/* GStreamer * * Copyright (C) 1999,2000 Erik Walthinsen * 2004 Wim Taymans * * gstbin.c: GstBin container object and support code * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Library General Public * License as published by the Free Software Foundation; either * version 2 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Library General Public License for more details. * * You should have received a copy of the GNU Library General Public * License along with this library; if not, write to the * Free Software Foundation, Inc., 59 Temple Place - Suite 330, * Boston, MA 02111-1307, USA. * * MT safe. */ #include "gst_private.h" #include "gstevent.h" #include "gstbin.h" #include "gstmarshal.h" #include "gstxml.h" #include "gstinfo.h" #include "gsterror.h" #include "gstscheduler.h" #include "gstindex.h" #include "gstutils.h" GST_DEBUG_CATEGORY_STATIC (bin_debug); #define GST_CAT_DEFAULT bin_debug #define GST_LOG_BIN_CONTENTS(bin, text) GST_LOG_OBJECT ((bin), \ text ": %d elements: %u PLAYING, %u PAUSED, %u READY, %u NULL, own state: %s", \ (bin)->numchildren, (guint) (bin)->child_states[3], \ (guint) (bin)->child_states[2], (bin)->child_states[1], \ (bin)->child_states[0], gst_element_state_get_name (GST_STATE (bin))) static GstElementDetails gst_bin_details = GST_ELEMENT_DETAILS ("Generic bin", "Generic/Bin", "Simple container object", "Erik Walthinsen ," "Wim Taymans "); GType _gst_bin_type = 0; static void gst_bin_dispose (GObject * object); static GstElementStateReturn gst_bin_change_state (GstElement * element); static GstElementStateReturn gst_bin_get_state (GstElement * element, GstElementState * state, GstElementState * pending, GTimeVal * timeout); static gboolean gst_bin_add_func (GstBin * bin, GstElement * element); static gboolean gst_bin_remove_func (GstBin * bin, GstElement * element); #ifndef GST_DISABLE_INDEX static void gst_bin_set_index_func (GstElement * element, GstIndex * index); #endif static GstClock *gst_bin_get_clock_func (GstElement * element); static void gst_bin_set_clock_func (GstElement * element, GstClock * clock); static void gst_bin_set_manager (GstElement * element, GstPipeline * manager); static void gst_bin_set_bus (GstElement * element, GstBus * bus); static void gst_bin_set_scheduler (GstElement * element, GstScheduler * sched); static gboolean gst_bin_send_event (GstElement * element, GstEvent * event); static gboolean gst_bin_query (GstElement * element, GstQuery * query); #ifndef GST_DISABLE_LOADSAVE static xmlNodePtr gst_bin_save_thyself (GstObject * object, xmlNodePtr parent); static void gst_bin_restore_thyself (GstObject * object, xmlNodePtr self); #endif static gint bin_element_is_sink (GstElement * child, GstBin * bin); /* Bin signals and args */ enum { ELEMENT_ADDED, ELEMENT_REMOVED, LAST_SIGNAL }; enum { ARG_0 /* FILL ME */ }; static void gst_bin_base_init (gpointer g_class); static void gst_bin_class_init (GstBinClass * klass); static void gst_bin_init (GstBin * bin); static GstElementClass *parent_class = NULL; static guint gst_bin_signals[LAST_SIGNAL] = { 0 }; /** * gst_bin_get_type: * * Returns: the type of #GstBin */ GType gst_bin_get_type (void) { if (!_gst_bin_type) { static const GTypeInfo bin_info = { sizeof (GstBinClass), gst_bin_base_init, NULL, (GClassInitFunc) gst_bin_class_init, NULL, NULL, sizeof (GstBin), 0, (GInstanceInitFunc) gst_bin_init, NULL }; _gst_bin_type = g_type_register_static (GST_TYPE_ELEMENT, "GstBin", &bin_info, 0); GST_DEBUG_CATEGORY_INIT (bin_debug, "bin", GST_DEBUG_BOLD, "debugging info for the 'bin' container element"); } return _gst_bin_type; } static void gst_bin_base_init (gpointer g_class) { GstElementClass *gstelement_class = GST_ELEMENT_CLASS (g_class); gst_element_class_set_details (gstelement_class, &gst_bin_details); } static void gst_bin_class_init (GstBinClass * klass) { GObjectClass *gobject_class; GstObjectClass *gstobject_class; GstElementClass *gstelement_class; gobject_class = (GObjectClass *) klass; gstobject_class = (GstObjectClass *) klass; gstelement_class = (GstElementClass *) klass; parent_class = g_type_class_ref (GST_TYPE_ELEMENT); gst_bin_signals[ELEMENT_ADDED] = g_signal_new ("element-added", G_TYPE_FROM_CLASS (klass), G_SIGNAL_RUN_FIRST, G_STRUCT_OFFSET (GstBinClass, element_added), NULL, NULL, gst_marshal_VOID__OBJECT, G_TYPE_NONE, 1, GST_TYPE_ELEMENT); gst_bin_signals[ELEMENT_REMOVED] = g_signal_new ("element-removed", G_TYPE_FROM_CLASS (klass), G_SIGNAL_RUN_FIRST, G_STRUCT_OFFSET (GstBinClass, element_removed), NULL, NULL, gst_marshal_VOID__OBJECT, G_TYPE_NONE, 1, GST_TYPE_ELEMENT); gobject_class->dispose = GST_DEBUG_FUNCPTR (gst_bin_dispose); #ifndef GST_DISABLE_LOADSAVE gstobject_class->save_thyself = GST_DEBUG_FUNCPTR (gst_bin_save_thyself); gstobject_class->restore_thyself = GST_DEBUG_FUNCPTR (gst_bin_restore_thyself); #endif gstelement_class->change_state = GST_DEBUG_FUNCPTR (gst_bin_change_state); gstelement_class->get_state = GST_DEBUG_FUNCPTR (gst_bin_get_state); #ifndef GST_DISABLE_INDEX gstelement_class->set_index = GST_DEBUG_FUNCPTR (gst_bin_set_index_func); #endif gstelement_class->get_clock = GST_DEBUG_FUNCPTR (gst_bin_get_clock_func); gstelement_class->set_clock = GST_DEBUG_FUNCPTR (gst_bin_set_clock_func); gstelement_class->set_manager = GST_DEBUG_FUNCPTR (gst_bin_set_manager); gstelement_class->set_bus = GST_DEBUG_FUNCPTR (gst_bin_set_bus); gstelement_class->set_scheduler = GST_DEBUG_FUNCPTR (gst_bin_set_scheduler); gstelement_class->send_event = GST_DEBUG_FUNCPTR (gst_bin_send_event); gstelement_class->query = GST_DEBUG_FUNCPTR (gst_bin_query); klass->add_element = GST_DEBUG_FUNCPTR (gst_bin_add_func); klass->remove_element = GST_DEBUG_FUNCPTR (gst_bin_remove_func); } static void gst_bin_init (GstBin * bin) { bin->numchildren = 0; bin->children = NULL; bin->children_cookie = 0; } /** * gst_bin_new: * @name: name of new bin * * Create a new bin with given name. * * Returns: new bin */ GstElement * gst_bin_new (const gchar * name) { return gst_element_factory_make ("bin", name); } /* set the index on all elements in this bin * * MT safe */ #ifndef GST_DISABLE_INDEX static void gst_bin_set_index_func (GstElement * element, GstIndex * index) { GstBin *bin; GList *children; bin = GST_BIN (element); GST_LOCK (bin); for (children = bin->children; children; children = g_list_next (children)) { GstElement *child = GST_ELEMENT (children->data); gst_element_set_index (child, index); } GST_UNLOCK (bin); } #endif /* set the clock on all elements in this bin * * MT safe */ static void gst_bin_set_clock_func (GstElement * element, GstClock * clock) { GList *children; GstBin *bin; bin = GST_BIN (element); GST_LOCK (bin); for (children = bin->children; children; children = g_list_next (children)) { GstElement *child = GST_ELEMENT (children->data); gst_element_set_clock (child, clock); } GST_UNLOCK (bin); } /* get the clock for this bin by asking all of the children in this bin * * MT safe */ static GstClock * gst_bin_get_clock_func (GstElement * element) { GstClock *result = NULL; GstBin *bin; GList *children; bin = GST_BIN (element); GST_LOCK (bin); for (children = bin->children; children; children = g_list_next (children)) { GstElement *child = GST_ELEMENT (children->data); result = gst_element_get_clock (child); if (result) break; } GST_UNLOCK (bin); return result; } /* set the bus on all of the children in this bin * * MT safe */ static void gst_bin_set_bus (GstElement * element, GstBus * bus) { GList *children; GstBin *bin; bin = GST_BIN (element); parent_class->set_bus (element, bus); GST_LOCK (bin); for (children = bin->children; children; children = g_list_next (children)) { GstElement *child = GST_ELEMENT (children->data); gst_element_set_bus (child, bus); } GST_UNLOCK (bin); } /* set the scheduler on all of the children in this bin * * MT safe */ static void gst_bin_set_scheduler (GstElement * element, GstScheduler * sched) { GList *children; GstBin *bin; bin = GST_BIN (element); parent_class->set_scheduler (element, sched); GST_LOCK (bin); for (children = bin->children; children; children = g_list_next (children)) { GstElement *child = GST_ELEMENT (children->data); gst_element_set_scheduler (child, sched); } GST_UNLOCK (bin); } /* set the manager on all of the children in this bin * * MT safe */ static void gst_bin_set_manager (GstElement * element, GstPipeline * manager) { GstBin *bin = GST_BIN (element); GList *kids; GstElement *kid; GST_ELEMENT_CLASS (parent_class)->set_manager (element, manager); GST_LOCK (element); for (kids = bin->children; kids != NULL; kids = kids->next) { kid = GST_ELEMENT (kids->data); gst_element_set_manager (kid, manager); } GST_UNLOCK (element); } /* add an element to this bin * * MT safe */ static gboolean gst_bin_add_func (GstBin * bin, GstElement * element) { gchar *elem_name; /* we obviously can't add ourself to ourself */ if (G_UNLIKELY (GST_ELEMENT_CAST (element) == GST_ELEMENT_CAST (bin))) goto adding_itself; /* get the element name to make sure it is unique in this bin, FIXME, another * thread can change the name after the unlock. */ GST_LOCK (element); elem_name = g_strdup (GST_ELEMENT_NAME (element)); GST_UNLOCK (element); GST_LOCK (bin); /* then check to see if the element's name is already taken in the bin, * we can safely take the lock here. This check is probably bogus because * you can safely change the element name after adding it to the bin. */ if (G_UNLIKELY (gst_object_check_uniqueness (bin->children, elem_name) == FALSE)) goto duplicate_name; /* set the element's parent and add the element to the bin's list of children */ if (G_UNLIKELY (!gst_object_set_parent (GST_OBJECT_CAST (element), GST_OBJECT_CAST (bin)))) goto had_parent; if (GST_FLAG_IS_SET (element, GST_ELEMENT_IS_SINK)) GST_FLAG_SET (bin, GST_ELEMENT_IS_SINK); bin->children = g_list_prepend (bin->children, element); bin->numchildren++; bin->children_cookie++; gst_element_set_manager (element, GST_ELEMENT (bin)->manager); gst_element_set_bus (element, GST_ELEMENT (bin)->bus); gst_element_set_scheduler (element, GST_ELEMENT_SCHEDULER (bin)); gst_element_set_clock (element, GST_ELEMENT_CLOCK (bin)); GST_UNLOCK (bin); GST_CAT_DEBUG_OBJECT (GST_CAT_PARENTAGE, bin, "added element \"%s\"", elem_name); g_free (elem_name); g_signal_emit (G_OBJECT (bin), gst_bin_signals[ELEMENT_ADDED], 0, element); return TRUE; /* ERROR handling here */ adding_itself: { GST_LOCK (bin); g_warning ("Cannot add bin %s to itself", GST_ELEMENT_NAME (bin)); GST_UNLOCK (bin); return FALSE; } duplicate_name: { g_warning ("Name %s is not unique in bin %s, not adding", elem_name, GST_ELEMENT_NAME (bin)); GST_UNLOCK (bin); g_free (elem_name); return FALSE; } had_parent: { g_warning ("Element %s already has parent", elem_name); GST_UNLOCK (bin); g_free (elem_name); return FALSE; } } /** * gst_bin_add: * @bin: #GstBin to add element to * @element: #GstElement to add to bin * * Adds the given element to the bin. Sets the element's parent, and thus * takes ownership of the element. An element can only be added to one bin. * * MT safe. * * Returns: TRUE if the element could be added, FALSE on wrong parameters or * the bin does not want to accept the element. */ gboolean gst_bin_add (GstBin * bin, GstElement * element) { GstBinClass *bclass; gboolean result; g_return_val_if_fail (GST_IS_BIN (bin), FALSE); g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE); bclass = GST_BIN_GET_CLASS (bin); if (G_UNLIKELY (bclass->add_element == NULL)) goto no_function; GST_CAT_DEBUG (GST_CAT_PARENTAGE, "adding element %s to bin %s", GST_ELEMENT_NAME (element), GST_ELEMENT_NAME (bin)); result = bclass->add_element (bin, element); return result; /* ERROR handling */ no_function: { g_warning ("adding elements to bin %s is not supported", GST_ELEMENT_NAME (bin)); return FALSE; } } /* remove an element from the bin * * MT safe */ static gboolean gst_bin_remove_func (GstBin * bin, GstElement * element) { gchar *elem_name; /* grab element name so we can print it */ GST_LOCK (element); elem_name = g_strdup (GST_ELEMENT_NAME (element)); GST_UNLOCK (element); GST_LOCK (bin); /* the element must be in the bin's list of children */ if (G_UNLIKELY (g_list_find (bin->children, element) == NULL)) goto not_in_bin; /* now remove the element from the list of elements */ bin->children = g_list_remove (bin->children, element); bin->numchildren--; bin->children_cookie++; /* check if we a sink */ if (GST_FLAG_IS_SET (element, GST_ELEMENT_IS_SINK)) { GList *other_sink; /* check if we removed the last sink */ other_sink = g_list_find_custom (bin->children, bin, (GCompareFunc) bin_element_is_sink); if (!other_sink) { /* yups, we're not a sink anymore */ GST_FLAG_UNSET (bin, GST_ELEMENT_IS_SINK); } } GST_UNLOCK (bin); GST_CAT_INFO_OBJECT (GST_CAT_PARENTAGE, bin, "removed child \"%s\"", elem_name); g_free (elem_name); gst_element_set_manager (element, NULL); gst_element_set_bus (element, NULL); gst_element_set_scheduler (element, NULL); /* unlock any waiters for the state change. It is possible that * we are waiting for an ASYNC state change on this element. The * element cannot be added to another bin yet as it is not yet * unparented. */ GST_STATE_LOCK (element); GST_STATE_BROADCAST (element); GST_STATE_UNLOCK (element); /* we ref here because after the _unparent() the element can be disposed * and we still need it to fire a signal. */ gst_object_ref (element); gst_object_unparent (GST_OBJECT_CAST (element)); g_signal_emit (G_OBJECT (bin), gst_bin_signals[ELEMENT_REMOVED], 0, element); /* element is really out of our control now */ gst_object_unref (element); return TRUE; /* ERROR handling */ not_in_bin: { g_warning ("Element %s is not in bin %s", elem_name, GST_ELEMENT_NAME (bin)); GST_UNLOCK (bin); g_free (elem_name); return FALSE; } } /** * gst_bin_remove: * @bin: #GstBin to remove element from * @element: #GstElement to remove * * Remove the element from its associated bin, unparenting it as well. * Unparenting the element means that the element will be dereferenced, * so if the bin holds the only reference to the element, the element * will be freed in the process of removing it from the bin. If you * want the element to still exist after removing, you need to call * #gst_object_ref before removing it from the bin. * * MT safe. * * Returns: TRUE if the element could be removed, FALSE on wrong parameters or * the bin does not want to remove the element. */ gboolean gst_bin_remove (GstBin * bin, GstElement * element) { GstBinClass *bclass; gboolean result; g_return_val_if_fail (GST_IS_BIN (bin), FALSE); g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE); bclass = GST_BIN_GET_CLASS (bin); if (G_UNLIKELY (bclass->remove_element == NULL)) goto no_function; GST_CAT_DEBUG (GST_CAT_PARENTAGE, "removing element %s from bin %s", GST_ELEMENT_NAME (element), GST_ELEMENT_NAME (bin)); result = bclass->remove_element (bin, element); return result; /* ERROR handling */ no_function: { g_warning ("removing elements from bin %s is not supported", GST_ELEMENT_NAME (bin)); return FALSE; } } static GstIteratorItem iterate_child (GstIterator * it, GstElement * child) { gst_object_ref (child); return GST_ITERATOR_ITEM_PASS; } /** * gst_bin_iterate_elements: * @bin: #Gstbin to iterate the elements of * * Get an iterator for the elements in this bin. * Each element will have its refcount increased, so unref * after use. * * MT safe. * * Returns: a #GstIterator of #GstElements. gst_iterator_free after * use. returns NULL when passing bad parameters. */ GstIterator * gst_bin_iterate_elements (GstBin * bin) { GstIterator *result; g_return_val_if_fail (GST_IS_BIN (bin), NULL); GST_LOCK (bin); /* add ref because the iterator refs the bin. When the iterator * is freed it will unref the bin again using the provided dispose * function. */ gst_object_ref (bin); result = gst_iterator_new_list (GST_GET_LOCK (bin), &bin->children_cookie, &bin->children, bin, (GstIteratorItemFunction) iterate_child, (GstIteratorDisposeFunction) gst_object_unref); GST_UNLOCK (bin); return result; } static GstIteratorItem iterate_child_recurse (GstIterator * it, GstElement * child) { gst_object_ref (child); if (GST_IS_BIN (child)) { GstIterator *other = gst_bin_iterate_recurse (GST_BIN (child)); gst_iterator_push (it, other); } return GST_ITERATOR_ITEM_PASS; } /** * gst_bin_iterate_recurse: * @bin: #Gstbin to iterate the elements of * * Get an iterator for the elements in this bin. * Each element will have its refcount increased, so unref * after use. This iterator recurses into GstBin children. * * MT safe. * * Returns: a #GstIterator of #GstElements. gst_iterator_free after * use. returns NULL when passing bad parameters. */ GstIterator * gst_bin_iterate_recurse (GstBin * bin) { GstIterator *result; g_return_val_if_fail (GST_IS_BIN (bin), NULL); GST_LOCK (bin); /* add ref because the iterator refs the bin. When the iterator * is freed it will unref the bin again using the provided dispose * function. */ gst_object_ref (bin); result = gst_iterator_new_list (GST_GET_LOCK (bin), &bin->children_cookie, &bin->children, bin, (GstIteratorItemFunction) iterate_child_recurse, (GstIteratorDisposeFunction) gst_object_unref); GST_UNLOCK (bin); return result; } /* returns 0 when TRUE because this is a GCompareFunc */ /* MT safe */ static gint bin_element_is_sink (GstElement * child, GstBin * bin) { gboolean is_sink; /* we lock the child here for the remainder of the function to * get its name safely. */ GST_LOCK (child); is_sink = GST_FLAG_IS_SET (child, GST_ELEMENT_IS_SINK); GST_UNLOCK (child); GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "child %s %s sink", GST_OBJECT_NAME (child), is_sink ? "is" : "is not"); return is_sink ? 0 : 1; } static gboolean has_ancestor (GstObject * object, GstObject * ancestor) { GstObject *parent; gboolean result = FALSE; if (object == NULL) return FALSE; if (object == ancestor) return TRUE; parent = gst_object_get_parent (object); result = has_ancestor (parent, ancestor); if (parent) gst_object_unref (parent); return result; } /* returns 0 when TRUE because this is a GCompareFunc. * This function returns elements that have no connected srcpads and * are therefore not reachable from a real sink. */ /* MT safe */ static gint bin_element_is_semi_sink (GstElement * child, GstBin * bin) { int ret = 1; /* we lock the child here for the remainder of the function to * get its pads and name safely. */ GST_LOCK (child); /* check if this is a sink element, these are the elements * without (linked) source pads. */ if (child->numsrcpads == 0) { /* shortcut */ GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "adding child %s as sink", GST_OBJECT_NAME (child)); ret = 0; } else { /* loop over all pads, try to figure out if this element * is a semi sink because it has no linked source pads */ GList *pads; gboolean connected_src = FALSE; for (pads = child->srcpads; pads; pads = g_list_next (pads)) { GstPad *peer; if ((peer = gst_pad_get_peer (GST_PAD_CAST (pads->data)))) { connected_src = has_ancestor (GST_OBJECT_CAST (peer), GST_OBJECT_CAST (bin)); gst_object_unref (peer); if (connected_src) { break; } } } if (connected_src) { GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "not adding child %s as sink: linked source pads", GST_OBJECT_NAME (child)); } else { GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, bin, "adding child %s as sink since it has unlinked source pads in this bin", GST_OBJECT_NAME (child)); ret = 0; } } GST_UNLOCK (child); return ret; } static gint sink_iterator_filter (GstElement * child, GstBin * bin) { if (bin_element_is_sink (child, bin) == 0) { /* returns 0 because this is a GCompareFunc */ return 0; } else { /* child carries a ref from gst_bin_iterate_elements -- drop if not passing through */ gst_object_unref ((GstObject *) child); return 1; } } /** * gst_bin_iterate_sinks: * @bin: #Gstbin to iterate on * * Get an iterator for the sink elements in this bin. * Each element will have its refcount increased, so unref * after use. * * The sink elements are those without any linked srcpads. * * MT safe. * * Returns: a #GstIterator of #GstElements. gst_iterator_free after use. */ GstIterator * gst_bin_iterate_sinks (GstBin * bin) { GstIterator *children; GstIterator *result; g_return_val_if_fail (GST_IS_BIN (bin), NULL); children = gst_bin_iterate_elements (bin); result = gst_iterator_filter (children, (GCompareFunc) sink_iterator_filter, bin); return result; } /* 2 phases: * 1) check state of all children with 0 timeout to find ERROR and * NO_PREROLL elements. return if found. * 2) perform full blocking wait with requested timeout. * * 2) cannot be performed when 1) returns results as the sinks might * not be able to complete the state change making 2) block forever. * * MT safe */ static