit->hash);
2064 gst_object_unref (bin);
2065 g_free (bit);
2066 }
2068 /* should be called with the bin LOCK held */
2069 static GstIterator *
2070 gst_bin_sort_iterator_new (GstBin * bin)
2071 {
2072 GstBinSortIterator *result;
2074 /* we don't need an ItemFunction because we ref the items in the _next
2075 * method already */
2076 result = (GstBinSortIterator *)
2077 gst_iterator_new (sizeof (GstBinSortIterator),
2078 GST_TYPE_ELEMENT,
2079 GST_OBJECT_GET_LOCK (bin),
2080 &bin->priv->structure_cookie,
2081 (GstIteratorNextFunction) gst_bin_sort_iterator_next,
2082 (GstIteratorItemFunction) NULL,
2083 (GstIteratorResyncFunction) gst_bin_sort_iterator_resync,
2084 (GstIteratorFreeFunction) gst_bin_sort_iterator_free);
2085 result->queue = g_queue_new ();
2086 result->hash = g_hash_table_new (NULL, NULL);
2087 gst_object_ref (bin);
2088 result->bin = bin;
2089 gst_bin_sort_iterator_resync (result);
2091 return (GstIterator *) result;
2092 }
2094 /**
2095 * gst_bin_iterate_sorted:
2096 * @bin: a #GstBin
2097 *
2098 * Gets an iterator for the elements in this bin in topologically
2099 * sorted order. This means that the elements are returned from
2100 * the most downstream elements (sinks) to the sources.
2101 *
2102 * This function is used internally to perform the state changes
2103 * of the bin elements and for clock selection.
2104 *
2105 * Each element yielded by the iterator will have its refcount increased, so
2106 * unref after use.
2107 *
2108 * MT safe. Caller owns returned value.
2109 *
2110 * Returns: (transfer full): a #GstIterator of #GstElement, or NULL
2111 */
2112 GstIterator *
2113 gst_bin_iterate_sorted (GstBin * bin)
2114 {
2115 GstIterator *result;
2117 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
2119 GST_OBJECT_LOCK (bin);
2120 result = gst_bin_sort_iterator_new (bin);
2121 GST_OBJECT_UNLOCK (bin);
2123 return result;
2124 }
2126 static GstStateChangeReturn
2127 gst_bin_element_set_state (GstBin * bin, GstElement * element,
2128 GstClockTime base_time, GstClockTime start_time, GstState current,
2129 GstState next)
2130 {
2131 GstStateChangeReturn ret;
2132 GstState pending, child_current, child_pending;
2133 gboolean locked;
2134 GList *found;
2136 GST_STATE_LOCK (element);
2138 GST_OBJECT_LOCK (element);
2139 /* set base_time and start time on child */
2140 GST_ELEMENT_START_TIME (element) = start_time;
2141 element->base_time = base_time;
2142 /* peel off the locked flag */
2143 locked = GST_OBJECT_FLAG_IS_SET (element, GST_ELEMENT_LOCKED_STATE);
2144 /* Get the previous set_state result to preserve NO_PREROLL and ASYNC */
2145 ret = GST_STATE_RETURN (element);
2146 child_current = GST_STATE (element);
2147 child_pending = GST_STATE_PENDING (element);
2148 GST_OBJECT_UNLOCK (element);
2150 /* skip locked elements */
2151 if (G_UNLIKELY (locked))
2152 goto locked;
2154 /* if the element was no preroll, just start changing the state regardless
2155 * if it had async elements (in the case of a bin) because they won't preroll
2156 * anyway. */
2157 if (G_UNLIKELY (ret == GST_STATE_CHANGE_NO_PREROLL)) {
2158 GST_DEBUG_OBJECT (element, "element is NO_PREROLL, ignore async elements");
2159 goto no_preroll;
2160 }
2162 GST_OBJECT_LOCK (bin);
2163 pending = GST_STATE_PENDING (bin);
2165 /* Try not to change the state of elements that are already in the state we're
2166 * going to */
2167 if (!(next == GST_STATE_PLAYING || child_pending != GST_STATE_VOID_PENDING ||
2168 (child_pending == GST_STATE_VOID_PENDING &&
2169 ((pending > child_current && next > child_current) ||
2170 (pending < child_current && next < child_current)))))
2171 goto unneeded;
2173 /* the element was busy with an upwards async state change, we must wait for
2174 * an ASYNC_DONE message before we attemp to change the state. */
2175 if ((found =
2176 find_message (bin, GST_OBJECT_CAST (element),
2177 GST_MESSAGE_ASYNC_START))) {
2178 #ifndef GST_DISABLE_GST_DEBUG
2179 GstMessage *message = GST_MESSAGE_CAST (found->data);
2181 GST_DEBUG_OBJECT (element, "element message %p, %s async busy",
2182 message, GST_ELEMENT_NAME (GST_MESSAGE_SRC (message)));
2183 #endif
2184 /* only wait for upward state changes */
2185 if (next > current) {
2186 /* We found an async element check if we can force its state to change or
2187 * if we have to wait for it to preroll. */
2188 if (G_UNLIKELY (!enable_latency)) {
2189 g_warning ("Future versions of GStreamer will wait for element \"%s\"\n"
2190 "\tto preroll in order to perform correct latency calculations.\n"
2191 "\tPlease verify that the application continues to work correctly by\n"
2192 "\tsetting the environment variable GST_COMPAT to a value containing\n"
2193 "\tthe string 'live-preroll'.", GST_ELEMENT_NAME (element));
2194 goto no_latency;
2195 }
2196 goto was_busy;
2197 }
2198 }
2199 no_latency:
2200 GST_OBJECT_UNLOCK (bin);
2202 no_preroll:
2203 GST_DEBUG_OBJECT (bin,
2204 "setting element %s to %s, base_time %" GST_TIME_FORMAT,
2205 GST_ELEMENT_NAME (element), gst_element_state_get_name (next),
2206 GST_TIME_ARGS (base_time));
2208 /* change state */
2209 ret = gst_element_set_state (element, next);
2211 GST_STATE_UNLOCK (element);
2213 return ret;
2215 locked:
2216 {
2217 GST_DEBUG_OBJECT (element,
2218 "element is locked, return previous return %s",
2219 gst_element_state_change_return_get_name (ret));
2220 GST_STATE_UNLOCK (element);
2221 return ret;
2222 }
2223 was_busy:
2224 {
2225 GST_DEBUG_OBJECT (element, "element was busy, delaying state change");
2226 GST_OBJECT_UNLOCK (bin);
2227 GST_STATE_UNLOCK (element);
2228 return GST_STATE_CHANGE_ASYNC;
2229 }
2230 unneeded:
2231 {
2232 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2233 "skipping transition from %s to %s, since bin pending"
2234 " is %s : last change state return follows",
2235 gst_element_state_get_name (child_current),
2236 gst_element_state_get_name (next),
2237 gst_element_state_get_name (pending));
2238 GST_OBJECT_UNLOCK (bin);
2239 GST_STATE_UNLOCK (element);
2240 return ret;
2241 }
2242 }
2244 /* gst_iterator_fold functions for pads_activate
2245 * Stop the iterator if activating one pad failed. */
2246 static gboolean
2247 activate_pads (GstPad * pad, GValue * ret, gboolean * active)
2248 {
2249 gboolean cont = TRUE;
2251 if (!(cont = gst_pad_set_active (pad, *active)))
2252 g_value_set_boolean (ret, FALSE);
2253 else if (!*active)
2254 gst_pad_set_caps (pad, NULL);
2256 /* unref the object that was reffed for us by _fold */
2257 gst_object_unref (pad);
2258 return cont;
2259 }
2261 /* returns false on error or early cutout of the fold, true if all
2262 * pads in @iter were (de)activated successfully. */
2263 static gboolean
2264 iterator_activate_fold_with_resync (GstIterator * iter, gpointer user_data)
2265 {
2266 GstIteratorResult ires;
2267 GValue ret = { 0 };
2269 /* no need to unset this later, it's just a boolean */
2270 g_value_init (&ret, G_TYPE_BOOLEAN);
2271 g_value_set_boolean (&ret, TRUE);
2273 while (1) {
2274 ires = gst_iterator_fold (iter, (GstIteratorFoldFunction) activate_pads,
2275 &ret, user_data);
2276 switch (ires) {
2277 case GST_ITERATOR_RESYNC:
2278 /* need to reset the result again */
2279 g_value_set_boolean (&ret, TRUE);
2280 gst_iterator_resync (iter);
2281 break;
2282 case GST_ITERATOR_DONE:
2283 /* all pads iterated, return collected value */
2284 goto done;
2285 default:
2286 /* iterator returned _ERROR or premature end with _OK,
2287 * mark an error and exit */
2288 g_value_set_boolean (&ret, FALSE);
2289 goto done;
2290 }
2291 }
2292 done:
2293 /* return collected value */
2294 return g_value_get_boolean (&ret);
2295 }
2297 /* is called with STATE_LOCK
2298 */
2299 static gboolean
2300 gst_bin_src_pads_activate (GstBin * bin, gboolean active)
2301 {
2302 GstIterator *iter;
2303 gboolean fold_ok;
2305 GST_DEBUG_OBJECT (bin, "src_pads_activate with active %d", active);
2307 iter = gst_element_iterate_src_pads ((GstElement *) bin);
2308 fold_ok = iterator_activate_fold_with_resync (iter, &active);
2309 gst_iterator_free (iter);
2310 if (G_UNLIKELY (!fold_ok))
2311 goto failed;
2313 GST_DEBUG_OBJECT (bin, "pads_activate successful");
2315 return TRUE;
2317 /* ERRORS */
2318 failed:
2319 {
2320 GST_DEBUG_OBJECT (bin, "source pads_activate failed");
2321 return FALSE;
2322 }
2323 }
2325 /**
2326 * gst_bin_recalculate_latency:
2327 * @bin: a #GstBin
2328 *
2329 * Query @bin for the current latency using and reconfigures this latency to all the
2330 * elements with a LATENCY event.
