/* GStreamer * Copyright (C) 1999,2000 Erik Walthinsen * 2000 Wim Taymans * 2005 Wim Taymans * * gstobject.c: Fundamental class used for all of GStreamer * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Library General Public * License as published by the Free Software Foundation; either * version 2 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Library General Public License for more details. * * You should have received a copy of the GNU Library General Public * License along with this library; if not, write to the * Free Software Foundation, Inc., 59 Temple Place - Suite 330, * Boston, MA 02111-1307, USA. */ /** * SECTION:gstobject * @short_description: Base class for the GStreamer object hierarchy * * GstObject provides a root for the object hierarchy tree filed in by the * GST library. It is currently a thin wrapper on top of * #GObject. It is an abstract class that is not very usable on its own. * * GstObject gives us basic refcounting, parenting functionality and locking. * Most of the function are just extended for special gstreamer needs and can be * found under the same name in the base class of GstObject which is GObject * (e.g. g_object_ref() becomes gst_object_ref()). * * The most interesting difference between GstObject and GObject is the "floating" * reference count. A GObject is created with a reference count of 1, owned by the * creator of the GObject. (The owner of a reference is the code section that has * the right to call gst_object_unref() in order to remove that reference.) * A GstObject is created with a reference count of 1 also, but it isn't owned by * anyone; calling gst_object_unref() on the newly-created GtkObject is incorrect. * Instead, the initial reference count of a GstObject is "floating". The floating * reference can be removed by anyone at any time, by calling gst_object_sink(). * gst_object_sink() does nothing if an object is already sunk (has no floating * reference). * * When you add a GstElement to its parent container, the parent container will do * this: * * * gst_object_ref (GST_OBJECT (child_element)); * gst_object_sink (GST_OBJECT (child_element)); * * * This means that the container now owns a reference to the child element (since * it called gst_object_ref()), and the child element has no floating reference. * * The purpose of the floating reference is to keep the child element alive until * you add it to a parent container: * * * element = gst_element_factory_make (factoryname, name); * // element has one floating reference to keep it alive * gst_bin_add (GST_BIN (bin), element); * // element has one non-floating reference owned by the container * * * * Another effect of this is, that calling gst_object_unref() on a bin object, will * also destoy all the GstElement objects in it. The same is true for calling * gst_bin_remove(). * * In contrast to GObject instances GstObject add a name property. The functions * gst_object_set_name() and gst_object_get_name() are used to set/get the name * of the object. */ #include "gst_private.h" #include "gstobject.h" #include "gstmarshal.h" #include "gstinfo.h" #include "gstutils.h" #ifndef GST_DISABLE_TRACE #include "gsttrace.h" #endif #define DEBUG_REFCOUNT #ifndef GST_HAVE_GLIB_2_8 #define REFCOUNT_HACK #endif /* Refcount hack: since glib is not threadsafe, the glib refcounter can be * screwed up and the object can be freed unexpectedly. We use an evil hack * to work around this problem. We set the glib refcount to a high value so * that glib will never unref the object under realistic circumstances. Then * we use our own atomic refcounting to do proper MT safe refcounting. * * The hack has several side-effect. At first you should use * gst_object_ref/unref() whenever you can. Next when using g_value_set/get_object(); * you need to manually fix the refcount. * * A proper fix is of course to make the glib refcounting threadsafe which is * planned. Update: atomic refcounting is now in glib >= 2.7.3 */ #ifdef REFCOUNT_HACK #define PATCH_REFCOUNT(obj) ((GObject*)(obj))->ref_count = 100000; #define PATCH_REFCOUNT1(obj) ((GObject*)(obj))->ref_count = 1; #else #define PATCH_REFCOUNT(obj) #define