GstElementStateReturn gst_bin_get_state (GstElement * element, GstElementState * state, GstElementState * pending, GTimeVal * timeout) { GstBin *bin = GST_BIN (element); GstElementStateReturn ret = GST_STATE_SUCCESS; GList *children; guint32 children_cookie; gboolean zero_timeout; gboolean have_no_preroll; GST_CAT_INFO_OBJECT (GST_CAT_STATES, element, "getting state"); zero_timeout = timeout != NULL && timeout->tv_sec == 0 && timeout->tv_usec == 0; /* lock bin, no element can be added or removed between going into * the quick scan and the blocking wait. */ GST_LOCK (bin); restart: have_no_preroll = FALSE; /* if we have a non zero timeout we must make sure not to block * on the sinks when we have NO_PREROLL elements. This is why we do * a quick check if there are still NO_PREROLL elements. We also * catch the error elements this way. */ if (!zero_timeout) { GTimeVal tv; gboolean have_async = FALSE; GST_CAT_INFO_OBJECT (GST_CAT_STATES, element, "checking for NO_PREROLL"); /* use 0 timeout so we don't block on the sinks */ GST_TIME_TO_TIMEVAL (0, tv); children = bin->children; children_cookie = bin->children_cookie; while (children) { GstElement *child = GST_ELEMENT_CAST (children->data); gst_object_ref (child); /* now we release the lock to enter a non blocking wait. We * release the lock anyway since we can. */ GST_UNLOCK (bin); ret = gst_element_get_state (child, NULL, NULL, &tv); gst_object_unref (child); /* now grab the lock to iterate to the next child */ GST_LOCK (bin); if (G_UNLIKELY (children_cookie != bin->children_cookie)) { /* child added/removed during state change, restart. We need * to restart with the quick check as a no-preroll element could * have been added here and we don't want to block on sinks then.*/ goto restart; } switch (ret) { /* report FAILURE or NO_PREROLL immediatly */ case GST_STATE_FAILURE: goto done; case GST_STATE_NO_PREROLL: /* we have to continue scanning as there might be * ERRORS too */ have_no_preroll = TRUE; break; case GST_STATE_ASYNC: have_async = TRUE; break; default: break; } children = g_list_next (children); } /* if we get here, we have no FAILURES, check for any NO_PREROLL * elements then. */ if (have_no_preroll) { ret = GST_STATE_NO_PREROLL; goto done; } /* if we get here, no NO_PREROLL elements are in the pipeline */ GST_CAT_INFO_OBJECT (GST_CAT_STATES, element, "no NO_PREROLL elements"); /* if no ASYNC elements exist we don't even have to poll with a * timeout again */ if (!have_async) { ret = GST_STATE_SUCCESS; goto done; } } /* next we poll all children for their state to see if one of them * is still busy with its state change. We did not release the bin lock * yet so the elements are the same as the ones from the quick scan. */ children = bin->children; children_cookie = bin->children_cookie; while (children) { GstElement *child = GST_ELEMENT_CAST (children->data); gst_object_ref (child); /* now we release the lock to enter the potentialy blocking wait */ GST_UNLOCK (bin); /* ret is ASYNC if some child is still performing the state change * ater the timeout. */ ret = gst_element_get_state (child, NULL, NULL, timeout); gst_object_unref (child); /* now grab the lock to iterate to the next child */ GST_LOCK (bin); if (G_UNLIKELY (children_cookie != bin->children_cookie)) { /* child added/removed during state change, restart. We need * to restart with the quick check as a no-preroll element could * have been added here and we don't want to block on sinks then.*/ goto restart; } switch (ret) { case GST_STATE_SUCCESS: break; case GST_STATE_FAILURE: case GST_STATE_NO_PREROLL: /* report FAILURE and NO_PREROLL immediatly */ goto done; break; case GST_STATE_ASYNC: /* since we checked for non prerollable elements before, * the first ASYNC return is the real return value */ if (!zero_timeout) goto done; break; default: g_assert_not_reached (); } children = g_list_next (children); } /* if we got here, all elements can do preroll */ have_no_preroll = FALSE; done: GST_UNLOCK (bin); /* now we can take the state lock, it is possible that new elements * are added now and we still report the old state. No problem though as * the return is still consistent, the effect is as if the element was * added after this function completed. */ GST_STATE_LOCK (bin); switch (ret) { case GST_STATE_SUCCESS: /* we can commit the state */ gst_element_commit_state (element); break; case GST_STATE_FAILURE: /* some element failed, abort the state change */ gst_element_abort_state (element); break; default: /* other cases are just passed along */ break; } /* and report the state if needed */ if (state) *state = GST_STATE (element); if (pending) *pending = GST_STATE_PENDING (element); GST_STATE_NO_PREROLL (element) = have_no_preroll; GST_CAT_INFO_OBJECT (GST_CAT_STATES, element, "state current: %s, pending: %s, error: %d, no_preroll: %d, result: %d", gst_element_state_get_name (GST_STATE (element)), gst_element_state_get_name (GST_STATE_PENDING (element)), GST_STATE_ERROR (element), GST_STATE_NO_PREROLL (element), ret); GST_STATE_UNLOCK (bin); return ret; } static void append_child (gpointer child, GQueue * queue) { g_queue_push_tail (queue, child); } /** * gst_bin_iterate_state_order: * @bin: #Gstbin to iterate on * * Get an iterator for the elements in this bin in the order * in which a state change should be performed on them. This * means that first the sinks and then the other elements will * be returned. * Each element will have its refcount increased, so unref * after use. * * MT safe. * * Returns: a #GstIterator of #GstElements. gst_iterator_free after use. */ GstIterator * gst_bin_iterate_state_order (GstBin * bin) { GstIterator *result; g_return_val_if_fail (GST_IS_BIN (bin), NULL); result = NULL; return result; } /* this function is called with the STATE_LOCK held. It works * as follows: * * 1) put all sink elements on the queue. * 2) put all semisink elements on the queue. * 3) change state of elements in queue, put linked elements to queue. * 4) while queue not empty goto 3) * * This will effectively change the state of all elements in the bin * from the sinks to the sources. We have to change the states this * way so that when a source element pushes data, the downstream element * is in the right state to receive the data. * * MT safe. */ static GstElementStateReturn gst_bin_change_state (GstElement * element) { GstBin *bin; GstElementStateReturn ret; GstElementState old_state, pending; gboolean have_async = FALSE; gboolean have_no_preroll = FALSE; GList *children; guint32 children_cookie; GQueue *elem_queue; /* list of elements waiting for a state change */ GQueue *semi_queue; /* list of elements with no connected srcpads */ GQueue *temp; /* queue of leftovers */ bin = GST_BIN (element); /* we don't need to take the STATE_LOCK, it is already taken */ old_state = GST_STATE (element); pending = GST_STATE_PENDING (element); GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element, "changing state of children from %s to %s", gst_element_state_get_name (old_state), gst_element_state_get_name (pending)); if (pending == GST_STATE_VOID_PENDING) return GST_STATE_SUCCESS; /* all elements added to these queues should have their refcount * incremented */ elem_queue = g_queue_new (); semi_queue = g_queue_new (); temp = g_queue_new (); /* first step, find all sink elements, these are the elements * without (linked) source pads. */ GST_LOCK (bin); restart: children = bin->children; children_cookie = bin->children_cookie; while (children) { GstElement *child = GST_ELEMENT_CAST (children->data); gst_object_ref (child); GST_UNLOCK (bin); if (bin_element_is_sink (child, bin) == 0) { g_queue_push_tail (elem_queue, child); } else if (bin_element_is_semi_sink (child, bin) == 0) { g_queue_push_tail (semi_queue, child); } else { g_queue_push_tail (temp, child); } GST_LOCK (bin); if (G_UNLIKELY (children_cookie != bin->children_cookie)) { /* undo what we had */ g_queue_foreach (elem_queue, (GFunc) gst_object_unref, NULL); g_queue_foreach (semi_queue, (GFunc) gst_object_unref, NULL); g_queue_foreach (temp, (GFunc) gst_object_unref, NULL); while (g_queue_pop_head (elem_queue)); while (g_queue_pop_head (semi_queue)); while (g_queue_pop_head (temp)); goto restart; } children = g_list_next (children); } GST_UNLOCK (bin); /* now change state for semi sink elements first so add them in * front of the other elements */ g_queue_foreach (temp, (GFunc) append_child, semi_queue); g_queue_free (temp); /* can be the case for a bin like ( identity ) */ if (g_queue_is_empty (elem_queue) && !g_queue_is_empty (semi_queue)) { GQueue *q = elem_queue; elem_queue = semi_queue; semi_queue = q; } /* second step, change state of elements in the queue */ while (!g_queue_is_empty (elem_queue)) { GstElement *qelement; GList *pads; gboolean locked; /* take element */ qelement = g_queue_pop_head (elem_queue); /* we don't need it in the semi_queue anymore */ g_queue_remove_all (semi_queue, qelement); /* if queue is empty now, continue with a non-sink */ if (g_queue_is_empty (elem_queue)) { GstElement *non_sink; GST_DEBUG ("sinks and upstream elements exhausted"); non_sink = g_queue_pop_head (semi_queue); if (non_sink) { GST_DEBUG ("found lefover non-sink %s", GST_OBJECT_NAME (non_sink)); g_queue_push_tail (elem_queue, non_sink); } } /* queue all elements connected to the sinkpads of this element */ GST_LOCK (qelement); pads = qelement->sinkpads; while (pads) { GstPad *pad = GST_PAD_CAST (pads->data); GstPad *peer; GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element, "found sinkpad %s:%s", GST_DEBUG_PAD_NAME (pad)); peer = gst_pad_get_peer (pad); if (peer) { GstElement *peer_elem; peer_elem = gst_pad_get_parent (peer); if (peer_elem) { GstObject *parent; /* see if this element is in the bin we are currently handling */ parent = gst_object_get_parent (GST_OBJECT_CAST (peer_elem)); if (parent && parent == GST_OBJECT_CAST (bin)) { GList *oldelem; GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element, "adding element %s to queue", GST_ELEMENT_NAME (peer_elem)); /* make sure we don't have duplicates */ while ((oldelem = g_queue_find (semi_queue, peer_elem))) { gst_object_unref (peer_elem); g_queue_delete_link (semi_queue, oldelem); } while ((oldelem = g_queue_find (elem_queue, peer_elem))) { gst_object_unref (peer_elem); g_queue_delete_link (elem_queue, oldelem); } /* was reffed before pushing on the queue