1 /* GObject - GLib Type, Object, Parameter and Signal Library
2 * Copyright (C) 1998-1999, 2000-2001 Tim Janik and Red Hat, Inc.
4 * This library is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Lesser General Public
6 * License as published by the Free Software Foundation; either
7 * version 2 of the License, or (at your option) any later version.
9 * This library is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * Lesser General Public License for more details.
14 * You should have received a copy of the GNU Lesser General
15 * Public License along with this library; if not, write to the
16 * Free Software Foundation, Inc., 59 Temple Place, Suite 330,
17 * Boston, MA 02111-1307, USA.
21 * MT safe with regards to reference counting.
30 #include "gtype-private.h"
31 #include "gvaluecollector.h"
33 #include "gparamspecs.h"
34 #include "gvaluetypes.h"
35 #include "gobject_trace.h"
36 #include "gconstructor.h"
41 * @short_description: The base object type
42 * @see_also: #GParamSpecObject, g_param_spec_object()
44 * GObject is the fundamental type providing the common attributes and
45 * methods for all object types in GTK+, Pango and other libraries
46 * based on GObject. The GObject class provides methods for object
47 * construction and destruction, property access methods, and signal
48 * support. Signals are described in detail in <xref
49 * linkend="gobject-Signals"/>.
51 * <para id="floating-ref">
52 * GInitiallyUnowned is derived from GObject. The only difference between
53 * the two is that the initial reference of a GInitiallyUnowned is flagged
54 * as a <firstterm>floating</firstterm> reference.
55 * This means that it is not specifically claimed to be "owned" by
56 * any code portion. The main motivation for providing floating references is
57 * C convenience. In particular, it allows code to be written as:
59 * container = create_container ();
60 * container_add_child (container, create_child());
62 * If <function>container_add_child()</function> will g_object_ref_sink() the
63 * passed in child, no reference of the newly created child is leaked.
64 * Without floating references, <function>container_add_child()</function>
65 * can only g_object_ref() the new child, so to implement this code without
66 * reference leaks, it would have to be written as:
69 * container = create_container ();
70 * child = create_child ();
71 * container_add_child (container, child);
72 * g_object_unref (child);
74 * The floating reference can be converted into
75 * an ordinary reference by calling g_object_ref_sink().
76 * For already sunken objects (objects that don't have a floating reference
77 * anymore), g_object_ref_sink() is equivalent to g_object_ref() and returns
79 * Since floating references are useful almost exclusively for C convenience,
80 * language bindings that provide automated reference and memory ownership
81 * maintenance (such as smart pointers or garbage collection) should not
82 * expose floating references in their API.
85 * Some object implementations may need to save an objects floating state
86 * across certain code portions (an example is #GtkMenu), to achieve this,
87 * the following sequence can be used:
90 * /* save floating state */
91 * gboolean was_floating = g_object_is_floating (object);
92 * g_object_ref_sink (object);
93 * /* protected code portion */
95 * /* restore floating state */
97 * g_object_force_floating (object);
99 * g_object_unref (object); /* release previously acquired reference */
105 #define PARAM_SPEC_PARAM_ID(pspec) ((pspec)->param_id)
106 #define PARAM_SPEC_SET_PARAM_ID(pspec, id) ((pspec)->param_id = (id))
108 #define OBJECT_HAS_TOGGLE_REF_FLAG 0x1
109 #define OBJECT_HAS_TOGGLE_REF(object) \
110 ((g_datalist_get_flags (&(object)->qdata) & OBJECT_HAS_TOGGLE_REF_FLAG) != 0)
111 #define OBJECT_FLOATING_FLAG 0x2
113 #define CLASS_HAS_PROPS_FLAG 0x1
114 #define CLASS_HAS_PROPS(class) \
115 ((class)->flags & CLASS_HAS_PROPS_FLAG)
116 #define CLASS_HAS_CUSTOM_CONSTRUCTOR(class) \
117 ((class)->constructor != g_object_constructor)
118 #define CLASS_HAS_CUSTOM_CONSTRUCTED(class) \
119 ((class)->constructed != g_object_constructed)
121 #define CLASS_HAS_DERIVED_CLASS_FLAG 0x2
122 #define CLASS_HAS_DERIVED_CLASS(class) \
123 ((class)->flags & CLASS_HAS_DERIVED_CLASS_FLAG)
125 /* --- signals --- */
132 /* --- properties --- */
138 /* --- prototypes --- */
139 static void g_object_base_class_init (GObjectClass *class);
140 static void g_object_base_class_finalize (GObjectClass *class);
141 static void g_object_do_class_init (GObjectClass *class);
142 static void g_object_init (GObject *object,
143 GObjectClass *class);
144 static GObject* g_object_constructor (GType type,
145 guint n_construct_properties,
146 GObjectConstructParam *construct_params);
147 static void g_object_constructed (GObject *object);
148 static void g_object_real_dispose (GObject *object);
149 static void g_object_finalize (GObject *object);
150 static void g_object_do_set_property (GObject *object,
154 static void g_object_do_get_property (GObject *object,
158 static void g_value_object_init (GValue *value);
159 static void g_value_object_free_value (GValue *value);
160 static void g_value_object_copy_value (const GValue *src_value,
162 static void g_value_object_transform_value (const GValue *src_value,
164 static gpointer g_value_object_peek_pointer (const GValue *value);
165 static gchar* g_value_object_collect_value (GValue *value,
166 guint n_collect_values,
167 GTypeCValue *collect_values,
168 guint collect_flags);
169 static gchar* g_value_object_lcopy_value (const GValue *value,
170 guint n_collect_values,
171 GTypeCValue *collect_values,
172 guint collect_flags);
173 static void g_object_dispatch_properties_changed (GObject *object,
175 GParamSpec **pspecs);
176 static guint object_floating_flag_handler (GObject *object,
179 static void object_interface_check_properties (gpointer check_data,
182 /* --- typedefs --- */
183 typedef struct _GObjectNotifyQueue GObjectNotifyQueue;
185 struct _GObjectNotifyQueue
189 guint16 freeze_count;
192 /* --- variables --- */
193 G_LOCK_DEFINE_STATIC (closure_array_mutex);
194 G_LOCK_DEFINE_STATIC (weak_refs_mutex);
195 G_LOCK_DEFINE_STATIC (toggle_refs_mutex);
196 static GQuark quark_closure_array = 0;
197 static GQuark quark_weak_refs = 0;
198 static GQuark quark_toggle_refs = 0;
199 static GQuark quark_notify_queue;
200 static GParamSpecPool *pspec_pool = NULL;
201 static gulong gobject_signals[LAST_SIGNAL] = { 0, };
202 static guint (*floating_flag_handler) (GObject*, gint) = object_floating_flag_handler;
203 G_LOCK_DEFINE_STATIC (construction_mutex);
204 static GSList *construction_objects = NULL;
205 /* qdata pointing to GSList<GWeakRef *>, protected by weak_locations_lock */
206 static GQuark quark_weak_locations = 0;
207 static GRWLock weak_locations_lock;
209 G_LOCK_DEFINE_STATIC(notify_lock);
211 /* --- functions --- */
213 g_object_notify_queue_free (gpointer data)
215 GObjectNotifyQueue *nqueue = data;
217 g_slist_free (nqueue->pspecs);
218 g_slice_free (GObjectNotifyQueue, nqueue);
221 static GObjectNotifyQueue*
222 g_object_notify_queue_freeze (GObject *object,
223 gboolean conditional)
225 GObjectNotifyQueue *nqueue;
228 nqueue = g_datalist_id_get_data (&object->qdata, quark_notify_queue);
233 G_UNLOCK(notify_lock);
237 nqueue = g_slice_new0 (GObjectNotifyQueue);
238 g_datalist_id_set_data_full (&object->qdata, quark_notify_queue,
239 nqueue, g_object_notify_queue_free);
242 if (nqueue->freeze_count >= 65535)
243 g_critical("Free queue for %s (%p) is larger than 65535,"
244 " called g_object_freeze_notify() too often."
245 " Forgot to call g_object_thaw_notify() or infinite loop",
246 G_OBJECT_TYPE_NAME (object), object);
248 nqueue->freeze_count++;
249 G_UNLOCK(notify_lock);
255 g_object_notify_queue_thaw (GObject *object,
256 GObjectNotifyQueue *nqueue)
258 GParamSpec *pspecs_mem[16], **pspecs, **free_me = NULL;
262 g_return_if_fail (nqueue->freeze_count > 0);
263 g_return_if_fail (g_atomic_int_get(&object->ref_count) > 0);
267 /* Just make sure we never get into some nasty race condition */
268 if (G_UNLIKELY(nqueue->freeze_count == 0)) {
269 G_UNLOCK(notify_lock);
270 g_warning ("%s: property-changed notification for %s(%p) is not frozen",
271 G_STRFUNC, G_OBJECT_TYPE_NAME (object), object);
275 nqueue->freeze_count--;
276 if (nqueue->freeze_count) {
277 G_UNLOCK(notify_lock);
281 pspecs = nqueue->n_pspecs > 16 ? free_me = g_new (GParamSpec*, nqueue->n_pspecs) : pspecs_mem;
283 for (slist = nqueue->pspecs; slist; slist = slist->next)
285 pspecs[n_pspecs++] = slist->data;
287 g_datalist_id_set_data (&object->qdata, quark_notify_queue, NULL);
289 G_UNLOCK(notify_lock);
292 G_OBJECT_GET_CLASS (object)->dispatch_properties_changed (object, n_pspecs, pspecs);
297 g_object_notify_queue_add (GObject *object,
298 GObjectNotifyQueue *nqueue,
303 g_return_if_fail (nqueue->n_pspecs < 65535);
305 if (g_slist_find (nqueue->pspecs, pspec) == NULL)
307 nqueue->pspecs = g_slist_prepend (nqueue->pspecs, pspec);
311 G_UNLOCK(notify_lock);
314 #ifdef G_ENABLE_DEBUG
315 #define IF_DEBUG(debug_type) if (_g_type_debug_flags & G_TYPE_DEBUG_ ## debug_type)
316 G_LOCK_DEFINE_STATIC (debug_objects);
317 static volatile GObject *g_trap_object_ref = NULL;
318 static guint debug_objects_count = 0;
319 static GHashTable *debug_objects_ht = NULL;
322 debug_objects_foreach (gpointer key,
326 GObject *object = value;
328 g_message ("[%p] stale %s\tref_count=%u",
330 G_OBJECT_TYPE_NAME (object),
334 #ifdef G_HAS_CONSTRUCTORS
335 #ifdef G_DEFINE_DESTRUCTOR_NEEDS_PRAGMA
336 #pragma G_DEFINE_DESTRUCTOR_PRAGMA_ARGS(debug_objects_atexit)
338 G_DEFINE_DESTRUCTOR(debug_objects_atexit)
339 #endif /* G_HAS_CONSTRUCTORS */
342 debug_objects_atexit (void)
346 G_LOCK (debug_objects);
347 g_message ("stale GObjects: %u", debug_objects_count);
348 g_hash_table_foreach (debug_objects_ht, debug_objects_foreach, NULL);
349 G_UNLOCK (debug_objects);
352 #endif /* G_ENABLE_DEBUG */
355 _g_object_type_init (void)
357 static gboolean initialized = FALSE;
358 static const GTypeFundamentalInfo finfo = {
359 G_TYPE_FLAG_CLASSED | G_TYPE_FLAG_INSTANTIATABLE | G_TYPE_FLAG_DERIVABLE | G_TYPE_FLAG_DEEP_DERIVABLE,
362 sizeof (GObjectClass),
363 (GBaseInitFunc) g_object_base_class_init,
364 (GBaseFinalizeFunc) g_object_base_class_finalize,
365 (GClassInitFunc) g_object_do_class_init,
366 NULL /* class_destroy */,
367 NULL /* class_data */,
370 (GInstanceInitFunc) g_object_init,
371 NULL, /* value_table */
373 static const GTypeValueTable value_table = {
374 g_value_object_init, /* value_init */
375 g_value_object_free_value, /* value_free */
376 g_value_object_copy_value, /* value_copy */
377 g_value_object_peek_pointer, /* value_peek_pointer */
378 "p", /* collect_format */
379 g_value_object_collect_value, /* collect_value */
380 "p", /* lcopy_format */
381 g_value_object_lcopy_value, /* lcopy_value */
385 g_return_if_fail (initialized == FALSE);
390 info.value_table = &value_table;
391 type = g_type_register_fundamental (G_TYPE_OBJECT, g_intern_static_string ("GObject"), &info, &finfo, 0);
392 g_assert (type == G_TYPE_OBJECT);
393 g_value_register_transform_func (G_TYPE_OBJECT, G_TYPE_OBJECT, g_value_object_transform_value);
395 #ifdef G_ENABLE_DEBUG
398 debug_objects_ht = g_hash_table_new (g_direct_hash, NULL);
399 #ifndef G_HAS_CONSTRUCTORS
400 g_atexit (debug_objects_atexit);
401 #endif /* G_HAS_CONSTRUCTORS */
403 #endif /* G_ENABLE_DEBUG */
407 g_object_base_class_init (GObjectClass *class)
409 GObjectClass *pclass = g_type_class_peek_parent (class);
411 /* Don't inherit HAS_DERIVED_CLASS flag from parent class */
412 class->flags &= ~CLASS_HAS_DERIVED_CLASS_FLAG;
415 pclass->flags |= CLASS_HAS_DERIVED_CLASS_FLAG;
417 /* reset instance specific fields and methods that don't get inherited */
418 class->construct_properties = pclass ? g_slist_copy (pclass->construct_properties) : NULL;
419 class->get_property = NULL;
420 class->set_property = NULL;
424 g_object_base_class_finalize (GObjectClass *class)
428 _g_signals_destroy (G_OBJECT_CLASS_TYPE (class));
430 g_slist_free (class->construct_properties);
431 class->construct_properties = NULL;
432 list = g_param_spec_pool_list_owned (pspec_pool, G_OBJECT_CLASS_TYPE (class));
433 for (node = list; node; node = node->next)
435 GParamSpec *pspec = node->data;
437 g_param_spec_pool_remove (pspec_pool, pspec);
438 PARAM_SPEC_SET_PARAM_ID (pspec, 0);
439 g_param_spec_unref (pspec);
445 g_object_do_class_init (GObjectClass *class)
447 /* read the comment about typedef struct CArray; on why not to change this quark */
448 quark_closure_array = g_quark_from_static_string ("GObject-closure-array");
450 quark_weak_refs = g_quark_from_static_string ("GObject-weak-references");
451 quark_weak_locations = g_quark_from_static_string ("GObject-weak-locations");
452 quark_toggle_refs = g_quark_from_static_string ("GObject-toggle-references");
453 quark_notify_queue = g_quark_from_static_string ("GObject-notify-queue");
454 pspec_pool = g_param_spec_pool_new (TRUE);
456 class->constructor = g_object_constructor;
457 class->constructed = g_object_constructed;
458 class->set_property = g_object_do_set_property;
459 class->get_property = g_object_do_get_property;
460 class->dispose = g_object_real_dispose;
461 class->finalize = g_object_finalize;
462 class->dispatch_properties_changed = g_object_dispatch_properties_changed;
463 class->notify = NULL;
467 * @gobject: the object which received the signal.
468 * @pspec: the #GParamSpec of the property which changed.
470 * The notify signal is emitted on an object when one of its
471 * properties has been changed. Note that getting this signal
472 * doesn't guarantee that the value of the property has actually
473 * changed, it may also be emitted when the setter for the property
474 * is called to reinstate the previous value.
476 * This signal is typically used to obtain change notification for a
477 * single property, by specifying the property name as a detail in the
478 * g_signal_connect() call, like this:
480 * g_signal_connect (text_view->buffer, "notify::paste-target-list",
481 * G_CALLBACK (gtk_text_view_target_list_notify),
484 * It is important to note that you must use
485 * <link linkend="canonical-parameter-name">canonical</link> parameter names as
486 * detail strings for the notify signal.
