1	/* GObject - GLib Type, Object, Parameter and Signal Library
2	* Copyright (C) 1998-1999, 2000-2001 Tim Janik and Red Hat, Inc.
3	*
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 2.1 of the License, or (at your option) any later version.
8	*
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.
13	*
14	* You should have received a copy of the GNU Lesser General
15	* Public License along with this library; if not, see <http://www.gnu.org/licenses/>.
16	*/
17
18	/*
19	* MT safe
20	*/
21
22	#include "config.h"
23
24	#include "../glib/gvalgrind.h"
25	#include <string.h>
26
27	#include "gtype.h"
28	#include "gtype-private.h"
29	#include "gtypeplugin.h"
30	#include "gvaluecollector.h"
31	#include "gatomicarray.h"
32	#include "gobject_trace.h"
33
34	#include "glib-private.h"
35	#include "gconstructor.h"
36
37	#ifdef G_OS_WIN32
38	#include <windows.h>
39	#endif
40
41	#ifdef G_ENABLE_DEBUG
42	#define IF_DEBUG(debug_type) if (_g_type_debug_flags & G_TYPE_DEBUG_ ## debug_type)
43	#endif
44
45	/**
46	* SECTION:gtype
47	* @short_description: The GLib Runtime type identification and
48	* management system
49	* @title:Type Information
50	*
51	* The GType API is the foundation of the GObject system. It provides the
52	* facilities for registering and managing all fundamental data types,
53	* user-defined object and interface types.
54	*
55	* For type creation and registration purposes, all types fall into one of
56	* two categories: static or dynamic. Static types are never loaded or
57	* unloaded at run-time as dynamic types may be. Static types are created
58	* with g_type_register_static() that gets type specific information passed
59	* in via a #GTypeInfo structure.
60	*
61	* Dynamic types are created with g_type_register_dynamic() which takes a
62	* #GTypePlugin structure instead. The remaining type information (the
63	* #GTypeInfo structure) is retrieved during runtime through #GTypePlugin
64	* and the g_type_plugin_*() API.
65	*
66	* These registration functions are usually called only once from a
67	* function whose only purpose is to return the type identifier for a
68	* specific class. Once the type (or class or interface) is registered,
69	* it may be instantiated, inherited, or implemented depending on exactly
70	* what sort of type it is.
71	*
72	* There is also a third registration function for registering fundamental
73	* types called g_type_register_fundamental() which requires both a #GTypeInfo
74	* structure and a #GTypeFundamentalInfo structure but it is seldom used
75	* since most fundamental types are predefined rather than user-defined.
76	*
77	* Type instance and class structs are limited to a total of 64 KiB,
78	* including all parent types. Similarly, type instances' private data
79	* (as created by G_ADD_PRIVATE()) are limited to a total of
80	* 64 KiB. If a type instance needs a large static buffer, allocate it
81	* separately (typically by using #GArray or #GPtrArray) and put a pointer
82	* to the buffer in the structure.
83	*
84	* As mentioned in the [GType conventions][gtype-conventions], type names must
85	* be at least three characters long. There is no upper length limit. The first
86	* character must be a letter (a–z or A–Z) or an underscore (‘_’). Subsequent
87	* characters can be letters, numbers or any of ‘-_+’.
88	*/
89
90
91	/* NOTE: some functions (some internal variants and exported ones)
92	* invalidate data portions of the TypeNodes. if external functions/callbacks
93	* are called, pointers to memory maintained by TypeNodes have to be looked up
94	* again. this affects most of the struct TypeNode fields, e.g. ->children or
95	* CLASSED_NODE_IFACES_ENTRIES() respectively IFACE_NODE_PREREQUISITES() (but
96	* not ->supers[]), as all those memory portions can get realloc()ed during
97	* callback invocation.
98	*
99	* LOCKING:
100	* lock handling issues when calling static functions are indicated by
101	* uppercase letter postfixes, all static functions have to have
102	* one of the below postfixes:
103	* - _I: [Indifferent about locking]
104	* function doesn't care about locks at all
105	* - _U: [Unlocked invocation]
106	* no read or write lock has to be held across function invocation
107	* (locks may be acquired and released during invocation though)
108	* - _L: [Locked invocation]
109	* a write lock or more than 0 read locks have to be held across
110	* function invocation
111	* - _W: [Write-locked invocation]
112	* a write lock has to be held across function invocation
113	* - _Wm: [Write-locked invocation, mutatable]
114	* like _W, but the write lock might be released and reacquired
115	* during invocation, watch your pointers
116	* - _WmREC: [Write-locked invocation, mutatable, recursive]
117	* like _Wm, but also acquires recursive mutex class_init_rec_mutex
118	*/
119
120	#ifdef LOCK_DEBUG
121	#define G_READ_LOCK(rw_lock) do { g_printerr (G_STRLOC ": readL++\n"); g_rw_lock_reader_lock (rw_lock); } while (0)
122	#define G_READ_UNLOCK(rw_lock) do { g_printerr (G_STRLOC ": readL--\n"); g_rw_lock_reader_unlock (rw_lock); } while (0)
123	#define G_WRITE_LOCK(rw_lock) do { g_printerr (G_STRLOC ": writeL++\n"); g_rw_lock_writer_lock (rw_lock); } while (0)
124	#define G_WRITE_UNLOCK(rw_lock) do { g_printerr (G_STRLOC ": writeL--\n"); g_rw_lock_writer_unlock (rw_lock); } while (0)
125	#else
126	#define G_READ_LOCK(rw_lock) g_rw_lock_reader_lock (rw_lock)
127	#define G_READ_UNLOCK(rw_lock) g_rw_lock_reader_unlock (rw_lock)
128	#define G_WRITE_LOCK(rw_lock) g_rw_lock_writer_lock (rw_lock)
129	#define G_WRITE_UNLOCK(rw_lock) g_rw_lock_writer_unlock (rw_lock)
130	#endif
131	#define INVALID_RECURSION(func, arg, type_name) G_STMT_START{ \
132	static const gchar _action[] = " invalidly modified type "; \
133	gpointer _arg = (gpointer) (arg); const gchar *_tname = (type_name), *_fname = (func); \
134	if (_arg) \
135	g_error ("%s(%p)%s'%s'", _fname, _arg, _action, _tname); \
136	else \
137	g_error ("%s()%s'%s'", _fname, _action, _tname); \
138	}G_STMT_END
139	#define g_assert_type_system_initialized() \
140	g_assert (static_quark_type_flags)
141
142	#define TYPE_FUNDAMENTAL_FLAG_MASK (G_TYPE_FLAG_CLASSED | \
143	G_TYPE_FLAG_INSTANTIATABLE | \
144	G_TYPE_FLAG_DERIVABLE | \
145	G_TYPE_FLAG_DEEP_DERIVABLE)
146	#define TYPE_FLAG_MASK (G_TYPE_FLAG_ABSTRACT | G_TYPE_FLAG_VALUE_ABSTRACT)
147	#define SIZEOF_FUNDAMENTAL_INFO ((gssize) MAX (MAX (sizeof (GTypeFundamentalInfo), \
148	sizeof (gpointer)), \
149	sizeof (glong)))
150
151	/* The 2*sizeof(size_t) alignment here is borrowed from
152	* GNU libc, so it should be good most everywhere.
153	* It is more conservative than is needed on some 64-bit
154	* platforms, but ia64 does require a 16-byte alignment.
155	* The SIMD extensions for x86 and ppc32 would want a
156	* larger alignment than this, but we don't need to
157	* do better than malloc.
158	*/
159	#define STRUCT_ALIGNMENT (2 * sizeof (gsize))
160	#define ALIGN_STRUCT(offset) \
161	((offset + (STRUCT_ALIGNMENT - 1)) & -STRUCT_ALIGNMENT)
162
163
164	/* --- typedefs --- */
165	typedef struct _TypeNode TypeNode;
166	typedef struct _CommonData CommonData;
167	typedef struct _BoxedData BoxedData;
168	typedef struct _IFaceData IFaceData;
169	typedef struct _ClassData ClassData;
170	typedef struct _InstanceData InstanceData;
171	typedef union _TypeData TypeData;
172	typedef struct _IFaceEntries IFaceEntries;
173	typedef struct _IFaceEntry IFaceEntry;
174	typedef struct _IFaceHolder IFaceHolder;
175
176
177	/* --- prototypes --- */
178	static inline GTypeFundamentalInfo* type_node_fundamental_info_I (TypeNode *node);
179	static void type_add_flags_W (TypeNode *node,
180	GTypeFlags flags);
181	static void type_data_make_W (TypeNode *node,
182	const GTypeInfo *info,
183	const GTypeValueTable *value_table);
184	static inline void type_data_ref_Wm (TypeNode *node);
185	static inline void type_data_unref_U (TypeNode *node,
186	gboolean uncached);
187	static void type_data_last_unref_Wm (TypeNode * node,
188	gboolean uncached);
189	static inline gpointer type_get_qdata_L (TypeNode *node,
190	GQuark quark);
191	static inline void type_set_qdata_W (TypeNode *node,
192	GQuark quark,
193	gpointer data);
194	static IFaceHolder* type_iface_peek_holder_L (TypeNode *iface,
195	GType instance_type);
196	static gboolean type_iface_vtable_base_init_Wm (TypeNode *iface,
197	TypeNode *node);
198	static void type_iface_vtable_iface_init_Wm (TypeNode *iface,
199	TypeNode *node);
200	static gboolean type_node_is_a_L (TypeNode *node,
201	TypeNode *iface_node);
202
203
204	/* --- enumeration --- */
205
206	/* The InitState enumeration is used to track the progress of initializing
207	* both classes and interface vtables. Keeping the state of initialization
208	* is necessary to handle new interfaces being added while we are initializing
209	* the class or other interfaces.