2331 *
2332 * This method is typically called on the pipeline when a #GST_MESSAGE_LATENCY
2333 * is posted on the bus.
2334 *
2335 * This function simply emits the 'do-latency' signal so any custom latency
2336 * calculations will be performed.
2337 *
2338 * Returns: %TRUE if the latency could be queried and reconfigured.
2339 *
2340 * Since: 0.10.22.
2341 */
2342 gboolean
2343 gst_bin_recalculate_latency (GstBin * bin)
2344 {
2345 gboolean res;
2347 g_signal_emit (bin, gst_bin_signals[DO_LATENCY], 0, &res);
2348 GST_DEBUG_OBJECT (bin, "latency returned %d", res);
2350 return res;
2351 }
2353 static gboolean
2354 gst_bin_do_latency_func (GstBin * bin)
2355 {
2356 GstQuery *query;
2357 GstElement *element;
2358 GstClockTime min_latency, max_latency;
2359 gboolean res;
2361 g_return_val_if_fail (GST_IS_BIN (bin), FALSE);
2363 element = GST_ELEMENT_CAST (bin);
2365 GST_DEBUG_OBJECT (element, "querying latency");
2367 query = gst_query_new_latency ();
2368 if ((res = gst_element_query (element, query))) {
2369 gboolean live;
2371 gst_query_parse_latency (query, &live, &min_latency, &max_latency);
2373 GST_DEBUG_OBJECT (element,
2374 "got min latency %" GST_TIME_FORMAT ", max latency %"
2375 GST_TIME_FORMAT ", live %d", GST_TIME_ARGS (min_latency),
2376 GST_TIME_ARGS (max_latency), live);
2378 if (max_latency < min_latency) {
2379 /* this is an impossible situation, some parts of the pipeline might not
2380 * work correctly. We post a warning for now. */
2381 GST_ELEMENT_WARNING (element, CORE, CLOCK, (NULL),
2382 ("Impossible to configure latency: max %" GST_TIME_FORMAT " < min %"
2383 GST_TIME_FORMAT ". Add queues or other buffering elements.",
2384 GST_TIME_ARGS (max_latency), GST_TIME_ARGS (min_latency)));
2385 }
2387 /* configure latency on elements */
2388 res = gst_element_send_event (element, gst_event_new_latency (min_latency));
2389 if (res) {
2390 GST_INFO_OBJECT (element, "configured latency of %" GST_TIME_FORMAT,
2391 GST_TIME_ARGS (min_latency));
2392 } else {
2393 GST_WARNING_OBJECT (element,
2394 "did not really configure latency of %" GST_TIME_FORMAT,
2395 GST_TIME_ARGS (min_latency));
2396 }
2397 } else {
2398 /* this is not a real problem, we just don't configure any latency. */
2399 GST_WARNING_OBJECT (element, "failed to query latency");
2400 }
2401 gst_query_unref (query);
2403 return res;
2404 }
2406 static void
2407 gst_bin_state_changed (GstElement * element, GstState oldstate,
2408 GstState newstate, GstState pending)
2409 {
2410 GstElementClass *pklass = (GstElementClass *) parent_class;
2412 if (newstate == GST_STATE_PLAYING && pending == GST_STATE_VOID_PENDING)
2413 bin_do_eos (GST_BIN_CAST (element));
2415 if (pklass->state_changed)
2416 pklass->state_changed (element, oldstate, newstate, pending);
2417 }
2419 static GstStateChangeReturn
2420 gst_bin_change_state_func (GstElement * element, GstStateChange transition)
2421 {
2422 GstBin *bin;
2423 GstStateChangeReturn ret;
2424 GstState current, next;
2425 gboolean have_async;
2426 gboolean have_no_preroll;
2427 GstClockTime base_time, start_time;
2428 GstIterator *it;
2429 gboolean done;
2431 /* we don't need to take the STATE_LOCK, it is already taken */
2432 current = (GstState) GST_STATE_TRANSITION_CURRENT (transition);
2433 next = (GstState) GST_STATE_TRANSITION_NEXT (transition);
2435 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element,
2436 "changing state of children from %s to %s",
2437 gst_element_state_get_name (current), gst_element_state_get_name (next));
2439 bin = GST_BIN_CAST (element);
2441 switch (next) {
2442 case GST_STATE_PLAYING:
2443 {
2444 gboolean toplevel;
2446 GST_OBJECT_LOCK (bin);
2447 toplevel = BIN_IS_TOPLEVEL (bin);
2448 GST_OBJECT_UNLOCK (bin);
2450 if (toplevel)
2451 gst_bin_recalculate_latency (bin);
2452 break;
2453 }
2454 case GST_STATE_PAUSED:
2455 /* Clear EOS list on next PAUSED */
2456 GST_OBJECT_LOCK (bin);
2457 GST_DEBUG_OBJECT (element, "clearing EOS elements");
2458 bin_remove_messages (bin, NULL, GST_MESSAGE_EOS);
2459 bin->priv->posted_eos = FALSE;
2460 GST_OBJECT_UNLOCK (bin);
2461 if (current == GST_STATE_READY)
2462 if (!(gst_bin_src_pads_activate (bin, TRUE)))
2463 goto activate_failure;
2464 break;
2465 case GST_STATE_READY:
2466 /* Clear message list on next READY */
2467 GST_OBJECT_LOCK (bin);
2468 GST_DEBUG_OBJECT (element, "clearing all cached messages");
2469 bin_remove_messages (bin, NULL, GST_MESSAGE_ANY);
2470 GST_OBJECT_UNLOCK (bin);
2471 if (current == GST_STATE_PAUSED)
2472 if (!(gst_bin_src_pads_activate (bin, FALSE)))
2473 goto activate_failure;
2474 break;
2475 case GST_STATE_NULL:
2476 if (current == GST_STATE_READY)
2477 if (!(gst_bin_src_pads_activate (bin, FALSE)))
2478 goto activate_failure;
2479 break;
2480 default:
2481 break;
2482 }
2484 /* this flag is used to make the async state changes return immediately. We
2485 * don't want them to interfere with this state change */
2486 GST_OBJECT_LOCK (bin);
2487 bin->polling = TRUE;
2488 GST_OBJECT_UNLOCK (bin);
2490 /* iterate in state change order */
2491 it = gst_bin_iterate_sorted (bin);
2493 /* mark if we've seen an ASYNC element in the bin when we did a state change.