488 gobject_signals[NOTIFY] =
489 g_signal_new (g_intern_static_string ("notify"),
490 G_TYPE_FROM_CLASS (class),
491 G_SIGNAL_RUN_FIRST | G_SIGNAL_NO_RECURSE | G_SIGNAL_DETAILED | G_SIGNAL_NO_HOOKS | G_SIGNAL_ACTION,
492 G_STRUCT_OFFSET (GObjectClass, notify),
494 g_cclosure_marshal_VOID__PARAM,
498 /* Install a check function that we'll use to verify that classes that
499 * implement an interface implement all properties for that interface
501 g_type_add_interface_check (NULL, object_interface_check_properties);
505 install_property_internal (GType g_type,
509 if (g_param_spec_pool_lookup (pspec_pool, pspec->name, g_type, FALSE))
511 g_warning ("When installing property: type `%s' already has a property named `%s'",
512 g_type_name (g_type),
517 g_param_spec_ref_sink (pspec);
518 PARAM_SPEC_SET_PARAM_ID (pspec, property_id);
519 g_param_spec_pool_insert (pspec_pool, pspec, g_type);
523 * g_object_class_install_property:
524 * @oclass: a #GObjectClass
525 * @property_id: the id for the new property
526 * @pspec: the #GParamSpec for the new property
528 * Installs a new property. This is usually done in the class initializer.
530 * Note that it is possible to redefine a property in a derived class,
531 * by installing a property with the same name. This can be useful at times,
532 * e.g. to change the range of allowed values or the default value.
535 g_object_class_install_property (GObjectClass *class,
539 g_return_if_fail (G_IS_OBJECT_CLASS (class));
540 g_return_if_fail (G_IS_PARAM_SPEC (pspec));
542 if (CLASS_HAS_DERIVED_CLASS (class))
543 g_error ("Attempt to add property %s::%s to class after it was derived",
544 G_OBJECT_CLASS_NAME (class), pspec->name);
546 class->flags |= CLASS_HAS_PROPS_FLAG;
548 g_return_if_fail (pspec->flags & (G_PARAM_READABLE | G_PARAM_WRITABLE));
549 if (pspec->flags & G_PARAM_WRITABLE)
550 g_return_if_fail (class->set_property != NULL);
551 if (pspec->flags & G_PARAM_READABLE)
552 g_return_if_fail (class->get_property != NULL);
553 g_return_if_fail (property_id > 0);
554 g_return_if_fail (PARAM_SPEC_PARAM_ID (pspec) == 0); /* paranoid */
555 if (pspec->flags & G_PARAM_CONSTRUCT)
556 g_return_if_fail ((pspec->flags & G_PARAM_CONSTRUCT_ONLY) == 0);
557 if (pspec->flags & (G_PARAM_CONSTRUCT | G_PARAM_CONSTRUCT_ONLY))
558 g_return_if_fail (pspec->flags & G_PARAM_WRITABLE);
560 install_property_internal (G_OBJECT_CLASS_TYPE (class), property_id, pspec);
562 if (pspec->flags & (G_PARAM_CONSTRUCT | G_PARAM_CONSTRUCT_ONLY))
563 class->construct_properties = g_slist_append (class->construct_properties, pspec);
565 /* for property overrides of construct properties, we have to get rid
566 * of the overidden inherited construct property
568 pspec = g_param_spec_pool_lookup (pspec_pool, pspec->name, g_type_parent (G_OBJECT_CLASS_TYPE (class)), TRUE);
569 if (pspec && pspec->flags & (G_PARAM_CONSTRUCT | G_PARAM_CONSTRUCT_ONLY))
570 class->construct_properties = g_slist_remove (class->construct_properties, pspec);
574 * g_object_class_install_properties:
575 * @oclass: a #GObjectClass
576 * @n_pspecs: the length of the #GParamSpec<!-- -->s array
577 * @pspecs: (array length=n_pspecs): the #GParamSpec<!-- -->s array
578 * defining the new properties
580 * Installs new properties from an array of #GParamSpec<!-- -->s. This is
581 * usually done in the class initializer.
583 * The property id of each property is the index of each #GParamSpec in
586 * The property id of 0 is treated specially by #GObject and it should not
587 * be used to store a #GParamSpec.
589 * This function should be used if you plan to use a static array of
590 * #GParamSpec<!-- -->s and g_object_notify_by_pspec(). For instance, this
591 * class initialization:
595 * PROP_0, PROP_FOO, PROP_BAR, N_PROPERTIES
598 * static GParamSpec *obj_properties[N_PROPERTIES] = { NULL, };
601 * my_object_class_init (MyObjectClass *klass)
603 * GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
605 * obj_properties[PROP_FOO] =
606 * g_param_spec_int ("foo", "Foo", "Foo",
609 * G_PARAM_READWRITE);
611 * obj_properties[PROP_BAR] =
612 * g_param_spec_string ("bar", "Bar", "Bar",
614 * G_PARAM_READWRITE);
616 * gobject_class->set_property = my_object_set_property;
617 * gobject_class->get_property = my_object_get_property;
618 * g_object_class_install_properties (gobject_class,
624 * allows calling g_object_notify_by_pspec() to notify of property changes:
628 * my_object_set_foo (MyObject *self, gint foo)
630 * if (self->foo != foo)
633 * g_object_notify_by_pspec (G_OBJECT (self), obj_properties[PROP_FOO]);
641 g_object_class_install_properties (GObjectClass *oclass,
645 GType oclass_type, parent_type;
648 g_return_if_fail (G_IS_OBJECT_CLASS (oclass));
649 g_return_if_fail (n_pspecs > 1);
650 g_return_if_fail (pspecs[0] == NULL);
652 if (CLASS_HAS_DERIVED_CLASS (oclass))
653 g_error ("Attempt to add properties to %s after it was derived",
654 G_OBJECT_CLASS_NAME (oclass));
656 oclass_type = G_OBJECT_CLASS_TYPE (oclass);
657 parent_type = g_type_parent (oclass_type);
659 /* we skip the first element of the array as it would have a 0 prop_id */
660 for (i = 1; i < n_pspecs; i++)
662 GParamSpec *pspec = pspecs[i];
664 g_return_if_fail (pspec != NULL);
666 if (pspec->flags & G_PARAM_WRITABLE)
667 g_return_if_fail (oclass->set_property != NULL);
668 if (pspec->flags & G_PARAM_READABLE)
669 g_return_if_fail (oclass->get_property != NULL);
670 g_return_if_fail (PARAM_SPEC_PARAM_ID (pspec) == 0); /* paranoid */
671 if (pspec->flags & G_PARAM_CONSTRUCT)
672 g_return_if_fail ((pspec->flags & G_PARAM_CONSTRUCT_ONLY) == 0);
673 if (pspec->flags & (G_PARAM_CONSTRUCT | G_PARAM_CONSTRUCT_ONLY))
674 g_return_if_fail (pspec->flags & G_PARAM_WRITABLE);
676 oclass->flags |= CLASS_HAS_PROPS_FLAG;
677 install_property_internal (oclass_type, i, pspec);
679 if (pspec->flags & (G_PARAM_CONSTRUCT | G_PARAM_CONSTRUCT_ONLY))
680 oclass->construct_properties = g_slist_append (oclass->construct_properties, pspec);
682 /* for property overrides of construct properties, we have to get rid
683 * of the overidden inherited construct property
685 pspec = g_param_spec_pool_lookup (pspec_pool, pspec->name, parent_type, TRUE);
686 if (pspec && pspec->flags & (G_PARAM_CONSTRUCT | G_PARAM_CONSTRUCT_ONLY))
687 oclass->construct_properties = g_slist_remove (oclass->construct_properties, pspec);
692 * g_object_interface_install_property:
693 * @g_iface: any interface vtable for the interface, or the default
694 * vtable for the interface.
695 * @pspec: the #GParamSpec for the new property
697 * Add a property to an interface; this is only useful for interfaces
698 * that are added to GObject-derived types. Adding a property to an
699 * interface forces all objects classes with that interface to have a
700 * compatible property. The compatible property could be a newly
701 * created #GParamSpec, but normally
702 * g_object_class_override_property() will be used so that the object
703 * class only needs to provide an implementation and inherits the
704 * property description, default value, bounds, and so forth from the
705 * interface property.
707 * This function is meant to be called from the interface's default
708 * vtable initialization function (the @class_init member of
709 * #GTypeInfo.) It must not be called after after @class_init has
710 * been called for any object types implementing this interface.
715 g_object_interface_install_property (gpointer g_iface,
718 GTypeInterface *iface_class = g_iface;
720 g_return_if_fail (G_TYPE_IS_INTERFACE (iface_class->g_type));
721 g_return_if_fail (G_IS_PARAM_SPEC (pspec));
722 g_return_if_fail (!G_IS_PARAM_SPEC_OVERRIDE (pspec)); /* paranoid */
723 g_return_if_fail (PARAM_SPEC_PARAM_ID (pspec) == 0); /* paranoid */
725 g_return_if_fail (pspec->flags & (G_PARAM_READABLE | G_PARAM_WRITABLE));
726 if (pspec->flags & G_PARAM_CONSTRUCT)
727 g_return_if_fail ((pspec->flags & G_PARAM_CONSTRUCT_ONLY) == 0);
728 if (pspec->flags & (G_PARAM_CONSTRUCT | G_PARAM_CONSTRUCT_ONLY))
729 g_return_if_fail (pspec->flags & G_PARAM_WRITABLE);
731 install_property_internal (iface_class->g_type, 0, pspec);
735 * g_object_class_find_property:
736 * @oclass: a #GObjectClass
737 * @property_name: the name of the property to look up
739 * Looks up the #GParamSpec for a property of a class.
741 * Returns: (transfer none): the #GParamSpec for the property, or
742 * %NULL if the class doesn't have a property of that name
745 g_object_class_find_property (GObjectClass *class,
746 const gchar *property_name)
749 GParamSpec *redirect;
751 g_return_val_if_fail (G_IS_OBJECT_CLASS (class), NULL);
752 g_return_val_if_fail (property_name != NULL, NULL);
754 pspec = g_param_spec_pool_lookup (pspec_pool,
756 G_OBJECT_CLASS_TYPE (class),
760 redirect = g_param_spec_get_redirect_target (pspec);
771 * g_object_interface_find_property:
772 * @g_iface: any interface vtable for the interface, or the default
773 * vtable for the interface
774 * @property_name: name of a property to lookup.
776 * Find the #GParamSpec with the given name for an
777 * interface. Generally, the interface vtable passed in as @g_iface
778 * will be the default vtable from g_type_default_interface_ref(), or,
779 * if you know the interface has already been loaded,
780 * g_type_default_interface_peek().
784 * Returns: (transfer none): the #GParamSpec for the property of the
785 * interface with the name @property_name, or %NULL if no
786 * such property exists.
789 g_object_interface_find_property (gpointer g_iface,
790 const gchar *property_name)
792 GTypeInterface *iface_class = g_iface;
794 g_return_val_if_fail (G_TYPE_IS_INTERFACE (iface_class->g_type), NULL);
795 g_return_val_if_fail (property_name != NULL, NULL);
797 return g_param_spec_pool_lookup (pspec_pool,
804 * g_object_class_override_property:
805 * @oclass: a #GObjectClass
806 * @property_id: the new property ID
807 * @name: the name of a property registered in a parent class or
808 * in an interface of this class.
810 * Registers @property_id as referring to a property with the
811 * name @name in a parent class or in an interface implemented
812 * by @oclass. This allows this class to <firstterm>override</firstterm>
813 * a property implementation in a parent class or to provide
814 * the implementation of a property from an interface.
817 * Internally, overriding is implemented by creating a property of type
818 * #GParamSpecOverride; generally operations that query the properties of
819 * the object class, such as g_object_class_find_property() or
820 * g_object_class_list_properties() will return the overridden
821 * property. However, in one case, the @construct_properties argument of
822 * the @constructor virtual function, the #GParamSpecOverride is passed
823 * instead, so that the @param_id field of the #GParamSpec will be
824 * correct. For virtually all uses, this makes no difference. If you
825 * need to get the overridden property, you can call
826 * g_param_spec_get_redirect_target().
832 g_object_class_override_property (GObjectClass *oclass,
836 GParamSpec *overridden = NULL;
840 g_return_if_fail (G_IS_OBJECT_CLASS (oclass));
841 g_return_if_fail (property_id > 0);
842 g_return_if_fail (name != NULL);
844 /* Find the overridden property; first check parent types
846 parent_type = g_type_parent (G_OBJECT_CLASS_TYPE (oclass));
847 if (parent_type != G_TYPE_NONE)
848 overridden = g_param_spec_pool_lookup (pspec_pool,
857 /* Now check interfaces
859 ifaces = g_type_interfaces (G_OBJECT_CLASS_TYPE (oclass), &n_ifaces);
860 while (n_ifaces-- && !overridden)
862 overridden = g_param_spec_pool_lookup (pspec_pool,
873 g_warning ("%s: Can't find property to override for '%s::%s'",
874 G_STRFUNC, G_OBJECT_CLASS_NAME (oclass), name);
878 new = g_param_spec_override (name, overridden);
879 g_object_class_install_property (oclass, property_id, new);
883 * g_object_class_list_properties:
884 * @oclass: a #GObjectClass
885 * @n_properties: (out): return location for the length of the returned array
887 * Get an array of #GParamSpec* for all properties of a class.
889 * Returns: (array length=n_properties) (transfer container): an array of
890 * #GParamSpec* which should be freed after use
892 GParamSpec** /* free result */
893 g_object_class_list_properties (GObjectClass *class,
894 guint *n_properties_p)
899 g_return_val_if_fail (G_IS_OBJECT_CLASS (class), NULL);
901 pspecs = g_param_spec_pool_list (pspec_pool,
902 G_OBJECT_CLASS_TYPE (class),
911 * g_object_interface_list_properties:
912 * @g_iface: any interface vtable for the interface, or the default
913 * vtable for the interface
914 * @n_properties_p: (out): location to store number of properties returned.
916 * Lists the properties of an interface.Generally, the interface
917 * vtable passed in as @g_iface will be the default vtable from
918 * g_type_default_interface_ref(), or, if you know the interface has
919 * already been loaded, g_type_default_interface_peek().
923 * Returns: (array length=n_properties_p) (transfer container): a
924 * pointer to an array of pointers to #GParamSpec
925 * structures. The paramspecs are owned by GLib, but the
926 * array should be freed with g_free() when you are done with
930 g_object_interface_list_properties (gpointer g_iface,
931 guint *n_properties_p)
933 GTypeInterface *iface_class = g_iface;
937 g_return_val_if_fail (G_TYPE_IS_INTERFACE (iface_class->g_type), NULL);
939 pspecs = g_param_spec_pool_list (pspec_pool,
949 g_object_init (GObject *object,
952 object->ref_count = 1;
953 object->qdata = NULL;
955 if (CLASS_HAS_PROPS (class))
957 /* freeze object's notification queue, g_object_newv() preserves pairedness */
958 g_object_notify_queue_freeze (object, FALSE);
961 if (CLASS_HAS_CUSTOM_CONSTRUCTOR (class))
963 /* enter construction list for notify_queue_thaw() and to allow construct-only properties */
964 G_LOCK (construction_mutex);
965 construction_objects = g_slist_prepend (construction_objects, object);
966 G_UNLOCK (construction_mutex);
969 #ifdef G_ENABLE_DEBUG
972 G_LOCK (debug_objects);
973 debug_objects_count++;
974 g_hash_table_insert (debug_objects_ht, object, object);
975 G_UNLOCK (debug_objects);
977 #endif /* G_ENABLE_DEBUG */
981 g_object_do_set_property (GObject *object,
989 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
995 g_object_do_get_property (GObject *object,
1000 switch (property_id)
1003 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
1009 g_object_real_dispose (GObject *object)
1011 g_signal_handlers_destroy (object);
1012 g_datalist_id_set_data (&object->qdata, quark_closure_array, NULL);
1013 g_datalist_id_set_data (&object->qdata, quark_weak_refs, NULL);
1017 g_object_finalize (GObject *object)
1019 g_datalist_clear (&object->qdata);
1021 #ifdef G_ENABLE_DEBUG
1024 G_LOCK (debug_objects);
1025 g_assert (g_hash_table_lookup (debug_objects_ht, object) == object);
1026 g_hash_table_remove (debug_objects_ht, object);
1027 debug_objects_count--;
1028 G_UNLOCK (debug_objects);
1030 #endif /* G_ENABLE_DEBUG */
1035 g_object_dispatch_properties_changed (GObject *object,
1037 GParamSpec **pspecs)
1041 for (i = 0; i < n_pspecs; i++)
1042 g_signal_emit (object, gobject_signals[NOTIFY], g_quark_from_string (pspecs[i]->name), pspecs[i]);
1046 * g_object_run_dispose:
1047 * @object: a #GObject
1049 * Releases all references to other objects. This can be used to break
1052 * This functions should only be called from object system implementations.