210	*/
211	typedef enum
212	{
213	UNINITIALIZED,
214	BASE_CLASS_INIT,
215	BASE_IFACE_INIT,
216	CLASS_INIT,
217	IFACE_INIT,
218	INITIALIZED
219	} InitState;
220
221	/* --- structures --- */
222	struct _TypeNode
223	{
224	guint ref_count; /* (atomic) */
225	#ifdef G_ENABLE_DEBUG
226	guint instance_count; /* (atomic) */
227	#endif
228	GTypePlugin *plugin;
229	guint n_children; /* writable with lock */
230	guint n_supers : 8;
231	guint n_prerequisites : 9;
232	guint is_classed : 1;
233	guint is_instantiatable : 1;
234	guint mutatable_check_cache : 1; /* combines some common path checks */
235	GType *children; /* writable with lock */
236	TypeData *data;
237	GQuark qname;
238	GData *global_gdata;
239	union {
240	GAtomicArray iface_entries; /* for !iface types */
241	GAtomicArray offsets;
242	} _prot;
243	GType *prerequisites;
244	GType supers[1]; /* flexible array */
245	};
246
247	#define SIZEOF_BASE_TYPE_NODE() (G_STRUCT_OFFSET (TypeNode, supers))
248	#define MAX_N_SUPERS (255)
249	#define MAX_N_CHILDREN (G_MAXUINT)
250	#define MAX_N_INTERFACES (255) /* Limited by offsets being 8 bits */
251	#define MAX_N_PREREQUISITES (511)
252	#define NODE_TYPE(node) (node->supers[0])
253	#define NODE_PARENT_TYPE(node) (node->supers[1])
254	#define NODE_FUNDAMENTAL_TYPE(node) (node->supers[node->n_supers])
255	#define NODE_NAME(node) (g_quark_to_string (node->qname))
256	#define NODE_REFCOUNT(node) ((guint) g_atomic_int_get ((int *) &(node)->ref_count))
257	#define NODE_IS_BOXED(node) (NODE_FUNDAMENTAL_TYPE (node) == G_TYPE_BOXED)
258	#define NODE_IS_IFACE(node) (NODE_FUNDAMENTAL_TYPE (node) == G_TYPE_INTERFACE)
259	#define CLASSED_NODE_IFACES_ENTRIES(node) (&(node)->_prot.iface_entries)
260	#define CLASSED_NODE_IFACES_ENTRIES_LOCKED(node)(G_ATOMIC_ARRAY_GET_LOCKED(CLASSED_NODE_IFACES_ENTRIES((node)), IFaceEntries))
261	#define IFACE_NODE_N_PREREQUISITES(node) ((node)->n_prerequisites)
262	#define IFACE_NODE_PREREQUISITES(node) ((node)->prerequisites)
263	#define iface_node_get_holders_L(node) ((IFaceHolder*) type_get_qdata_L ((node), static_quark_iface_holder))
264	#define iface_node_set_holders_W(node, holders) (type_set_qdata_W ((node), static_quark_iface_holder, (holders)))
265	#define iface_node_get_dependants_array_L(n) ((GType*) type_get_qdata_L ((n), static_quark_dependants_array))
266	#define iface_node_set_dependants_array_W(n,d) (type_set_qdata_W ((n), static_quark_dependants_array, (d)))
267	#define TYPE_ID_MASK ((GType) ((1 << G_TYPE_FUNDAMENTAL_SHIFT) - 1))
268
269	#define NODE_IS_ANCESTOR(ancestor, node) \
270	((ancestor)->n_supers <= (node)->n_supers && \
271	(node)->supers[(node)->n_supers - (ancestor)->n_supers] == NODE_TYPE (ancestor))
272
273	struct _IFaceHolder
274	{
275	GType instance_type;
276	GInterfaceInfo *info;
277	GTypePlugin *plugin;
278	IFaceHolder *next;
279	};
280
281	struct _IFaceEntry
282	{
283	GType iface_type;
284	GTypeInterface *vtable;
285	InitState init_state;
286	};
287
288	struct _IFaceEntries {
289	gsize offset_index;
290	IFaceEntry entry[1];
291	};
292
293	#define IFACE_ENTRIES_HEADER_SIZE (sizeof(IFaceEntries) - sizeof(IFaceEntry))
294	#define IFACE_ENTRIES_N_ENTRIES(_entries) ( (G_ATOMIC_ARRAY_DATA_SIZE((_entries)) - IFACE_ENTRIES_HEADER_SIZE) / sizeof(IFaceEntry) )
295
296	struct _CommonData
297	{
298	GTypeValueTable *value_table;
299	};
300
301	struct _BoxedData
302	{
303	CommonData data;
304	GBoxedCopyFunc copy_func;
305	GBoxedFreeFunc free_func;
306	};
307
308	struct _IFaceData
309	{
310	CommonData common;
311	guint16 vtable_size;
312	GBaseInitFunc vtable_init_base;
313	GBaseFinalizeFunc vtable_finalize_base;
314	GClassInitFunc dflt_init;
315	GClassFinalizeFunc dflt_finalize;
316	gconstpointer dflt_data;
317	gpointer dflt_vtable;
318	};
319
320	struct _ClassData
321	{
322	CommonData common;
323	guint16 class_size;
324	guint16 class_private_size;
325	int init_state; /* (atomic) - g_type_class_ref reads it unlocked */
326	GBaseInitFunc class_init_base;
327	GBaseFinalizeFunc class_finalize_base;
328	GClassInitFunc class_init;
329	GClassFinalizeFunc class_finalize;
330	gconstpointer class_data;
331	gpointer class;
332	};
333
334	struct _InstanceData
335	{
336	CommonData common;
337	guint16 class_size;
338	guint16 class_private_size;
339	int init_state; /* (atomic) - g_type_class_ref reads it unlocked */
340	GBaseInitFunc class_init_base;
341	GBaseFinalizeFunc class_finalize_base;
342	GClassInitFunc class_init;
343	GClassFinalizeFunc class_finalize;
344	gconstpointer class_data;
345	gpointer class;
346	guint16 instance_size;
347	guint16 private_size;
348	guint16 n_preallocs;
349	GInstanceInitFunc instance_init;
350	};
351
352	union _TypeData
353	{
354	CommonData common;
355	BoxedData boxed;
356	IFaceData iface;
357	ClassData class;
358	InstanceData instance;
359	};
360
361	typedef struct {
362	gpointer cache_data;
363	GTypeClassCacheFunc cache_func;
364	} ClassCacheFunc;
365
366	typedef struct {
367	gpointer check_data;
368	GTypeInterfaceCheckFunc check_func;
369	} IFaceCheckFunc;
370
371
372	/* --- variables --- */
373	static GRWLock type_rw_lock;
374	static GRecMutex class_init_rec_mutex;
375	static guint static_n_class_cache_funcs = 0;
376	static ClassCacheFunc *static_class_cache_funcs = NULL;
377	static guint static_n_iface_check_funcs = 0;
378	static IFaceCheckFunc *static_iface_check_funcs = NULL;
379	static GQuark static_quark_type_flags = 0;
380	static GQuark static_quark_iface_holder = 0;
381	static GQuark static_quark_dependants_array = 0;
382	static guint type_registration_serial = 0;
383
384	G_GNUC_BEGIN_IGNORE_DEPRECATIONS
385	GTypeDebugFlags _g_type_debug_flags = 0;
386	G_GNUC_END_IGNORE_DEPRECATIONS
387
388	/* --- type nodes --- */
389	static GHashTable *static_type_nodes_ht = NULL;
390	static TypeNode *static_fundamental_type_nodes[(G_TYPE_FUNDAMENTAL_MAX >> G_TYPE_FUNDAMENTAL_SHIFT) + 1] = { NULL, };
391	static GType static_fundamental_next = G_TYPE_RESERVED_USER_FIRST;
392
393	static inline TypeNode*
394	lookup_type_node_I (GType utype)
395	{
396	if (utype > G_TYPE_FUNDAMENTAL_MAX)
397	return (TypeNode*) (utype & ~TYPE_ID_MASK);
398	else
399	return static_fundamental_type_nodes[utype >> G_TYPE_FUNDAMENTAL_SHIFT];
400	}
401
402	/**
403	* g_type_get_type_registration_serial:
404	*
405	* Returns an opaque serial number that represents the state of the set
406	* of registered types. Any time a type is registered this serial changes,
407	* which means you can cache information based on type lookups (such as
408	* g_type_from_name()) and know if the cache is still valid at a later
409	* time by comparing the current serial with the one at the type lookup.
410	*
411	* Since: 2.36
412	*
413	* Returns: An unsigned int, representing the state of type registrations
414	*/
415	guint
416	g_type_get_type_registration_serial (void)
417	{
418	return (guint)g_atomic_int_get ((gint *)&type_registration_serial);
419	}
420
421	static TypeNode*
422	type_node_any_new_W (TypeNode *pnode,
423	GType ftype,
424	const gchar *name,
425	GTypePlugin *plugin,
426	GTypeFundamentalFlags type_flags)
427	{
428	guint n_supers;
429	GType type;
430	TypeNode *node;
431	guint i, node_size = 0;
432
433	n_supers = pnode ? pnode->n_supers + 1 : 0;
434
435	if (!pnode)
436	node_size += SIZEOF_FUNDAMENTAL_INFO; /* fundamental type info */
437	node_size += SIZEOF_BASE_TYPE_NODE (); /* TypeNode structure */
438	node_size += (sizeof (GType) * (1 + n_supers + 1)); /* self + ancestors + (0) for ->supers[] */
439	node = g_malloc0 (n_bytes: node_size);
440	if (!pnode) /* offset fundamental types */
441	{
442	node = G_STRUCT_MEMBER_P (node, SIZEOF_FUNDAMENTAL_INFO);
443	static_fundamental_type_nodes[ftype >> G_TYPE_FUNDAMENTAL_SHIFT] = node;
444	type = ftype;
445
446	#if ENABLE_VALGRIND
447	VALGRIND_MALLOCLIKE_BLOCK (node, node_size - SIZEOF_FUNDAMENTAL_INFO, FALSE, TRUE);
448	#endif
449	}
450	else
451	type = (GType) node;
452
453	g_assert ((type & TYPE_ID_MASK) == 0);
454
455	node->n_supers = n_supers;
456	if (!pnode)
457	{
458	node->supers[0] = type;
459	node->supers[1] = 0;
460
461	node->is_classed = (type_flags & G_TYPE_FLAG_CLASSED) != 0;
462	node->is_instantiatable = (type_flags & G_TYPE_FLAG_INSTANTIATABLE) != 0;
463
464	if (NODE_IS_IFACE (node))
465	{
466	IFACE_NODE_N_PREREQUISITES (node) = 0;
467	IFACE_NODE_PREREQUISITES (node) = NULL;
468	}
469	else
470	_g_atomic_array_init (CLASSED_NODE_IFACES_ENTRIES (node));
471	}
472	else
473	{
474	node->supers[0] = type;
475	memcpy (dest: node->supers + 1, src: pnode->supers, n: sizeof (GType) * (1 + pnode->n_supers + 1));
476
477	node->is_classed = pnode->is_classed;
478	node->is_instantiatable = pnode->is_instantiatable;
479
480	if (NODE_IS_IFACE (node))
481	{
482	IFACE_NODE_N_PREREQUISITES (node) = 0;
483	IFACE_NODE_PREREQUISITES (node) = NULL;
484	}
485	else
486	{
487	guint j;
488	IFaceEntries *entries;
489
490	entries = _g_atomic_array_copy (CLASSED_NODE_IFACES_ENTRIES (pnode),
491	IFACE_ENTRIES_HEADER_SIZE,
492	additional_element_size: 0);
493	if (entries)
494	{
495	for (j = 0; j < IFACE_ENTRIES_N_ENTRIES (entries); j++)
496	{
497	entries->entry[j].vtable = NULL;
498	entries->entry[j].init_state = UNINITIALIZED;
499	}
500	_g_atomic_array_update (CLASSED_NODE_IFACES_ENTRIES (node),
501	new_data: entries);
502	}
503	}
504
505	i = pnode->n_children++;
506	pnode->children = g_renew (GType, pnode->children, pnode->n_children);
507	pnode->children[i] = type;
508	}
509
510	TRACE(GOBJECT_TYPE_NEW(name, node->supers[1], type));
511
512	node->plugin = plugin;
513	node->n_children = 0;
514	node->children = NULL;
515	node->data = NULL;
516	node->qname = g_quark_from_string (string: name);
517	node->global_gdata = NULL;