2494 * Note how we don't reset this value when a resync happens, the reason being
2495 * that the async element posted ASYNC_START and we want to post ASYNC_DONE
2496 * even after a resync when the async element is gone */
2497 have_async = FALSE;
2499 restart:
2500 /* take base_time */
2501 base_time = gst_element_get_base_time (element);
2502 start_time = gst_element_get_start_time (element);
2504 have_no_preroll = FALSE;
2506 done = FALSE;
2507 while (!done) {
2508 gpointer data;
2510 switch (gst_iterator_next (it, &data)) {
2511 case GST_ITERATOR_OK:
2512 {
2513 GstElement *child;
2515 child = GST_ELEMENT_CAST (data);
2517 /* set state and base_time now */
2518 ret = gst_bin_element_set_state (bin, child, base_time, start_time,
2519 current, next);
2521 switch (ret) {
2522 case GST_STATE_CHANGE_SUCCESS:
2523 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2524 "child '%s' changed state to %d(%s) successfully",
2525 GST_ELEMENT_NAME (child), next,
2526 gst_element_state_get_name (next));
2527 break;
2528 case GST_STATE_CHANGE_ASYNC:
2529 {
2530 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2531 "child '%s' is changing state asynchronously to %s",
2532 GST_ELEMENT_NAME (child), gst_element_state_get_name (next));
2533 have_async = TRUE;
2534 break;
2535 }
2536 case GST_STATE_CHANGE_FAILURE:{
2537 GstObject *parent;
2539 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2540 "child '%s' failed to go to state %d(%s)",
2541 GST_ELEMENT_NAME (child),
2542 next, gst_element_state_get_name (next));
2544 /* Only fail if the child is still inside
2545 * this bin. It might've been removed already
2546 * because of the error by the bin subclass
2547 * to ignore the error. */
2548 parent = gst_object_get_parent (GST_OBJECT_CAST (child));
2549 if (parent == GST_OBJECT_CAST (element)) {
2550 /* element is still in bin, really error now */
2551 gst_object_unref (child);
2552 gst_object_unref (parent);
2553 goto done;
2554 }
2555 /* child removed from bin, let the resync code redo the state
2556 * change */
2557 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2558 "child '%s' was removed from the bin",
2559 GST_ELEMENT_NAME (child));
2561 if (parent)
2562 gst_object_unref (parent);
2564 break;
2565 }
2566 case GST_STATE_CHANGE_NO_PREROLL:
2567 GST_CAT_INFO_OBJECT (GST_CAT_STATES, element,
2568 "child '%s' changed state to %d(%s) successfully without preroll",
2569 GST_ELEMENT_NAME (child), next,
2570 gst_element_state_get_name (next));
2571 have_no_preroll = TRUE;
2572 break;
2573 default:
2574 g_assert_not_reached ();
2575 break;
2576 }
2577 gst_object_unref (child);
2578 break;
2579 }
2580 case GST_ITERATOR_RESYNC:
2581 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element, "iterator doing resync");
2582 gst_iterator_resync (it);
2583 goto restart;
2584 default:
2585 case GST_ITERATOR_DONE:
2586 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element, "iterator done");
2587 done = TRUE;
2588 break;
2589 }
2590 }
2592 ret = parent_class->change_state (element, transition);
2593 if (G_UNLIKELY (ret == GST_STATE_CHANGE_FAILURE))
2594 goto done;
2596 if (have_no_preroll) {
2597 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin,
2598 "we have NO_PREROLL elements %s -> NO_PREROLL",
2599 gst_element_state_change_return_get_name (ret));
2600 ret = GST_STATE_CHANGE_NO_PREROLL;
2601 } else if (have_async) {
2602 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin,
2603 "we have ASYNC elements %s -> ASYNC",
2604 gst_element_state_change_return_get_name (ret));
2605 ret = GST_STATE_CHANGE_ASYNC;
2606 }
2608 done:
2609 gst_iterator_free (it);
2611 GST_OBJECT_LOCK (bin);
2612 bin->polling = FALSE;
2613 /* it's possible that we did not get ASYNC from the children while the bin is
2614 * simulating ASYNC behaviour by posting an ASYNC_DONE message on the bus with
2615 * itself as the source. In that case we still want to check if the state
2616 * change completed. */
2617 if (ret != GST_STATE_CHANGE_ASYNC && !bin->priv->pending_async_done) {
2618 /* no element returned ASYNC and there are no pending async_done messages,
2619 * we can just complete. */
2620 GST_DEBUG_OBJECT (bin, "no async elements");
2621 goto state_end;
2622 }
2623 /* when we get here an ASYNC element was found */
2624 if (GST_STATE_TARGET (bin) <= GST_STATE_READY) {
2625 /* we ignore ASYNC state changes when we go to READY or NULL */
2626 GST_DEBUG_OBJECT (bin, "target state %s <= READY",
2627 gst_element_state_get_name (GST_STATE_TARGET (bin)));
2628 goto state_end;
2629 }
2631 GST_DEBUG_OBJECT (bin, "check async elements");
2632 /* check if all elements managed to commit their state already */
2633 if (!find_message (bin, NULL, GST_MESSAGE_ASYNC_START)) {
2634 /* nothing found, remove all old ASYNC_DONE messages. This can happen when
2635 * all the elements commited their state while we were doing the state
2636 * change. We will still return ASYNC for consistency but we commit the
2637 * state already so that a _get_state() will return immediately. */
2638 bin_remove_messages (bin, NULL, GST_MESSAGE_ASYNC_DONE);
2640 GST_DEBUG_OBJECT (bin, "async elements commited");
2641 bin_handle_async_done (bin, GST_STATE_CHANGE_SUCCESS, FALSE);
2642 }
2644 state_end:
2645 bin->priv->pending_async_done = FALSE;
2646 GST_OBJECT_UNLOCK (bin);
2648 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element,
2649 "done changing bin's state from %s to %s, now in %s, ret %s",
2650 gst_element_state_get_name (current),
2651 gst_element_state_get_name (next),
2652 gst_element_state_get_name (GST_STATE (element)),
2653 gst_element_state_change_return_get_name (ret));
2655 return ret;
2657 /* ERRORS */
2658 activate_failure:
2659 {
2660 GST_CAT_WARNING_OBJECT (GST_CAT_STATES, element,
2661 "failure (de)activating src pads");
2662 return GST_STATE_CHANGE_FAILURE;
2663 }
2664 }
2666 /*
2667 * This function is a utility event handler for seek events.
2668 * It will send the event to all sinks or sources depending on the
2669 * event-direction.
2670 *
2671 * Applications are free to override this behaviour and
2672 * implement their own seek handler, but this will work for
2673 * pretty much all cases in practice.
2674 */
2675 static gboolean
2676 gst_bin_send_event (GstElement * element, GstEvent * event)
2677 {
2678 GstBin *bin = GST_BIN_CAST (element);
2679 GstIterator *iter;
2680 gboolean res = TRUE;
2681 gboolean done = FALSE;
2683 if (GST_EVENT_IS_DOWNSTREAM (event)) {
2684 iter = gst_bin_iterate_sources (bin);
2685 GST_DEBUG_OBJECT (bin, "Sending %s event to src children",
2686 GST_EVENT_TYPE_NAME (event));
2687 } else {
2688 iter = gst_bin_iterate_sinks (bin);
2689 GST_DEBUG_OBJECT (bin, "Sending %s event to sink children",
2690 GST_EVENT_TYPE_NAME (event));
2691 }
2693 while (!done) {
2694 gpointer data;
2696 switch (gst_iterator_next (iter, &data)) {
2697 case GST_ITERATOR_OK:
2698 {
2699 GstElement *child;
2701 gst_event_ref (event);
2702 child = GST_ELEMENT_CAST (data);
2703 res &= gst_element_send_event (child, event);
2704 GST_LOG_OBJECT (child, "After handling %s event: %d",
2705 GST_EVENT_TYPE_NAME (event), res);
2706 gst_object_unref (child);
2707 break;
2708 }
2709 case GST_ITERATOR_RESYNC:
2710 gst_iterator_resync (iter);
2711 res = TRUE;
2712 break;
2713 case GST_ITERATOR_DONE:
2714 done = TRUE;
2715 break;
2716 case GST_ITERATOR_ERROR:
2717 g_assert_not_reached ();
2718 break;
2719 }
2720 }
2721 gst_iterator_free (iter);
2722 gst_event_unref (event);
2724 return res;
2725 }
2727 /* this is the function called by the threadpool. When async elements commit
2728 * their state, this function will attempt to bring the bin to the next state.