1055 g_object_run_dispose (GObject *object)
1057 g_return_if_fail (G_IS_OBJECT (object));
1058 g_return_if_fail (object->ref_count > 0);
1060 g_object_ref (object);
1061 TRACE (GOBJECT_OBJECT_DISPOSE(object,G_TYPE_FROM_INSTANCE(object), 0));
1062 G_OBJECT_GET_CLASS (object)->dispose (object);
1063 TRACE (GOBJECT_OBJECT_DISPOSE_END(object,G_TYPE_FROM_INSTANCE(object), 0));
1064 g_object_unref (object);
1068 * g_object_freeze_notify:
1069 * @object: a #GObject
1071 * Increases the freeze count on @object. If the freeze count is
1072 * non-zero, the emission of "notify" signals on @object is
1073 * stopped. The signals are queued until the freeze count is decreased
1074 * to zero. Duplicate notifications are squashed so that at most one
1075 * #GObject::notify signal is emitted for each property modified while the
1078 * This is necessary for accessors that modify multiple properties to prevent
1079 * premature notification while the object is still being modified.
1082 g_object_freeze_notify (GObject *object)
1084 g_return_if_fail (G_IS_OBJECT (object));
1086 if (g_atomic_int_get (&object->ref_count) == 0)
1089 g_object_ref (object);
1090 g_object_notify_queue_freeze (object, FALSE);
1091 g_object_unref (object);
1095 get_notify_pspec (GParamSpec *pspec)
1097 GParamSpec *redirected;
1099 /* we don't notify on non-READABLE parameters */
1100 if (~pspec->flags & G_PARAM_READABLE)
1103 /* if the paramspec is redirected, notify on the target */
1104 redirected = g_param_spec_get_redirect_target (pspec);
1105 if (redirected != NULL)
1108 /* else, notify normally */
1113 g_object_notify_by_spec_internal (GObject *object,
1116 GParamSpec *notify_pspec;
1118 notify_pspec = get_notify_pspec (pspec);
1120 if (notify_pspec != NULL)
1122 GObjectNotifyQueue *nqueue;
1124 /* conditional freeze: only increase freeze count if already frozen */
1125 nqueue = g_object_notify_queue_freeze (object, TRUE);
1129 /* we're frozen, so add to the queue and release our freeze */
1130 g_object_notify_queue_add (object, nqueue, notify_pspec);
1131 g_object_notify_queue_thaw (object, nqueue);
1134 /* not frozen, so just dispatch the notification directly */
1135 G_OBJECT_GET_CLASS (object)
1136 ->dispatch_properties_changed (object, 1, ¬ify_pspec);
1142 * @object: a #GObject
1143 * @property_name: the name of a property installed on the class of @object.
1145 * Emits a "notify" signal for the property @property_name on @object.
1147 * When possible, eg. when signaling a property change from within the class
1148 * that registered the property, you should use g_object_notify_by_pspec()
1152 g_object_notify (GObject *object,
1153 const gchar *property_name)
1157 g_return_if_fail (G_IS_OBJECT (object));
1158 g_return_if_fail (property_name != NULL);
1159 if (g_atomic_int_get (&object->ref_count) == 0)
1162 g_object_ref (object);
1163 /* We don't need to get the redirect target
1164 * (by, e.g. calling g_object_class_find_property())
1165 * because g_object_notify_queue_add() does that
1167 pspec = g_param_spec_pool_lookup (pspec_pool,
1169 G_OBJECT_TYPE (object),
1173 g_warning ("%s: object class `%s' has no property named `%s'",
1175 G_OBJECT_TYPE_NAME (object),
1178 g_object_notify_by_spec_internal (object, pspec);
1179 g_object_unref (object);
1183 * g_object_notify_by_pspec:
1184 * @object: a #GObject
1185 * @pspec: the #GParamSpec of a property installed on the class of @object.
1187 * Emits a "notify" signal for the property specified by @pspec on @object.
1189 * This function omits the property name lookup, hence it is faster than
1190 * g_object_notify().
1192 * One way to avoid using g_object_notify() from within the
1193 * class that registered the properties, and using g_object_notify_by_pspec()
1194 * instead, is to store the GParamSpec used with
1195 * g_object_class_install_property() inside a static array, e.g.:
1205 * static GParamSpec *properties[PROP_LAST];
1208 * my_object_class_init (MyObjectClass *klass)
1210 * properties[PROP_FOO] = g_param_spec_int ("foo", "Foo", "The foo",
1213 * G_PARAM_READWRITE);
1214 * g_object_class_install_property (gobject_class,
1216 * properties[PROP_FOO]);
1220 * and then notify a change on the "foo" property with:
1223 * g_object_notify_by_pspec (self, properties[PROP_FOO]);
1229 g_object_notify_by_pspec (GObject *object,
1233 g_return_if_fail (G_IS_OBJECT (object));
1234 g_return_if_fail (G_IS_PARAM_SPEC (pspec));
1236 g_object_ref (object);
1237 g_object_notify_by_spec_internal (object, pspec);
1238 g_object_unref (object);
1242 * g_object_thaw_notify:
1243 * @object: a #GObject
1245 * Reverts the effect of a previous call to
1246 * g_object_freeze_notify(). The freeze count is decreased on @object
1247 * and when it reaches zero, queued "notify" signals are emitted.
1249 * Duplicate notifications for each property are squashed so that at most one
1250 * #GObject::notify signal is emitted for each property.
1252 * It is an error to call this function when the freeze count is zero.
1255 g_object_thaw_notify (GObject *object)
1257 GObjectNotifyQueue *nqueue;
1259 g_return_if_fail (G_IS_OBJECT (object));
1260 if (g_atomic_int_get (&object->ref_count) == 0)
1263 g_object_ref (object);
1265 /* FIXME: Freezing is the only way to get at the notify queue.
1266 * So we freeze once and then thaw twice.
1268 nqueue = g_object_notify_queue_freeze (object, FALSE);
1269 g_object_notify_queue_thaw (object, nqueue);
1270 g_object_notify_queue_thaw (object, nqueue);
1272 g_object_unref (object);
1276 object_get_property (GObject *object,
1280 GObjectClass *class = g_type_class_peek (pspec->owner_type);
1281 guint param_id = PARAM_SPEC_PARAM_ID (pspec);
1282 GParamSpec *redirect;
1286 g_warning ("'%s::%s' is not a valid property name; '%s' is not a GObject subtype",
1287 g_type_name (pspec->owner_type), pspec->name, g_type_name (pspec->owner_type));
1291 redirect = g_param_spec_get_redirect_target (pspec);
1295 class->get_property (object, param_id, value, pspec);
1299 object_set_property (GObject *object,
1301 const GValue *value,
1302 GObjectNotifyQueue *nqueue)
1304 GValue tmp_value = G_VALUE_INIT;
1305 GObjectClass *class = g_type_class_peek (pspec->owner_type);
1306 guint param_id = PARAM_SPEC_PARAM_ID (pspec);
1307 GParamSpec *redirect;
1308 static const gchar * enable_diagnostic = NULL;
1312 g_warning ("'%s::%s' is not a valid property name; '%s' is not a GObject subtype",
1313 g_type_name (pspec->owner_type), pspec->name, g_type_name (pspec->owner_type));
1317 redirect = g_param_spec_get_redirect_target (pspec);
1321 if (G_UNLIKELY (!enable_diagnostic))
1323 enable_diagnostic = g_getenv ("G_ENABLE_DIAGNOSTIC");
1324 if (!enable_diagnostic)
1325 enable_diagnostic = "0";
1328 if (enable_diagnostic[0] == '1')
1330 if (pspec->flags & G_PARAM_DEPRECATED)
1331 g_warning ("The property %s:%s is deprecated and shouldn't be used "
1332 "anymore. It will be removed in a future version.",
1333 G_OBJECT_TYPE_NAME (object), pspec->name);
1336 /* provide a copy to work from, convert (if necessary) and validate */
1337 g_value_init (&tmp_value, pspec->value_type);
1338 if (!g_value_transform (value, &tmp_value))
1339 g_warning ("unable to set property `%s' of type `%s' from value of type `%s'",
1341 g_type_name (pspec->value_type),
1342 G_VALUE_TYPE_NAME (value));
1343 else if (g_param_value_validate (pspec, &tmp_value) && !(pspec->flags & G_PARAM_LAX_VALIDATION))
1345 gchar *contents = g_strdup_value_contents (value);
1347 g_warning ("value \"%s\" of type `%s' is invalid or out of range for property `%s' of type `%s'",
1349 G_VALUE_TYPE_NAME (value),
1351 g_type_name (pspec->value_type));
1356 GParamSpec *notify_pspec;
1358 class->set_property (object, param_id, &tmp_value, pspec);
1360 notify_pspec = get_notify_pspec (pspec);
1362 if (notify_pspec != NULL)
1363 g_object_notify_queue_add (object, nqueue, notify_pspec);
1365 g_value_unset (&tmp_value);
1369 object_interface_check_properties (gpointer check_data,
1372 GTypeInterface *iface_class = g_iface;
1373 GObjectClass *class;
1374 GType iface_type = iface_class->g_type;
1375 GParamSpec **pspecs;
1378 class = g_type_class_ref (iface_class->g_instance_type);
1380 if (!G_IS_OBJECT_CLASS (class))
1383 pspecs = g_param_spec_pool_list (pspec_pool, iface_type, &n);
1387 GParamSpec *class_pspec = g_param_spec_pool_lookup (pspec_pool,
1389 G_OBJECT_CLASS_TYPE (class),
1394 g_critical ("Object class %s doesn't implement property "
1395 "'%s' from interface '%s'",
1396 g_type_name (G_OBJECT_CLASS_TYPE (class)),
1398 g_type_name (iface_type));
1403 /* We do a number of checks on the properties of an interface to
1404 * make sure that all classes implementing the interface are
1405 * overriding the properties in a sane way.
1407 * We do the checks in order of importance so that we can give
1408 * more useful error messages first.
1410 * First, we check that the implementation doesn't remove the
1411 * basic functionality (readability, writability) advertised by
1412 * the interface. Next, we check that it doesn't introduce
1413 * additional restrictions (such as construct-only). Finally, we
1414 * make sure the types are compatible.
1417 #define SUBSET(a,b,mask) (((a) & ~(b) & (mask)) == 0)
1418 /* If the property on the interface is readable then the
1419 * implementation must be readable. If the interface is writable
1420 * then the implementation must be writable.
1422 if (!SUBSET (pspecs[n]->flags, class_pspec->flags, G_PARAM_READABLE | G_PARAM_WRITABLE))
1424 g_critical ("Flags for property '%s' on class '%s' remove functionality compared with the "
1425 "property on interface '%s'\n", pspecs[n]->name,
1426 g_type_name (G_OBJECT_CLASS_TYPE (class)), g_type_name (iface_type));
1430 /* If the property on the interface is writable then we need to
1431 * make sure the implementation doesn't introduce new restrictions
1432 * on that writability (ie: construct-only).
1434 * If the interface was not writable to begin with then we don't
1435 * really have any problems here because "writable at construct
1436 * type only" is still more permissive than "read only".
1438 if (pspecs[n]->flags & G_PARAM_WRITABLE)
1440 if (!SUBSET (class_pspec->flags, pspecs[n]->flags, G_PARAM_CONSTRUCT_ONLY))
1442 g_critical ("Flags for property '%s' on class '%s' introduce additional restrictions on "
1443 "writability compared with the property on interface '%s'\n", pspecs[n]->name,
1444 g_type_name (G_OBJECT_CLASS_TYPE (class)), g_type_name (iface_type));
1450 /* If the property on the interface is readable then we are
1451 * effectively advertising that reading the property will return a
1452 * value of a specific type. All implementations of the interface
1453 * need to return items of this type -- but may be more
1454 * restrictive. For example, it is legal to have:
1456 * GtkWidget *get_item();
1458 * that is implemented by a function that always returns a
1459 * GtkEntry. In short: readability implies that the
1460 * implementation value type must be equal or more restrictive.
1462 * Similarly, if the property on the interface is writable then
1463 * must be able to accept the property being set to any value of
1464 * that type, including subclasses. In this case, we may also be
1465 * less restrictive. For example, it is legal to have:
1467 * set_item (GtkEntry *);
1469 * that is implemented by a function that will actually work with
1470 * any GtkWidget. In short: writability implies that the
1471 * implementation value type must be equal or less restrictive.
1473 * In the case that the property is both readable and writable
1474 * then the only way that both of the above can be satisfied is
1475 * with a type that is exactly equal.
1477 switch (pspecs[n]->flags & (G_PARAM_READABLE | G_PARAM_WRITABLE))
1479 case G_PARAM_READABLE | G_PARAM_WRITABLE:
1480 /* class pspec value type must have exact equality with interface */
1481 if (pspecs[n]->value_type != class_pspec->value_type)
1482 g_critical ("Read/writable property '%s' on class '%s' has type '%s' which is not exactly equal to the "
1483 "type '%s' of the property on the interface '%s'\n", pspecs[n]->name,
1484 g_type_name (G_OBJECT_CLASS_TYPE (class)), g_type_name (G_PARAM_SPEC_VALUE_TYPE (class_pspec)),
1485 g_type_name (G_PARAM_SPEC_VALUE_TYPE (pspecs[n])), g_type_name (iface_type));
1488 case G_PARAM_READABLE:
1489 /* class pspec value type equal or more restrictive than interface */
1490 if (!g_type_is_a (class_pspec->value_type, pspecs[n]->value_type))
1491 g_critical ("Read-only property '%s' on class '%s' has type '%s' which is not equal to or more "
1492 "restrictive than the type '%s' of the property on the interface '%s'\n", pspecs[n]->name,
1493 g_type_name (G_OBJECT_CLASS_TYPE (class)), g_type_name (G_PARAM_SPEC_VALUE_TYPE (class_pspec)),
1494 g_type_name (G_PARAM_SPEC_VALUE_TYPE (pspecs[n])), g_type_name (iface_type));
1497 case G_PARAM_WRITABLE:
1498 /* class pspec value type equal or less restrictive than interface */
1499 if (!g_type_is_a (pspecs[n]->value_type, class_pspec->value_type))
1500 g_critical ("Write-only property '%s' on class '%s' has type '%s' which is not equal to or less "
1501 "restrictive than the type '%s' of the property on the interface '%s' \n", pspecs[n]->name,
1502 g_type_name (G_OBJECT_CLASS_TYPE (class)), g_type_name (G_PARAM_SPEC_VALUE_TYPE (class_pspec)),
1503 g_type_name (G_PARAM_SPEC_VALUE_TYPE (pspecs[n])), g_type_name (iface_type));
1507 g_assert_not_reached ();
1513 g_type_class_unref (class);
1517 g_object_get_type (void)
1519 return G_TYPE_OBJECT;
1523 * g_object_new: (skip)
1524 * @object_type: the type id of the #GObject subtype to instantiate
1525 * @first_property_name: the name of the first property
1526 * @...: the value of the first property, followed optionally by more
1527 * name/value pairs, followed by %NULL
1529 * Creates a new instance of a #GObject subtype and sets its properties.
1531 * Construction parameters (see #G_PARAM_CONSTRUCT, #G_PARAM_CONSTRUCT_ONLY)
1532 * which are not explicitly specified are set to their default values.