518	g_hash_table_insert (hash_table: static_type_nodes_ht,
519	key: (gpointer) g_quark_to_string (quark: node->qname),
520	value: (gpointer) type);
521
522	g_atomic_int_inc ((gint *)&type_registration_serial);
523
524	return node;
525	}
526
527	static inline GTypeFundamentalInfo*
528	type_node_fundamental_info_I (TypeNode *node)
529	{
530	GType ftype = NODE_FUNDAMENTAL_TYPE (node);
531
532	if (ftype != NODE_TYPE (node))
533	node = lookup_type_node_I (utype: ftype);
534
535	return node ? G_STRUCT_MEMBER_P (node, -SIZEOF_FUNDAMENTAL_INFO) : NULL;
536	}
537
538	static TypeNode*
539	type_node_fundamental_new_W (GType ftype,
540	const gchar *name,
541	GTypeFundamentalFlags type_flags)
542	{
543	GTypeFundamentalInfo *finfo;
544	TypeNode *node;
545
546	g_assert ((ftype & TYPE_ID_MASK) == 0);
547	g_assert (ftype <= G_TYPE_FUNDAMENTAL_MAX);
548
549	if (ftype >> G_TYPE_FUNDAMENTAL_SHIFT == static_fundamental_next)
550	static_fundamental_next++;
551
552	type_flags &= TYPE_FUNDAMENTAL_FLAG_MASK;
553
554	node = type_node_any_new_W (NULL, ftype, name, NULL, type_flags);
555
556	finfo = type_node_fundamental_info_I (node);
557	finfo->type_flags = type_flags;
558
559	return node;
560	}
561
562	static TypeNode*
563	type_node_new_W (TypeNode *pnode,
564	const gchar *name,
565	GTypePlugin *plugin)
566
567	{
568	g_assert (pnode);
569	g_assert (pnode->n_supers < MAX_N_SUPERS);
570	g_assert (pnode->n_children < MAX_N_CHILDREN);
571
572	return type_node_any_new_W (pnode, NODE_FUNDAMENTAL_TYPE (pnode), name, plugin, type_flags: 0);
573	}
574
575	static inline IFaceEntry*
576	lookup_iface_entry_I (IFaceEntries *entries,
577	TypeNode *iface_node)
578	{
579	guint8 *offsets;
580	gsize offset_index;
581	IFaceEntry *check;
582	gsize index;
583	IFaceEntry *entry;
584
585	if (entries == NULL)
586	return NULL;
587
588	G_ATOMIC_ARRAY_DO_TRANSACTION
589	(&iface_node->_prot.offsets, guint8,
590
591	entry = NULL;
592	offsets = transaction_data;
593	offset_index = entries->offset_index;
594	if (offsets != NULL &&
595	offset_index < G_ATOMIC_ARRAY_DATA_SIZE(offsets))
596	{
597	index = offsets[offset_index];
598	if (index > 0)
599	{
600	/* zero means unset, subtract one to get real index */
601	index -= 1;
602
603	if (index < IFACE_ENTRIES_N_ENTRIES (entries))
604	{
605	check = (IFaceEntry *)&entries->entry[index];
606	if (check->iface_type == NODE_TYPE (iface_node))
607	entry = check;
608	}
609	}
610	}
611	);
612
613	return entry;
614	}
615
616	static inline IFaceEntry*
617	type_lookup_iface_entry_L (TypeNode *node,
618	TypeNode *iface_node)
619	{
620	if (!NODE_IS_IFACE (iface_node))
621	return NULL;
622
623	return lookup_iface_entry_I (CLASSED_NODE_IFACES_ENTRIES_LOCKED (node),
624	iface_node);
625	}
626
627
628	static inline gboolean
629	type_lookup_iface_vtable_I (TypeNode *node,
630	TypeNode *iface_node,
631	gpointer *vtable_ptr)
632	{
633	IFaceEntry *entry;
634	gboolean res;
635
636	if (!NODE_IS_IFACE (iface_node))
637	{
638	if (vtable_ptr)
639	*vtable_ptr = NULL;
640	return FALSE;
641	}
642
643	G_ATOMIC_ARRAY_DO_TRANSACTION
644	(CLASSED_NODE_IFACES_ENTRIES (node), IFaceEntries,
645
646	entry = lookup_iface_entry_I (transaction_data, iface_node);
647	res = entry != NULL;
648	if (vtable_ptr)
649	{
650	if (entry)
651	*vtable_ptr = entry->vtable;
652	else
653	*vtable_ptr = NULL;
654	}
655	);
656
657	return res;
658	}
659
660	static inline gboolean
661	type_lookup_prerequisite_L (TypeNode *iface,
662	GType prerequisite_type)
663	{
664	if (NODE_IS_IFACE (iface) && IFACE_NODE_N_PREREQUISITES (iface))
665	{
666	GType *prerequisites = IFACE_NODE_PREREQUISITES (iface) - 1;
667	guint n_prerequisites = IFACE_NODE_N_PREREQUISITES (iface);
668
669	do
670	{
671	guint i;
672	GType *check;
673
674	i = (n_prerequisites + 1) >> 1;
675	check = prerequisites + i;
676	if (prerequisite_type == *check)
677	return TRUE;
678	else if (prerequisite_type > *check)
679	{
680	n_prerequisites -= i;
681	prerequisites = check;
682	}
683	else /* if (prerequisite_type < *check) */
684	n_prerequisites = i - 1;
685	}
686	while (n_prerequisites);
687	}
688	return FALSE;
689	}
690
691	static const gchar*
692	type_descriptive_name_I (GType type)
693	{
694	if (type)
695	{
696	TypeNode *node = lookup_type_node_I (utype: type);
697
698	return node ? NODE_NAME (node) : "<unknown>";
699	}
700	else
701	return "<invalid>";
702	}
703
704
705	/* --- type consistency checks --- */
706	static gboolean
707	check_plugin_U (GTypePlugin *plugin,
708	gboolean need_complete_type_info,
709	gboolean need_complete_interface_info,
710	const gchar *type_name)
711	{
712	/* G_IS_TYPE_PLUGIN() and G_TYPE_PLUGIN_GET_CLASS() are external calls: _U
713	*/
714	if (!plugin)
715	{
716	g_warning ("plugin handle for type '%s' is NULL",
717	type_name);
718	return FALSE;
719	}
720	if (!G_IS_TYPE_PLUGIN (plugin))
721	{
722	g_warning ("plugin pointer (%p) for type '%s' is invalid",
723	plugin, type_name);
724	return FALSE;
725	}
726	if (need_complete_type_info && !G_TYPE_PLUGIN_GET_CLASS (plugin)->complete_type_info)
727	{
728	g_warning ("plugin for type '%s' has no complete_type_info() implementation",
729	type_name);
730	return FALSE;
731	}
732	if (need_complete_interface_info && !G_TYPE_PLUGIN_GET_CLASS (plugin)->complete_interface_info)
733	{
734	g_warning ("plugin for type '%s' has no complete_interface_info() implementation",
735	type_name);
736	return FALSE;
737	}
738	return TRUE;
739	}
740
741	static gboolean
742	check_type_name_I (const gchar *type_name)
743	{
744	static const gchar extra_chars[] = "-_+";
745	const gchar *p = type_name;
746	gboolean name_valid;
747
748	if (!type_name[0] || !type_name[1] || !type_name[2])
749	{
750	g_warning ("type name '%s' is too short", type_name);
751	return FALSE;
752	}
753	/* check the first letter */
754	name_valid = (p[0] >= 'A' && p[0] <= 'Z') || (p[0] >= 'a' && p[0] <= 'z') || p[0] == '_';
755	for (p = type_name + 1; *p; p++)
756	name_valid &= ((p[0] >= 'A' && p[0] <= 'Z') ||
757	(p[0] >= 'a' && p[0] <= 'z') ||
758	(p[0] >= '0' && p[0] <= '9') ||
759	strchr (s: extra_chars, c: p[0]));
760	if (!name_valid)
761	{
762	g_warning ("type name '%s' contains invalid characters", type_name);
763	return FALSE;
764	}
765	if (g_type_from_name (name: type_name))
766	{
767	g_warning ("cannot register existing type '%s'", type_name);
768	return FALSE;
769	}
770
771	return TRUE;
772	}
773
774	static gboolean
775	check_derivation_I (GType parent_type,
776	const gchar *type_name)
777	{
778	TypeNode *pnode;
779	GTypeFundamentalInfo* finfo;
780
781	pnode = lookup_type_node_I (utype: parent_type);
782	if (!pnode)
783	{
784	g_warning ("cannot derive type '%s' from invalid parent type '%s'",
785	type_name,
786	type_descriptive_name_I (parent_type));
787	return FALSE;
788	}
789	finfo = type_node_fundamental_info_I (node: pnode);
790	/* ensure flat derivability */
791	if (!(finfo->type_flags & G_TYPE_FLAG_DERIVABLE))
792	{
793	g_warning ("cannot derive '%s' from non-derivable parent type '%s'",
794	type_name,
795	NODE_NAME (pnode));
796	return FALSE;
797	}
798	/* ensure deep derivability */
799	if (parent_type != NODE_FUNDAMENTAL_TYPE (pnode) &&
800	!(finfo->type_flags & G_TYPE_FLAG_DEEP_DERIVABLE))
801	{
802	g_warning ("cannot derive '%s' from non-fundamental parent type '%s'",
803	type_name,
804	NODE_NAME (pnode));
805	return FALSE;
806	}
807
808	return TRUE;
809	}
810
811	static gboolean
812	check_collect_format_I (const gchar *collect_format)
813	{
814	const gchar *p = collect_format;
815	gchar valid_format[] = { G_VALUE_COLLECT_INT, G_VALUE_COLLECT_LONG,
816	G_VALUE_COLLECT_INT64, G_VALUE_COLLECT_DOUBLE,
817	G_VALUE_COLLECT_POINTER, 0 };
818
819	while (*p)
820	if (!strchr (s: valid_format, c: *p++))
821	return FALSE;
822	return p - collect_format <= G_VALUE_COLLECT_FORMAT_MAX_LENGTH;
823	}
824
825	static gboolean
826	check_value_table_I (const gchar *type_name,
827	const GTypeValueTable *value_table)
828	{
829	if (!value_table)
830	return FALSE;
831	else if (value_table->value_init == NULL)
832	{
833	if (value_table->value_free || value_table->value_copy ||
834	value_table->value_peek_pointer ||
835	value_table->collect_format || value_table->collect_value ||
836	value_table->lcopy_format || value_table->lcopy_value)
837	g_warning ("cannot handle uninitializable values of type '%s'",
838	type_name);
839	return FALSE;
840	}
841	else /* value_table->value_init != NULL */
842	{
843	if (!value_table->value_free)
844	{
845	/* +++ optional +++
846	* g_warning ("missing 'value_free()' for type '%s'", type_name);
847	* return FALSE;
848	*/
849	}
850	if (!value_table->value_copy)
851	{
852	g_warning ("missing 'value_copy()' for type '%s'", type_name);
853	return FALSE;
854	}
855	if ((value_table->collect_format || value_table->collect_value) &&
856	(!value_table->collect_format || !value_table->collect_value))
857	{
858	g_warning ("one of 'collect_format' and 'collect_value()' is unspecified for type '%s'",
859	type_name);
860	return FALSE;
861	}
862	if (value_table->collect_format && !check_collect_format_I (collect_format: value_table->collect_format))
863	{
864	g_warning ("the '%s' specification for type '%s' is too long or invalid",
865	"collect_format",
866	type_name);
867	return FALSE;
868	}
869	if ((value_table->lcopy_format || value_table->lcopy_value) &&
870	(!value_table->lcopy_format || !value_table->lcopy_value))
871	{
872	g_warning ("one of 'lcopy_format' and 'lcopy_value()' is unspecified for type '%s'",
873	type_name);
874	return FALSE;
875	}
876	if (value_table->lcopy_format && !check_collect_format_I (collect_format: value_table->lcopy_format))
877	{
878	g_warning ("the '%s' specification for type '%s' is too long or invalid",