2729 */
2730 static void
2731 gst_bin_continue_func (BinContinueData * data)
2732 {
2733 GstBin *bin;
2734 GstState current, next, pending;
2735 GstStateChange transition;
2737 bin = data->bin;
2738 pending = data->pending;
2740 GST_DEBUG_OBJECT (bin, "waiting for state lock");
2741 GST_STATE_LOCK (bin);
2743 GST_DEBUG_OBJECT (bin, "doing state continue");
2744 GST_OBJECT_LOCK (bin);
2746 /* if a new state change happened after this thread was scheduled, we return
2747 * immediately. */
2748 if (data->cookie != GST_ELEMENT_CAST (bin)->state_cookie)
2749 goto interrupted;
2751 current = GST_STATE (bin);
2752 next = GST_STATE_GET_NEXT (current, pending);
2753 transition = (GstStateChange) GST_STATE_TRANSITION (current, next);
2755 GST_STATE_NEXT (bin) = next;
2756 GST_STATE_PENDING (bin) = pending;
2757 /* mark busy */
2758 GST_STATE_RETURN (bin) = GST_STATE_CHANGE_ASYNC;
2759 GST_OBJECT_UNLOCK (bin);
2761 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
2762 "continue state change %s to %s, final %s",
2763 gst_element_state_get_name (current),
2764 gst_element_state_get_name (next), gst_element_state_get_name (pending));
2766 gst_element_change_state (GST_ELEMENT_CAST (bin), transition);
2768 GST_STATE_UNLOCK (bin);
2769 GST_DEBUG_OBJECT (bin, "state continue done");
2771 gst_object_unref (bin);
2772 g_slice_free (BinContinueData, data);
2773 return;
2775 interrupted:
2776 {
2777 GST_OBJECT_UNLOCK (bin);
2778 GST_STATE_UNLOCK (bin);
2779 GST_DEBUG_OBJECT (bin, "state continue aborted due to intervening change");
2780 gst_object_unref (bin);
2781 g_slice_free (BinContinueData, data);
2782 return;
2783 }
2784 }
2786 static GstBusSyncReply
2787 bin_bus_handler (GstBus * bus, GstMessage * message, GstBin * bin)
2788 {
2789 GstBinClass *bclass;
2791 bclass = GST_BIN_GET_CLASS (bin);
2792 if (bclass->handle_message)
2793 bclass->handle_message (bin, message);
2794 else
2795 gst_message_unref (message);
2797 return GST_BUS_DROP;
2798 }
2800 static void
2801 bin_push_state_continue (BinContinueData * data)
2802 {
2803 GstBinClass *klass;
2804 GstBin *bin;
2806 /* ref was taken */
2807 bin = data->bin;
2808 klass = GST_BIN_GET_CLASS (bin);
2810 GST_DEBUG_OBJECT (bin, "pushing continue on thread pool");
2811 g_thread_pool_push (klass->pool, data, NULL);
2812 }
2814 /* an element started an async state change, if we were not busy with a state
2815 * change, we perform a lost state.
2816 * This function is called with the OBJECT lock.
2817 */
2818 static void
2819 bin_handle_async_start (GstBin * bin, gboolean new_base_time)
2820 {
2821 GstState old_state, new_state;
2822 gboolean toplevel;
2823 GstMessage *amessage = NULL;
2825 if (GST_STATE_RETURN (bin) == GST_STATE_CHANGE_FAILURE)
2826 goto had_error;
2828 /* get our toplevel state */
2829 toplevel = BIN_IS_TOPLEVEL (bin);
2831 /* prepare an ASYNC_START message, we always post the start message even if we
2832 * are busy with a state change or when we are NO_PREROLL. */
2833 if (!toplevel)
2834 /* non toplevel bin, prepare async-start for the parent */
2835 amessage =
2836 gst_message_new_async_start (GST_OBJECT_CAST (bin), new_base_time);
2838 if (bin->polling || GST_STATE_PENDING (bin) != GST_STATE_VOID_PENDING)
2839 goto was_busy;
2841 /* async starts are ignored when we are NO_PREROLL */
2842 if (GST_STATE_RETURN (bin) == GST_STATE_CHANGE_NO_PREROLL)
2843 goto was_no_preroll;
2845 old_state = GST_STATE (bin);
2847 /* when we PLAYING we go back to PAUSED, when preroll happens, we go back to
2848 * PLAYING after optionally redistributing the base_time. */
2849 if (old_state > GST_STATE_PAUSED)
2850 new_state = GST_STATE_PAUSED;
2851 else
2852 new_state = old_state;
2854 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin,
2855 "lost state of %s, new %s", gst_element_state_get_name (old_state),
2856 gst_element_state_get_name (new_state));
2858 GST_STATE (bin) = new_state;
2859 GST_STATE_NEXT (bin) = new_state;
2860 GST_STATE_PENDING (bin) = new_state;
2861 GST_STATE_RETURN (bin) = GST_STATE_CHANGE_ASYNC;
2862 GST_OBJECT_UNLOCK (bin);
2864 /* post message */
2865 _priv_gst_element_state_changed (GST_ELEMENT_CAST (bin), new_state, new_state,
2866 new_state);
2868 post_start:
2869 if (amessage) {
2870 /* post our ASYNC_START. */
2871 GST_DEBUG_OBJECT (bin, "posting ASYNC_START to parent");
2872 gst_element_post_message (GST_ELEMENT_CAST (bin), amessage);
2873 }
2874 GST_OBJECT_LOCK (bin);
2876 return;
2878 had_error:
2879 {
2880 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "we had an error");
2881 return;
2882 }
2883 was_busy:
2884 {
2885 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "state change busy");
2886 GST_OBJECT_UNLOCK (bin);
2887 goto post_start;
2888 }
2889 was_no_preroll:
2890 {
2891 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "ignoring, we are NO_PREROLL");
2892 GST_OBJECT_UNLOCK (bin);
2893 goto post_start;
2894 }
2895 }
2897 /* this function is called when there are no more async elements in the bin. We
2898 * post a state changed message and an ASYNC_DONE message.
2899 * This function is called with the OBJECT lock.
2900 */
2901 static void
2902 bin_handle_async_done (GstBin * bin, GstStateChangeReturn ret,
2903 gboolean flag_pending)
2904 {
2905 GstState current, pending, target;
2906 GstStateChangeReturn old_ret;
2907 GstState old_state, old_next;
2908 gboolean toplevel, state_changed = FALSE;
2909 GstMessage *amessage = NULL;
2910 BinContinueData *cont = NULL;
2912 if (GST_STATE_RETURN (bin) == GST_STATE_CHANGE_FAILURE)
2913 goto had_error;
2915 pending = GST_STATE_PENDING (bin);
2917 if (bin->polling)
2918 goto was_busy;
2920 /* check if there is something to commit */
2921 if (pending == GST_STATE_VOID_PENDING)
2922 goto nothing_pending;
2924 old_ret = GST_STATE_RETURN (bin);
2925 GST_STATE_RETURN (bin) = ret;
2927 /* move to the next target state */
2928 target = GST_STATE_TARGET (bin);
2929 pending = GST_STATE_PENDING (bin) = target;
2931 amessage = gst_message_new_async_done (GST_OBJECT_CAST (bin));
2933 old_state = GST_STATE (bin);
2934 /* this is the state we should go to next */
2935 old_next = GST_STATE_NEXT (bin);
2937 if (old_next != GST_STATE_PLAYING) {
2938 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
2939 "committing state from %s to %s, old pending %s",
2940 gst_element_state_get_name (old_state),
2941 gst_element_state_get_name (old_next),
2942 gst_element_state_get_name (pending));
2944 /* update current state */
2945 current = GST_STATE (bin) = old_next;
2946 } else {
2947 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
2948 "setting state from %s to %s, pending %s",
2949 gst_element_state_get_name (old_state),
2950 gst_element_state_get_name (old_state),
2951 gst_element_state_get_name (pending));
2952 current = old_state;
2953 }
2955 /* get our toplevel state */
2956 toplevel = BIN_IS_TOPLEVEL (bin);
2958 /* see if we reached the final state. If we are not toplevel, we also have to
2959 * stop here, the parent will continue our state. */
2960 if ((pending == current) || !toplevel) {
2961 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
2962 "completed state change, pending VOID");
2964 /* mark VOID pending */
2965 pending = GST_STATE_VOID_PENDING;
2966 GST_STATE_PENDING (bin) = pending;
2967 GST_STATE_NEXT (bin) = GST_STATE_VOID_PENDING;
2968 } else {