1534 * Returns: (transfer full): a new instance of @object_type
1537 g_object_new (GType object_type,
1538 const gchar *first_property_name,
1544 g_return_val_if_fail (G_TYPE_IS_OBJECT (object_type), NULL);
1546 /* short circuit for calls supplying no properties */
1547 if (!first_property_name)
1548 return g_object_newv (object_type, 0, NULL);
1550 va_start (var_args, first_property_name);
1551 object = g_object_new_valist (object_type, first_property_name, var_args);
1558 slist_maybe_remove (GSList **slist,
1561 GSList *last = NULL, *node = *slist;
1564 if (node->data == data)
1567 last->next = node->next;
1569 *slist = node->next;
1570 g_slist_free_1 (node);
1579 static inline gboolean
1580 object_in_construction_list (GObject *object)
1582 gboolean in_construction;
1583 G_LOCK (construction_mutex);
1584 in_construction = g_slist_find (construction_objects, object) != NULL;
1585 G_UNLOCK (construction_mutex);
1586 return in_construction;
1590 g_object_new_with_custom_constructor (GObjectClass *class,
1591 GObjectConstructParam *params,
1594 GObjectNotifyQueue *nqueue = NULL;
1595 gboolean newly_constructed;
1596 GObjectConstructParam *cparams;
1604 /* If we have ->constructed() then we have to do a lot more work.
1605 * It's possible that this is a singleton and it's also possible
1606 * that the user's constructor() will attempt to modify the values
1607 * that we pass in, so we'll need to allocate copies of them.
1608 * It's also possible that the user may attempt to call
1609 * g_object_set() from inside of their constructor, so we need to
1610 * add ourselves to a list of objects for which that is allowed
1611 * while their constructor() is running.
1614 /* Create the array of GObjectConstructParams for constructor() */
1615 n_cparams = g_slist_length (class->construct_properties);
1616 cparams = g_new (GObjectConstructParam, n_cparams);
1617 cvalues = g_new0 (GValue, n_cparams);
1621 /* As above, we may find the value in the passed-in params list.
1623 * If we have the value passed in then we can use the GValue from
1624 * it directly because it is safe to modify. If we use the
1625 * default value from the class, we had better not pass that in
1626 * and risk it being modified, so we create a new one.
1628 for (node = class->construct_properties; node; node = node->next)
1635 value = NULL; /* to silence gcc... */
1637 for (j = 0; j < n_params; j++)
1638 if (params[j].pspec == pspec)
1640 value = params[j].value;
1646 value = &cvalues[cvals_used++];
1647 g_value_init (value, pspec->value_type);
1648 g_param_value_set_default (pspec, value);
1651 cparams[i].pspec = pspec;
1652 cparams[i].value = value;
1656 /* construct object from construction parameters */
1657 object = class->constructor (class->g_type_class.g_type, n_cparams, cparams);
1658 /* free construction values */
1660 while (cvals_used--)
1661 g_value_unset (&cvalues[cvals_used]);
1664 /* There is code in the wild that relies on being able to return NULL
1665 * from its custom constructor. This was never a supported operation
1666 * and will leak memory, but since the code is already out there...
1670 g_critical ("Custom constructor for class %s returned NULL (which is invalid). Unable to remove object "
1671 "from construction_objects list, so memory was probably just leaked. Please use GInitable "
1672 "instead.", G_OBJECT_CLASS_NAME (class));
1676 /* g_object_init() will have added us to the construction_objects
1677 * list. Check if we're in it (and remove us) in order to find
1678 * out if we were newly-constructed or this is an already-existing
1679 * singleton (in which case we should not do 'constructed').
1681 G_LOCK (construction_mutex);
1682 newly_constructed = slist_maybe_remove (&construction_objects, object);
1683 G_UNLOCK (construction_mutex);
1685 if (CLASS_HAS_PROPS (class))
1687 /* If this object was newly_constructed then g_object_init()
1688 * froze the queue. We need to freeze it here in order to get
1689 * the handle so that we can thaw it below (otherwise it will
1690 * be frozen forever).
1692 * We also want to do a freeze if we have any params to set,
1693 * even on a non-newly_constructed object.
1695 * It's possible that we have the case of non-newly created
1696 * singleton and all of the passed-in params were construct
1697 * properties so n_params > 0 but we will actually set no
1698 * properties. This is a pretty lame case to optimise, so
1699 * just ignore it and freeze anyway.
1701 if (newly_constructed || n_params)
1702 nqueue = g_object_notify_queue_freeze (object, FALSE);
1704 /* Remember: if it was newly_constructed then g_object_init()
1705 * already did a freeze, so we now have two. Release one.
1707 if (newly_constructed)
1708 g_object_notify_queue_thaw (object, nqueue);
1711 /* run 'constructed' handler if there is a custom one */
1712 if (newly_constructed && CLASS_HAS_CUSTOM_CONSTRUCTED (class))
1713 class->constructed (object);
1715 /* set remaining properties */
1716 for (i = 0; i < n_params; i++)
1717 if (!(params[i].pspec->flags & (G_PARAM_CONSTRUCT | G_PARAM_CONSTRUCT_ONLY)))
1718 object_set_property (object, params[i].pspec, params[i].value, nqueue);
1720 /* If nqueue is non-NULL then we are frozen. Thaw it. */
1722 g_object_notify_queue_thaw (object, nqueue);
1728 g_object_new_internal (GObjectClass *class,
1729 GObjectConstructParam *params,
1732 GObjectNotifyQueue *nqueue = NULL;
1735 if G_UNLIKELY (CLASS_HAS_CUSTOM_CONSTRUCTOR (class))
1736 return g_object_new_with_custom_constructor (class, params, n_params);
1738 object = (GObject *) g_type_create_instance (class->g_type_class.g_type);
1740 if (CLASS_HAS_PROPS (class))
1744 /* This will have been setup in g_object_init() */
1745 nqueue = g_datalist_id_get_data (&object->qdata, quark_notify_queue);
1746 g_assert (nqueue != NULL);
1748 /* We will set exactly n_construct_properties construct
1749 * properties, but they may come from either the class default
1750 * values or the passed-in parameter list.
1752 for (node = class->construct_properties; node; node = node->next)
1754 const GValue *value;
1759 value = NULL; /* to silence gcc... */
1761 for (j = 0; j < n_params; j++)
1762 if (params[j].pspec == pspec)
1764 value = params[j].value;
1769 value = g_param_spec_get_default_value (pspec);
1771 object_set_property (object, pspec, value, nqueue);
1775 /* run 'constructed' handler if there is a custom one */
1776 if (CLASS_HAS_CUSTOM_CONSTRUCTED (class))
1777 class->constructed (object);
1783 /* Set remaining properties. The construct properties will
1784 * already have been taken, so set only the non-construct
1787 for (i = 0; i < n_params; i++)
1788 if (!(params[i].pspec->flags & (G_PARAM_CONSTRUCT | G_PARAM_CONSTRUCT_ONLY)))
1789 object_set_property (object, params[i].pspec, params[i].value, nqueue);
1791 g_object_notify_queue_thaw (object, nqueue);
1799 * @object_type: the type id of the #GObject subtype to instantiate
1800 * @n_parameters: the length of the @parameters array
1801 * @parameters: (array length=n_parameters): an array of #GParameter
1803 * Creates a new instance of a #GObject subtype and sets its properties.
1805 * Construction parameters (see #G_PARAM_CONSTRUCT, #G_PARAM_CONSTRUCT_ONLY)
1806 * which are not explicitly specified are set to their default values.
1808 * Rename to: g_object_new
1809 * Returns: (type GObject.Object) (transfer full): a new instance of
1813 g_object_newv (GType object_type,
1815 GParameter *parameters)
1817 GObjectClass *class, *unref_class = NULL;
1820 g_return_val_if_fail (G_TYPE_IS_OBJECT (object_type), NULL);
1821 g_return_val_if_fail (n_parameters == 0 || parameters != NULL, NULL);
1823 /* Try to avoid thrashing the ref_count if we don't need to (since
1824 * it's a locked operation).
1826 class = g_type_class_peek_static (object_type);
1829 class = unref_class = g_type_class_ref (object_type);
1833 GObjectConstructParam *cparams;
1836 cparams = g_newa (GObjectConstructParam, n_parameters);
1839 for (i = 0; i < n_parameters; i++)
1844 pspec = g_param_spec_pool_lookup (pspec_pool, parameters[i].name, object_type, TRUE);
1846 if G_UNLIKELY (!pspec)
1848 g_critical ("%s: object class `%s' has no property named `%s'",
1849 G_STRFUNC, g_type_name (object_type), parameters[i].name);
1853 if G_UNLIKELY (~pspec->flags & G_PARAM_WRITABLE)
1855 g_critical ("%s: property `%s' of object class `%s' is not writable",
1856 G_STRFUNC, pspec->name, g_type_name (object_type));
1860 if (pspec->flags & (G_PARAM_CONSTRUCT | G_PARAM_CONSTRUCT_ONLY))
1862 for (k = 0; k < j; k++)
1863 if (cparams[k].pspec == pspec)
1865 if G_UNLIKELY (k != j)
1867 g_critical ("%s: construct property `%s' for type `%s' cannot be set twice",
1868 G_STRFUNC, parameters[i].name, g_type_name (object_type));
1873 cparams[j].pspec = pspec;
1874 cparams[j].value = ¶meters[i].value;
1878 object = g_object_new_internal (class, cparams, j);
1881 /* Fast case: no properties passed in. */
1882 object = g_object_new_internal (class, NULL, 0);
1885 g_type_class_unref (unref_class);
1891 * g_object_new_valist: (skip)
1892 * @object_type: the type id of the #GObject subtype to instantiate
1893 * @first_property_name: the name of the first property
1894 * @var_args: the value of the first property, followed optionally by more
1895 * name/value pairs, followed by %NULL
1897 * Creates a new instance of a #GObject subtype and sets its properties.
1899 * Construction parameters (see #G_PARAM_CONSTRUCT, #G_PARAM_CONSTRUCT_ONLY)
1900 * which are not explicitly specified are set to their default values.
1902 * Returns: a new instance of @object_type
1905 g_object_new_valist (GType object_type,
1906 const gchar *first_property_name,
1909 GObjectClass *class, *unref_class = NULL;
1912 g_return_val_if_fail (G_TYPE_IS_OBJECT (object_type), NULL);
1914 /* Try to avoid thrashing the ref_count if we don't need to (since
1915 * it's a locked operation).
1917 class = g_type_class_peek_static (object_type);
1920 class = unref_class = g_type_class_ref (object_type);
1922 if (first_property_name)
1924 GObjectConstructParam stack_params[16];
1925 GObjectConstructParam *params;
1929 name = first_property_name;
1930 params = stack_params;
1934 gchar *error = NULL;
1938 pspec = g_param_spec_pool_lookup (pspec_pool, name, object_type, TRUE);
1940 if G_UNLIKELY (!pspec)
1942 g_critical ("%s: object class `%s' has no property named `%s'",
1943 G_STRFUNC, g_type_name (object_type), name);
1944 /* Can't continue because arg list will be out of sync. */
1948 if G_UNLIKELY (~pspec->flags & G_PARAM_WRITABLE)
1950 g_critical ("%s: property `%s' of object class `%s' is not writable",
1951 G_STRFUNC, pspec->name, g_type_name (object_type));
1955 if (pspec->flags & (G_PARAM_CONSTRUCT | G_PARAM_CONSTRUCT_ONLY))
1957 for (i = 0; i < n_params; i++)
1958 if (params[i].pspec == pspec)
1960 if G_UNLIKELY (i != n_params)
1962 g_critical ("%s: property `%s' for type `%s' cannot be set twice",
1963 G_STRFUNC, name, g_type_name (object_type));
1970 params = g_new (GObjectConstructParam, n_params + 1);
1971 memcpy (params, stack_params, sizeof stack_params);
1973 else if (n_params > 16)
1974 params = g_renew (GObjectConstructParam, params, n_params + 1);
1976 params[n_params].pspec = pspec;
1977 params[n_params].value = g_newa (GValue, 1);
1978 memset (params[n_params].value, 0, sizeof (GValue));
1980 G_VALUE_COLLECT_INIT (params[n_params].value, pspec->value_type, var_args, 0, &error);
1984 g_critical ("%s: %s", G_STRFUNC, error);
1985 g_value_unset (params[n_params].value);
1992 while ((name = va_arg (var_args, const gchar *)));
1994 object = g_object_new_internal (class, params, n_params);
1997 g_value_unset (params[n_params].value);
1999 if (params != stack_params)
2003 /* Fast case: no properties passed in. */
2004 object = g_object_new_internal (class, NULL, 0);
2007 g_type_class_unref (unref_class);
2013 g_object_constructor (GType type,
2014 guint n_construct_properties,
2015 GObjectConstructParam *construct_params)
2020 object = (GObject*) g_type_create_instance (type);
2022 /* set construction parameters */
2023 if (n_construct_properties)
2025 GObjectNotifyQueue *nqueue = g_object_notify_queue_freeze (object, FALSE);
2027 /* set construct properties */
2028 while (n_construct_properties--)
2030 GValue *value = construct_params->value;
2031 GParamSpec *pspec = construct_params->pspec;
2034 object_set_property (object, pspec, value, nqueue);
2036 g_object_notify_queue_thaw (object, nqueue);
2037 /* the notification queue is still frozen from g_object_init(), so
2038 * we don't need to handle it here, g_object_newv() takes
2047 g_object_constructed (GObject *object)
2049 /* empty default impl to allow unconditional upchaining */
2053 * g_object_set_valist: (skip)
2054 * @object: a #GObject
2055 * @first_property_name: name of the first property to set
2056 * @var_args: value for the first property, followed optionally by more
2057 * name/value pairs, followed by %NULL
2059 * Sets properties on an object.
2062 g_object_set_valist (GObject *object,
2063 const gchar *first_property_name,
2066 GObjectNotifyQueue *nqueue;
2069 g_return_if_fail (G_IS_OBJECT (object));
2071 g_object_ref (object);
2072 nqueue = g_object_notify_queue_freeze (object, FALSE);
2074 name = first_property_name;
2077 GValue value = G_VALUE_INIT;
2079 gchar *error = NULL;
2081 pspec = g_param_spec_pool_lookup (pspec_pool,
2083 G_OBJECT_TYPE (object),
2087 g_warning ("%s: object class `%s' has no property named `%s'",
2089 G_OBJECT_TYPE_NAME (object),
2093 if (!(pspec->flags & G_PARAM_WRITABLE))
2095 g_warning ("%s: property `%s' of object class `%s' is not writable",
2098 G_OBJECT_TYPE_NAME (object));
2101 if ((pspec->flags & G_PARAM_CONSTRUCT_ONLY) && !object_in_construction_list (object))
2103 g_warning ("%s: construct property \"%s\" for object `%s' can't be set after construction",
2104 G_STRFUNC, pspec->name, G_OBJECT_TYPE_NAME (object));
2108 G_VALUE_COLLECT_INIT (&value, pspec->value_type, var_args,
2112 g_warning ("%s: %s", G_STRFUNC, error);
2114 g_value_unset (&value);
2118 object_set_property (object, pspec, &value, nqueue);
2119 g_value_unset (&value);
2121 name = va_arg (var_args, gchar*);
2124 g_object_notify_queue_thaw (object, nqueue);
2125 g_object_unref (object);
2129 * g_object_get_valist: (skip)
2130 * @object: a #GObject
2131 * @first_property_name: name of the first property to get
2132 * @var_args: return location for the first property, followed optionally by more
2133 * name/return location pairs, followed by %NULL
2135 * Gets properties of an object.
2137 * In general, a copy is made of the property contents and the caller
2138 * is responsible for freeing the memory in the appropriate manner for
2139 * the type, for instance by calling g_free() or g_object_unref().
2141 * See g_object_get().
2144 g_object_get_valist (GObject *object,
2145 const gchar *first_property_name,
2150 g_return_if_fail (G_IS_OBJECT (object));
2152 g_object_ref (object);
2154 name = first_property_name;
2158 GValue value = G_VALUE_INIT;
2162 pspec = g_param_spec_pool_lookup (pspec_pool,
2164 G_OBJECT_TYPE (object),
2168 g_warning ("%s: object class `%s' has no property named `%s'",
2170 G_OBJECT_TYPE_NAME (object),
2174 if (!(pspec->flags & G_PARAM_READABLE))
2176 g_warning ("%s: property `%s' of object class `%s' is not readable",
2179 G_OBJECT_TYPE_NAME (object));
2183 g_value_init (&value, pspec->value_type);
2185 object_get_property (object, pspec, &value);
2187 G_VALUE_LCOPY (&value, var_args, 0, &error);
2190 g_warning ("%s: %s", G_STRFUNC, error);
2192 g_value_unset (&value);
2196 g_value_unset (&value);
2198 name = va_arg (var_args, gchar*);
2201 g_object_unref (object);
2205 * g_object_set: (skip)
2206 * @object: a #GObject
2207 * @first_property_name: name of the first property to set
2208 * @...: value for the first property, followed optionally by more
2209 * name/value pairs, followed by %NULL
2211 * Sets properties on an object.