879	"lcopy_format",
880	type_name);
881	return FALSE;
882	}
883	}
884	return TRUE;
885	}
886
887	static gboolean
888	check_type_info_I (TypeNode *pnode,
889	GType ftype,
890	const gchar *type_name,
891	const GTypeInfo *info)
892	{
893	GTypeFundamentalInfo *finfo = type_node_fundamental_info_I (node: lookup_type_node_I (utype: ftype));
894	gboolean is_interface = ftype == G_TYPE_INTERFACE;
895
896	g_assert (ftype <= G_TYPE_FUNDAMENTAL_MAX && !(ftype & TYPE_ID_MASK));
897
898	/* check instance members */
899	if (!(finfo->type_flags & G_TYPE_FLAG_INSTANTIATABLE) &&
900	(info->instance_size || info->n_preallocs || info->instance_init))
901	{
902	if (pnode)
903	g_warning ("cannot instantiate '%s', derived from non-instantiatable parent type '%s'",
904	type_name,
905	NODE_NAME (pnode));
906	else
907	g_warning ("cannot instantiate '%s' as non-instantiatable fundamental",
908	type_name);
909	return FALSE;
910	}
911	/* check class & interface members */
912	if (!((finfo->type_flags & G_TYPE_FLAG_CLASSED) || is_interface) &&
913	(info->class_init || info->class_finalize || info->class_data ||
914	info->class_size || info->base_init || info->base_finalize))
915	{
916	if (pnode)
917	g_warning ("cannot create class for '%s', derived from non-classed parent type '%s'",
918	type_name,
919	NODE_NAME (pnode));
920	else
921	g_warning ("cannot create class for '%s' as non-classed fundamental",
922	type_name);
923	return FALSE;
924	}
925	/* check interface size */
926	if (is_interface && info->class_size < sizeof (GTypeInterface))
927	{
928	g_warning ("specified interface size for type '%s' is smaller than 'GTypeInterface' size",
929	type_name);
930	return FALSE;
931	}
932	/* check class size */
933	if (finfo->type_flags & G_TYPE_FLAG_CLASSED)
934	{
935	if (info->class_size < sizeof (GTypeClass))
936	{
937	g_warning ("specified class size for type '%s' is smaller than 'GTypeClass' size",
938	type_name);
939	return FALSE;
940	}
941	if (pnode && info->class_size < pnode->data->class.class_size)
942	{
943	g_warning ("specified class size for type '%s' is smaller "
944	"than the parent type's '%s' class size",
945	type_name,
946	NODE_NAME (pnode));
947	return FALSE;
948	}
949	}
950	/* check instance size */
951	if (finfo->type_flags & G_TYPE_FLAG_INSTANTIATABLE)
952	{
953	if (info->instance_size < sizeof (GTypeInstance))
954	{
955	g_warning ("specified instance size for type '%s' is smaller than 'GTypeInstance' size",
956	type_name);
957	return FALSE;
958	}
959	if (pnode && info->instance_size < pnode->data->instance.instance_size)
960	{
961	g_warning ("specified instance size for type '%s' is smaller "
962	"than the parent type's '%s' instance size",
963	type_name,
964	NODE_NAME (pnode));
965	return FALSE;
966	}
967	}
968
969	return TRUE;
970	}
971
972	static TypeNode*
973	find_conforming_child_type_L (TypeNode *pnode,
974	TypeNode *iface)
975	{
976	TypeNode *node = NULL;
977	guint i;
978
979	if (type_lookup_iface_entry_L (node: pnode, iface_node: iface))
980	return pnode;
981
982	for (i = 0; i < pnode->n_children && !node; i++)
983	node = find_conforming_child_type_L (pnode: lookup_type_node_I (utype: pnode->children[i]), iface);
984
985	return node;
986	}
987
988	static gboolean
989	check_add_interface_L (GType instance_type,
990	GType iface_type)
991	{
992	TypeNode *node = lookup_type_node_I (utype: instance_type);
993	TypeNode *iface = lookup_type_node_I (utype: iface_type);
994	IFaceEntry *entry;
995	TypeNode *tnode;
996	GType *prerequisites;
997	guint i;
998
999
1000	if (!node || !node->is_instantiatable)
1001	{
1002	g_warning ("cannot add interfaces to invalid (non-instantiatable) type '%s'",
1003	type_descriptive_name_I (instance_type));
1004	return FALSE;
1005	}
1006	if (!iface || !NODE_IS_IFACE (iface))
1007	{
1008	g_warning ("cannot add invalid (non-interface) type '%s' to type '%s'",
1009	type_descriptive_name_I (iface_type),
1010	NODE_NAME (node));
1011	return FALSE;
1012	}
1013	if (node->data && node->data->class.class)
1014	{
1015	g_warning ("attempting to add an interface (%s) to class (%s) after class_init",
1016	NODE_NAME (iface), NODE_NAME (node));
1017	return FALSE;
1018	}
1019	tnode = lookup_type_node_I (NODE_PARENT_TYPE (iface));
1020	if (NODE_PARENT_TYPE (tnode) && !type_lookup_iface_entry_L (node, iface_node: tnode))
1021	{
1022	/* 2001/7/31:timj: erk, i guess this warning is junk as interface derivation is flat */
1023	g_warning ("cannot add sub-interface '%s' to type '%s' which does not conform to super-interface '%s'",
1024	NODE_NAME (iface),
1025	NODE_NAME (node),
1026	NODE_NAME (tnode));
1027	return FALSE;
1028	}
1029	/* allow overriding of interface type introduced for parent type */
1030	entry = type_lookup_iface_entry_L (node, iface_node: iface);
1031	if (entry && entry->vtable == NULL && !type_iface_peek_holder_L (iface, NODE_TYPE (node)))
1032	{
1033	/* ok, we do conform to this interface already, but the interface vtable was not
1034	* yet initialized, and we just conform to the interface because it got added to
1035	* one of our parents. so we allow overriding of holder info here.
1036	*/
1037	return TRUE;
1038	}
1039	/* check whether one of our children already conforms (or whether the interface
1040	* got added to this node already)
1041	*/
1042	tnode = find_conforming_child_type_L (pnode: node, iface); /* tnode is_a node */
1043	if (tnode)
1044	{
1045	g_warning ("cannot add interface type '%s' to type '%s', since type '%s' already conforms to interface",
1046	NODE_NAME (iface),
1047	NODE_NAME (node),
1048	NODE_NAME (tnode));
1049	return FALSE;
1050	}
1051	prerequisites = IFACE_NODE_PREREQUISITES (iface);
1052	for (i = 0; i < IFACE_NODE_N_PREREQUISITES (iface); i++)
1053	{
1054	tnode = lookup_type_node_I (utype: prerequisites[i]);
1055	if (!type_node_is_a_L (node, iface_node: tnode))
1056	{
1057	g_warning ("cannot add interface type '%s' to type '%s' which does not conform to prerequisite '%s'",
1058	NODE_NAME (iface),
1059	NODE_NAME (node),
1060	NODE_NAME (tnode));
1061	return FALSE;
1062	}
1063	}
1064	return TRUE;
1065	}
1066
1067	static gboolean
1068	check_interface_info_I (TypeNode *iface,
1069	GType instance_type,
1070	const GInterfaceInfo *info)
1071	{
1072	if ((info->interface_finalize || info->interface_data) && !info->interface_init)
1073	{
1074	g_warning ("interface type '%s' for type '%s' comes without initializer",
1075	NODE_NAME (iface),
1076	type_descriptive_name_I (instance_type));
1077	return FALSE;
1078	}
1079
1080	return TRUE;
1081	}
1082
1083	/* --- type info (type node data) --- */
1084	static void
1085	type_data_make_W (TypeNode *node,
1086	const GTypeInfo *info,
1087	const GTypeValueTable *value_table)
1088	{
1089	TypeData *data;
1090	GTypeValueTable *vtable = NULL;
1091	guint vtable_size = 0;
1092
1093	g_assert (node->data == NULL && info != NULL);
1094
1095	if (!value_table)
1096	{
1097	TypeNode *pnode = lookup_type_node_I (NODE_PARENT_TYPE (node));
1098
1099	if (pnode)
1100	vtable = pnode->data->common.value_table;
1101	else
1102	{
1103	static const GTypeValueTable zero_vtable = { NULL, };
1104
1105	value_table = &zero_vtable;
1106	}
1107	}
1108	if (value_table)
1109	{
1110	/* need to setup vtable_size since we have to allocate it with data in one chunk */
1111	vtable_size = sizeof (GTypeValueTable);
1112	if (value_table->collect_format)
1113	vtable_size += strlen (s: value_table->collect_format);
1114	if (value_table->lcopy_format)
1115	vtable_size += strlen (s: value_table->lcopy_format);
1116	vtable_size += 2;
1117	}
1118
1119	if (node->is_instantiatable) /* careful, is_instantiatable is also is_classed */
1120	{
1121	TypeNode *pnode = lookup_type_node_I (NODE_PARENT_TYPE (node));
1122
1123	data = g_malloc0 (n_bytes: sizeof (InstanceData) + vtable_size);
1124	if (vtable_size)
1125	vtable = G_STRUCT_MEMBER_P (data, sizeof (InstanceData));
1126	data->instance.class_size = info->class_size;
1127	data->instance.class_init_base = info->base_init;
1128	data->instance.class_finalize_base = info->base_finalize;
1129	data->instance.class_init = info->class_init;
1130	data->instance.class_finalize = info->class_finalize;
1131	data->instance.class_data = info->class_data;
1132	data->instance.class = NULL;
1133	data->instance.init_state = UNINITIALIZED;
1134	data->instance.instance_size = info->instance_size;
1135	/* We'll set the final value for data->instance.private size
1136	* after the parent class has been initialized
1137	*/
1138	data->instance.private_size = 0;
1139	data->instance.class_private_size = 0;
1140	if (pnode)
1141	data->instance.class_private_size = pnode->data->instance.class_private_size;
1142	data->instance.n_preallocs = MIN (info->n_preallocs, 1024);
1143	data->instance.instance_init = info->instance_init;
1144	}
1145	else if (node->is_classed) /* only classed */
1146	{
1147	TypeNode *pnode = lookup_type_node_I (NODE_PARENT_TYPE (node));
1148
1149	data = g_malloc0 (n_bytes: sizeof (ClassData) + vtable_size);
1150	if (vtable_size)
1151	vtable = G_STRUCT_MEMBER_P (data, sizeof (ClassData));
1152	data->class.class_size = info->class_size;
1153	data->class.class_init_base = info->base_init;
1154	data->class.class_finalize_base = info->base_finalize;
1155	data->class.class_init = info->class_init;
1156	data->class.class_finalize = info->class_finalize;
1157	data->class.class_data = info->class_data;
1158	data->class.class = NULL;
1159	data->class.class_private_size = 0;
1160	if (pnode)
1161	data->class.class_private_size = pnode->data->class.class_private_size;
1162	data->class.init_state = UNINITIALIZED;
1163	}
1164	else if (NODE_IS_IFACE (node))
1165	{