by the * gst_object_get_parent() call we used to get the element. */ g_queue_push_tail (elem_queue, peer_elem); } else { GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element, "not adding element %s to queue, it is in another bin", GST_ELEMENT_NAME (peer_elem)); gst_object_unref (peer_elem); } if (parent) { gst_object_unref (parent); } } gst_object_unref (peer); } else { GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element, "pad %s:%s does not have a peer", GST_DEBUG_PAD_NAME (pad)); } pads = g_list_next (pads); } /* peel off the locked flag and release the element lock */ locked = GST_FLAG_IS_SET (qelement, GST_ELEMENT_LOCKED_STATE); GST_UNLOCK (qelement); if (G_UNLIKELY (locked)) goto next_element; qelement->base_time = element->base_time; ret = gst_element_set_state (qelement, pending); switch (ret) { case GST_STATE_SUCCESS: GST_CAT_DEBUG (GST_CAT_STATES, "child '%s' changed state to %d(%s) successfully", GST_ELEMENT_NAME (qelement), pending, gst_element_state_get_name (pending)); break; case GST_STATE_ASYNC: GST_CAT_INFO_OBJECT (GST_CAT_STATES, element, "child '%s' is changing state asynchronously", GST_ELEMENT_NAME (qelement)); have_async = TRUE; break; case GST_STATE_FAILURE: GST_CAT_INFO_OBJECT (GST_CAT_STATES, element, "child '%s' failed to go to state %d(%s)", GST_ELEMENT_NAME (qelement), pending, gst_element_state_get_name (pending)); ret = GST_STATE_FAILURE; /* release refcount of element we popped off the queue */ gst_object_unref (qelement); goto exit; case GST_STATE_NO_PREROLL: GST_CAT_DEBUG (GST_CAT_STATES, "child '%s' changed state to %d(%s) successfully without preroll", GST_ELEMENT_NAME (qelement), pending, gst_element_state_get_name (pending)); have_no_preroll = TRUE; break; default: g_assert_not_reached (); break; } next_element: gst_object_unref (qelement); } if (have_no_preroll) { ret = GST_STATE_NO_PREROLL; } else if (have_async) { ret = GST_STATE_ASYNC; } else { if ((ret = parent_class->change_state (element)) == GST_STATE_SUCCESS) { /* we can commit the state change now */ gst_element_commit_state (element); } } GST_CAT_DEBUG_OBJECT (GST_CAT_STATES, element, "done changing bin's state from %s to %s, now in %s", gst_element_state_get_name (old_state), gst_element_state_get_name (pending), gst_element_state_get_name (GST_STATE (element))); exit: /* release refcounts in queue, should normally be empty unless we * had an error. */ g_queue_foreach (elem_queue, (GFunc) gst_object_unref, NULL); g_queue_free (elem_queue); g_queue_foreach (semi_queue, (GFunc) gst_object_unref, NULL); g_queue_free (semi_queue); return ret; } static void gst_bin_dispose (GObject * object) { GstBin *bin = GST_BIN (object); GST_CAT_DEBUG_OBJECT (GST_CAT_REFCOUNTING, object, "dispose"); /* ref to not hit 0 again */ gst_object_ref (object); while (bin->children) { gst_bin_remove (bin, GST_ELEMENT (bin->children->data)); } GST_CAT_DEBUG_OBJECT (GST_CAT_REFCOUNTING, object, "dispose no children"); g_assert (bin->children == NULL); g_assert (bin->numchildren == 0); G_OBJECT_CLASS (parent_class)->dispose (object); } /* * This function is a utility event handler for seek events. * It will send the event to all sinks. * Applications are free to override this behaviour and * implement their own seek handler, but this will work for * pretty much all cases in practice. */ static gboolean gst_bin_send_event (GstElement * element, GstEvent * event) { GstBin *bin = GST_BIN (element); GstIterator *iter; gboolean res = TRUE; gboolean done = FALSE; iter = gst_bin_iterate_sinks (bin); GST_DEBUG_OBJECT (bin, "Sending event to sink children"); while (!done) { gpointer data; switch (gst_iterator_next (iter, &data)) { case GST_ITERATOR_OK: { GstElement *sink; gst_event_ref (event); sink = GST_ELEMENT_CAST (data); res &= gst_element_send_event (sink, event); gst_object_unref (sink); break; } case GST_ITERATOR_RESYNC: gst_iterator_resync (iter); res = TRUE; break; default: case GST_ITERATOR_DONE: done = TRUE; break; } } gst_iterator_free (iter); gst_event_unref (event); return res; } static gboolean gst_bin_query (GstElement * element, GstQuery * query) { GstBin *bin = GST_BIN (element); GstIterator *iter; gboolean res = FALSE, done = FALSE; iter = gst_bin_iterate_sinks (bin); GST_DEBUG_OBJECT (bin, "Sending event to sink children"); while (!(res || done)) { gpointer data; switch (gst_iterator_next (iter, &data)) { case GST_ITERATOR_OK: { GstElement *sink; sink = GST_ELEMENT_CAST (data); res = gst_element_query (sink, query); gst_object_unref (sink); break; } case GST_ITERATOR_RESYNC: gst_iterator_resync (iter); break; default: case GST_ITERATOR_DONE: done = TRUE; break; } } gst_iterator_free (iter); return res; } static gint compare_name (GstElement * element, const gchar * name) { gint eq; GST_LOCK (element); eq = strcmp (GST_ELEMENT_NAME (element), name); GST_UNLOCK (element); if (eq != 0) { gst_object_unref (element); } return eq; } /** * gst_bin_get_by_name: * @bin: #Gstbin to search * @name: the element name to search for * * Get the element with the given name from this bin. This * function recurses into subbins. * * MT safe. * * Returns: the element with the given name. Returns NULL if the * element