2214 g_object_set (gpointer _object,
2215 const gchar *first_property_name,
2218 GObject *object = _object;
2221 g_return_if_fail (G_IS_OBJECT (object));
2223 va_start (var_args, first_property_name);
2224 g_object_set_valist (object, first_property_name, var_args);
2229 * g_object_get: (skip)
2230 * @object: a #GObject
2231 * @first_property_name: name of the first property to get
2232 * @...: return location for the first property, followed optionally by more
2233 * name/return location pairs, followed by %NULL
2235 * Gets properties of an object.
2237 * In general, a copy is made of the property contents and the caller
2238 * is responsible for freeing the memory in the appropriate manner for
2239 * the type, for instance by calling g_free() or g_object_unref().
2242 * <title>Using g_object_get(<!-- -->)</title>
2243 * An example of using g_object_get() to get the contents
2244 * of three properties - one of type #G_TYPE_INT,
2245 * one of type #G_TYPE_STRING, and one of type #G_TYPE_OBJECT:
2251 * g_object_get (my_object,
2252 * "int-property", &intval,
2253 * "str-property", &strval,
2254 * "obj-property", &objval,
2257 * // Do something with intval, strval, objval
2260 * g_object_unref (objval);
2265 g_object_get (gpointer _object,
2266 const gchar *first_property_name,
2269 GObject *object = _object;
2272 g_return_if_fail (G_IS_OBJECT (object));
2274 va_start (var_args, first_property_name);
2275 g_object_get_valist (object, first_property_name, var_args);
2280 * g_object_set_property:
2281 * @object: a #GObject
2282 * @property_name: the name of the property to set
2285 * Sets a property on an object.
2288 g_object_set_property (GObject *object,
2289 const gchar *property_name,
2290 const GValue *value)
2292 GObjectNotifyQueue *nqueue;
2295 g_return_if_fail (G_IS_OBJECT (object));
2296 g_return_if_fail (property_name != NULL);
2297 g_return_if_fail (G_IS_VALUE (value));
2299 g_object_ref (object);
2300 nqueue = g_object_notify_queue_freeze (object, FALSE);
2302 pspec = g_param_spec_pool_lookup (pspec_pool,
2304 G_OBJECT_TYPE (object),
2307 g_warning ("%s: object class `%s' has no property named `%s'",
2309 G_OBJECT_TYPE_NAME (object),
2311 else if (!(pspec->flags & G_PARAM_WRITABLE))
2312 g_warning ("%s: property `%s' of object class `%s' is not writable",
2315 G_OBJECT_TYPE_NAME (object));
2316 else if ((pspec->flags & G_PARAM_CONSTRUCT_ONLY) && !object_in_construction_list (object))
2317 g_warning ("%s: construct property \"%s\" for object `%s' can't be set after construction",
2318 G_STRFUNC, pspec->name, G_OBJECT_TYPE_NAME (object));
2320 object_set_property (object, pspec, value, nqueue);
2322 g_object_notify_queue_thaw (object, nqueue);
2323 g_object_unref (object);
2327 * g_object_get_property:
2328 * @object: a #GObject
2329 * @property_name: the name of the property to get
2330 * @value: return location for the property value
2332 * Gets a property of an object. @value must have been initialized to the
2333 * expected type of the property (or a type to which the expected type can be
2334 * transformed) using g_value_init().
2336 * In general, a copy is made of the property contents and the caller is
2337 * responsible for freeing the memory by calling g_value_unset().
2339 * Note that g_object_get_property() is really intended for language
2340 * bindings, g_object_get() is much more convenient for C programming.
2343 g_object_get_property (GObject *object,
2344 const gchar *property_name,
2349 g_return_if_fail (G_IS_OBJECT (object));
2350 g_return_if_fail (property_name != NULL);
2351 g_return_if_fail (G_IS_VALUE (value));
2353 g_object_ref (object);
2355 pspec = g_param_spec_pool_lookup (pspec_pool,
2357 G_OBJECT_TYPE (object),
2360 g_warning ("%s: object class `%s' has no property named `%s'",
2362 G_OBJECT_TYPE_NAME (object),
2364 else if (!(pspec->flags & G_PARAM_READABLE))
2365 g_warning ("%s: property `%s' of object class `%s' is not readable",
2368 G_OBJECT_TYPE_NAME (object));
2371 GValue *prop_value, tmp_value = G_VALUE_INIT;
2373 /* auto-conversion of the callers value type
2375 if (G_VALUE_TYPE (value) == pspec->value_type)
2377 g_value_reset (value);
2380 else if (!g_value_type_transformable (pspec->value_type, G_VALUE_TYPE (value)))
2382 g_warning ("%s: can't retrieve property `%s' of type `%s' as value of type `%s'",
2383 G_STRFUNC, pspec->name,
2384 g_type_name (pspec->value_type),
2385 G_VALUE_TYPE_NAME (value));
2386 g_object_unref (object);
2391 g_value_init (&tmp_value, pspec->value_type);
2392 prop_value = &tmp_value;
2394 object_get_property (object, pspec, prop_value);
2395 if (prop_value != value)
2397 g_value_transform (prop_value, value);
2398 g_value_unset (&tmp_value);
2402 g_object_unref (object);
2406 * g_object_connect: (skip)
2407 * @object: a #GObject
2408 * @signal_spec: the spec for the first signal
2409 * @...: #GCallback for the first signal, followed by data for the
2410 * first signal, followed optionally by more signal
2411 * spec/callback/data triples, followed by %NULL
2413 * A convenience function to connect multiple signals at once.
2415 * The signal specs expected by this function have the form
2416 * "modifier::signal_name", where modifier can be one of the following:
2419 * <term>signal</term>
2421 * equivalent to <literal>g_signal_connect_data (..., NULL, 0)</literal>
2422 * </para></listitem>
2425 * <term>object_signal</term>
2426 * <term>object-signal</term>
2428 * equivalent to <literal>g_signal_connect_object (..., 0)</literal>
2429 * </para></listitem>
2432 * <term>swapped_signal</term>
2433 * <term>swapped-signal</term>
2435 * equivalent to <literal>g_signal_connect_data (..., NULL, G_CONNECT_SWAPPED)</literal>
2436 * </para></listitem>
2439 * <term>swapped_object_signal</term>
2440 * <term>swapped-object-signal</term>
2442 * equivalent to <literal>g_signal_connect_object (..., G_CONNECT_SWAPPED)</literal>
2443 * </para></listitem>
2446 * <term>signal_after</term>
2447 * <term>signal-after</term>
2449 * equivalent to <literal>g_signal_connect_data (..., NULL, G_CONNECT_AFTER)</literal>
2450 * </para></listitem>
2453 * <term>object_signal_after</term>
2454 * <term>object-signal-after</term>
2456 * equivalent to <literal>g_signal_connect_object (..., G_CONNECT_AFTER)</literal>
2457 * </para></listitem>
2460 * <term>swapped_signal_after</term>
2461 * <term>swapped-signal-after</term>
2463 * equivalent to <literal>g_signal_connect_data (..., NULL, G_CONNECT_SWAPPED | G_CONNECT_AFTER)</literal>
2464 * </para></listitem>
2467 * <term>swapped_object_signal_after</term>
2468 * <term>swapped-object-signal-after</term>
2470 * equivalent to <literal>g_signal_connect_object (..., G_CONNECT_SWAPPED | G_CONNECT_AFTER)</literal>
2471 * </para></listitem>
2476 * menu->toplevel = g_object_connect (g_object_new (GTK_TYPE_WINDOW,
2477 * "type", GTK_WINDOW_POPUP,
2480 * "signal::event", gtk_menu_window_event, menu,
2481 * "signal::size_request", gtk_menu_window_size_request, menu,
2482 * "signal::destroy", gtk_widget_destroyed, &menu->toplevel,
2486 * Returns: (transfer none): @object
2489 g_object_connect (gpointer _object,
2490 const gchar *signal_spec,
2493 GObject *object = _object;
2496 g_return_val_if_fail (G_IS_OBJECT (object), NULL);
2497 g_return_val_if_fail (object->ref_count > 0, object);
2499 va_start (var_args, signal_spec);
2502 GCallback callback = va_arg (var_args, GCallback);
2503 gpointer data = va_arg (var_args, gpointer);
2505 if (strncmp (signal_spec, "signal::", 8) == 0)
2506 g_signal_connect_data (object, signal_spec + 8,
2507 callback, data, NULL,
2509 else if (strncmp (signal_spec, "object_signal::", 15) == 0 ||
2510 strncmp (signal_spec, "object-signal::", 15) == 0)
2511 g_signal_connect_object (object, signal_spec + 15,
2514 else if (strncmp (signal_spec, "swapped_signal::", 16) == 0 ||
2515 strncmp (signal_spec, "swapped-signal::", 16) == 0)
2516 g_signal_connect_data (object, signal_spec + 16,
2517 callback, data, NULL,
2519 else if (strncmp (signal_spec, "swapped_object_signal::", 23) == 0 ||
2520 strncmp (signal_spec, "swapped-object-signal::", 23) == 0)
2521 g_signal_connect_object (object, signal_spec + 23,
2524 else if (strncmp (signal_spec, "signal_after::", 14) == 0 ||
2525 strncmp (signal_spec, "signal-after::", 14) == 0)
2526 g_signal_connect_data (object, signal_spec + 14,
2527 callback, data, NULL,
2529 else if (strncmp (signal_spec, "object_signal_after::", 21) == 0 ||
2530 strncmp (signal_spec, "object-signal-after::", 21) == 0)
2531 g_signal_connect_object (object, signal_spec + 21,
2534 else if (strncmp (signal_spec, "swapped_signal_after::", 22) == 0 ||
2535 strncmp (signal_spec, "swapped-signal-after::", 22) == 0)
2536 g_signal_connect_data (object, signal_spec + 22,
2537 callback, data, NULL,
2538 G_CONNECT_SWAPPED | G_CONNECT_AFTER);
2539 else if (strncmp (signal_spec, "swapped_object_signal_after::", 29) == 0 ||
2540 strncmp (signal_spec, "swapped-object-signal-after::", 29) == 0)
2541 g_signal_connect_object (object, signal_spec + 29,
2543 G_CONNECT_SWAPPED | G_CONNECT_AFTER);
2546 g_warning ("%s: invalid signal spec \"%s\"", G_STRFUNC, signal_spec);
2549 signal_spec = va_arg (var_args, gchar*);
2557 * g_object_disconnect: (skip)
2558 * @object: a #GObject
2559 * @signal_spec: the spec for the first signal
2560 * @...: #GCallback for the first signal, followed by data for the first signal,
2561 * followed optionally by more signal spec/callback/data triples,
2564 * A convenience function to disconnect multiple signals at once.
2566 * The signal specs expected by this function have the form
2567 * "any_signal", which means to disconnect any signal with matching
2568 * callback and data, or "any_signal::signal_name", which only
2569 * disconnects the signal named "signal_name".
2572 g_object_disconnect (gpointer _object,
2573 const gchar *signal_spec,
2576 GObject *object = _object;
2579 g_return_if_fail (G_IS_OBJECT (object));
2580 g_return_if_fail (object->ref_count > 0);
2582 va_start (var_args, signal_spec);
2585 GCallback callback = va_arg (var_args, GCallback);
2586 gpointer data = va_arg (var_args, gpointer);
2587 guint sid = 0, detail = 0, mask = 0;
2589 if (strncmp (signal_spec, "any_signal::", 12) == 0 ||
2590 strncmp (signal_spec, "any-signal::", 12) == 0)
2593 mask = G_SIGNAL_MATCH_ID | G_SIGNAL_MATCH_FUNC | G_SIGNAL_MATCH_DATA;
2595 else if (strcmp (signal_spec, "any_signal") == 0 ||
2596 strcmp (signal_spec, "any-signal") == 0)
2599 mask = G_SIGNAL_MATCH_FUNC | G_SIGNAL_MATCH_DATA;
2603 g_warning ("%s: invalid signal spec \"%s\"", G_STRFUNC, signal_spec);
2607 if ((mask & G_SIGNAL_MATCH_ID) &&
2608 !g_signal_parse_name (signal_spec, G_OBJECT_TYPE (object), &sid, &detail, FALSE))
2609 g_warning ("%s: invalid signal name \"%s\"", G_STRFUNC, signal_spec);
2610 else if (!g_signal_handlers_disconnect_matched (object, mask | (detail ? G_SIGNAL_MATCH_DETAIL : 0),
2612 NULL, (gpointer)callback, data))
2613 g_warning ("%s: signal handler %p(%p) is not connected", G_STRFUNC, callback, data);
2614 signal_spec = va_arg (var_args, gchar*);
2625 } weak_refs[1]; /* flexible array */
2629 weak_refs_notify (gpointer data)
2631 WeakRefStack *wstack = data;
2634 for (i = 0; i < wstack->n_weak_refs; i++)
2635 wstack->weak_refs[i].notify (wstack->weak_refs[i].data, wstack->object);
2640 * g_object_weak_ref: (skip)
2641 * @object: #GObject to reference weakly
2642 * @notify: callback to invoke before the object is freed
2643 * @data: extra data to pass to notify
2645 * Adds a weak reference callback to an object. Weak references are
2646 * used for notification when an object is finalized. They are called
2647 * "weak references" because they allow you to safely hold a pointer
2648 * to an object without calling g_object_ref() (g_object_ref() adds a
2649 * strong reference, that is, forces the object to stay alive).
2651 * Note that the weak references created by this method are not
2652 * thread-safe: they cannot safely be used in one thread if the
2653 * object's last g_object_unref() might happen in another thread.
2654 * Use #GWeakRef if thread-safety is required.
2657 g_object_weak_ref (GObject *object,
2661 WeakRefStack *wstack;
2664 g_return_if_fail (G_IS_OBJECT (object));
2665 g_return_if_fail (notify != NULL);
2666 g_return_if_fail (object->ref_count >= 1);
2668 G_LOCK (weak_refs_mutex);
2669 wstack = g_datalist_id_remove_no_notify (&object->qdata, quark_weak_refs);
2672 i = wstack->n_weak_refs++;
2673 wstack = g_realloc (wstack, sizeof (*wstack) + sizeof (wstack->weak_refs[0]) * i);
2677 wstack = g_renew (WeakRefStack, NULL, 1);
2678 wstack->object = object;
2679 wstack->n_weak_refs = 1;
2682 wstack->weak_refs[i].notify = notify;
2683 wstack->weak_refs[i].data = data;
2684 g_datalist_id_set_data_full (&object->qdata, quark_weak_refs, wstack, weak_refs_notify);
2685 G_UNLOCK (weak_refs_mutex);
2689 * g_object_weak_unref: (skip)
2690 * @object: #GObject to remove a weak reference from
2691 * @notify: callback to search for
2692 * @data: data to search for
2694 * Removes a weak reference callback to an object.
2697 g_object_weak_unref (GObject *object,
2701 WeakRefStack *wstack;
2702 gboolean found_one = FALSE;
2704 g_return_if_fail (G_IS_OBJECT (object));
2705 g_return_if_fail (notify != NULL);
2707 G_LOCK (weak_refs_mutex);
2708 wstack = g_datalist_id_get_data (&object->qdata, quark_weak_refs);
2713 for (i = 0; i < wstack->n_weak_refs; i++)
2714 if (wstack->weak_refs[i].notify == notify &&
2715 wstack->weak_refs[i].data == data)
2718 wstack->n_weak_refs -= 1;
2719 if (i != wstack->n_weak_refs)
2720 wstack->weak_refs[i] = wstack->weak_refs[wstack->n_weak_refs];
2725 G_UNLOCK (weak_refs_mutex);
2727 g_warning ("%s: couldn't find weak ref %p(%p)", G_STRFUNC, notify, data);
2731 * g_object_add_weak_pointer: (skip)
2732 * @object: The object that should be weak referenced.
2733 * @weak_pointer_location: (inout): The memory address of a pointer.
2735 * Adds a weak reference from weak_pointer to @object to indicate that
2736 * the pointer located at @weak_pointer_location is only valid during
2737 * the lifetime of @object. When the @object is finalized,
2738 * @weak_pointer will be set to %NULL.