1166	data = g_malloc0 (n_bytes: sizeof (IFaceData) + vtable_size);
1167	if (vtable_size)
1168	vtable = G_STRUCT_MEMBER_P (data, sizeof (IFaceData));
1169	data->iface.vtable_size = info->class_size;
1170	data->iface.vtable_init_base = info->base_init;
1171	data->iface.vtable_finalize_base = info->base_finalize;
1172	data->iface.dflt_init = info->class_init;
1173	data->iface.dflt_finalize = info->class_finalize;
1174	data->iface.dflt_data = info->class_data;
1175	data->iface.dflt_vtable = NULL;
1176	}
1177	else if (NODE_IS_BOXED (node))
1178	{
1179	data = g_malloc0 (n_bytes: sizeof (BoxedData) + vtable_size);
1180	if (vtable_size)
1181	vtable = G_STRUCT_MEMBER_P (data, sizeof (BoxedData));
1182	}
1183	else
1184	{
1185	data = g_malloc0 (n_bytes: sizeof (CommonData) + vtable_size);
1186	if (vtable_size)
1187	vtable = G_STRUCT_MEMBER_P (data, sizeof (CommonData));
1188	}
1189
1190	node->data = data;
1191
1192	if (vtable_size)
1193	{
1194	gchar *p;
1195
1196	/* we allocate the vtable and its strings together with the type data, so
1197	* children can take over their parent's vtable pointer, and we don't
1198	* need to worry freeing it or not when the child data is destroyed
1199	*/
1200	*vtable = *value_table;
1201	p = G_STRUCT_MEMBER_P (vtable, sizeof (*vtable));
1202	p[0] = 0;
1203	vtable->collect_format = p;
1204	if (value_table->collect_format)
1205	{
1206	strcat (dest: p, src: value_table->collect_format);
1207	p += strlen (s: value_table->collect_format);
1208	}
1209	p++;
1210	p[0] = 0;
1211	vtable->lcopy_format = p;
1212	if (value_table->lcopy_format)
1213	strcat (dest: p, src: value_table->lcopy_format);
1214	}
1215	node->data->common.value_table = vtable;
1216	node->mutatable_check_cache = (node->data->common.value_table->value_init != NULL &&
1217	!((G_TYPE_FLAG_VALUE_ABSTRACT | G_TYPE_FLAG_ABSTRACT) &
1218	GPOINTER_TO_UINT (type_get_qdata_L (node, static_quark_type_flags))));
1219
1220	g_assert (node->data->common.value_table != NULL); /* paranoid */
1221
1222	g_atomic_int_set ((int *) &node->ref_count, 1);
1223	}
1224
1225	static inline void
1226	type_data_ref_Wm (TypeNode *node)
1227	{
1228	if (!node->data)
1229	{
1230	TypeNode *pnode = lookup_type_node_I (NODE_PARENT_TYPE (node));
1231	GTypeInfo tmp_info;
1232	GTypeValueTable tmp_value_table;
1233
1234	g_assert (node->plugin != NULL);
1235
1236	if (pnode)
1237	{
1238	type_data_ref_Wm (node: pnode);
1239	if (node->data)
1240	INVALID_RECURSION ("g_type_plugin_*", node->plugin, NODE_NAME (node));
1241	}
1242
1243	memset (s: &tmp_info, c: 0, n: sizeof (tmp_info));
1244	memset (s: &tmp_value_table, c: 0, n: sizeof (tmp_value_table));
1245
1246	G_WRITE_UNLOCK (&type_rw_lock);
1247	g_type_plugin_use (plugin: node->plugin);
1248	g_type_plugin_complete_type_info (plugin: node->plugin, NODE_TYPE (node), info: &tmp_info, value_table: &tmp_value_table);
1249	G_WRITE_LOCK (&type_rw_lock);
1250	if (node->data)
1251	INVALID_RECURSION ("g_type_plugin_*", node->plugin, NODE_NAME (node));
1252
1253	check_type_info_I (pnode, NODE_FUNDAMENTAL_TYPE (node), NODE_NAME (node), info: &tmp_info);
1254	type_data_make_W (node, info: &tmp_info,
1255	value_table: check_value_table_I (NODE_NAME (node),
1256	value_table: &tmp_value_table) ? &tmp_value_table : NULL);
1257	}
1258	else
1259	{
1260	g_assert (NODE_REFCOUNT (node) > 0);
1261
1262	g_atomic_int_inc ((int *) &node->ref_count);
1263	}
1264	}
1265
1266	static inline gboolean
1267	type_data_ref_U (TypeNode *node)
1268	{
1269	guint current;
1270
1271	do {
1272	current = NODE_REFCOUNT (node);
1273
1274	if (current < 1)
1275	return FALSE;
1276	} while (!g_atomic_int_compare_and_exchange ((int *) &node->ref_count, current, current + 1));
1277
1278	return TRUE;
1279	}
1280
1281	static gboolean
1282	iface_node_has_available_offset_L (TypeNode *iface_node,
1283	gsize offset,
1284	int for_index)
1285	{
1286	guint8 *offsets;
1287
1288	offsets = G_ATOMIC_ARRAY_GET_LOCKED (&iface_node->_prot.offsets, guint8);
1289	if (offsets == NULL)
1290	return TRUE;
1291
1292	if (G_ATOMIC_ARRAY_DATA_SIZE (offsets) <= offset)
1293	return TRUE;
1294
1295	if (offsets[offset] == 0 ||
1296	offsets[offset] == for_index+1)
1297	return TRUE;
1298
1299	return FALSE;
1300	}
1301
1302	static gsize
1303	find_free_iface_offset_L (IFaceEntries *entries)
1304	{
1305	IFaceEntry *entry;
1306	TypeNode *iface_node;
1307	gsize offset;
1308	int i;
1309	int n_entries;
1310
1311	n_entries = IFACE_ENTRIES_N_ENTRIES (entries);
1312	offset = 0;
1313	do
1314	{
1315	for (i = 0; i < n_entries; i++)
1316	{
1317	entry = &entries->entry[i];
1318	iface_node = lookup_type_node_I (utype: entry->iface_type);
1319
1320	if (!iface_node_has_available_offset_L (iface_node, offset, for_index: i))
1321	{
1322	offset++;
1323	break;
1324	}
1325	}
1326	}
1327	while (i != n_entries);
1328
1329	return offset;
1330	}
1331
1332	static void
1333	iface_node_set_offset_L (TypeNode *iface_node,
1334	gsize offset,
1335	int index)
1336	{
1337	guint8 *offsets, *old_offsets;
1338	gsize new_size, old_size;
1339	gsize i;
1340
1341	old_offsets = G_ATOMIC_ARRAY_GET_LOCKED (&iface_node->_prot.offsets, guint8);
1342	if (old_offsets == NULL)
1343	old_size = 0;
1344	else
1345	{
1346	old_size = G_ATOMIC_ARRAY_DATA_SIZE (old_offsets);
1347	if (offset < old_size &&
1348	old_offsets[offset] == index + 1)
1349	return; /* Already set to this index, return */
1350	}
1351	new_size = MAX (old_size, offset + 1);
1352
1353	offsets = _g_atomic_array_copy (array: &iface_node->_prot.offsets,
1354	header_size: 0, additional_element_size: new_size - old_size);
1355
1356	/* Mark new area as unused */
1357	for (i = old_size; i < new_size; i++)
1358	offsets[i] = 0;
1359
1360	offsets[offset] = index + 1;
1361
1362	_g_atomic_array_update (array: &iface_node->_prot.offsets, new_data: offsets);
1363	}
1364
1365	static void
1366	type_node_add_iface_entry_W (TypeNode *node,
1367	GType iface_type,
1368	IFaceEntry *parent_entry)
1369	{
1370	IFaceEntries *entries;
1371	IFaceEntry *entry;
1372	TypeNode *iface_node;
1373	guint i, j;
1374	guint num_entries;
1375
1376	g_assert (node->is_instantiatable);
1377
1378	entries = CLASSED_NODE_IFACES_ENTRIES_LOCKED (node);
1379	if (entries != NULL)
1380	{
1381	num_entries = IFACE_ENTRIES_N_ENTRIES (entries);
1382
1383	g_assert (num_entries < MAX_N_INTERFACES);
1384
1385	for (i = 0; i < num_entries; i++)
1386	{
1387	entry = &entries->entry[i];
1388	if (entry->iface_type == iface_type)
1389	{
1390	/* this can happen in two cases:
1391	* - our parent type already conformed to iface_type and node
1392	* got its own holder info. here, our children already have
1393	* entries and NULL vtables, since this will only work for
1394	* uninitialized classes.
1395	* - an interface type is added to an ancestor after it was
1396	* added to a child type.
1397	*/
1398	if (!parent_entry)
1399	g_assert (entry->vtable == NULL && entry->init_state == UNINITIALIZED);
1400	else
1401	{
1402	/* sick, interface is added to ancestor *after* child type;
1403	* nothing todo, the entry and our children were already setup correctly
1404	*/
1405	}
1406	return;
1407	}
1408	}
1409	}
1410
1411	entries = _g_atomic_array_copy (CLASSED_NODE_IFACES_ENTRIES (node),
1412	IFACE_ENTRIES_HEADER_SIZE,
1413	additional_element_size: sizeof (IFaceEntry));
1414	num_entries = IFACE_ENTRIES_N_ENTRIES (entries);
1415	i = num_entries - 1;
1416	if (i == 0)
1417	entries->offset_index = 0;
1418	entries->entry[i].iface_type = iface_type;
1419	entries->entry[i].vtable = NULL;
1420	entries->entry[i].init_state = UNINITIALIZED;
1421
1422	if (parent_entry)
1423	{
1424	if (node->data && g_atomic_int_get (&node->data->class.init_state) >= BASE_IFACE_INIT)
1425	{
1426	entries->entry[i].init_state = INITIALIZED;
1427	entries->entry[i].vtable = parent_entry->vtable;
1428	}
1429	}
1430
1431	/* Update offsets in iface */
1432	iface_node = lookup_type_node_I (utype: iface_type);
1433
1434	if (iface_node_has_available_offset_L (iface_node,
1435	offset: entries->offset_index,
1436	for_index: i))
1437	{
1438	iface_node_set_offset_L (iface_node,
1439	offset: entries->offset_index, index: i);
1440	}
1441	else
1442	{
1443	entries->offset_index =
1444	find_free_iface_offset_L (entries);
1445	for (j = 0; j < IFACE_ENTRIES_N_ENTRIES (entries); j++)
1446	{
1447	entry = &entries->entry[j];
1448	iface_node =
1449	lookup_type_node_I (utype: entry->iface_type);
1450	iface_node_set_offset_L (iface_node,
1451	offset: entries->offset_index, index: j);
1452	}
1453	}
1454
1455	_g_atomic_array_update (CLASSED_NODE_IFACES_ENTRIES (node), new_data: entries);
1456
1457	if (parent_entry)
1458	{
1459	for (i = 0; i < node->n_children; i++)
1460	type_node_add_iface_entry_W (node: lookup_type_node_I (utype: node->children[i]), iface_type, parent_entry: &entries->entry[i]);
1461	}
1462	}
1463
1464	static void
1465	type_add_interface_Wm (TypeNode *node,
1466	TypeNode *iface,
1467	const GInterfaceInfo *info,
1468	GTypePlugin *plugin)
1469	{
1470	IFaceHolder *iholder = g_new0 (IFaceHolder, 1);
1471	IFaceEntry *entry;
1472	guint i;
1473
1474	g_assert (node->is_instantiatable && NODE_IS_IFACE (iface) && ((info && !plugin) || (!info && plugin)));
1475
1476	iholder->next = iface_node_get_holders_L (iface);
1477	iface_node_set_holders_W (iface, iholder);
1478	iholder->instance_type = NODE_TYPE (node);
1479	iholder->info = info ? g_memdup2 (mem: info, byte_size: sizeof (*info)) : NULL;
1480	iholder->plugin = plugin;
1481
1482	/* create an iface entry for this type */
1483	type_node_add_iface_entry_W (node, NODE_TYPE (iface), NULL);
1484
1485	/* if the class is already (partly) initialized, we may need to base
1486	* initialize and/or initialize the new interface.