PATCH_REFCOUNT1(obj) #endif /* Object signals and args */ enum { PARENT_SET, PARENT_UNSET, #ifndef GST_DISABLE_LOADSAVE_REGISTRY OBJECT_SAVED, #endif DEEP_NOTIFY, LAST_SIGNAL }; enum { ARG_0, ARG_NAME /* FILL ME */ }; enum { SO_OBJECT_LOADED, SO_LAST_SIGNAL }; GType _gst_object_type = 0; static GHashTable *object_name_counts = NULL; G_LOCK_DEFINE_STATIC (object_name_mutex); typedef struct _GstSignalObject GstSignalObject; typedef struct _GstSignalObjectClass GstSignalObjectClass; static GType gst_signal_object_get_type (void); static void gst_signal_object_class_init (GstSignalObjectClass * klass); static void gst_signal_object_init (GstSignalObject * object); #ifndef GST_DISABLE_LOADSAVE_REGISTRY static guint gst_signal_object_signals[SO_LAST_SIGNAL] = { 0 }; #endif static void gst_object_class_init (GstObjectClass * klass); static void gst_object_init (GTypeInstance * instance, gpointer g_class); #ifndef GST_DISABLE_TRACE static GObject *gst_object_constructor (GType type, guint n_construct_properties, GObjectConstructParam * construct_params); #endif static void gst_object_set_property (GObject * object, guint prop_id, const GValue * value, GParamSpec * pspec); static void gst_object_get_property (GObject * object, guint prop_id, GValue * value, GParamSpec * pspec); static void gst_object_dispatch_properties_changed (GObject * object, guint n_pspecs, GParamSpec ** pspecs); static void gst_object_dispose (GObject * object); static void gst_object_finalize (GObject * object); static gboolean gst_object_set_name_default (GstObject * object, const gchar * type_name); #ifndef GST_DISABLE_LOADSAVE_REGISTRY static void gst_object_real_restore_thyself (GstObject * object, xmlNodePtr self); #endif static GObjectClass *parent_class = NULL; static guint gst_object_signals[LAST_SIGNAL] = { 0 }; GType gst_object_get_type (void) { if (!_gst_object_type) { static const GTypeInfo object_info = { sizeof (GstObjectClass), NULL, NULL, (GClassInitFunc) gst_object_class_init, NULL, NULL, sizeof (GstObject), 0, gst_object_init, NULL }; _gst_object_type = g_type_register_static (G_TYPE_OBJECT, "GstObject", &object_info, G_TYPE_FLAG_ABSTRACT); } return _gst_object_type; } static void gst_object_class_init (GstObjectClass * klass) { GObjectClass *gobject_class; gobject_class = (GObjectClass *) klass; parent_class = g_type_class_ref (G_TYPE_OBJECT); gobject_class->set_property = GST_DEBUG_FUNCPTR (gst_object_set_property); gobject_class->get_property = GST_DEBUG_FUNCPTR (gst_object_get_property); g_object_class_install_property (G_OBJECT_CLASS (klass), ARG_NAME, g_param_spec_string ("name", "Name", "The name of the object", NULL, G_PARAM_READWRITE | G_PARAM_CONSTRUCT)); /** * GstObject::parent-set: * @gstobject: the object which received the signal. * @parent: the new parent * * Is emitted when the parent of an object is set. */ gst_object_signals[PARENT_SET] = g_signal_new ("parent-set", G_TYPE_FROM_CLASS (klass), G_SIGNAL_RUN_LAST, G_STRUCT_OFFSET (GstObjectClass, parent_set), NULL, NULL, g_cclosure_marshal_VOID__OBJECT, G_TYPE_NONE, 1, G_TYPE_OBJECT); /** * GstObject::parent-unset: * @gstobject: the object which received the signal. * @parent: the old parent * * Is emitted when the parent of an object is unset. */ gst_object_signals[PARENT_UNSET] = g_signal_new ("parent-unset", G_TYPE_FROM_CLASS (klass), G_SIGNAL_RUN_LAST, G_STRUCT_OFFSET (GstObjectClass, parent_unset), NULL, NULL, g_cclosure_marshal_VOID__OBJECT, G_TYPE_NONE, 1, G_TYPE_OBJECT); #ifndef GST_DISABLE_LOADSAVE_REGISTRY /** * GstObject::object-saved: * @gstobject: the object which received the signal. * @xml_node: the xmlNodePtr of the parent node * * Is trigered whenever a new object is saved to XML. You can connect to this * signal to insert custom XML tags into the core XML. */ /* FIXME This should be the GType of xmlNodePtr instead of G_TYPE_POINTER * (if libxml would use GObject) */ gst_object_signals[OBJECT_SAVED] = g_signal_new ("object-saved", G_TYPE_FROM_CLASS (klass), G_SIGNAL_RUN_LAST, G_STRUCT_OFFSET (GstObjectClass, object_saved), NULL, NULL, g_cclosure_marshal_VOID__POINTER, G_TYPE_NONE, 1, G_TYPE_POINTER); klass->restore_thyself = gst_object_real_restore_thyself; #endif /** * GstObject::deep-notify: * @gstobject: the object which received the signal. * @prop_object: the object that originated the signal * @prop: the property that changed * * The deep notify signal is used to be notified of property changes. It is * typically attached to the toplevel bin to receive notifications from all * the elements contained in that bin. */ gst_object_signals[DEEP_NOTIFY] = g_signal_new ("deep-notify", G_TYPE_FROM_CLASS (klass), G_SIGNAL_RUN_FIRST | G_SIGNAL_NO_RECURSE | G_SIGNAL_DETAILED | G_SIGNAL_NO_HOOKS, G_STRUCT_OFFSET (GstObjectClass, deep_notify), NULL, NULL, gst_marshal_VOID__OBJECT_PARAM, G_TYPE_NONE, 2, G_TYPE_OBJECT, G_TYPE_PARAM); klass->path_string_separator = "/"; klass->lock = g_new0 (GStaticRecMutex, 1); g_static_rec_mutex_init (klass->lock); klass->signal_object = g_object_new (gst_signal_object_get_type (), NULL); /* see the comments at gst_object_dispatch_properties_changed */ gobject_class->dispatch_properties_changed = GST_DEBUG_FUNCPTR (gst_object_dispatch_properties_changed); gobject_class->dispose = gst_object_dispose; gobject_class->finalize = gst_object_finalize; #ifndef GST_DISABLE_TRACE gobject_class->constructor = gst_object_constructor; #endif } static void gst_object_init (GTypeInstance * instance, gpointer g_class) { GstObject *object = GST_OBJECT (instance); object->lock = g_mutex_new (); object->parent = NULL; object->name = NULL; GST_CAT_LOG_OBJECT (GST_CAT_REFCOUNTING, object, "%p new", object); #ifdef REFCOUNT_HACK gst_atomic_int_set (&object->refcount, 1); #endif PATCH_REFCOUNT (object); object->flags = 0; GST_FLAG_SET (object, GST_OBJECT_FLOATING); } #ifndef GST_DISABLE_TRACE static GObject * gst_object_constructor (GType type, guint n_construct_properties, GObjectConstructParam * construct_params) { const gchar *name; GstAllocTrace *trace; GObject *obj = G_OBJECT_CLASS (parent_class)->constructor (type, n_construct_properties, construct_params); name = g_type_name (type); trace = gst_alloc_trace_get (name); if (!trace) { trace = gst_alloc_trace_register (name); } gst_alloc_trace_new (trace, obj); return obj; } #endif /** * gst_object_ref: * @object: GstObject to reference * * Increments the refence count on the object. This function * does not take the lock on the object because it relies on * atomic refcounting. * * This object returns the input parameter to ease writing * constructs like : * result = gst_object_ref (object->parent); * * Returns: A pointer to the object */ gpointer gst_object_ref (gpointer object) { g_return_val_if_fail (GST_IS_OBJECT (object), NULL); #ifdef DEBUG_REFCOUNT #ifdef REFCOUNT_HACK GST_CAT_LOG_OBJECT (GST_CAT_REFCOUNTING, object, "%p ref %d->%d", object, GST_OBJECT_REFCOUNT_VALUE (object), GST_OBJECT_REFCOUNT_VALUE (object) + 1); #else GST_CAT_LOG_OBJECT (GST_CAT_REFCOUNTING, object, "%p ref %d->%d", object, ((GObject *) object)->ref_count, ((GObject *) object)->ref_count + 1); #endif #endif #ifdef REFCOUNT_HACK g_atomic_int_inc (&((GstObject *) object)->refcount); PATCH_REFCOUNT (object); #else /* FIXME, not MT safe because glib is not MT safe */ g_object_ref (object); #endif return object; } /** * gst_object_unref: * @object: GstObject to unreference * * Decrements the refence count on the object. If reference count hits * zero, destroy the object. This function does not take the lock * on the object as it relies on atomic refcounting. * * The unref method should never be called with the LOCK held since * this might deadlock the dispose function. */ void gst_object_unref (gpointer object) { g_return_if_fail (GST_IS_OBJECT (object)); #ifdef REFCOUNT_HACK g_return_if_fail (GST_OBJECT_REFCOUNT_VALUE (object) > 0); #else g_return_if_fail (((GObject *) object)->ref_count > 0); #endif #ifdef DEBUG_REFCOUNT #ifdef REFCOUNT_HACK GST_CAT_LOG_OBJECT (GST_CAT_REFCOUNTING, object, "%p unref %d->%d", object, GST_OBJECT_REFCOUNT_VALUE (object), GST_OBJECT_REFCOUNT_VALUE (object) - 1); #else GST_CAT_LOG_OBJECT (GST_CAT_REFCOUNTING, object, "%p unref %d->%d", object, ((GObject *) object)->ref_count, ((GObject *) object)->ref_count - 1); #endif #endif #ifdef REFCOUNT_HACK if (G_UNLIKELY (g_atomic_int_dec_and_test (&((GstObject *) object)-> refcount))) { PATCH_REFCOUNT1 (object); g_object_unref (object); } else { PATCH_REFCOUNT (object); } #else /* FIXME, not MT safe because glib is not MT safe */ g_object_unref (object); #endif } /** * gst_object_sink: * @object: GstObject to sink * * Removes floating reference on an object. Any newly created object has * a refcount of 1 and is FLOATING. This function should be used when * creating a new object to symbolically 'take ownership' of the object. * Use #gst_object_set_parent to have this done for you. * * MT safe. This function grabs and releases the object lock. */ void gst_object_sink (gpointer object) { g_return_if_fail (GST_IS_OBJECT (object)); GST_CAT_LOG_OBJECT (GST_CAT_REFCOUNTING, object, "sink"); GST_LOCK (object); if (G_LIKELY (GST_OBJECT_IS_FLOATING (object))) { GST_FLAG_UNSET (object, GST_OBJECT_FLOATING); GST_UNLOCK (object); gst_object_unref (object); } else { GST_UNLOCK (object); } } /** * gst_object_replace: * @oldobj: pointer to place of old GstObject * @newobj: new GstObject * * Unrefs the object pointer to by oldobj, refs the newobj and * puts the newobj in *oldobj. Be carefull when calling this * function, it does not take any locks. You might want to lock * the object owning the oldobj pointer before calling this * function. * * Make sure not to LOCK the oldobj because it might be unreffed * which could cause a deadlock when it is disposed. */ void gst_object_replace (GstObject ** oldobj, GstObject * newobj) { g_return_if_fail (oldobj != NULL); g_return_if_fail (*oldobj == NULL || GST_IS_OBJECT (*oldobj)); g_return_if_fail (newobj == NULL || GST_IS_OBJECT (newobj)); #ifdef DEBUG_REFCOUNT #ifdef REFCOUNT_HACK GST_CAT_LOG (GST_CAT_REFCOUNTING, "replace %s (%d) with %s (%d)", *oldobj ? GST_STR_NULL (GST_OBJECT_NAME (*oldobj)) : "(NONE)", *oldobj ? GST_OBJECT_REFCOUNT_VALUE (*oldobj) : 0, newobj ? GST_STR_NULL (GST_OBJECT_NAME (newobj)) : "(NONE)", newobj ? GST_OBJECT_REFCOUNT_VALUE (newobj) : 0); #else GST_CAT_LOG (GST_CAT_REFCOUNTING, "replace %s (%d) with %s (%d)", *oldobj ? GST_STR_NULL (GST_OBJECT_NAME (*oldobj)) : "(NONE)", *oldobj ? G_OBJECT (*oldobj)->ref_count : 0, newobj ? GST_STR_NULL (GST_OBJECT_NAME (newobj)) : "(NONE)", newobj ? G_OBJECT (newobj)->ref_count : 0); #endif #endif if (G_LIKELY (*oldobj != newobj)) { if (newobj) gst_object_ref (newobj); if (*oldobj) gst_object_unref (*oldobj); *oldobj = newobj; } } /* dispose is called when the object has to release all links * to other objects */ static void gst_object_dispose (GObject * object) { GST_CAT_LOG_OBJECT (GST_CAT_REFCOUNTING, object, "dispose"); GST_LOCK (object); GST_OBJECT_PARENT (object) = NULL; GST_UNLOCK (object); /* need to patch refcount so it is finalized */ PATCH_REFCOUNT1 (object); parent_class->dispose (object); } /* finalize is called when the object has to free its resources */ static void gst_object_finalize (GObject * object) { GstObject *gstobject = GST_OBJECT (object); GST_CAT_LOG_OBJECT (GST_CAT_REFCOUNTING, object, "finalize"); g_signal_handlers_destroy (object); g_free (gstobject->name); g_mutex_free (gstobject->lock); #ifndef GST_DISABLE_TRACE { const gchar *name; GstAllocTrace *trace; name = g_type_name (G_OBJECT_TYPE (object)); trace = gst_alloc_trace_get (name); g_assert (trace); gst_alloc_trace_free (trace, object); } #endif parent_class->finalize (object); } /* Changing a GObject property of a GstObject will result in "deep_notify" * signals being emitted by the object itself, as well as in each parent * object. This is so that an application can connect a listener to the * top-level bin to catch property-change notifications for all contained * elements. * * This function is not MT safe in glib so we need to lock it with a * classwide mutex. * * MT safe. */ static void gst_object_dispatch_properties_changed (GObject * object, guint n_pspecs, GParamSpec ** pspecs) { GstObject *gst_object, *parent, *old_parent; guint i; gchar *name, *debug_name; GstObjectClass *klass; /* we fail when this is not a GstObject */ g_return_if_fail (GST_IS_OBJECT (object)); klass = GST_OBJECT_GET_CLASS (object); GST_CLASS_LOCK (klass); /* do the standard