2740 * Note that as with g_object_weak_ref(), the weak references created by
2741 * this method are not thread-safe: they cannot safely be used in one
2742 * thread if the object's last g_object_unref() might happen in another
2743 * thread. Use #GWeakRef if thread-safety is required.
2746 g_object_add_weak_pointer (GObject *object,
2747 gpointer *weak_pointer_location)
2749 g_return_if_fail (G_IS_OBJECT (object));
2750 g_return_if_fail (weak_pointer_location != NULL);
2752 g_object_weak_ref (object,
2753 (GWeakNotify) g_nullify_pointer,
2754 weak_pointer_location);
2758 * g_object_remove_weak_pointer: (skip)
2759 * @object: The object that is weak referenced.
2760 * @weak_pointer_location: (inout): The memory address of a pointer.
2762 * Removes a weak reference from @object that was previously added
2763 * using g_object_add_weak_pointer(). The @weak_pointer_location has
2764 * to match the one used with g_object_add_weak_pointer().
2767 g_object_remove_weak_pointer (GObject *object,
2768 gpointer *weak_pointer_location)
2770 g_return_if_fail (G_IS_OBJECT (object));
2771 g_return_if_fail (weak_pointer_location != NULL);
2773 g_object_weak_unref (object,
2774 (GWeakNotify) g_nullify_pointer,
2775 weak_pointer_location);
2779 object_floating_flag_handler (GObject *object,
2785 case +1: /* force floating if possible */
2787 oldvalue = g_atomic_pointer_get (&object->qdata);
2788 while (!g_atomic_pointer_compare_and_exchange ((void**) &object->qdata, oldvalue,
2789 (gpointer) ((gsize) oldvalue | OBJECT_FLOATING_FLAG)));
2790 return (gsize) oldvalue & OBJECT_FLOATING_FLAG;
2791 case -1: /* sink if possible */
2793 oldvalue = g_atomic_pointer_get (&object->qdata);
2794 while (!g_atomic_pointer_compare_and_exchange ((void**) &object->qdata, oldvalue,
2795 (gpointer) ((gsize) oldvalue & ~(gsize) OBJECT_FLOATING_FLAG)));
2796 return (gsize) oldvalue & OBJECT_FLOATING_FLAG;
2797 default: /* check floating */
2798 return 0 != ((gsize) g_atomic_pointer_get (&object->qdata) & OBJECT_FLOATING_FLAG);
2803 * g_object_is_floating:
2804 * @object: (type GObject.Object): a #GObject
2806 * Checks whether @object has a <link linkend="floating-ref">floating</link>
2811 * Returns: %TRUE if @object has a floating reference
2814 g_object_is_floating (gpointer _object)
2816 GObject *object = _object;
2817 g_return_val_if_fail (G_IS_OBJECT (object), FALSE);
2818 return floating_flag_handler (object, 0);
2822 * g_object_ref_sink:
2823 * @object: (type GObject.Object): a #GObject
2825 * Increase the reference count of @object, and possibly remove the
2826 * <link linkend="floating-ref">floating</link> reference, if @object
2827 * has a floating reference.
2829 * In other words, if the object is floating, then this call "assumes
2830 * ownership" of the floating reference, converting it to a normal
2831 * reference by clearing the floating flag while leaving the reference
2832 * count unchanged. If the object is not floating, then this call
2833 * adds a new normal reference increasing the reference count by one.
2837 * Returns: (type GObject.Object) (transfer none): @object
2840 g_object_ref_sink (gpointer _object)
2842 GObject *object = _object;
2843 gboolean was_floating;
2844 g_return_val_if_fail (G_IS_OBJECT (object), object);
2845 g_return_val_if_fail (object->ref_count >= 1, object);
2846 g_object_ref (object);
2847 was_floating = floating_flag_handler (object, -1);
2849 g_object_unref (object);
2854 * g_object_force_floating:
2855 * @object: a #GObject
2857 * This function is intended for #GObject implementations to re-enforce a
2858 * <link linkend="floating-ref">floating</link> object reference.
2859 * Doing this is seldom required: all
2860 * #GInitiallyUnowned<!-- -->s are created with a floating reference which
2861 * usually just needs to be sunken by calling g_object_ref_sink().
2866 g_object_force_floating (GObject *object)
2868 g_return_if_fail (G_IS_OBJECT (object));
2869 g_return_if_fail (object->ref_count >= 1);
2871 floating_flag_handler (object, +1);
2876 guint n_toggle_refs;
2878 GToggleNotify notify;
2880 } toggle_refs[1]; /* flexible array */
2884 toggle_refs_notify (GObject *object,
2885 gboolean is_last_ref)
2887 ToggleRefStack tstack, *tstackptr;
2889 G_LOCK (toggle_refs_mutex);
2890 tstackptr = g_datalist_id_get_data (&object->qdata, quark_toggle_refs);
2891 tstack = *tstackptr;
2892 G_UNLOCK (toggle_refs_mutex);
2894 /* Reentrancy here is not as tricky as it seems, because a toggle reference
2895 * will only be notified when there is exactly one of them.
2897 g_assert (tstack.n_toggle_refs == 1);
2898 tstack.toggle_refs[0].notify (tstack.toggle_refs[0].data, tstack.object, is_last_ref);
2902 * g_object_add_toggle_ref: (skip)
2903 * @object: a #GObject
2904 * @notify: a function to call when this reference is the
2905 * last reference to the object, or is no longer
2906 * the last reference.
2907 * @data: data to pass to @notify
2909 * Increases the reference count of the object by one and sets a
2910 * callback to be called when all other references to the object are
2911 * dropped, or when this is already the last reference to the object
2912 * and another reference is established.
2914 * This functionality is intended for binding @object to a proxy
2915 * object managed by another memory manager. This is done with two
2916 * paired references: the strong reference added by
2917 * g_object_add_toggle_ref() and a reverse reference to the proxy
2918 * object which is either a strong reference or weak reference.
2920 * The setup is that when there are no other references to @object,
2921 * only a weak reference is held in the reverse direction from @object
2922 * to the proxy object, but when there are other references held to
2923 * @object, a strong reference is held. The @notify callback is called
2924 * when the reference from @object to the proxy object should be
2925 * <firstterm>toggled</firstterm> from strong to weak (@is_last_ref
2926 * true) or weak to strong (@is_last_ref false).
2928 * Since a (normal) reference must be held to the object before
2929 * calling g_object_add_toggle_ref(), the initial state of the reverse
2930 * link is always strong.
2932 * Multiple toggle references may be added to the same gobject,
2933 * however if there are multiple toggle references to an object, none
2934 * of them will ever be notified until all but one are removed. For
2935 * this reason, you should only ever use a toggle reference if there
2936 * is important state in the proxy object.
2941 g_object_add_toggle_ref (GObject *object,
2942 GToggleNotify notify,
2945 ToggleRefStack *tstack;
2948 g_return_if_fail (G_IS_OBJECT (object));
2949 g_return_if_fail (notify != NULL);
2950 g_return_if_fail (object->ref_count >= 1);
2952 g_object_ref (object);
2954 G_LOCK (toggle_refs_mutex);
2955 tstack = g_datalist_id_remove_no_notify (&object->qdata, quark_toggle_refs);
2958 i = tstack->n_toggle_refs++;
2959 /* allocate i = tstate->n_toggle_refs - 1 positions beyond the 1 declared
2960 * in tstate->toggle_refs */
2961 tstack = g_realloc (tstack, sizeof (*tstack) + sizeof (tstack->toggle_refs[0]) * i);
2965 tstack = g_renew (ToggleRefStack, NULL, 1);
2966 tstack->object = object;
2967 tstack->n_toggle_refs = 1;
2971 /* Set a flag for fast lookup after adding the first toggle reference */
2972 if (tstack->n_toggle_refs == 1)
2973 g_datalist_set_flags (&object->qdata, OBJECT_HAS_TOGGLE_REF_FLAG);
2975 tstack->toggle_refs[i].notify = notify;
2976 tstack->toggle_refs[i].data = data;
2977 g_datalist_id_set_data_full (&object->qdata, quark_toggle_refs, tstack,
2978 (GDestroyNotify)g_free);
2979 G_UNLOCK (toggle_refs_mutex);
2983 * g_object_remove_toggle_ref: (skip)
2984 * @object: a #GObject
2985 * @notify: a function to call when this reference is the
2986 * last reference to the object, or is no longer
2987 * the last reference.
2988 * @data: data to pass to @notify
2990 * Removes a reference added with g_object_add_toggle_ref(). The
2991 * reference count of the object is decreased by one.
2996 g_object_remove_toggle_ref (GObject *object,
2997 GToggleNotify notify,
3000 ToggleRefStack *tstack;
3001 gboolean found_one = FALSE;
3003 g_return_if_fail (G_IS_OBJECT (object));
3004 g_return_if_fail (notify != NULL);
3006 G_LOCK (toggle_refs_mutex);
3007 tstack = g_datalist_id_get_data (&object->qdata, quark_toggle_refs);
3012 for (i = 0; i < tstack->n_toggle_refs; i++)
3013 if (tstack->toggle_refs[i].notify == notify &&
3014 tstack->toggle_refs[i].data == data)
3017 tstack->n_toggle_refs -= 1;
3018 if (i != tstack->n_toggle_refs)
3019 tstack->toggle_refs[i] = tstack->toggle_refs[tstack->n_toggle_refs];
3021 if (tstack->n_toggle_refs == 0)
3022 g_datalist_unset_flags (&object->qdata, OBJECT_HAS_TOGGLE_REF_FLAG);
3027 G_UNLOCK (toggle_refs_mutex);
3030 g_object_unref (object);
3032 g_warning ("%s: couldn't find toggle ref %p(%p)", G_STRFUNC, notify, data);
3037 * @object: (type GObject.Object): a #GObject
3039 * Increases the reference count of @object.
3041 * Returns: (type GObject.Object) (transfer none): the same @object
3044 g_object_ref (gpointer _object)
3046 GObject *object = _object;
3049 g_return_val_if_fail (G_IS_OBJECT (object), NULL);
3050 g_return_val_if_fail (object->ref_count > 0, NULL);
3052 #ifdef G_ENABLE_DEBUG
3053 if (g_trap_object_ref == object)
3055 #endif /* G_ENABLE_DEBUG */
3058 old_val = g_atomic_int_add (&object->ref_count, 1);
3060 if (old_val == 1 && OBJECT_HAS_TOGGLE_REF (object))
3061 toggle_refs_notify (object, FALSE);
3063 TRACE (GOBJECT_OBJECT_REF(object,G_TYPE_FROM_INSTANCE(object),old_val));
3070 * @object: (type GObject.Object): a #GObject
3072 * Decreases the reference count of @object. When its reference count
3073 * drops to 0, the object is finalized (i.e. its memory is freed).
3076 g_object_unref (gpointer _object)
3078 GObject *object = _object;
3081 g_return_if_fail (G_IS_OBJECT (object));
3082 g_return_if_fail (object->ref_count > 0);
3084 #ifdef G_ENABLE_DEBUG
3085 if (g_trap_object_ref == object)
3087 #endif /* G_ENABLE_DEBUG */
3089 /* here we want to atomically do: if (ref_count>1) { ref_count--; return; } */
3090 retry_atomic_decrement1:
3091 old_ref = g_atomic_int_get (&object->ref_count);
3094 /* valid if last 2 refs are owned by this call to unref and the toggle_ref */
3095 gboolean has_toggle_ref = OBJECT_HAS_TOGGLE_REF (object);
3097 if (!g_atomic_int_compare_and_exchange ((int *)&object->ref_count, old_ref, old_ref - 1))
3098 goto retry_atomic_decrement1;
3100 TRACE (GOBJECT_OBJECT_UNREF(object,G_TYPE_FROM_INSTANCE(object),old_ref));
3102 /* if we went from 2->1 we need to notify toggle refs if any */
3103 if (old_ref == 2 && has_toggle_ref) /* The last ref being held in this case is owned by the toggle_ref */
3104 toggle_refs_notify (object, TRUE);
3108 GSList **weak_locations;
3110 /* The only way that this object can live at this point is if
3111 * there are outstanding weak references already established
3112 * before we got here.
3114 * If there were not already weak references then no more can be
3115 * established at this time, because the other thread would have
3116 * to hold a strong ref in order to call
3117 * g_object_add_weak_pointer() and then we wouldn't be here.
3119 weak_locations = g_datalist_id_get_data (&object->qdata, quark_weak_locations);
3121 if (weak_locations != NULL)
3123 g_rw_lock_writer_lock (&weak_locations_lock);
3125 /* It is possible that one of the weak references beat us to
3126 * the lock. Make sure the refcount is still what we expected
3129 old_ref = g_atomic_int_get (&object->ref_count);
3132 g_rw_lock_writer_unlock (&weak_locations_lock);
3133 goto retry_atomic_decrement1;
3136 /* We got the lock first, so the object will definitely die
3137 * now. Clear out all the weak references.
3139 while (*weak_locations)
3141 GWeakRef *weak_ref_location = (*weak_locations)->data;
3143 weak_ref_location->priv.p = NULL;
3144 *weak_locations = g_slist_delete_link (*weak_locations, *weak_locations);
3147 g_rw_lock_writer_unlock (&weak_locations_lock);
3150 /* we are about to remove the last reference */
3151 TRACE (GOBJECT_OBJECT_DISPOSE(object,G_TYPE_FROM_INSTANCE(object), 1));
3152 G_OBJECT_GET_CLASS (object)->dispose (object);
3153 TRACE (GOBJECT_OBJECT_DISPOSE_END(object,G_TYPE_FROM_INSTANCE(object), 1));
3155 /* may have been re-referenced meanwhile */
3156 retry_atomic_decrement2:
3157 old_ref = g_atomic_int_get ((int *)&object->ref_count);
3160 /* valid if last 2 refs are owned by this call to unref and the toggle_ref */
3161 gboolean has_toggle_ref = OBJECT_HAS_TOGGLE_REF (object);
3163 if (!g_atomic_int_compare_and_exchange ((int *)&object->ref_count, old_ref, old_ref - 1))
3164 goto retry_atomic_decrement2;
3166 TRACE (GOBJECT_OBJECT_UNREF(object,G_TYPE_FROM_INSTANCE(object),old_ref));
3168 /* if we went from 2->1 we need to notify toggle refs if any */
3169 if (old_ref == 2 && has_toggle_ref) /* The last ref being held in this case is owned by the toggle_ref */
3170 toggle_refs_notify (object, TRUE);
3175 /* we are still in the process of taking away the last ref */
3176 g_datalist_id_set_data (&object->qdata, quark_closure_array, NULL);
3177 g_signal_handlers_destroy (object);
3178 g_datalist_id_set_data (&object->qdata, quark_weak_refs, NULL);
3180 /* decrement the last reference */
3181 old_ref = g_atomic_int_add (&object->ref_count, -1);
3183 TRACE (GOBJECT_OBJECT_UNREF(object,G_TYPE_FROM_INSTANCE(object),old_ref));
3185 /* may have been re-referenced meanwhile */
3186 if (G_LIKELY (old_ref == 1))
3188 TRACE (GOBJECT_OBJECT_FINALIZE(object,G_TYPE_FROM_INSTANCE(object)));
3189 G_OBJECT_GET_CLASS (object)->finalize (object);
3191 TRACE (GOBJECT_OBJECT_FINALIZE_END(object,G_TYPE_FROM_INSTANCE(object)));
3193 #ifdef G_ENABLE_DEBUG
3196 /* catch objects not chaining finalize handlers */
3197 G_LOCK (debug_objects);
3198 g_assert (g_hash_table_lookup (debug_objects_ht, object) == NULL);
3199 G_UNLOCK (debug_objects);
3201 #endif /* G_ENABLE_DEBUG */
3202 g_type_free_instance ((GTypeInstance*) object);
3208 * g_clear_object: (skip)
3209 * @object_ptr: a pointer to a #GObject reference
3211 * Clears a reference to a #GObject.
3213 * @object_ptr must not be %NULL.
3215 * If the reference is %NULL then this function does nothing.
3216 * Otherwise, the reference count of the object is decreased and the
3217 * pointer is set to %NULL.