1487	*/
1488	if (node->data)
1489	{
1490	InitState class_state = g_atomic_int_get (&node->data->class.init_state);
1491
1492	if (class_state >= BASE_IFACE_INIT)
1493	type_iface_vtable_base_init_Wm (iface, node);
1494
1495	if (class_state >= IFACE_INIT)
1496	type_iface_vtable_iface_init_Wm (iface, node);
1497	}
1498
1499	/* create iface entries for children of this type */
1500	entry = type_lookup_iface_entry_L (node, iface_node: iface);
1501	for (i = 0; i < node->n_children; i++)
1502	type_node_add_iface_entry_W (node: lookup_type_node_I (utype: node->children[i]), NODE_TYPE (iface), parent_entry: entry);
1503	}
1504
1505	static void
1506	type_iface_add_prerequisite_W (TypeNode *iface,
1507	TypeNode *prerequisite_node)
1508	{
1509	GType prerequisite_type = NODE_TYPE (prerequisite_node);
1510	GType *prerequisites, *dependants;
1511	guint n_dependants, i;
1512
1513	g_assert (NODE_IS_IFACE (iface) &&
1514	IFACE_NODE_N_PREREQUISITES (iface) < MAX_N_PREREQUISITES &&
1515	(prerequisite_node->is_instantiatable || NODE_IS_IFACE (prerequisite_node)));
1516
1517	prerequisites = IFACE_NODE_PREREQUISITES (iface);
1518	for (i = 0; i < IFACE_NODE_N_PREREQUISITES (iface); i++)
1519	if (prerequisites[i] == prerequisite_type)
1520	return; /* we already have that prerequisiste */
1521	else if (prerequisites[i] > prerequisite_type)
1522	break;
1523	IFACE_NODE_N_PREREQUISITES (iface) += 1;
1524	IFACE_NODE_PREREQUISITES (iface) = g_renew (GType,
1525	IFACE_NODE_PREREQUISITES (iface),
1526	IFACE_NODE_N_PREREQUISITES (iface));
1527	prerequisites = IFACE_NODE_PREREQUISITES (iface);
1528	memmove (dest: prerequisites + i + 1, src: prerequisites + i,
1529	n: sizeof (prerequisites[0]) * (IFACE_NODE_N_PREREQUISITES (iface) - i - 1));
1530	prerequisites[i] = prerequisite_type;
1531
1532	/* we want to get notified when prerequisites get added to prerequisite_node */
1533	if (NODE_IS_IFACE (prerequisite_node))
1534	{
1535	dependants = iface_node_get_dependants_array_L (prerequisite_node);
1536	n_dependants = dependants ? dependants[0] : 0;
1537	n_dependants += 1;
1538	dependants = g_renew (GType, dependants, n_dependants + 1);
1539	dependants[n_dependants] = NODE_TYPE (iface);
1540	dependants[0] = n_dependants;
1541	iface_node_set_dependants_array_W (prerequisite_node, dependants);
1542	}
1543
1544	/* we need to notify all dependants */
1545	dependants = iface_node_get_dependants_array_L (iface);
1546	n_dependants = dependants ? dependants[0] : 0;
1547	for (i = 1; i <= n_dependants; i++)
1548	type_iface_add_prerequisite_W (iface: lookup_type_node_I (utype: dependants[i]), prerequisite_node);
1549	}
1550
1551	/**
1552	* g_type_interface_add_prerequisite:
1553	* @interface_type: #GType value of an interface type
1554	* @prerequisite_type: #GType value of an interface or instantiatable type
1555	*
1556	* Adds @prerequisite_type to the list of prerequisites of @interface_type.
1557	* This means that any type implementing @interface_type must also implement
1558	* @prerequisite_type. Prerequisites can be thought of as an alternative to
1559	* interface derivation (which GType doesn't support). An interface can have
1560	* at most one instantiatable prerequisite type.
1561	*/
1562	void
1563	g_type_interface_add_prerequisite (GType interface_type,
1564	GType prerequisite_type)
1565	{
1566	TypeNode *iface, *prerequisite_node;
1567	IFaceHolder *holders;
1568
1569	g_return_if_fail (G_TYPE_IS_INTERFACE (interface_type)); /* G_TYPE_IS_INTERFACE() is an external call: _U */
1570	g_return_if_fail (!g_type_is_a (interface_type, prerequisite_type));
1571	g_return_if_fail (!g_type_is_a (prerequisite_type, interface_type));
1572
1573	iface = lookup_type_node_I (utype: interface_type);
1574	prerequisite_node = lookup_type_node_I (utype: prerequisite_type);
1575	if (!iface || !prerequisite_node || !NODE_IS_IFACE (iface))
1576	{
1577	g_warning ("interface type '%s' or prerequisite type '%s' invalid",
1578	type_descriptive_name_I (interface_type),
1579	type_descriptive_name_I (prerequisite_type));
1580	return;
1581	}
1582	G_WRITE_LOCK (&type_rw_lock);
1583	holders = iface_node_get_holders_L (iface);
1584	if (holders)
1585	{
1586	G_WRITE_UNLOCK (&type_rw_lock);
1587	g_warning ("unable to add prerequisite '%s' to interface '%s' which is already in use for '%s'",
1588	type_descriptive_name_I (prerequisite_type),
1589	type_descriptive_name_I (interface_type),
1590	type_descriptive_name_I (holders->instance_type));
1591	return;
1592	}
1593	if (prerequisite_node->is_instantiatable)
1594	{
1595	guint i;
1596
1597	/* can have at most one publicly installable instantiatable prerequisite */
1598	for (i = 0; i < IFACE_NODE_N_PREREQUISITES (iface); i++)
1599	{
1600	TypeNode *prnode = lookup_type_node_I (IFACE_NODE_PREREQUISITES (iface)[i]);
1601
1602	if (prnode->is_instantiatable)
1603	{
1604	G_WRITE_UNLOCK (&type_rw_lock);
1605	g_warning ("adding prerequisite '%s' to interface '%s' conflicts with existing prerequisite '%s'",
1606	type_descriptive_name_I (prerequisite_type),
1607	type_descriptive_name_I (interface_type),
1608	type_descriptive_name_I (NODE_TYPE (prnode)));
1609	return;
1610	}
1611	}
1612
1613	for (i = 0; i < prerequisite_node->n_supers + 1u; i++)
1614	type_iface_add_prerequisite_W (iface, prerequisite_node: lookup_type_node_I (utype: prerequisite_node->supers[i]));
1615	G_WRITE_UNLOCK (&type_rw_lock);
1616	}
1617	else if (NODE_IS_IFACE (prerequisite_node))
1618	{
1619	GType *prerequisites;
1620	guint i;
1621
1622	prerequisites = IFACE_NODE_PREREQUISITES (prerequisite_node);
1623	for (i = 0; i < IFACE_NODE_N_PREREQUISITES (prerequisite_node); i++)
1624	type_iface_add_prerequisite_W (iface, prerequisite_node: lookup_type_node_I (utype: prerequisites[i]));
1625	type_iface_add_prerequisite_W (iface, prerequisite_node);
1626	G_WRITE_UNLOCK (&type_rw_lock);
1627	}
1628	else
1629	{
1630	G_WRITE_UNLOCK (&type_rw_lock);
1631	g_warning ("prerequisite '%s' for interface '%s' is neither instantiatable nor interface",
1632	type_descriptive_name_I (prerequisite_type),
1633	type_descriptive_name_I (interface_type));
1634	}
1635	}
1636
1637	/**
1638	* g_type_interface_prerequisites:
1639	* @interface_type: an interface type
1640	* @n_prerequisites: (out) (optional): location to return the number
1641	* of prerequisites, or %NULL
1642	*
1643	* Returns the prerequisites of an interfaces type.
1644	*
1645	* Since: 2.2
1646	*
1647	* Returns: (array length=n_prerequisites) (transfer full): a
1648	* newly-allocated zero-terminated array of #GType containing
1649	* the prerequisites of @interface_type
1650	*/
1651	GType*
1652	g_type_interface_prerequisites (GType interface_type,
1653	guint *n_prerequisites)
1654	{
1655	TypeNode *iface;
1656
1657	g_return_val_if_fail (G_TYPE_IS_INTERFACE (interface_type), NULL);
1658
1659	iface = lookup_type_node_I (utype: interface_type);
1660	if (iface)
1661	{
1662	GType *types;
1663	TypeNode *inode = NULL;
1664	guint i, n = 0;
1665
1666	G_READ_LOCK (&type_rw_lock);
1667	types = g_new0 (GType, IFACE_NODE_N_PREREQUISITES (iface) + 1);
1668	for (i = 0; i < IFACE_NODE_N_PREREQUISITES (iface); i++)
1669	{
1670	GType prerequisite = IFACE_NODE_PREREQUISITES (iface)[i];
1671	TypeNode *node = lookup_type_node_I (utype: prerequisite);
1672	if (node->is_instantiatable)
1673	{
1674	if (!inode || type_node_is_a_L (node, iface_node: inode))
1675	inode = node;
1676	}
1677	else
1678	types[n++] = NODE_TYPE (node);
1679	}
1680	if (inode)
1681	types[n++] = NODE_TYPE (inode);
1682
1683	if (n_prerequisites)
1684	*n_prerequisites = n;
1685	G_READ_UNLOCK (&type_rw_lock);
1686
1687	return types;
1688	}
1689	else
1690	{
1691	if (n_prerequisites)
1692	*n_prerequisites = 0;
1693
1694	return NULL;
1695	}
1696	}
1697
1698	/**
1699	* g_type_interface_instantiatable_prerequisite:
1700	* @interface_type: an interface type
1701	*
1702	* Returns the most specific instantiatable prerequisite of an
1703	* interface type. If the interface type has no instantiatable
1704	* prerequisite, %G_TYPE_INVALID is returned.
1705	*
1706	* See g_type_interface_add_prerequisite() for more information
1707	* about prerequisites.