is not found or when bad parameters were given. Unref after * use. */ GstElement * gst_bin_get_by_name (GstBin * bin, const gchar * name) { GstIterator *children; GstIterator *result; g_return_val_if_fail (GST_IS_BIN (bin), NULL); GST_CAT_INFO (GST_CAT_PARENTAGE, "[%s]: looking up child element %s", GST_ELEMENT_NAME (bin), name); children = gst_bin_iterate_recurse (bin); result = gst_iterator_find_custom (children, (GCompareFunc) compare_name, (gpointer) name); gst_iterator_free (children); return GST_ELEMENT_CAST (result); } /** * gst_bin_get_by_name_recurse_up: * @bin: #Gstbin to search * @name: the element name to search for * * MT safe. * * Get the element with the given name from this bin. If the * element is not found, a recursion is performed on the parent bin. * * Returns: the element with the given name or NULL when the element * was not found or bad parameters were given. Unref after use. */ GstElement * gst_bin_get_by_name_recurse_up (GstBin * bin, const gchar * name) { GstElement *result; g_return_val_if_fail (GST_IS_BIN (bin), NULL); g_return_val_if_fail (name != NULL, NULL); result = gst_bin_get_by_name (bin, name); if (!result) { GstObject *parent; parent = gst_object_get_parent (GST_OBJECT_CAST (bin)); if (parent) { if (GST_IS_BIN (parent)) { result = gst_bin_get_by_name_recurse_up (GST_BIN_CAST (parent), name); } gst_object_unref (parent); } } return result; } static gint compare_interface (GstElement * element, gpointer interface) { gint ret; if (G_TYPE_CHECK_INSTANCE_TYPE (element, GPOINTER_TO_INT (interface))) { ret = 0; } else { /* we did not find the element, need to release the ref * added by the iterator */ gst_object_unref (element); ret = 1; } return ret; } /** * gst_bin_get_by_interface: * @bin: bin to find element in * @interface: interface to be implemented by interface * * Looks for the first element inside the bin that implements the given * interface. If such an element is found, it returns the element. You can * cast this element to the given interface afterwards. * If you want all elements that implement the interface, use * gst_bin_iterate_all_by_interface(). The function recurses inside bins. * * MT safe. * * Returns: An #GstElement inside the bin implementing the interface. * Unref after use. */ GstElement * gst_bin_get_by_interface (GstBin * bin, GType interface) { GstIterator *children; GstIterator *result; g_return_val_if_fail (GST_IS_BIN (bin), NULL); children = gst_bin_iterate_recurse (bin); result = gst_iterator_find_custom (children, (GCompareFunc) compare_interface, GINT_TO_POINTER (interface)); gst_iterator_free (children); return GST_ELEMENT_CAST (result); } /** * gst_bin_get_all_by_interface: * @bin: bin to find elements in * @interface: interface to be implemented by interface * * Looks for all elements inside the bin that implements the given * interface. You can safely cast all returned elements to the given interface. * The function recurses bins inside bins. The iterator will return a series * of #GstElement that should be unreffed after use. * * MT safe. * * Returns: A #GstIterator for the elements inside the bin implementing the * given interface. */ GstIterator * gst_bin_iterate_all_by_interface (GstBin * bin, GType interface) { GstIterator *children; GstIterator *result; g_return_val_if_fail (GST_IS_BIN (bin), NULL); children = gst_bin_iterate_recurse (bin); result = gst_iterator_filter (children, (GCompareFunc) compare_interface, GINT_TO_POINTER (interface)); return result; } #ifndef GST_DISABLE_LOADSAVE static xmlNodePtr gst_bin_save_thyself (GstObject * object, xmlNodePtr parent) { GstBin *bin = GST_BIN (object); xmlNodePtr childlist, elementnode; GList *children; GstElement *child; if (GST_OBJECT_CLASS (parent_class)->save_thyself) GST_OBJECT_CLASS (parent_class)->save_thyself (GST_OBJECT (bin), parent); childlist = xmlNewChild (parent, NULL, (xmlChar *) "children", NULL); GST_CAT_INFO (GST_CAT_XML, "[%s]: saving %d children", GST_ELEMENT_NAME (bin), bin->numchildren); children = bin->children; while (children) { child = GST_ELEMENT (children->data); elementnode = xmlNewChild (childlist, NULL, (xmlChar *) "element", NULL); gst_object_save_thyself (GST_OBJECT (child), elementnode); children = g_list_next (children); } return childlist; } static void gst_bin_restore_thyself (GstObject * object, xmlNodePtr self) { GstBin *bin = GST_BIN (object); xmlNodePtr field = self->xmlChildrenNode; xmlNodePtr childlist; while (field) { if (!strcmp ((char *) field->name, "children")) { GST_CAT_INFO (GST_CAT_XML, "[%s]: loading children", GST_ELEMENT_NAME (object)); childlist = field->xmlChildrenNode; while (childlist) { if (!strcmp ((char *) childlist->name, "element")) { GstElement *element = gst_xml_make_element (childlist, GST_OBJECT (bin)); /* it had to be parented to find the pads, now we ref and unparent so * we can add it to the bin */ gst_object_ref (element); gst_object_unparent (GST_OBJECT (element)); gst_bin_add (bin, element); } childlist = childlist->next; } } field = field->next; } if (GST_OBJECT_CLASS (parent_class)->restore_thyself) (GST_OBJECT_CLASS (parent_class)->restore_thyself) (object, self); } #endif /* GST_DISABLE_LOADSAVE */