dispatching */ PATCH_REFCOUNT (object); G_OBJECT_CLASS (parent_class)->dispatch_properties_changed (object, n_pspecs, pspecs); PATCH_REFCOUNT (object); gst_object = GST_OBJECT_CAST (object); name = gst_object_get_name (gst_object); debug_name = GST_STR_NULL (name); /* now let the parent dispatch those, too */ parent = gst_object_get_parent (gst_object); while (parent) { /* for debugging ... */ gchar *parent_name = gst_object_get_name (parent); #ifndef GST_DISABLE_GST_DEBUG gchar *debug_parent_name = GST_STR_NULL (parent_name); #endif /* need own category? */ for (i = 0; i < n_pspecs; i++) { GST_CAT_LOG (GST_CAT_EVENT, "deep notification from %s to %s (%s)", debug_name, debug_parent_name, pspecs[i]->name); /* not MT safe because of glib, fixed by taking class lock higher up */ PATCH_REFCOUNT (parent); PATCH_REFCOUNT (object); g_signal_emit (parent, gst_object_signals[DEEP_NOTIFY], g_quark_from_string (pspecs[i]->name), GST_OBJECT_CAST (object), pspecs[i]); PATCH_REFCOUNT (parent); PATCH_REFCOUNT (object); } g_free (parent_name); old_parent = parent; parent = gst_object_get_parent (old_parent); gst_object_unref (old_parent); } g_free (name); GST_CLASS_UNLOCK (klass); } /** * gst_object_default_deep_notify: * @object: the #GObject that signalled the notify. * @orig: a #GstObject that initiated the notify. * @pspec: a #GParamSpec of the property. * @excluded_props: a set of user-specified properties to exclude or * NULL to show all changes. * * A default deep_notify signal callback for an element. The user data * should contain a pointer to an array of strings that should be excluded * from the notify. The default handler will print the new value of the property * using g_print. * * MT safe. This function grabs and releases the object's LOCK or getting the * path string of the object. */ void gst_object_default_deep_notify (GObject * object, GstObject * orig, GParamSpec * pspec, gchar ** excluded_props) { GValue value = { 0, }; /* the important thing is that value.type = 0 */ gchar *str = NULL; gchar *name = NULL; if (pspec->flags & G_PARAM_READABLE) { /* let's not print these out for excluded properties... */ while (excluded_props != NULL && *excluded_props != NULL) { if (strcmp (pspec->name, *excluded_props) == 0) return; excluded_props++; } g_value_init (&value, G_PARAM_SPEC_VALUE_TYPE (pspec)); g_object_get_property (G_OBJECT (orig), pspec->name, &value); if (G_IS_PARAM_SPEC_ENUM (pspec)) { GEnumValue *enum_value; enum_value = g_enum_get_value (G_ENUM_CLASS (g_type_class_ref (pspec->value_type)), g_value_get_enum (&value)); str = g_strdup_printf ("%s (%d)", enum_value->value_nick, enum_value->value); } else { str = g_strdup_value_contents (&value); } name = gst_object_get_path_string (orig); g_print ("%s: %s = %s\n", name, pspec->name, str); g_free (name); g_free (str); g_value_unset (&value); } else { name = gst_object_get_path_string (orig); g_warning ("Parameter %s not readable in %s.", pspec->name, name); g_free (name); } } static gboolean gst_object_set_name_default (GstObject * object, const gchar * type_name) { gint count; gchar *name, *tmp; gboolean result; /* to ensure guaranteed uniqueness across threads, only one thread * may ever assign a name */ G_LOCK (object_name_mutex); if (!object_name_counts) { object_name_counts = g_hash_table_new_full (g_str_hash, g_str_equal, g_free, NULL); } count = GPOINTER_TO_INT (g_hash_table_lookup (object_name_counts, type_name)); g_hash_table_insert (object_name_counts, g_strdup (type_name), GINT_TO_POINTER (count + 1)); G_UNLOCK (object_name_mutex); /* GstFooSink -> foosinkN */ if (strncmp (type_name, "Gst", 3) == 0) type_name += 3; tmp = g_strdup_printf ("%s%d", type_name, count); name = g_ascii_strdown (tmp, strlen (tmp)); g_free (tmp); result = gst_object_set_name (object, name); g_free (name); return result; } /** * gst_object_set_name: * @object: a #GstObject to set the name of * @name: new name of object * * Sets the name of the object, or gives the object a guaranteed unique * name (if @name is NULL). * This function makes a copy of the provided name, so the caller * retains ownership of the name it sent. * * Returns: TRUE if the name could