1708	*
1709	* Returns: the instantiatable prerequisite type or %G_TYPE_INVALID if none
1710	*
1711	* Since: 2.68
1712	**/
1713	GType
1714	g_type_interface_instantiatable_prerequisite (GType interface_type)
1715	{
1716	TypeNode *inode = NULL;
1717	TypeNode *iface;
1718	guint i;
1719
1720	g_return_val_if_fail (G_TYPE_IS_INTERFACE (interface_type), G_TYPE_INVALID);
1721
1722	iface = lookup_type_node_I (utype: interface_type);
1723	if (iface == NULL)
1724	return G_TYPE_INVALID;
1725
1726	G_READ_LOCK (&type_rw_lock);
1727
1728	for (i = 0; i < IFACE_NODE_N_PREREQUISITES (iface); i++)
1729	{
1730	GType prerequisite = IFACE_NODE_PREREQUISITES (iface)[i];
1731	TypeNode *node = lookup_type_node_I (utype: prerequisite);
1732	if (node->is_instantiatable)
1733	{
1734	if (!inode || type_node_is_a_L (node, iface_node: inode))
1735	inode = node;
1736	}
1737	}
1738
1739	G_READ_UNLOCK (&type_rw_lock);
1740
1741	if (inode)
1742	return NODE_TYPE (inode);
1743	else
1744	return G_TYPE_INVALID;
1745	}
1746
1747	static IFaceHolder*
1748	type_iface_peek_holder_L (TypeNode *iface,
1749	GType instance_type)
1750	{
1751	IFaceHolder *iholder;
1752
1753	g_assert (NODE_IS_IFACE (iface));
1754
1755	iholder = iface_node_get_holders_L (iface);
1756	while (iholder && iholder->instance_type != instance_type)
1757	iholder = iholder->next;
1758	return iholder;
1759	}
1760
1761	static IFaceHolder*
1762	type_iface_retrieve_holder_info_Wm (TypeNode *iface,
1763	GType instance_type,
1764	gboolean need_info)
1765	{
1766	IFaceHolder *iholder = type_iface_peek_holder_L (iface, instance_type);
1767
1768	if (iholder && !iholder->info && need_info)
1769	{
1770	GInterfaceInfo tmp_info;
1771
1772	g_assert (iholder->plugin != NULL);
1773
1774	type_data_ref_Wm (node: iface);
1775	if (iholder->info)
1776	INVALID_RECURSION ("g_type_plugin_*", iface->plugin, NODE_NAME (iface));
1777
1778	memset (s: &tmp_info, c: 0, n: sizeof (tmp_info));
1779
1780	G_WRITE_UNLOCK (&type_rw_lock);
1781	g_type_plugin_use (plugin: iholder->plugin);
1782	g_type_plugin_complete_interface_info (plugin: iholder->plugin, instance_type, NODE_TYPE (iface), info: &tmp_info);
1783	G_WRITE_LOCK (&type_rw_lock);
1784	if (iholder->info)
1785	INVALID_RECURSION ("g_type_plugin_*", iholder->plugin, NODE_NAME (iface));
1786
1787	check_interface_info_I (iface, instance_type, info: &tmp_info);
1788	iholder->info = g_memdup2 (mem: &tmp_info, byte_size: sizeof (tmp_info));
1789	}
1790
1791	return iholder; /* we don't modify write lock upon returning NULL */
1792	}
1793
1794	static void
1795	type_iface_blow_holder_info_Wm (TypeNode *iface,
1796	GType instance_type)
1797	{
1798	IFaceHolder *iholder = iface_node_get_holders_L (iface);
1799
1800	g_assert (NODE_IS_IFACE (iface));
1801
1802	while (iholder->instance_type != instance_type)
1803	iholder = iholder->next;
1804
1805	if (iholder->info && iholder->plugin)
1806	{
1807	g_free (mem: iholder->info);
1808	iholder->info = NULL;
1809
1810	G_WRITE_UNLOCK (&type_rw_lock);
1811	g_type_plugin_unuse (plugin: iholder->plugin);
1812	type_data_unref_U (node: iface, FALSE);
1813	G_WRITE_LOCK (&type_rw_lock);
1814	}
1815	}
1816
1817	/**
1818	* g_type_create_instance: (skip)
1819	* @type: an instantiatable type to create an instance for
1820	*
1821	* Creates and initializes an instance of @type if @type is valid and
1822	* can be instantiated. The type system only performs basic allocation
1823	* and structure setups for instances: actual instance creation should
1824	* happen through functions supplied by the type's fundamental type
1825	* implementation. So use of g_type_create_instance() is reserved for
1826	* implementers of fundamental types only. E.g. instances of the
1827	* #GObject hierarchy should be created via g_object_new() and never
1828	* directly through g_type_create_instance() which doesn't handle things
1829	* like singleton objects or object construction.
1830	*
1831	* The extended members of the returned instance are guaranteed to be filled
1832	* with zeros.
1833	*
1834	* Note: Do not use this function, unless you're implementing a
1835	* fundamental type. Also language bindings should not use this
1836	* function, but g_object_new() instead.
1837	*
1838	* Returns: an allocated and initialized instance, subject to further
1839	* treatment by the fundamental type implementation
1840	*/
1841	GTypeInstance*
1842	g_type_create_instance (GType type)
1843	{
1844	TypeNode *node;
1845	GTypeInstance *instance;
1846	GTypeClass *class;
1847	gchar *allocated;
1848	gint private_size;
1849	gint ivar_size;
1850	guint i;
1851
1852	node = lookup_type_node_I (utype: type);
1853	if (!node || !node->is_instantiatable)
1854	{
1855	g_error ("cannot create new instance of invalid (non-instantiatable) type '%s'",
1856	type_descriptive_name_I (type));
1857	}
1858	/* G_TYPE_IS_ABSTRACT() is an external call: _U */
1859	if (!node->mutatable_check_cache && G_TYPE_IS_ABSTRACT (type))
1860	{
1861	g_error ("cannot create instance of abstract (non-instantiatable) type '%s'",
1862	type_descriptive_name_I (type));
1863	}
1864
1865	class = g_type_class_ref (type);
1866
1867	/* We allocate the 'private' areas before the normal instance data, in
1868	* reverse order. This allows the private area of a particular class
1869	* to always be at a constant relative address to the instance data.
1870	* If we stored the private data after the instance data this would
1871	* not be the case (since a subclass that added more instance
1872	* variables would push the private data further along).
1873	*
1874	* This presents problems for valgrindability, of course, so we do a
1875	* workaround for that case. We identify the start of the object to
1876	* valgrind as an allocated block (so that pointers to objects show up
1877	* as 'reachable' instead of 'possibly lost'). We then add an extra
1878	* pointer at the end of the object, after all instance data, back to
1879	* the start of the private area so that it is also recorded as
1880	* reachable. We also add extra private space at the start because
1881	* valgrind doesn't seem to like us claiming to have allocated an
1882	* address that it saw allocated by malloc().
1883	*/
1884	private_size = node->data->instance.private_size;
1885	ivar_size = node->data->instance.instance_size;
1886
1887	#ifdef ENABLE_VALGRIND
1888	if (private_size && RUNNING_ON_VALGRIND)
1889	{
1890	private_size += ALIGN_STRUCT (1);
1891
1892	/* Allocate one extra pointer size... */
1893	allocated = g_slice_alloc0 (block_size: private_size + ivar_size + sizeof (gpointer));
1894	/* ... and point it back to the start of the private data. */
1895	*(gpointer *) (allocated + private_size + ivar_size) = allocated + ALIGN_STRUCT (1);
1896
1897	/* Tell valgrind that it should treat the object itself as such */
1898	VALGRIND_MALLOCLIKE_BLOCK (allocated + private_size, ivar_size + sizeof (gpointer), 0, TRUE);
1899	VALGRIND_MALLOCLIKE_BLOCK (allocated + ALIGN_STRUCT (1), private_size - ALIGN_STRUCT (1), 0, TRUE);
1900	}
1901	else
1902	#endif
1903	allocated = g_slice_alloc0 (block_size: private_size + ivar_size);
1904
1905	instance = (GTypeInstance *) (allocated + private_size);
1906
1907	for (i = node->n_supers; i > 0; i--)
1908	{
1909	TypeNode *pnode;
1910
1911	pnode = lookup_type_node_I (utype: node->supers[i]);
1912	if (pnode->data->instance.instance_init)
1913	{
1914	instance->g_class = pnode->data->instance.class;
1915	pnode->data->instance.instance_init (instance, class);
1916	}
1917	}
1918
1919	instance->g_class = class;
1920	if (node->data->instance.instance_init)
1921	node->data->instance.instance_init (instance, class);
1922
1923	#ifdef G_ENABLE_DEBUG
1924	IF_DEBUG (INSTANCE_COUNT)
1925	{
1926	g_atomic_int_inc ((int *) &node->instance_count);
1927	}
1928	#endif
1929
1930	TRACE(GOBJECT_OBJECT_NEW(instance, type));
1931
1932	return instance;
1933	}
1934
1935	/**
1936	* g_type_free_instance:
1937	* @instance: an instance of a type
1938	*
1939	* Frees an instance of a type, returning it to the instance pool for
1940	* the type, if there is one.
1941	*
1942	* Like g_type_create_instance(), this function is reserved for
1943	* implementors of fundamental types.
1944	*/
1945	void
1946	g_type_free_instance (GTypeInstance *instance)
1947	{
1948	TypeNode *node;
1949	GTypeClass *class;
1950	gchar *allocated;
1951	gint private_size;
1952	gint ivar_size;
1953
1954	g_return_if_fail (instance != NULL && instance->g_class != NULL);
1955
1956	class = instance->g_class;
1957	node = lookup_type_node_I (utype: class->g_type);
1958	if (!node || !node->is_instantiatable || !node->data || node->data->class.class != (gpointer) class)
1959	{
1960	g_warning ("cannot free instance of invalid (non-instantiatable) type '%s'",
1961	type_descriptive_name_I (class->g_type));
1962	return;
1963	}
1964	/* G_TYPE_IS_ABSTRACT() is an external call: _U */
1965	if (!node->mutatable_check_cache && G_TYPE_IS_ABSTRACT (NODE_TYPE (node)))
1966	{
1967	g_warning ("cannot free instance of abstract (non-instantiatable) type '%s'",
1968	NODE_NAME (node));
1969	return;
1970	}
1971
1972	instance->g_class = NULL;
1973	private_size = node->data->instance.private_size;
1974	ivar_size = node->data->instance.instance_size;
1975	allocated = ((gchar *) instance) - private_size;
1976
1977	#ifdef G_ENABLE_DEBUG
1978	memset (s: allocated, c: 0xaa, n: ivar_size + private_size);
1979	#endif
1980
1981	#ifdef ENABLE_VALGRIND
1982	/* See comment in g_type_create_instance() about what's going on here.
1983	* We're basically unwinding what we put into motion there.
1984	*/
1985	if (private_size && RUNNING_ON_VALGRIND)
1986	{
1987	private_size += ALIGN_STRUCT (1);
1988	allocated -= ALIGN_STRUCT (1);
1989
1990	/* Clear out the extra pointer... */
1991	*(gpointer *) (allocated + private_size + ivar_size) = NULL;
1992	/* ... and ensure we include it in the size we free. */
1993	g_slice_free1 (block_size: private_size + ivar_size + sizeof (gpointer), mem_block: allocated);
1994
1995	VALGRIND_FREELIKE_BLOCK (allocated + ALIGN_STRUCT (1), 0);
1996	VALGRIND_FREELIKE_BLOCK (instance, 0);
1997	}
1998	else
1999	#endif
2000	g_slice_free1 (block_size: private_size + ivar_size, mem_block: allocated);
2001
2002	#ifdef G_ENABLE_DEBUG
2003	IF_DEBUG (INSTANCE_COUNT)
2004	{
2005	g_atomic_int_add ((int *) &node->instance_count, -1);
2006	}
2007	#endif
2008
2009	g_type_class_unref (g_class: class);
2010	}
2011
2012	static void
2013	type_iface_ensure_dflt_vtable_Wm (TypeNode *iface)
2014	{
2015	g_assert (iface->data);
2016
2017	if (!iface->data->iface.dflt_vtable)
2018	{
2019	GTypeInterface *vtable = g_malloc0 (n_bytes: iface->data->iface.vtable_size);
2020	iface->data->iface.dflt_vtable = vtable;
2021	vtable->g_type = NODE_TYPE (iface);
2022	vtable->g_instance_type = 0;
2023	if (iface->data->iface.vtable_init_base ||
2024	iface->data->iface.dflt_init)
2025	{
2026	G_WRITE_UNLOCK (&type_rw_lock);
2027	if (iface->data->iface.vtable_init_base)
2028	iface->data->iface.vtable_init_base (vtable);
2029	if (iface->data->iface.dflt_init)
2030	iface->data->iface.dflt_init (vtable, (gpointer) iface->data->iface.dflt_data);
2031	G_WRITE_LOCK (&type_rw_lock);
2032	}
2033	}
2034	}
2035
2036
2037	/* This is called to allocate and do the first part of initializing
2038	* the interface vtable; type_iface_vtable_iface_init_Wm() does the remainder.