3219 * This function is threadsafe and modifies the pointer atomically,
3220 * using memory barriers where needed.
3222 * A macro is also included that allows this function to be used without
3227 #undef g_clear_object
3229 g_clear_object (volatile GObject **object_ptr)
3231 g_clear_pointer (object_ptr, g_object_unref);
3235 * g_object_get_qdata:
3236 * @object: The GObject to get a stored user data pointer from
3237 * @quark: A #GQuark, naming the user data pointer
3239 * This function gets back user data pointers stored via
3240 * g_object_set_qdata().
3242 * Returns: (transfer none): The user data pointer set, or %NULL
3245 g_object_get_qdata (GObject *object,
3248 g_return_val_if_fail (G_IS_OBJECT (object), NULL);
3250 return quark ? g_datalist_id_get_data (&object->qdata, quark) : NULL;
3254 * g_object_set_qdata: (skip)
3255 * @object: The GObject to set store a user data pointer
3256 * @quark: A #GQuark, naming the user data pointer
3257 * @data: An opaque user data pointer
3259 * This sets an opaque, named pointer on an object.
3260 * The name is specified through a #GQuark (retrived e.g. via
3261 * g_quark_from_static_string()), and the pointer
3262 * can be gotten back from the @object with g_object_get_qdata()
3263 * until the @object is finalized.
3264 * Setting a previously set user data pointer, overrides (frees)
3265 * the old pointer set, using #NULL as pointer essentially
3266 * removes the data stored.
3269 g_object_set_qdata (GObject *object,
3273 g_return_if_fail (G_IS_OBJECT (object));
3274 g_return_if_fail (quark > 0);
3276 g_datalist_id_set_data (&object->qdata, quark, data);
3280 * g_object_dup_qdata:
3281 * @object: the #GObject to store user data on
3282 * @quark: a #GQuark, naming the user data pointer
3283 * @dup_func: (allow-none): function to dup the value
3284 * @user_data: (allow-none): passed as user_data to @dup_func
3286 * This is a variant of g_object_get_qdata() which returns
3287 * a 'duplicate' of the value. @dup_func defines the
3288 * meaning of 'duplicate' in this context, it could e.g.
3289 * take a reference on a ref-counted object.
3291 * If the @quark is not set on the object then @dup_func
3292 * will be called with a %NULL argument.
3294 * Note that @dup_func is called while user data of @object
3297 * This function can be useful to avoid races when multiple
3298 * threads are using object data on the same key on the same
3301 * Returns: the result of calling @dup_func on the value
3302 * associated with @quark on @object, or %NULL if not set.
3303 * If @dup_func is %NULL, the value is returned
3309 g_object_dup_qdata (GObject *object,
3311 GDuplicateFunc dup_func,
3314 g_return_val_if_fail (G_IS_OBJECT (object), NULL);
3315 g_return_val_if_fail (quark > 0, NULL);
3317 return g_datalist_id_dup_data (&object->qdata, quark, dup_func, user_data);
3321 * g_object_replace_qdata:
3322 * @object: the #GObject to store user data on
3323 * @quark: a #GQuark, naming the user data pointer
3324 * @oldval: (allow-none): the old value to compare against
3325 * @newval: (allow-none): the new value
3326 * @destroy: (allow-none): a destroy notify for the new value
3327 * @old_destroy: (allow-none): destroy notify for the existing value
3329 * Compares the user data for the key @quark on @object with
3330 * @oldval, and if they are the same, replaces @oldval with
3333 * This is like a typical atomic compare-and-exchange
3334 * operation, for user data on an object.
3336 * If the previous value was replaced then ownership of the
3337 * old value (@oldval) is passed to the caller, including
3338 * the registred destroy notify for it (passed out in @old_destroy).
3339 * Its up to the caller to free this as he wishes, which may
3340 * or may not include using @old_destroy as sometimes replacement
3341 * should not destroy the object in the normal way.
3343 * Return: %TRUE if the existing value for @quark was replaced
3344 * by @newval, %FALSE otherwise.
3349 g_object_replace_qdata (GObject *object,
3353 GDestroyNotify destroy,
3354 GDestroyNotify *old_destroy)
3356 g_return_val_if_fail (G_IS_OBJECT (object), FALSE);
3357 g_return_val_if_fail (quark > 0, FALSE);
3359 return g_datalist_id_replace_data (&object->qdata, quark,
3360 oldval, newval, destroy,
3365 * g_object_set_qdata_full: (skip)
3366 * @object: The GObject to set store a user data pointer
3367 * @quark: A #GQuark, naming the user data pointer
3368 * @data: An opaque user data pointer
3369 * @destroy: Function to invoke with @data as argument, when @data
3372 * This function works like g_object_set_qdata(), but in addition,
3373 * a void (*destroy) (gpointer) function may be specified which is
3374 * called with @data as argument when the @object is finalized, or
3375 * the data is being overwritten by a call to g_object_set_qdata()
3376 * with the same @quark.
3379 g_object_set_qdata_full (GObject *object,
3382 GDestroyNotify destroy)
3384 g_return_if_fail (G_IS_OBJECT (object));
3385 g_return_if_fail (quark > 0);
3387 g_datalist_id_set_data_full (&object->qdata, quark, data,
3388 data ? destroy : (GDestroyNotify) NULL);
3392 * g_object_steal_qdata:
3393 * @object: The GObject to get a stored user data pointer from
3394 * @quark: A #GQuark, naming the user data pointer
3396 * This function gets back user data pointers stored via
3397 * g_object_set_qdata() and removes the @data from object
3398 * without invoking its destroy() function (if any was
3400 * Usually, calling this function is only required to update
3401 * user data pointers with a destroy notifier, for example:
3404 * object_add_to_user_list (GObject *object,
3405 * const gchar *new_string)
3407 * // the quark, naming the object data
3408 * GQuark quark_string_list = g_quark_from_static_string ("my-string-list");
3409 * // retrive the old string list
3410 * GList *list = g_object_steal_qdata (object, quark_string_list);
3412 * // prepend new string
3413 * list = g_list_prepend (list, g_strdup (new_string));
3414 * // this changed 'list', so we need to set it again
3415 * g_object_set_qdata_full (object, quark_string_list, list, free_string_list);
3418 * free_string_list (gpointer data)
3420 * GList *node, *list = data;
3422 * for (node = list; node; node = node->next)
3423 * g_free (node->data);
3424 * g_list_free (list);
3427 * Using g_object_get_qdata() in the above example, instead of
3428 * g_object_steal_qdata() would have left the destroy function set,
3429 * and thus the partial string list would have been freed upon
3430 * g_object_set_qdata_full().
3432 * Returns: (transfer full): The user data pointer set, or %NULL
3435 g_object_steal_qdata (GObject *object,
3438 g_return_val_if_fail (G_IS_OBJECT (object), NULL);
3439 g_return_val_if_fail (quark > 0, NULL);
3441 return g_datalist_id_remove_no_notify (&object->qdata, quark);
3445 * g_object_get_data:
3446 * @object: #GObject containing the associations
3447 * @key: name of the key for that association
3449 * Gets a named field from the objects table of associations (see g_object_set_data()).
3451 * Returns: (transfer none): the data if found, or %NULL if no such data exists.
3454 g_object_get_data (GObject *object,
3457 g_return_val_if_fail (G_IS_OBJECT (object), NULL);
3458 g_return_val_if_fail (key != NULL, NULL);
3460 return g_datalist_get_data (&object->qdata, key);
3464 * g_object_set_data:
3465 * @object: #GObject containing the associations.
3466 * @key: name of the key
3467 * @data: data to associate with that key
3469 * Each object carries around a table of associations from
3470 * strings to pointers. This function lets you set an association.
3472 * If the object already had an association with that name,
3473 * the old association will be destroyed.
3476 g_object_set_data (GObject *object,
3480 g_return_if_fail (G_IS_OBJECT (object));
3481 g_return_if_fail (key != NULL);
3483 g_datalist_id_set_data (&object->qdata, g_quark_from_string (key), data);
3487 * g_object_dup_data:
3488 * @object: the #GObject to store user data on
3489 * @key: a string, naming the user data pointer
3490 * @dup_func: (allow-none): function to dup the value
3491 * @user_data: (allow-none): passed as user_data to @dup_func
3493 * This is a variant of g_object_get_data() which returns
3494 * a 'duplicate' of the value. @dup_func defines the
3495 * meaning of 'duplicate' in this context, it could e.g.
3496 * take a reference on a ref-counted object.
3498 * If the @key is not set on the object then @dup_func
3499 * will be called with a %NULL argument.
3501 * Note that @dup_func is called while user data of @object
3504 * This function can be useful to avoid races when multiple
3505 * threads are using object data on the same key on the same
3508 * Returns: the result of calling @dup_func on the value
3509 * associated with @key on @object, or %NULL if not set.
3510 * If @dup_func is %NULL, the value is returned
3516 g_object_dup_data (GObject *object,
3518 GDuplicateFunc dup_func,
3521 g_return_val_if_fail (G_IS_OBJECT (object), NULL);
3522 g_return_val_if_fail (key != NULL, NULL);
3524 return g_datalist_id_dup_data (&object->qdata,
3525 g_quark_from_string (key),
3526 dup_func, user_data);
3530 * g_object_replace_data:
3531 * @object: the #GObject to store user data on
3532 * @key: a string, naming the user data pointer
3533 * @oldval: (allow-none): the old value to compare against
3534 * @newval: (allow-none): the new value
3535 * @destroy: (allow-none): a destroy notify for the new value
3536 * @old_destroy: (allow-none): destroy notify for the existing value
3538 * Compares the user data for the key @key on @object with
3539 * @oldval, and if they are the same, replaces @oldval with
3542 * This is like a typical atomic compare-and-exchange
3543 * operation, for user data on an object.
3545 * If the previous value was replaced then ownership of the
3546 * old value (@oldval) is passed to the caller, including
3547 * the registred destroy notify for it (passed out in @old_destroy).
3548 * Its up to the caller to free this as he wishes, which may
3549 * or may not include using @old_destroy as sometimes replacement
3550 * should not destroy the object in the normal way.
3552 * Return: %TRUE if the existing value for @key was replaced
3553 * by @newval, %FALSE otherwise.
3558 g_object_replace_data (GObject *object,
3562 GDestroyNotify destroy,
3563 GDestroyNotify *old_destroy)
3565 g_return_val_if_fail (G_IS_OBJECT (object), FALSE);
3566 g_return_val_if_fail (key != NULL, FALSE);
3568 return g_datalist_id_replace_data (&object->qdata,
3569 g_quark_from_string (key),
3570 oldval, newval, destroy,
3575 * g_object_set_data_full: (skip)
3576 * @object: #GObject containing the associations
3577 * @key: name of the key
3578 * @data: data to associate with that key
3579 * @destroy: function to call when the association is destroyed
3581 * Like g_object_set_data() except it adds notification
3582 * for when the association is destroyed, either by setting it
3583 * to a different value or when the object is destroyed.
3585 * Note that the @destroy callback is not called if @data is %NULL.
3588 g_object_set_data_full (GObject *object,
3591 GDestroyNotify destroy)
3593 g_return_if_fail (G_IS_OBJECT (object));
3594 g_return_if_fail (key != NULL);
3596 g_datalist_id_set_data_full (&object->qdata, g_quark_from_string (key), data,
3597 data ? destroy : (GDestroyNotify) NULL);
3601 * g_object_steal_data:
3602 * @object: #GObject containing the associations
3603 * @key: name of the key
3605 * Remove a specified datum from the object's data associations,
3606 * without invoking the association's destroy handler.
3608 * Returns: (transfer full): the data if found, or %NULL if no such data exists.
3611 g_object_steal_data (GObject *object,
3616 g_return_val_if_fail (G_IS_OBJECT (object), NULL);
3617 g_return_val_if_fail (key != NULL, NULL);
3619 quark = g_quark_try_string (key);
3621 return quark ? g_datalist_id_remove_no_notify (&object->qdata, quark) : NULL;
3625 g_value_object_init (GValue *value)
3627 value->data[0].v_pointer = NULL;
3631 g_value_object_free_value (GValue *value)
3633 if (value->data[0].v_pointer)
3634 g_object_unref (value->data[0].v_pointer);
3638 g_value_object_copy_value (const GValue *src_value,
3641 if (src_value->data[0].v_pointer)
3642 dest_value->data[0].v_pointer = g_object_ref (src_value->data[0].v_pointer);
3644 dest_value->data[0].v_pointer = NULL;
3648 g_value_object_transform_value (const GValue *src_value,
3651 if (src_value->data[0].v_pointer && g_type_is_a (G_OBJECT_TYPE (src_value->data[0].v_pointer), G_VALUE_TYPE (dest_value)))
3652 dest_value->data[0].v_pointer = g_object_ref (src_value->data[0].v_pointer);
3654 dest_value->data[0].v_pointer = NULL;
3658 g_value_object_peek_pointer (const GValue *value)
3660 return value->data[0].v_pointer;
3664 g_value_object_collect_value (GValue *value,
3665 guint n_collect_values,
3666 GTypeCValue *collect_values,
3667 guint collect_flags)
3669 if (collect_values[0].v_pointer)
3671 GObject *object = collect_values[0].v_pointer;
3673 if (object->g_type_instance.g_class == NULL)
3674 return g_strconcat ("invalid unclassed object pointer for value type `",
3675 G_VALUE_TYPE_NAME (value),
3678 else if (!g_value_type_compatible (G_OBJECT_TYPE (object), G_VALUE_TYPE (value)))
3679 return g_strconcat ("invalid object type `",
3680 G_OBJECT_TYPE_NAME (object),
3681 "' for value type `",
3682 G_VALUE_TYPE_NAME (value),
3685 /* never honour G_VALUE_NOCOPY_CONTENTS for ref-counted types */
3686 value->data[0].v_pointer = g_object_ref (object);
3689 value->data[0].v_pointer = NULL;
3695 g_value_object_lcopy_value (const GValue *value,
3696 guint n_collect_values,
3697 GTypeCValue *collect_values,
3698 guint collect_flags)
3700 GObject **object_p = collect_values[0].v_pointer;
3703 return g_strdup_printf ("value location for `%s' passed as NULL", G_VALUE_TYPE_NAME (value));
3705 if (!value->data[0].v_pointer)
3707 else if (collect_flags & G_VALUE_NOCOPY_CONTENTS)
3708 *object_p = value->data[0].v_pointer;
3710 *object_p = g_object_ref (value->data[0].v_pointer);
3716 * g_value_set_object:
3717 * @value: a valid #GValue of %G_TYPE_OBJECT derived type
3718 * @v_object: (type GObject.Object) (allow-none): object value to be set
3720 * Set the contents of a %G_TYPE_OBJECT derived #GValue to @v_object.
3722 * g_value_set_object() increases the reference count of @v_object
3723 * (the #GValue holds a reference to @v_object). If you do not wish
3724 * to increase the reference count of the object (i.e. you wish to
3725 * pass your current reference to the #GValue because you no longer
3726 * need it), use g_value_take_object() instead.
3728 * It is important that your #GValue holds a reference to @v_object (either its
3729 * own, or one it has taken) to ensure that the object won't be destroyed while
3730 * the #GValue still exists).
3733 g_value_set_object (GValue *value,
3738 g_return_if_fail (G_VALUE_HOLDS_OBJECT (value));
3740 old = value->data[0].v_pointer;
3744 g_return_if_fail (G_IS_OBJECT (v_object));
3745 g_return_if_fail (g_value_type_compatible (G_OBJECT_TYPE (v_object), G_VALUE_TYPE (value)));
3747 value->data[0].v_pointer = v_object;
3748 g_object_ref (value->data[0].v_pointer);
3751 value->data[0].v_pointer = NULL;
3754 g_object_unref (old);
3758 * g_value_set_object_take_ownership: (skip)
3759 * @value: a valid #GValue of %G_TYPE_OBJECT derived type
3760 * @v_object: (allow-none): object value to be set
3762 * This is an internal function introduced mainly for C marshallers.
3764 * Deprecated: 2.4: Use g_value_take_object() instead.