2969 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin,
2970 "continue state change, pending %s",
2971 gst_element_state_get_name (pending));
2973 cont = g_slice_new (BinContinueData);
2975 /* ref to the bin */
2976 cont->bin = gst_object_ref (bin);
2977 /* cookie to detect concurrent state change */
2978 cont->cookie = GST_ELEMENT_CAST (bin)->state_cookie;
2979 /* pending target state */
2980 cont->pending = pending;
2981 /* mark busy */
2982 GST_STATE_RETURN (bin) = GST_STATE_CHANGE_ASYNC;
2983 GST_STATE_NEXT (bin) = GST_STATE_GET_NEXT (old_state, pending);
2984 }
2986 if (old_next != GST_STATE_PLAYING) {
2987 if (old_state != old_next || old_ret == GST_STATE_CHANGE_ASYNC) {
2988 state_changed = TRUE;
2989 }
2990 }
2991 GST_OBJECT_UNLOCK (bin);
2993 if (state_changed) {
2994 _priv_gst_element_state_changed (GST_ELEMENT_CAST (bin), old_state,
2995 old_next, pending);
2996 }
2997 if (amessage) {
2998 /* post our combined ASYNC_DONE when all is ASYNC_DONE. */
2999 GST_DEBUG_OBJECT (bin, "posting ASYNC_DONE to parent");
3000 gst_element_post_message (GST_ELEMENT_CAST (bin), amessage);
3001 }
3003 GST_OBJECT_LOCK (bin);
3004 if (cont) {
3005 /* toplevel, start continue state */
3006 GST_DEBUG_OBJECT (bin, "all async-done, starting state continue");
3007 bin_push_state_continue (cont);
3008 } else {
3009 GST_DEBUG_OBJECT (bin, "state change complete");
3010 GST_STATE_BROADCAST (bin);
3011 }
3012 return;
3014 had_error:
3015 {
3016 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "we had an error");
3017 return;
3018 }
3019 was_busy:
3020 {
3021 GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "state change busy");
3022 /* if we were busy with a state change and we are requested to flag a
3023 * pending async done, we do so here */
3024 if (flag_pending)
3025 bin->priv->pending_async_done = TRUE;
3026 return;
3027 }
3028 nothing_pending:
3029 {
3030 GST_CAT_INFO_OBJECT (GST_CAT_STATES, bin, "nothing pending");
3031 return;
3032 }
3033 }
3035 static void
3036 bin_do_eos (GstBin * bin)
3037 {
3038 guint32 seqnum = 0;
3039 gboolean eos;
3041 GST_OBJECT_LOCK (bin);
3042 /* If all sinks are EOS, we're in PLAYING and no state change is pending
3043 * we forward the EOS message to the parent bin or application
3044 */
3045 eos = GST_STATE (bin) == GST_STATE_PLAYING
3046 && GST_STATE_PENDING (bin) == GST_STATE_VOID_PENDING
3047 && is_eos (bin, &seqnum);
3048 GST_OBJECT_UNLOCK (bin);
3050 if (eos
3051 && g_atomic_int_compare_and_exchange (&bin->priv->posted_eos, FALSE,
3052 TRUE)) {
3053 GstMessage *tmessage;
3054 tmessage = gst_message_new_eos (GST_OBJECT_CAST (bin));
3055 gst_message_set_seqnum (tmessage, seqnum);
3056 GST_DEBUG_OBJECT (bin,
3057 "all sinks posted EOS, posting seqnum #%" G_GUINT32_FORMAT, seqnum);
3058 gst_element_post_message (GST_ELEMENT_CAST (bin), tmessage);
3059 }
3060 }
3062 /* must be called with the object lock. This function releases the lock to post
3063 * the message. */
3064 static void
3065 bin_do_message_forward (GstBin * bin, GstMessage * message)
3066 {
3067 if (bin->priv->message_forward) {
3068 GstMessage *forwarded;
3070 GST_DEBUG_OBJECT (bin, "pass %s message upward",
3071 GST_MESSAGE_TYPE_NAME (message));
3072 GST_OBJECT_UNLOCK (bin);
3074 /* we need to convert these messages to element messages so that our parent
3075 * bin can easily ignore them and so that the application can easily
3076 * distinguish between the internally forwarded and the real messages. */
3077 forwarded = gst_message_new_element (GST_OBJECT_CAST (bin),
3078 gst_structure_new ("GstBinForwarded",
3079 "message", GST_TYPE_MESSAGE, message, NULL));
3081 gst_element_post_message (GST_ELEMENT_CAST (bin), forwarded);
3083 GST_OBJECT_LOCK (bin);
3084 }
3085 }
3087 /* handle child messages:
3088 *
3089 * This method is called synchronously when a child posts a message on
3090 * the internal bus.
3091 *
3092 * GST_MESSAGE_EOS: This message is only posted by sinks
3093 * in the PLAYING state. If all sinks posted the EOS message, post
3094 * one upwards.
3095 *
3096 * GST_MESSAGE_STATE_DIRTY: Deprecated
3097 *
3098 * GST_MESSAGE_SEGMENT_START: just collect, never forward upwards. If an
3099 * element posts segment_start twice, only the last message is kept.
3100 *
3101 * GST_MESSAGE_SEGMENT_DONE: replace SEGMENT_START message from same poster
3102 * with the segment_done message. If there are no more segment_start
3103 * messages, post segment_done message upwards.
3104 *
3105 * GST_MESSAGE_DURATION: remove all previously cached duration messages.
3106 * Whenever someone performs a duration query on the bin, we store the
3107 * result so we can answer it quicker the next time. Any element that
3108 * changes its duration marks our cached values invalid.
3109 * This message is also posted upwards. This is currently disabled
3110 * because too many elements don't post DURATION messages when the
3111 * duration changes.
3112 *
3113 * GST_MESSAGE_CLOCK_LOST: This message is posted by an element when it
3114 * can no longer provide a clock. The default bin behaviour is to
3115 * check if the lost clock was the one provided by the bin. If so and
3116 * we are currently in the PLAYING state, we forward the message to
3117 * our parent.
3118 * This message is also generated when we remove a clock provider from
3119 * a bin. If this message is received by the application, it should
3120 * PAUSE the pipeline and set it back to PLAYING to force a new clock
3121 * and a new base_time distribution.
3122 *
3123 * GST_MESSAGE_CLOCK_PROVIDE: This message is generated when an element
3124 * can provide a clock. This mostly happens when we add a new clock
3125 * provider to the bin. The default behaviour of the bin is to mark the
3126 * currently selected clock as dirty, which will perform a clock
3127 * recalculation the next time we are asked to provide a clock.
3128 * This message is never sent to the application but is forwarded to
3129 * the parent.
3130 *
3131 * GST_MESSAGE_ASYNC_START: Create an internal ELEMENT message that stores
3132 * the state of the element and the fact that the element will need a
3133 * new base_time. This message is not forwarded to the application.
3134 *
3135 * GST_MESSAGE_ASYNC_DONE: Find the internal ELEMENT message we kept for the
3136 * element when it posted ASYNC_START. If all elements are done, post a
3137 * ASYNC_DONE message to the parent.
3138 *
3139 * OTHER: post upwards.
3140 */
3141 static void
3142 gst_bin_handle_message_func (GstBin * bin, GstMessage * message)
3143 {
3144 GstObject *src;
3145 GstMessageType type;
3146 GstMessage *tmessage;
3147 guint32 seqnum;
3149 src = GST_MESSAGE_SRC (message);
3150 type = GST_MESSAGE_TYPE (message);
3152 GST_DEBUG_OBJECT (bin, "[msg %p] handling child %s message of type %s",
3153 message, src ? GST_ELEMENT_NAME (src) : "(NULL)",
3154 GST_MESSAGE_TYPE_NAME (message));
3156 switch (type) {
3157 case GST_MESSAGE_ERROR:
3158 {
3159 GST_OBJECT_LOCK (bin);
3160 /* flag error */
3161 GST_DEBUG_OBJECT (bin, "got ERROR message, unlocking state change");
3162 GST_STATE_RETURN (bin) = GST_STATE_CHANGE_FAILURE;
3163 GST_STATE_BROADCAST (bin);
3164 GST_OBJECT_UNLOCK (bin);
3166 goto forward;
3167 }
3168 case GST_MESSAGE_EOS:
3169 {
3171 /* collect all eos messages from the children */
3172 GST_OBJECT_LOCK (bin);
3173 bin_do_message_forward (bin, message);