be set. Objects that have * a parent cannot be renamed. * * MT safe. This function grabs and releases the object's LOCK. */ gboolean gst_object_set_name (GstObject * object, const gchar * name) { gboolean result; g_return_val_if_fail (GST_IS_OBJECT (object), FALSE); GST_LOCK (object); /* parented objects cannot be renamed */ if (G_UNLIKELY (object->parent != NULL)) goto had_parent; if (name != NULL) { g_free (object->name); object->name = g_strdup (name); GST_UNLOCK (object); result = TRUE; } else { GST_UNLOCK (object); result = gst_object_set_name_default (object, G_OBJECT_TYPE_NAME (object)); } return result; /* error */ had_parent: { GST_UNLOCK (object); return FALSE; } } /** * gst_object_get_name: * @object: a #GstObject to get the name of * * Returns a copy of the name of the object. * Caller should g_free() the return value after usage. * For a nameless object, this returns NULL, which you can safely g_free() * as well. * * Returns: the name of the object. g_free() after usage. * * MT safe. This function grabs and releases the object's LOCK. */ gchar * gst_object_get_name (GstObject * object) { gchar *result = NULL; g_return_val_if_fail (GST_IS_OBJECT (object), NULL); GST_LOCK (object); result = g_strdup (object->name); GST_UNLOCK (object); return result; } /** * gst_object_set_name_prefix: * @object: a #GstObject to set the name prefix of * @name_prefix: new name prefix of object * * Sets the name prefix of the object. * This function makes a copy of the provided name prefix, so the caller * retains ownership of the name prefix it sent. * * MT safe. This function grabs and releases the object's LOCK. */ void gst_object_set_name_prefix (GstObject * object, const gchar * name_prefix) { g_return_if_fail (GST_IS_OBJECT (object)); GST_LOCK (object); g_free (object->name_prefix); object->name_prefix = g_strdup (name_prefix); /* NULL gives NULL */ GST_UNLOCK (object); } /** * gst_object_get_name_prefix: * @object: a #GstObject to get the name prefix of * * Returns a copy of the name prefix of the object. * Caller should g_free() the return value after usage. * For a prefixless object, this returns NULL, which you can safely g_free() * as well. * * Returns: the name prefix of the object. g_free() after usage. * * MT safe. This function grabs and releases the object's LOCK. */ gchar * gst_object_get_name_prefix (GstObject * object) { gchar *result = NULL; g_return_val_if_fail (GST_IS_OBJECT (object), NULL); GST_LOCK (object); result = g_strdup (object->name_prefix); GST_UNLOCK (object); return result; } /** * gst_object_set_parent: * @object: GstObject to set parent of * @parent: new parent of object * * Sets the parent of @object. The object's reference count will be incremented, * and any floating reference will be removed (see gst_object_sink()). * * Causes the parent-set signal to be emitted. * * Returns: TRUE if the parent could be set or FALSE when the object * already had a parent, the object and parent are the same or wrong * parameters were provided. * * MT safe. Grabs and releases the object's LOCK. */ gboolean gst_object_set_parent (GstObject * object, GstObject * parent) { g_return_val_if_fail (GST_IS_OBJECT (object), FALSE); g_return_val_if_fail (GST_IS_OBJECT (parent), FALSE); g_return_val_if_fail (object != parent, FALSE); GST_CAT_LOG_OBJECT (GST_CAT_REFCOUNTING, object, "set parent (ref and sink)"); GST_LOCK (object); if (G_UNLIKELY (object->parent != NULL)) goto had_parent; /* sink object, we don't call our own function because we don't * need to release/acquire the lock needlessly or touch the refcount * in the floating case. */ object->parent = parent; if (G_LIKELY (GST_OBJECT_IS_FLOATING (object))) { GST_FLAG_UNSET (object, GST_OBJECT_FLOATING); GST_UNLOCK (object); } else { GST_UNLOCK (object); gst_object_ref (object); } g_signal_emit (G_OBJECT (object), gst_object_signals[PARENT_SET], 0, parent); return TRUE; /* ERROR handling */ had_parent: { GST_UNLOCK (object); return FALSE; } } /** * gst_object_get_parent: * @object: GstObject to get parent of * * Returns the parent of @object. This function increases the refcount * of the parent object so you should gst_object_unref() it