3767 g_value_set_object_take_ownership (GValue *value,
3770 g_value_take_object (value, v_object);
3774 * g_value_take_object: (skip)
3775 * @value: a valid #GValue of %G_TYPE_OBJECT derived type
3776 * @v_object: (allow-none): object value to be set
3778 * Sets the contents of a %G_TYPE_OBJECT derived #GValue to @v_object
3779 * and takes over the ownership of the callers reference to @v_object;
3780 * the caller doesn't have to unref it any more (i.e. the reference
3781 * count of the object is not increased).
3783 * If you want the #GValue to hold its own reference to @v_object, use
3784 * g_value_set_object() instead.
3789 g_value_take_object (GValue *value,
3792 g_return_if_fail (G_VALUE_HOLDS_OBJECT (value));
3794 if (value->data[0].v_pointer)
3796 g_object_unref (value->data[0].v_pointer);
3797 value->data[0].v_pointer = NULL;
3802 g_return_if_fail (G_IS_OBJECT (v_object));
3803 g_return_if_fail (g_value_type_compatible (G_OBJECT_TYPE (v_object), G_VALUE_TYPE (value)));
3805 value->data[0].v_pointer = v_object; /* we take over the reference count */
3810 * g_value_get_object:
3811 * @value: a valid #GValue of %G_TYPE_OBJECT derived type
3813 * Get the contents of a %G_TYPE_OBJECT derived #GValue.
3815 * Returns: (type GObject.Object) (transfer none): object contents of @value
3818 g_value_get_object (const GValue *value)
3820 g_return_val_if_fail (G_VALUE_HOLDS_OBJECT (value), NULL);
3822 return value->data[0].v_pointer;
3826 * g_value_dup_object:
3827 * @value: a valid #GValue whose type is derived from %G_TYPE_OBJECT
3829 * Get the contents of a %G_TYPE_OBJECT derived #GValue, increasing
3830 * its reference count. If the contents of the #GValue are %NULL, then
3831 * %NULL will be returned.
3833 * Returns: (type GObject.Object) (transfer full): object content of @value,
3834 * should be unreferenced when no longer needed.
3837 g_value_dup_object (const GValue *value)
3839 g_return_val_if_fail (G_VALUE_HOLDS_OBJECT (value), NULL);
3841 return value->data[0].v_pointer ? g_object_ref (value->data[0].v_pointer) : NULL;
3845 * g_signal_connect_object: (skip)
3846 * @instance: the instance to connect to.
3847 * @detailed_signal: a string of the form "signal-name::detail".
3848 * @c_handler: the #GCallback to connect.
3849 * @gobject: the object to pass as data to @c_handler.
3850 * @connect_flags: a combination of #GConnectFlags.
3852 * This is similar to g_signal_connect_data(), but uses a closure which
3853 * ensures that the @gobject stays alive during the call to @c_handler
3854 * by temporarily adding a reference count to @gobject.
3856 * When the @gobject is destroyed the signal handler will be automatically
3857 * disconnected. Note that this is not currently threadsafe (ie:
3858 * emitting a signal while @gobject is being destroyed in another thread
3861 * Returns: the handler id.
3864 g_signal_connect_object (gpointer instance,
3865 const gchar *detailed_signal,
3866 GCallback c_handler,
3868 GConnectFlags connect_flags)
3870 g_return_val_if_fail (G_TYPE_CHECK_INSTANCE (instance), 0);
3871 g_return_val_if_fail (detailed_signal != NULL, 0);
3872 g_return_val_if_fail (c_handler != NULL, 0);
3878 g_return_val_if_fail (G_IS_OBJECT (gobject), 0);
3880 closure = ((connect_flags & G_CONNECT_SWAPPED) ? g_cclosure_new_object_swap : g_cclosure_new_object) (c_handler, gobject);
3882 return g_signal_connect_closure (instance, detailed_signal, closure, connect_flags & G_CONNECT_AFTER);
3885 return g_signal_connect_data (instance, detailed_signal, c_handler, NULL, NULL, connect_flags);
3891 GClosure *closures[1]; /* flexible array */
3893 /* don't change this structure without supplying an accessor for
3894 * watched closures, e.g.:
3895 * GSList* g_object_list_watched_closures (GObject *object)
3898 * g_return_val_if_fail (G_IS_OBJECT (object), NULL);
3899 * carray = g_object_get_data (object, "GObject-closure-array");
3902 * GSList *slist = NULL;
3904 * for (i = 0; i < carray->n_closures; i++)
3905 * slist = g_slist_prepend (slist, carray->closures[i]);
3913 object_remove_closure (gpointer data,
3916 GObject *object = data;
3920 G_LOCK (closure_array_mutex);
3921 carray = g_object_get_qdata (object, quark_closure_array);
3922 for (i = 0; i < carray->n_closures; i++)
3923 if (carray->closures[i] == closure)
3925 carray->n_closures--;
3926 if (i < carray->n_closures)
3927 carray->closures[i] = carray->closures[carray->n_closures];
3928 G_UNLOCK (closure_array_mutex);
3931 G_UNLOCK (closure_array_mutex);
3932 g_assert_not_reached ();
3936 destroy_closure_array (gpointer data)
3938 CArray *carray = data;
3939 GObject *object = carray->object;
3940 guint i, n = carray->n_closures;
3942 for (i = 0; i < n; i++)
3944 GClosure *closure = carray->closures[i];
3946 /* removing object_remove_closure() upfront is probably faster than
3947 * letting it fiddle with quark_closure_array which is empty anyways
3949 g_closure_remove_invalidate_notifier (closure, object, object_remove_closure);
3950 g_closure_invalidate (closure);
3956 * g_object_watch_closure:
3957 * @object: GObject restricting lifetime of @closure
3958 * @closure: GClosure to watch
3960 * This function essentially limits the life time of the @closure to
3961 * the life time of the object. That is, when the object is finalized,
3962 * the @closure is invalidated by calling g_closure_invalidate() on
3963 * it, in order to prevent invocations of the closure with a finalized
3964 * (nonexisting) object. Also, g_object_ref() and g_object_unref() are
3965 * added as marshal guards to the @closure, to ensure that an extra
3966 * reference count is held on @object during invocation of the
3967 * @closure. Usually, this function will be called on closures that
3968 * use this @object as closure data.
3971 g_object_watch_closure (GObject *object,
3977 g_return_if_fail (G_IS_OBJECT (object));
3978 g_return_if_fail (closure != NULL);
3979 g_return_if_fail (closure->is_invalid == FALSE);
3980 g_return_if_fail (closure->in_marshal == FALSE);
3981 g_return_if_fail (object->ref_count > 0); /* this doesn't work on finalizing objects */
3983 g_closure_add_invalidate_notifier (closure, object, object_remove_closure);
3984 g_closure_add_marshal_guards (closure,
3985 object, (GClosureNotify) g_object_ref,
3986 object, (GClosureNotify) g_object_unref);
3987 G_LOCK (closure_array_mutex);
3988 carray = g_datalist_id_remove_no_notify (&object->qdata, quark_closure_array);
3991 carray = g_renew (CArray, NULL, 1);
3992 carray->object = object;
3993 carray->n_closures = 1;
3998 i = carray->n_closures++;
3999 carray = g_realloc (carray, sizeof (*carray) + sizeof (carray->closures[0]) * i);
4001 carray->closures[i] = closure;
4002 g_datalist_id_set_data_full (&object->qdata, quark_closure_array, carray, destroy_closure_array);
4003 G_UNLOCK (closure_array_mutex);
4007 * g_closure_new_object:
4008 * @sizeof_closure: the size of the structure to allocate, must be at least
4009 * <literal>sizeof (GClosure)</literal>
4010 * @object: a #GObject pointer to store in the @data field of the newly
4011 * allocated #GClosure
4013 * A variant of g_closure_new_simple() which stores @object in the
4014 * @data field of the closure and calls g_object_watch_closure() on
4015 * @object and the created closure. This function is mainly useful
4016 * when implementing new types of closures.
4018 * Returns: (transfer full): a newly allocated #GClosure
4021 g_closure_new_object (guint sizeof_closure,
4026 g_return_val_if_fail (G_IS_OBJECT (object), NULL);
4027 g_return_val_if_fail (object->ref_count > 0, NULL); /* this doesn't work on finalizing objects */
4029 closure = g_closure_new_simple (sizeof_closure, object);
4030 g_object_watch_closure (object, closure);
4036 * g_cclosure_new_object: (skip)
4037 * @callback_func: the function to invoke
4038 * @object: a #GObject pointer to pass to @callback_func
4040 * A variant of g_cclosure_new() which uses @object as @user_data and
4041 * calls g_object_watch_closure() on @object and the created
4042 * closure. This function is useful when you have a callback closely
4043 * associated with a #GObject, and want the callback to no longer run
4044 * after the object is is freed.
4046 * Returns: a new #GCClosure
4049 g_cclosure_new_object (GCallback callback_func,
4054 g_return_val_if_fail (G_IS_OBJECT (object), NULL);
4055 g_return_val_if_fail (object->ref_count > 0, NULL); /* this doesn't work on finalizing objects */
4056 g_return_val_if_fail (callback_func != NULL, NULL);
4058 closure = g_cclosure_new (callback_func, object, NULL);
4059 g_object_watch_closure (object, closure);
4065 * g_cclosure_new_object_swap: (skip)
4066 * @callback_func: the function to invoke
4067 * @object: a #GObject pointer to pass to @callback_func
4069 * A variant of g_cclosure_new_swap() which uses @object as @user_data
4070 * and calls g_object_watch_closure() on @object and the created
4071 * closure. This function is useful when you have a callback closely
4072 * associated with a #GObject, and want the callback to no longer run
4073 * after the object is is freed.
4075 * Returns: a new #GCClosure
4078 g_cclosure_new_object_swap (GCallback callback_func,
4083 g_return_val_if_fail (G_IS_OBJECT (object), NULL);
4084 g_return_val_if_fail (object->ref_count > 0, NULL); /* this doesn't work on finalizing objects */
4085 g_return_val_if_fail (callback_func != NULL, NULL);
4087 closure = g_cclosure_new_swap (callback_func, object, NULL);
4088 g_object_watch_closure (object, closure);
4094 g_object_compat_control (gsize what,
4100 case 1: /* floating base type */
4101 return G_TYPE_INITIALLY_UNOWNED;
4102 case 2: /* FIXME: remove this once GLib/Gtk+ break ABI again */
4103 floating_flag_handler = (guint(*)(GObject*,gint)) data;
4105 case 3: /* FIXME: remove this once GLib/Gtk+ break ABI again */
4107 *pp = floating_flag_handler;
4114 G_DEFINE_TYPE (GInitiallyUnowned, g_initially_unowned, G_TYPE_OBJECT);
4117 g_initially_unowned_init (GInitiallyUnowned *object)
4119 g_object_force_floating (object);
4123 g_initially_unowned_class_init (GInitiallyUnownedClass *klass)
4130 * A structure containing a weak reference to a #GObject. It can either
4131 * be empty (i.e. point to %NULL), or point to an object for as long as
4132 * at least one "strong" reference to that object exists. Before the
4133 * object's #GObjectClass.dispose method is called, every #GWeakRef
4134 * associated with becomes empty (i.e. points to %NULL).
4136 * Like #GValue, #GWeakRef can be statically allocated, stack- or
4137 * heap-allocated, or embedded in larger structures.
4139 * Unlike g_object_weak_ref() and g_object_add_weak_pointer(), this weak
4140 * reference is thread-safe: converting a weak pointer to a reference is
4141 * atomic with respect to invalidation of weak pointers to destroyed
4144 * If the object's #GObjectClass.dispose method results in additional
4145 * references to the object being held, any #GWeakRef<!-- -->s taken
4146 * before it was disposed will continue to point to %NULL. If
4147 * #GWeakRef<!-- -->s are taken after the object is disposed and
4148 * re-referenced, they will continue to point to it until its refcount
4149 * goes back to zero, at which point they too will be invalidated.
4153 * g_weak_ref_init: (skip)
4154 * @weak_ref: (inout): uninitialized or empty location for a weak
4156 * @object: (allow-none): a #GObject or %NULL
4158 * Initialise a non-statically-allocated #GWeakRef.
4160 * This function also calls g_weak_ref_set() with @object on the
4161 * freshly-initialised weak reference.
4163 * This function should always be matched with a call to
4164 * g_weak_ref_clear(). It is not necessary to use this function for a
4165 * #GWeakRef in static storage because it will already be
4166 * properly initialised. Just use g_weak_ref_set() directly.
4171 g_weak_ref_init (GWeakRef *weak_ref,
4174 weak_ref->priv.p = NULL;
4176 g_weak_ref_set (weak_ref, object);
4180 * g_weak_ref_clear: (skip)
4181 * @weak_ref: (inout): location of a weak reference, which
4184 * Frees resources associated with a non-statically-allocated #GWeakRef.
4185 * After this call, the #GWeakRef is left in an undefined state.
4187 * You should only call this on a #GWeakRef that previously had
4188 * g_weak_ref_init() called on it.
4193 g_weak_ref_clear (GWeakRef *weak_ref)
4195 g_weak_ref_set (weak_ref, NULL);
4198 weak_ref->priv.p = (void *) 0xccccccccu;
4202 * g_weak_ref_get: (skip)
4203 * @weak_ref: (inout): location of a weak reference to a #GObject
4205 * If @weak_ref is not empty, atomically acquire a strong
4206 * reference to the object it points to, and return that reference.
4208 * This function is needed because of the potential race between taking
4209 * the pointer value and g_object_ref() on it, if the object was losing
4210 * its last reference at the same time in a different thread.
4212 * The caller should release the resulting reference in the usual way,
4213 * by using g_object_unref().
4215 * Returns: (transfer full) (type GObject.Object): the object pointed to
4216 * by @weak_ref, or %NULL if it was empty
4221 g_weak_ref_get (GWeakRef *weak_ref)
4223 gpointer object_or_null;
4225 g_return_val_if_fail (weak_ref!= NULL, NULL);
4227 g_rw_lock_reader_lock (&weak_locations_lock);
4229 object_or_null = weak_ref->priv.p;
4231 if (object_or_null != NULL)
4232 g_object_ref (object_or_null);
4234 g_rw_lock_reader_unlock (&weak_locations_lock);
4236 return object_or_null;
4240 * g_weak_ref_set: (skip)
4241 * @weak_ref: location for a weak reference
4242 * @object: (allow-none): a #GObject or %NULL
4244 * Change the object to which @weak_ref points, or set it to
4247 * You must own a strong reference on @object while calling this
4253 g_weak_ref_set (GWeakRef *weak_ref,
4256 GSList **weak_locations;
4257 GObject *new_object;
4258 GObject *old_object;
4260 g_return_if_fail (weak_ref != NULL);
4261 g_return_if_fail (object == NULL || G_IS_OBJECT (object));
4263 new_object = object;
4265 g_rw_lock_writer_lock (&weak_locations_lock);
4267 /* We use the extra level of indirection here so that if we have ever
4268 * had a weak pointer installed at any point in time on this object,
4269 * we can see that there is a non-NULL value associated with the
4270 * weak-pointer quark and know that this value will not change at any
4271 * point in the object's lifetime.
4273 * Both properties are important for reducing the amount of times we
4274 * need to acquire locks and for decreasing the duration of time the
4275 * lock is held while avoiding some rather tricky races.
4277 * Specifically: we can avoid having to do an extra unconditional lock
4278 * in g_object_unref() without worrying about some extremely tricky
4282 old_object = weak_ref->priv.p;
4283 if (new_object != old_object)
4285 weak_ref->priv.p = new_object;
4287 /* Remove the weak ref from the old object */
4288 if (old_object != NULL)
4290 weak_locations = g_datalist_id_get_data (&old_object->qdata, quark_weak_locations);
4291 /* for it to point to an object, the object must have had it added once */
4292 g_assert (weak_locations != NULL);
4294 *weak_locations = g_slist_remove (*weak_locations, weak_ref);
4297 /* Add the weak ref to the new object */
4298 if (new_object != NULL)
4300 weak_locations = g_datalist_id_get_data (&new_object->qdata, quark_weak_locations);
4302 if (weak_locations == NULL)
4304 weak_locations = g_new0 (GSList *, 1);
4305 g_datalist_id_set_data_full (&new_object->qdata, quark_weak_locations, weak_locations, g_free);
4308 *weak_locations = g_slist_prepend (*weak_locations, weak_ref);
4312 g_rw_lock_writer_unlock (&weak_locations_lock);