3174 /* ref message for future use */
3175 bin_replace_message (bin, message, GST_MESSAGE_EOS);
3176 GST_OBJECT_UNLOCK (bin);
3178 bin_do_eos (bin);
3179 break;
3180 }
3181 case GST_MESSAGE_STATE_DIRTY:
3182 {
3183 GST_WARNING_OBJECT (bin, "received deprecated STATE_DIRTY message");
3185 /* free message */
3186 gst_message_unref (message);
3187 break;
3188 }
3189 case GST_MESSAGE_SEGMENT_START:{
3190 gboolean post = FALSE;
3191 GstFormat format;
3192 gint64 position;
3194 gst_message_parse_segment_start (message, &format, &position);
3195 seqnum = gst_message_get_seqnum (message);
3197 GST_OBJECT_LOCK (bin);
3198 bin_do_message_forward (bin, message);
3199 /* if this is the first segment-start, post to parent but not to the
3200 * application */
3201 if (!find_message (bin, NULL, GST_MESSAGE_SEGMENT_START) &&
3202 (GST_OBJECT_PARENT (bin) != NULL)) {
3203 post = TRUE;
3204 }
3205 /* replace any previous segment_start message from this source
3206 * with the new segment start message */
3207 bin_replace_message (bin, message, GST_MESSAGE_SEGMENT_START);
3208 GST_OBJECT_UNLOCK (bin);
3209 if (post) {
3210 tmessage = gst_message_new_segment_start (GST_OBJECT_CAST (bin),
3211 format, position);
3212 gst_message_set_seqnum (tmessage, seqnum);
3214 /* post segment start with initial format and position. */
3215 GST_DEBUG_OBJECT (bin, "posting SEGMENT_START (%u) bus message: %p",
3216 seqnum, message);
3217 gst_element_post_message (GST_ELEMENT_CAST (bin), tmessage);
3218 }
3219 break;
3220 }
3221 case GST_MESSAGE_SEGMENT_DONE:
3222 {
3223 gboolean post = FALSE;
3224 GstFormat format;
3225 gint64 position;
3227 gst_message_parse_segment_done (message, &format, &position);
3228 seqnum = gst_message_get_seqnum (message);
3230 GST_OBJECT_LOCK (bin);
3231 bin_do_message_forward (bin, message);
3232 bin_replace_message (bin, message, GST_MESSAGE_SEGMENT_START);
3233 /* if there are no more segment_start messages, everybody posted
3234 * a segment_done and we can post one on the bus. */
3236 /* we don't care who still has a pending segment start */
3237 if (!find_message (bin, NULL, GST_MESSAGE_SEGMENT_START)) {
3238 /* nothing found */
3239 post = TRUE;
3240 /* remove all old segment_done messages */
3241 bin_remove_messages (bin, NULL, GST_MESSAGE_SEGMENT_DONE);
3242 }
3243 GST_OBJECT_UNLOCK (bin);
3244 if (post) {
3245 tmessage = gst_message_new_segment_done (GST_OBJECT_CAST (bin),
3246 format, position);
3247 gst_message_set_seqnum (tmessage, seqnum);
3249 /* post segment done with latest format and position. */
3250 GST_DEBUG_OBJECT (bin, "posting SEGMENT_DONE (%u) bus message: %p",
3251 seqnum, message);
3252 gst_element_post_message (GST_ELEMENT_CAST (bin), tmessage);
3253 }
3254 break;
3255 }
3256 case GST_MESSAGE_DURATION:
3257 {
3258 /* remove all cached duration messages, next time somebody asks
3259 * for duration, we will recalculate. */
3260 GST_OBJECT_LOCK (bin);
3261 bin_remove_messages (bin, NULL, GST_MESSAGE_DURATION);
3262 GST_OBJECT_UNLOCK (bin);
3263 goto forward;
3264 }
3265 case GST_MESSAGE_CLOCK_LOST:
3266 {
3267 GstClock **provided_clock_p;
3268 GstElement **clock_provider_p;
3269 gboolean playing, provided, forward;
3270 GstClock *clock;
3272 gst_message_parse_clock_lost (message, &clock);
3274 GST_OBJECT_LOCK (bin);
3275 bin->clock_dirty = TRUE;
3276 /* if we lost the clock that we provided, post to parent but
3277 * only if we are PLAYING. */
3278 provided = (clock == bin->provided_clock);
3279 playing = (GST_STATE (bin) == GST_STATE_PLAYING);
3280 forward = playing & provided;
3281 if (provided) {
3282 GST_DEBUG_OBJECT (bin,
3283 "Lost clock %" GST_PTR_FORMAT " provided by %" GST_PTR_FORMAT,
3284 bin->provided_clock, bin->clock_provider);
3285 provided_clock_p = &bin->provided_clock;
3286 clock_provider_p = &bin->clock_provider;
3287 gst_object_replace ((GstObject **) provided_clock_p, NULL);
3288 gst_object_replace ((GstObject **) clock_provider_p, NULL);
3289 }
3290 GST_DEBUG_OBJECT (bin, "provided %d, playing %d, forward %d",
3291 provided, playing, forward);
3292 GST_OBJECT_UNLOCK (bin);
3294 if (forward)
3295 goto forward;
3297 /* free message */
3298 gst_message_unref (message);
3299 break;
3300 }
3301 case GST_MESSAGE_CLOCK_PROVIDE:
3302 {
3303 gboolean forward;
3305 GST_OBJECT_LOCK (bin);
3306 bin->clock_dirty = TRUE;
3307 /* a new clock is available, post to parent but not
3308 * to the application */
3309 forward = GST_OBJECT_PARENT (bin) != NULL;
3310 GST_OBJECT_UNLOCK (bin);
3312 if (forward)
3313 goto forward;
3315 /* free message */
3316 gst_message_unref (message);
3317 break;
3318 }
3319 case GST_MESSAGE_ASYNC_START:
3320 {
3321 gboolean new_base_time;
3322 GstState target;
3324 GST_DEBUG_OBJECT (bin, "ASYNC_START message %p, %s", message,
3325 src ? GST_OBJECT_NAME (src) : "(NULL)");
3327 gst_message_parse_async_start (message, &new_base_time);
3329 GST_OBJECT_LOCK (bin);
3330 bin_do_message_forward (bin, message);
3332 /* we ignore the message if we are going to <= READY */
3333 if ((target = GST_STATE_TARGET (bin)) <= GST_STATE_READY)
3334 goto ignore_start_message;
3336 /* takes ownership of the message */
3337 bin_replace_message (bin, message, GST_MESSAGE_ASYNC_START);
3339 bin_handle_async_start (bin, new_base_time);
3340 GST_OBJECT_UNLOCK (bin);
3341 break;
3343 ignore_start_message:
3344 {
3345 GST_DEBUG_OBJECT (bin, "ignoring message, target %s",
3346 gst_element_state_get_name (target));
3347 GST_OBJECT_UNLOCK (bin);
3348 gst_message_unref (message);
3349 break;
3350 }
3351 }
3352 case GST_MESSAGE_ASYNC_DONE:
3353 {
3354 GstState target;
3356 GST_DEBUG_OBJECT (bin, "ASYNC_DONE message %p, %s", message,
3357 src ? GST_OBJECT_NAME (src) : "(NULL)");
3359 GST_OBJECT_LOCK (bin);
3360 bin_do_message_forward (bin, message);
3362 /* ignore messages if we are shutting down */
3363 if ((target = GST_STATE_TARGET (bin)) <= GST_STATE_READY)
3364 goto ignore_done_message;
3366 bin_replace_message (bin, message, GST_MESSAGE_ASYNC_START);
3367 /* if there are no more ASYNC_START messages, everybody posted
3368 * a ASYNC_DONE and we can post one on the bus. When checking, we
3369 * don't care who still has a pending ASYNC_START */
3370 if (!find_message (bin, NULL, GST_MESSAGE_ASYNC_START)) {
3371 /* nothing found, remove all old ASYNC_DONE messages */
3372 bin_remove_messages (bin, NULL, GST_MESSAGE_ASYNC_DONE);
3374 GST_DEBUG_OBJECT (bin, "async elements commited");
3375 /* when we get an async done message when a state change was busy, we
3376 * need to set the pending_done flag so that at the end of the state
3377 * change we can see if we need to verify pending async elements, hence
3378 * the TRUE argument here. */
3379 bin_handle_async_done (bin, GST_STATE_CHANGE_SUCCESS, TRUE);
3380 } else {
3381 GST_DEBUG_OBJECT (bin, "there are more async elements pending");
3382 }
3383 GST_OBJECT_UNLOCK (bin);
3384 break;
3386 ignore_done_message:
3387 {
3388 GST_DEBUG_OBJECT (bin, "ignoring message, target %s",
3389 gst_element_state_get_name (target));
3390 GST_OBJECT_UNLOCK (bin);
3391 gst_message_unref (message);
3392 break;
3393 }
3394 }
3395 case GST_MESSAGE_STRUCTURE_CHANGE:
3396 {
3397 gboolean busy;
3399 gst_message_parse_structure_change (message, NULL, NULL, &busy);
3401 GST_OBJECT_LOCK (bin);
3402 if (busy) {
3403 /* while the pad is busy, avoid following it when doing state changes.