after usage. * * Returns: parent of the object, this can be NULL if the object has no * parent. unref after usage. * * MT safe. Grabs and releases the object's LOCK. */ GstObject * gst_object_get_parent (GstObject * object) { GstObject *result = NULL; g_return_val_if_fail (GST_IS_OBJECT (object), NULL); GST_LOCK (object); result = object->parent; if (G_LIKELY (result)) gst_object_ref (result); GST_UNLOCK (object); return result; } /** * gst_object_unparent: * @object: GstObject to unparent * * Clear the parent of @object, removing the associated reference. * This function decreases the refcount of the object so the object * might not point to valid memory anymore after calling this function. * * MT safe. Grabs and releases the object's lock. */ void gst_object_unparent (GstObject * object) { GstObject *parent; g_return_if_fail (GST_IS_OBJECT (object)); GST_LOCK (object); parent = object->parent; if (G_LIKELY (parent != NULL)) { GST_CAT_LOG_OBJECT (GST_CAT_REFCOUNTING, object, "unparent"); object->parent = NULL; GST_UNLOCK (object); g_signal_emit (G_OBJECT (object), gst_object_signals[PARENT_UNSET], 0, parent); gst_object_unref (object); } else { GST_UNLOCK (object); } } /** * gst_object_check_uniqueness: * @list: a list of #GstObject to check through * @name: the name to search for * * Checks to see if there is any object named @name in @list. This function * does not do any locking of any kind. You might want to protect the * provided list with the lock of the owner of the list. This function * will lock each GstObject in the list to compare the name, so be * carefull when passing a list with a locked object. * * Returns: TRUE if the name does not appear in the list, FALSE if it does. * * MT safe. Grabs and releases the LOCK of each object in the list. */ gboolean gst_object_check_uniqueness (GList * list, const gchar * name) { gboolean result = TRUE; g_return_val_if_fail (name != NULL, FALSE); for (; list; list = g_list_next (list)) { GstObject *child; gboolean eq; child = GST_OBJECT (list->data); GST_LOCK (child); eq = strcmp (GST_OBJECT_NAME (child), name) == 0; GST_UNLOCK (child); if (G_UNLIKELY (eq)) { result = FALSE; break; } } return result; } #ifndef GST_DISABLE_LOADSAVE_REGISTRY /** * gst_object_save_thyself: * @object: GstObject to save * @parent: The parent XML node to save the object into * * Saves the given object into the parent XML node. * * Returns: the new xmlNodePtr with the saved object */ xmlNodePtr gst_object_save_thyself (GstObject * object, xmlNodePtr parent) { GstObjectClass *oclass; g_return_val_if_fail (GST_IS_OBJECT (object), parent); g_return_val_if_fail (parent != NULL, parent); oclass = GST_OBJECT_GET_CLASS (object); if (oclass->save_thyself) oclass->save_thyself (object, parent); g_signal_emit (G_OBJECT (object), gst_object_signals[OBJECT_SAVED], 0, parent); return parent; } /** * gst_object_restore_thyself: * @object: GstObject to load into * @self: The XML node to load the object from * * Restores the given object with the data from the parent XML node. */ void gst_object_restore_thyself (GstObject * object, xmlNodePtr self) { GstObjectClass *oclass; g_return_if_fail (GST_IS_OBJECT (object)); g_return_if_fail (self != NULL); oclass = GST_OBJECT_GET_CLASS (object); if (oclass->restore_thyself) oclass->restore_thyself (object, self); } static void gst_object_real_restore_thyself (GstObject * object, xmlNodePtr self) { g_return_if_fail (GST_IS_OBJECT (object)); g_return_if_fail (self != NULL); gst_class_signal_emit_by_name (object, "object_loaded", self); } #endif /* GST_DISABLE_LOADSAVE_REGISTRY */ static void gst_object_set_property (GObject * object, guint prop_id, const GValue * value, GParamSpec * pspec) { GstObject *gstobject; gstobject = GST_OBJECT (object); switch (prop_id) { case ARG_NAME: gst_object_set_name (gstobject, g_value_get_string (value)); break; default: G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec); break; } } static void gst_object_get_property (GObject * object, guint prop_id, GValue * value, GParamSpec * pspec) { GstObject *gstobject; gstobject = GST_OBJECT (object); switch (prop_id) { case ARG_NAME: g_value_take_string (value, gst_object_get_name (gstobject)); break; default: G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec); break; } } /** * gst_object_get_path_string: * @object: GstObject to get the path from * * Generates a string describing the path of the object in * the object hierarchy. Only useful (or used) for debugging. * * Returns: a string describing the path of the object. You must * g_free() the string after usage. * * MT safe. Grabs and releases the object's LOCK for all objects * in the hierarchy. */ gchar * gst_object_get_path_string (GstObject * object) { GSList *parentage; GSList *parents; void *parent; gchar *prevpath, *path; gchar *component; gchar *separator; /* ref object before adding to list */ gst_object_ref (object); parentage = g_slist_prepend (NULL, object); path = g_strdup (""); /* first walk the object hierarchy to build a list of the parents, * be carefull here with refcounting. */ do { if (GST_IS_OBJECT (object)) { parent = gst_object_get_parent (object); /* add parents to list, refcount remains increased while * we handle the object */ if (parent) parentage = g_slist_prepend (parentage, parent); } else { break; } object = parent; } while (object != NULL); /* then walk the parent list and print them out. we need to * decrease the refcounting on each element after we handled * it. */ for (parents = parentage; parents; parents = g_slist_next (parents)) { if (GST_IS_OBJECT (parents->data)) { GstObject *item = GST_OBJECT_CAST (parents->data); GstObjectClass *oclass = GST_OBJECT_GET_CLASS (item); component = gst_object_get_name (item); separator = oclass->path_string_separator; /* and unref now */ gst_object_unref (item); } else { component = g_strdup_printf ("%p", parents->data); separator = "/"; } prevpath = path; path = g_strjoin (separator, prevpath, component, NULL); g_free (prevpath); g_free (component); } g_slist_free (parentage); return path; } struct _GstSignalObject { GObject object; }; struct _GstSignalObjectClass { GObjectClass parent_class; /* signals */ #ifndef GST_DISABLE_LOADSAVE_REGISTRY void (*object_loaded) (GstSignalObject * object, GstObject * new, xmlNodePtr self); #endif /* GST_DISABLE_LOADSAVE_REGISTRY */ }; static GType gst_signal_object_get_type (void) { static GType signal_object_type = 0; if (!signal_object_type) { static const GTypeInfo signal_object_info = { sizeof (GstSignalObjectClass), NULL, NULL, (GClassInitFunc) gst_signal_object_class_init, NULL, NULL, sizeof (GstSignalObject), 0, (GInstanceInitFunc) gst_signal_object_init, NULL }; signal_object_type = g_type_register_static (G_TYPE_OBJECT, "GstSignalObject", &signal_object_info, 0); } return signal_object_type; } static void gst_signal_object_class_init (GstSignalObjectClass * klass) { GObjectClass *gobject_class; gobject_class = (GObjectClass *) klass; parent_class = g_type_class_ref (G_TYPE_OBJECT); #ifndef GST_DISABLE_LOADSAVE_REGISTRY gst_signal_object_signals[SO_OBJECT_LOADED] = g_signal_new ("object-loaded", G_TYPE_FROM_CLASS (klass), G_SIGNAL_RUN_LAST, G_STRUCT_OFFSET (GstSignalObjectClass, object_loaded), NULL, NULL, gst_marshal_VOID__OBJECT_POINTER, G_TYPE_NONE, 2, G_TYPE_OBJECT, G_TYPE_POINTER); #endif } static void gst_signal_object_init (GstSignalObject * object) { } /** * gst_class_signal_connect * @klass: the GstObjectClass to attach the signal to * @name: the name of the signal to attach to * @func: the signal function * @func_data: a pointer to user data * * Connect to a class signal. * * Returns: the signal id. */ guint gst_class_signal_connect (GstObjectClass * klass, const gchar * name, gpointer func, gpointer func_data) { return g_signal_connect (klass->signal_object, name, func, func_data); } #ifndef GST_DISABLE_LOADSAVE_REGISTRY /** * gst_class_signal_emit_by_name: * @object: the object that sends the signal * @name: the name of the signal to emit * @self: data for the signal * * emits the named class signal. */ void gst_class_signal_emit_by_name (GstObject * object, const gchar * name, xmlNodePtr self) { GstObjectClass *oclass; oclass = GST_OBJECT_GET_CLASS (object); g_signal_emit_by_name (oclass->signal_object, name, object, self); } #endif /* GST_DISABLE_LOADSAVE_REGISTRY */