3404 * Don't update the cookie yet, we will do that after the structure
3405 * change finished and we are ready to inspect the new updated
3406 * structure. */
3407 bin_replace_message (bin, message, GST_MESSAGE_STRUCTURE_CHANGE);
3408 message = NULL;
3409 } else {
3410 /* a pad link/unlink ended, signal the state change iterator that we
3411 * need to resync by updating the structure_cookie. */
3412 bin_remove_messages (bin, GST_MESSAGE_SRC (message),
3413 GST_MESSAGE_STRUCTURE_CHANGE);
3414 bin->priv->structure_cookie++;
3415 }
3416 GST_OBJECT_UNLOCK (bin);
3418 if (message)
3419 gst_message_unref (message);
3421 break;
3422 }
3423 default:
3424 goto forward;
3425 }
3426 return;
3428 forward:
3429 {
3430 /* Send all other messages upward */
3431 GST_DEBUG_OBJECT (bin, "posting message upward");
3432 gst_element_post_message (GST_ELEMENT_CAST (bin), message);
3433 return;
3434 }
3435 }
3437 /* generic struct passed to all query fold methods */
3438 typedef struct
3439 {
3440 GstQuery *query;
3441 gint64 min;
3442 gint64 max;
3443 gboolean live;
3444 } QueryFold;
3446 typedef void (*QueryInitFunction) (GstBin * bin, QueryFold * fold);
3447 typedef void (*QueryDoneFunction) (GstBin * bin, QueryFold * fold);
3449 /* for duration/position we collect all durations/positions and take
3450 * the MAX of all valid results */
3451 static void
3452 bin_query_min_max_init (GstBin * bin, QueryFold * fold)
3453 {
3454 fold->min = 0;
3455 fold->max = -1;
3456 fold->live = FALSE;
3457 }
3459 static gboolean
3460 bin_query_duration_fold (GstElement * item, GValue * ret, QueryFold * fold)
3461 {
3462 if (gst_element_query (item, fold->query)) {
3463 gint64 duration;
3465 g_value_set_boolean (ret, TRUE);
3467 gst_query_parse_duration (fold->query, NULL, &duration);
3469 GST_DEBUG_OBJECT (item, "got duration %" G_GINT64_FORMAT, duration);
3471 if (duration > fold->max)
3472 fold->max = duration;
3473 }
3475 gst_object_unref (item);
3476 return TRUE;
3477 }
3479 static void
3480 bin_query_duration_done (GstBin * bin, QueryFold * fold)
3481 {
3482 GstFormat format;
3484 gst_query_parse_duration (fold->query, &format, NULL);
3485 /* store max in query result */
3486 gst_query_set_duration (fold->query, format, fold->max);
3488 GST_DEBUG_OBJECT (bin, "max duration %" G_GINT64_FORMAT, fold->max);
3490 #ifdef DURATION_CACHING
3491 /* and cache now */
3492 GST_OBJECT_LOCK (bin);
3493 bin->messages = g_list_prepend (bin->messages,
3494 gst_message_new_duration (GST_OBJECT_CAST (bin), format, fold->max));
3495 GST_OBJECT_UNLOCK (bin);
3496 #endif
3497 }
3499 static gboolean
3500 bin_query_position_fold (GstElement * item, GValue * ret, QueryFold * fold)
3501 {
3502 if (gst_element_query (item, fold->query)) {
3503 gint64 position;
3505 g_value_set_boolean (ret, TRUE);
3507 gst_query_parse_position (fold->query, NULL, &position);
3509 GST_DEBUG_OBJECT (item, "got position %" G_GINT64_FORMAT, position);
3511 if (position > fold->max)
3512 fold->max = position;
3513 }
3515 gst_object_unref (item);
3516 return TRUE;
3517 }
3519 static void
3520 bin_query_position_done (GstBin * bin, QueryFold * fold)
3521 {
3522 GstFormat format;
3524 gst_query_parse_position (fold->query, &format, NULL);
3525 /* store max in query result */
3526 gst_query_set_position (fold->query, format, fold->max);
3528 GST_DEBUG_OBJECT (bin, "max position %" G_GINT64_FORMAT, fold->max);
3529 }
3531 static gboolean
3532 bin_query_latency_fold (GstElement * item, GValue * ret, QueryFold * fold)
3533 {
3534 if (gst_element_query (item, fold->query)) {
3535 GstClockTime min, max;
3536 gboolean live;
3538 gst_query_parse_latency (fold->query, &live, &min, &max);
3540 GST_DEBUG_OBJECT (item,
3541 "got latency min %" GST_TIME_FORMAT ", max %" GST_TIME_FORMAT
3542 ", live %d", GST_TIME_ARGS (min), GST_TIME_ARGS (max), live);
3544 /* for the combined latency we collect the MAX of all min latencies and
3545 * the MIN of all max latencies */
3546 if (live) {
3547 if (min > fold->min)
3548 fold->min = min;
3549 if (fold->max == -1)
3550 fold->max = max;
3551 else if (max < fold->max)
3552 fold->max = max;
3553 if (fold->live == FALSE)
3554 fold->live = live;
3555 }
3556 } else {
3557 g_value_set_boolean (ret, FALSE);
3558 GST_DEBUG_OBJECT (item, "failed query");
3559 }
3561 gst_object_unref (item);
3562 return TRUE;
3563 }
3565 static void
3566 bin_query_latency_done (GstBin * bin, QueryFold * fold)
3567 {
3568 /* store max in query result */
3569 gst_query_set_latency (fold->query, fold->live, fold->min, fold->max);
3571 GST_DEBUG_OBJECT (bin,
3572 "latency min %" GST_TIME_FORMAT ", max %" GST_TIME_FORMAT
3573 ", live %d", GST_TIME_ARGS (fold->min), GST_TIME_ARGS (fold->max),
3574 fold->live);
3575 }
3577 /* generic fold, return first valid result */
3578 static gboolean
3579 bin_query_generic_fold (GstElement * item, GValue * ret, QueryFold * fold)
3580 {
3581 gboolean res;
3583 if ((res = gst_element_query (item, fold->query))) {
3584 g_value_set_boolean (ret, TRUE);
3585 GST_DEBUG_OBJECT (item, "answered query %p", fold->query);
3586 }
3588 gst_object_unref (item);
3590 /* and stop as soon as we have a valid result */
3591 return !res;
3592 }
3594 static gboolean
3595 gst_bin_query (GstElement * element, GstQuery * query)
3596 {
3597 GstBin *bin = GST_BIN_CAST (element);
3598 GstIterator *iter;
3599 gboolean res = FALSE;
3600 GstIteratorFoldFunction fold_func;
3601 QueryInitFunction fold_init = NULL;
3602 QueryDoneFunction fold_done = NULL;
3603 QueryFold fold_data;
3604 GValue ret = { 0 };
3606 switch (GST_QUERY_TYPE (query)) {
3607 case GST_QUERY_DURATION:
3608 {
3609 #ifdef DURATION_CACHING
3610 GList *cached;
3611 GstFormat qformat;
3613 gst_query_parse_duration (query, &qformat, NULL);
3615 /* find cached duration query */
3616 GST_OBJECT_LOCK (bin);
3617 for (cached = bin->messages; cached; cached = g_list_next (cached)) {
3618 GstMessage *message = (GstMessage *) cached->data;
3620 if (GST_MESSAGE_TYPE (message) == GST_MESSAGE_DURATION &&
3621 GST_MESSAGE_SRC (message) == GST_OBJECT_CAST (bin)) {
3622 GstFormat format;
3623 gint64 duration;
3625 gst_message_parse_duration (message, &format, &duration);
3627 /* if cached same format, copy duration in query result */
3628 if (format == qformat) {
3629 GST_DEBUG_OBJECT (bin, "return cached duration %" G_GINT64_FORMAT,
3630 duration);
3631 GST_OBJECT_UNLOCK (bin);
3633 gst_query_set_duration (query, qformat, duration);
3634 res = TRUE;
3635 goto exit;
3636 }
3637 }
3638 }
3639 GST_OBJECT_UNLOCK (bin);
3640 #endif
3641 /* no cached value found, iterate and collect durations */
3642 fold_func = (GstIteratorFoldFunction) bin_query_duration_fold;
3643 fold_init = bin_query_min_max_init;
3644 fold_done = bin_query_duration_done;
3645 break;
3646 }
3647 case GST_QUERY_POSITION:
3648 {
3649 fold_func = (GstIteratorFoldFunction) bin_query_position_fold;
3650 fold_init = bin_query_min_max_init;
3651 fold_done = bin_query_position_done;
3652 break;
3653 }
3654 case GST_QUERY_LATENCY:
3655 {
3656 fold_func = (GstIteratorFoldFunction) bin_query_latency_fold;
3657 fold_init = bin_query_min_max_init;
3658 fold_done = bin_query_latency_done;
3659 res = TRUE;
3660 break;
3661 }
3662 default:
3663 fold_func = (GstIteratorFoldFunction) bin_query_generic_fold;
3664 break;
3665 }
3667 fold_data.query = query;
3669 /* set the result of the query to FALSE initially */
3670 g_value_init (&ret, G_TYPE_BOOLEAN);
3671 g_value_set_boolean (&ret, res);
3673 iter = gst_bin_iterate_sinks (bin);
3674 GST_DEBUG_OBJECT (bin, "Sending query %p (type %s) to sink children",
3675 query, GST_QUERY_TYPE_NAME (query));
3677 if (fold_init)
3678 fold_init (bin, &fold_data);
3680 while (TRUE) {
3681 GstIteratorResult ires;
3683 ires = gst_iterator_fold (iter, fold_func, &ret, &fold_data);
3685 switch (ires) {
3686 case GST_ITERATOR_RESYNC:
3687 gst_iterator_resync (iter);
3688 if (fold_init)
3689 fold_init (bin, &fold_data);
3690 g_value_set_boolean (&ret, res);
3691 break;
3692 case GST_ITERATOR_OK:
3693 case GST_ITERATOR_DONE:
3694 res = g_value_get_boolean (&ret);
3695 if (fold_done != NULL && res)
3696 fold_done (bin, &fold_data);
3697 goto done;
3698 default:
3699 res = FALSE;
3700 goto done;
3701 }
3702 }
3703 done:
3704 gst_iterator_free (iter);
3706 #ifdef DURATION_CACHING
3707 exit:
3708 #endif
3709 GST_DEBUG_OBJECT (bin, "query %p result %d", query, res);
3711 return res;
3712 }
3714 static gint
3715 compare_name (GstElement * element, const gchar * name)
3716 {
3717 gint eq;
3719 GST_OBJECT_LOCK (element);
3720 eq = strcmp (GST_ELEMENT_NAME (element), name);
3721 GST_OBJECT_UNLOCK (element);
3723 if (eq != 0) {
3724 gst_object_unref (element);
3725 }
3726 return eq;
3727 }
3729 /**
3730 * gst_bin_get_by_name:
3731 * @bin: a #GstBin
3732 * @name: the element name to search for
3733 *
3734 * Gets the element with the given name from a bin. This
3735 * function recurses into child bins.
3736 *
3737 * Returns NULL if no element with the given name is found in the bin.
3738 *
3739 * MT safe. Caller owns returned reference.
3740 *
3741 * Returns: (transfer full): the #GstElement with the given name, or NULL
3742 */
3743 GstElement *
3744 gst_bin_get_by_name (GstBin * bin, const gchar * name)
3745 {
3746 GstIterator *children;
3747 gpointer result;
3749 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
3751 GST_CAT_INFO (GST_CAT_PARENTAGE, "[%s]: looking up child element %s",
3752 GST_ELEMENT_NAME (bin), name);
3754 children = gst_bin_iterate_recurse (bin);
3755 result = gst_iterator_find_custom (children,
3756 (GCompareFunc) compare_name, (gpointer) name);
3757 gst_iterator_free (children);
3759 return GST_ELEMENT_CAST (result);
3760 }
3762 /**
3763 * gst_bin_get_by_name_recurse_up:
3764 * @bin: a #GstBin
3765 * @name: the element name to search for
3766 *
3767 * Gets the element with the given name from this bin. If the
3768 * element is not found, a recursion is performed on the parent bin.
3769 *
3770 * Returns NULL if:
3771 * - no element with the given name is found in the bin
3772 *
3773 * MT safe. Caller owns returned reference.
3774 *
3775 * Returns: (transfer full): the #GstElement with the given name, or NULL
3776 */
3777 GstElement *
3778 gst_bin_get_by_name_recurse_up (GstBin * bin, const gchar * name)
3779 {
3780 GstElement *result;
3782 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
3783 g_return_val_if_fail (name != NULL, NULL);
3785 result = gst_bin_get_by_name (bin, name);
3787 if (!result) {
3788 GstObject *parent;
3790 parent = gst_object_get_parent (GST_OBJECT_CAST (bin));
3791 if (parent) {
3792 if (GST_IS_BIN (parent)) {
3793 result = gst_bin_get_by_name_recurse_up (GST_BIN_CAST (parent), name);
3794 }
3795 gst_object_unref (parent);
3796 }
3797 }
3799 return result;
3800 }
3802 static gint
3803 compare_interface (GstElement * element, gpointer interface)
3804 {
3805 GType interface_type = (GType) interface;
3806 gint ret;
3808 if (G_TYPE_CHECK_INSTANCE_TYPE (element, interface_type)) {
3809 ret = 0;
3810 } else {
3811 /* we did not find the element, need to release the ref
3812 * added by the iterator */
3813 gst_object_unref (element);
3814 ret = 1;
3815 }
3816 return ret;
3817 }
3819 /**
3820 * gst_bin_get_by_interface:
3821 * @bin: a #GstBin
3822 * @iface: the #GType of an interface
3823 *
3824 * Looks for an element inside the bin that implements the given
3825 * interface. If such an element is found, it returns the element.
3826 * You can cast this element to the given interface afterwards. If you want
3827 * all elements that implement the interface, use
3828 * gst_bin_iterate_all_by_interface(). This function recurses into child bins.
3829 *
3830 * MT safe. Caller owns returned reference.
3831 *
3832 * Returns: (transfer full): A #GstElement inside the bin implementing the interface
3833 */
3834 GstElement *
3835 gst_bin_get_by_interface (GstBin * bin, GType iface)
3836 {
3837 GstIterator *children;
3838 gpointer result;
3840 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
3841 g_return_val_if_fail (G_TYPE_IS_INTERFACE (iface), NULL);
3843 children = gst_bin_iterate_recurse (bin);
3844 result = gst_iterator_find_custom (children, (GCompareFunc) compare_interface,
3845 (gpointer) iface);
3846 gst_iterator_free (children);
3848 return GST_ELEMENT_CAST (result);
3849 }
3851 /**
3852 * gst_bin_iterate_all_by_interface:
3853 * @bin: a #GstBin
3854 * @iface: the #GType of an interface
3855 *
3856 * Looks for all elements inside the bin that implements the given
3857 * interface. You can safely cast all returned elements to the given interface.
3858 * The function recurses inside child bins. The iterator will yield a series
3859 * of #GstElement that should be unreffed after use.
3860 *
3861 * Each element yielded by the iterator will have its refcount increased, so
3862 * unref after use.
3863 *
3864 * MT safe. Caller owns returned value.
3865 *
3866 * Returns: (transfer full): a #GstIterator of #GstElement for all elements
3867 * in the bin implementing the given interface, or NULL
3868 */
3869 GstIterator *
3870 gst_bin_iterate_all_by_interface (GstBin * bin, GType iface)
3871 {
3872 GstIterator *children;
3873 GstIterator *result;
3875 g_return_val_if_fail (GST_IS_BIN (bin), NULL);
3876 g_return_val_if_fail (G_TYPE_IS_INTERFACE (iface), NULL);
3878 children = gst_bin_iterate_recurse (bin);
3879 result = gst_iterator_filter (children, (GCompareFunc) compare_interface,
3880 (gpointer) iface);
3882 return result;
3883 }
3885 #if !defined(GST_DISABLE_LOADSAVE) && !defined(GST_REMOVE_DEPRECATED)
3886 static xmlNodePtr
3887 gst_bin_save_thyself (GstObject * object, xmlNodePtr parent)
3888 {
3889 GstBin *bin = GST_BIN_CAST (object);
3890 xmlNodePtr childlist, elementnode;
3891 GList *children;
3892 GstElement *child;
3894 if (GST_OBJECT_CLASS (parent_class)->save_thyself)
3895 GST_OBJECT_CLASS (parent_class)->save_thyself (GST_OBJECT (bin), parent);
3897 childlist = xmlNewChild (parent, NULL, (xmlChar *) "children", NULL);
3899 GST_CAT_INFO (GST_CAT_XML, "[%s]: saving %d children",
3900 GST_ELEMENT_NAME (bin), bin->numchildren);
3902 children = g_list_last (bin->children);
3903 while (children) {
3904 child = GST_ELEMENT_CAST (children->data);
3905 elementnode = xmlNewChild (childlist, NULL, (xmlChar *) "element", NULL);
3906 gst_object_save_thyself (GST_OBJECT (child), elementnode);
3907 children = g_list_previous (children);
3908 }
3909 return childlist;
3910 }
3912 static void
3913 gst_bin_restore_thyself (GstObject * object, xmlNodePtr self)
3914 {
3915 GstBin *bin = GST_BIN_CAST (object);
3916 xmlNodePtr field = self->xmlChildrenNode;
3917 xmlNodePtr childlist;
3919 while (field) {
3920 if (!strcmp ((char *) field->name, "children")) {
3921 GST_CAT_INFO (GST_CAT_XML, "[%s]: loading children",
3922 GST_ELEMENT_NAME (object));
3923 childlist = field->xmlChildrenNode;
3924 while (childlist) {
3925 if (!strcmp ((char *) childlist->name, "element")) {
3926 /* gst_xml_make_element will gst_bin_add() the element to ourself */
3927 gst_xml_make_element (childlist, GST_OBJECT (bin));
3928 }
3929 childlist = childlist->next;
3930 }
3931 }
3933 field = field->next;
3934 }
3935 if (GST_OBJECT_CLASS (parent_class)->restore_thyself)
3936 (GST_OBJECT_CLASS (parent_class)->restore_thyself) (object, self);
3937 }
3938 #endif /* GST_DISABLE_LOADSAVE */