2039	*
2040	* A FALSE return indicates that we didn't find an init function for
2041	* this type/iface pair, so the vtable from the parent type should
2042	* be used. Note that the write lock is not modified upon a FALSE
2043	* return.
2044	*/
2045	static gboolean
2046	type_iface_vtable_base_init_Wm (TypeNode *iface,
2047	TypeNode *node)
2048	{
2049	IFaceEntry *entry;
2050	IFaceHolder *iholder;
2051	GTypeInterface *vtable = NULL;
2052	TypeNode *pnode;
2053
2054	/* type_iface_retrieve_holder_info_Wm() doesn't modify write lock for returning NULL */
2055	iholder = type_iface_retrieve_holder_info_Wm (iface, NODE_TYPE (node), TRUE);
2056	if (!iholder)
2057	return FALSE; /* we don't modify write lock upon FALSE */
2058
2059	type_iface_ensure_dflt_vtable_Wm (iface);
2060
2061	entry = type_lookup_iface_entry_L (node, iface_node: iface);
2062
2063	g_assert (iface->data && entry && entry->vtable == NULL && iholder && iholder->info);
2064
2065	entry->init_state = IFACE_INIT;
2066
2067	pnode = lookup_type_node_I (NODE_PARENT_TYPE (node));
2068	if (pnode) /* want to copy over parent iface contents */
2069	{
2070	IFaceEntry *pentry = type_lookup_iface_entry_L (node: pnode, iface_node: iface);
2071
2072	if (pentry)
2073	vtable = g_memdup2 (mem: pentry->vtable, byte_size: iface->data->iface.vtable_size);
2074	}
2075	if (!vtable)
2076	vtable = g_memdup2 (mem: iface->data->iface.dflt_vtable, byte_size: iface->data->iface.vtable_size);
2077	entry->vtable = vtable;
2078	vtable->g_type = NODE_TYPE (iface);
2079	vtable->g_instance_type = NODE_TYPE (node);
2080
2081	if (iface->data->iface.vtable_init_base)
2082	{
2083	G_WRITE_UNLOCK (&type_rw_lock);
2084	iface->data->iface.vtable_init_base (vtable);
2085	G_WRITE_LOCK (&type_rw_lock);
2086	}
2087	return TRUE; /* initialized the vtable */
2088	}
2089
2090	/* Finishes what type_iface_vtable_base_init_Wm started by
2091	* calling the interface init function.
2092	* this function may only be called for types with their
2093	* own interface holder info, i.e. types for which
2094	* g_type_add_interface*() was called and not children thereof.
2095	*/
2096	static void
2097	type_iface_vtable_iface_init_Wm (TypeNode *iface,
2098	TypeNode *node)
2099	{
2100	IFaceEntry *entry = type_lookup_iface_entry_L (node, iface_node: iface);
2101	IFaceHolder *iholder = type_iface_peek_holder_L (iface, NODE_TYPE (node));
2102	GTypeInterface *vtable = NULL;
2103	guint i;
2104
2105	/* iholder->info should have been filled in by type_iface_vtable_base_init_Wm() */
2106	g_assert (iface->data && entry && iholder && iholder->info);
2107	g_assert (entry->init_state == IFACE_INIT); /* assert prior base_init() */
2108
2109	entry->init_state = INITIALIZED;
2110
2111	vtable = entry->vtable;
2112
2113	if (iholder->info->interface_init)
2114	{
2115	G_WRITE_UNLOCK (&type_rw_lock);
2116	if (iholder->info->interface_init)
2117	iholder->info->interface_init (vtable, iholder->info->interface_data);
2118	G_WRITE_LOCK (&type_rw_lock);
2119	}
2120
2121	for (i = 0; i < static_n_iface_check_funcs; i++)
2122	{
2123	GTypeInterfaceCheckFunc check_func = static_iface_check_funcs[i].check_func;
2124	gpointer check_data = static_iface_check_funcs[i].check_data;
2125
2126	G_WRITE_UNLOCK (&type_rw_lock);
2127	check_func (check_data, (gpointer)vtable);
2128	G_WRITE_LOCK (&type_rw_lock);
2129	}
2130	}
2131
2132	static gboolean
2133	type_iface_vtable_finalize_Wm (TypeNode *iface,
2134	TypeNode *node,
2135	GTypeInterface *vtable)
2136	{
2137	IFaceEntry *entry = type_lookup_iface_entry_L (node, iface_node: iface);
2138	IFaceHolder *iholder;
2139
2140	/* type_iface_retrieve_holder_info_Wm() doesn't modify write lock for returning NULL */
2141	iholder = type_iface_retrieve_holder_info_Wm (iface, NODE_TYPE (node), FALSE);
2142	if (!iholder)
2143	return FALSE; /* we don't modify write lock upon FALSE */
2144
2145	g_assert (entry && entry->vtable == vtable && iholder->info);
2146
2147	entry->vtable = NULL;
2148	entry->init_state = UNINITIALIZED;
2149	if (iholder->info->interface_finalize || iface->data->iface.vtable_finalize_base)
2150	{
2151	G_WRITE_UNLOCK (&type_rw_lock);
2152	if (iholder->info->interface_finalize)
2153	iholder->info->interface_finalize (vtable, iholder->info->interface_data);
2154	if (iface->data->iface.vtable_finalize_base)
2155	iface->data->iface.vtable_finalize_base (vtable);
2156	G_WRITE_LOCK (&type_rw_lock);
2157	}
2158	vtable->g_type = 0;
2159	vtable->g_instance_type = 0;
2160	g_free (mem: vtable);
2161
2162	type_iface_blow_holder_info_Wm (iface, NODE_TYPE (node));
2163
2164	return TRUE; /* write lock modified */
2165	}
2166
2167	static void
2168	type_class_init_Wm (TypeNode *node,
2169	GTypeClass *pclass)
2170	{
2171	GSList *slist, *init_slist = NULL;
2172	GTypeClass *class;
2173	IFaceEntries *entries;
2174	IFaceEntry *entry;
2175	TypeNode *bnode, *pnode;
2176	guint i;
2177
2178	/* Accessing data->class will work for instantiatable types
2179	* too because ClassData is a subset of InstanceData
2180	*/
2181	g_assert (node->is_classed && node->data &&
2182	node->data->class.class_size &&
2183	!node->data->class.class &&
2184	g_atomic_int_get (&node->data->class.init_state) == UNINITIALIZED);
2185	if (node->data->class.class_private_size)
2186	class = g_malloc0 (ALIGN_STRUCT (node->data->class.class_size) + node->data->class.class_private_size);
2187	else
2188	class = g_malloc0 (n_bytes: node->data->class.class_size);
2189	node->data->class.class = class;
2190	g_atomic_int_set (&node->data->class.init_state, BASE_CLASS_INIT);
2191
2192	if (pclass)
2193	{
2194	TypeNode *pnode = lookup_type_node_I (utype: pclass->g_type);
2195
2196	memcpy (dest: class, src: pclass, n: pnode->data->class.class_size);
2197	memcpy (G_STRUCT_MEMBER_P (class, ALIGN_STRUCT (node->data->class.class_size)), G_STRUCT_MEMBER_P (pclass, ALIGN_STRUCT (pnode->data->class.class_size)), n: pnode->data->class.class_private_size);
2198
2199	if (node->is_instantiatable)
2200	{
2201	/* We need to initialize the private_size here rather than in
2202	* type_data_make_W() since the class init for the parent
2203	* class may have changed pnode->data->instance.private_size.
2204	*/
2205	node->data->instance.private_size = pnode->data->instance.private_size;
2206	}
2207	}
2208	class->g_type = NODE_TYPE (node);
2209
2210	G_WRITE_UNLOCK (&type_rw_lock);
2211
2212	/* stack all base class initialization functions, so we
2213	* call them in ascending order.
2214	*/
2215	for (bnode = node; bnode; bnode = lookup_type_node_I (NODE_PARENT_TYPE (bnode)))
2216	if (bnode->data->class.class_init_base)
2217	init_slist = g_slist_prepend (list: init_slist, data: (gpointer) bnode->data->class.class_init_base);
2218	for (slist = init_slist; slist; slist = slist->next)
2219	{
2220	GBaseInitFunc class_init_base = (GBaseInitFunc) slist->data;
2221
2222	class_init_base (class);
2223	}
2224	g_slist_free (list: init_slist);
2225
2226	G_WRITE_LOCK (&type_rw_lock);
2227
2228	g_atomic_int_set (&node->data->class.init_state, BASE_IFACE_INIT);
2229
2230	/* Before we initialize the class, base initialize all interfaces, either
2231	* from parent, or through our holder info
2232	*/
2233	pnode = lookup_type_node_I (NODE_PARENT_TYPE (node));
2234
2235	i = 0;
2236	while ((entries = CLASSED_NODE_IFACES_ENTRIES_LOCKED (node)) != NULL &&
2237	i < IFACE_ENTRIES_N_ENTRIES (entries))
2238	{
2239	entry = &entries->entry[i];
2240	while (i < IFACE_ENTRIES_N_ENTRIES (entries) &&
2241	entry->init_state == IFACE_INIT)
2242	{
2243	entry++;
2244	i++;
2245	}
2246
2247	if (i == IFACE_ENTRIES_N_ENTRIES (entries))
2248	break;
2249
2250	if (!type_iface_vtable_base_init_Wm (iface: lookup_type_node_I (utype: entry->iface_type), node))
2251	{
2252	guint j;
2253	IFaceEntries *pentries = CLASSED_NODE_IFACES_ENTRIES_LOCKED (pnode);
2254
2255	/* need to get this interface from parent, type_iface_vtable_base_init_Wm()
2256	* doesn't modify write lock upon FALSE, so entry is still valid;
2257	*/
2258	g_assert (pnode != NULL);
2259
2260	if (pentries)
2261	for (j = 0; j < IFACE_ENTRIES_N_ENTRIES (pentries); j++)
2262	{
2263	IFaceEntry *pentry = &pentries->entry[j];
2264
2265	if (pentry->iface_type == entry->iface_type)
2266	{
2267	entry->vtable = pentry->vtable;
2268	entry->init_state = INITIALIZED;
2269	break;
2270	}
2271	}
2272	g_assert (entry->vtable != NULL);
2273	}
2274
2275	/* If the write lock was released, additional interface entries might
2276	* have been inserted into CLASSED_NODE_IFACES_ENTRIES (node); they'll
2277	* be base-initialized when inserted, so we don't have to worry that
2278	* we might miss them. Uninitialized entries can only be moved higher
2279	* when new ones are inserted.
2280	*/
2281	i++;
2282	}
2283
2284	g_atomic_int_set (&node->data->class.init_state, CLASS_INIT);
2285
2286	G_WRITE_UNLOCK (&type_rw_lock);
2287
2288	if (node->data->class.class_init)
2289	node->data->class.class_init (class, (gpointer) node->data->class.class_data);
2290
2291	G_WRITE_LOCK (&type_rw_lock);
2292
2293	g_atomic_int_set (&node->data->class.init_state, IFACE_INIT);
2294
2295	/* finish initializing the interfaces through our holder info.
2296	* inherited interfaces are already init_state == INITIALIZED, because
2297	* they either got setup in the above base_init loop, or during
2298	* class_init from within type_add_interface_Wm() for this or
2299	* an ancestor type.
2300	*/
2301	i = 0;
2302	while ((entries = CLASSED_NODE_IFACES_ENTRIES_LOCKED (node)) != NULL)
2303	{
2304	entry = &entries->entry[i];
2305	while (i < IFACE_ENTRIES_N_ENTRIES (entries) &&
2306	entry->init_state == INITIALIZED)
2307	{
2308	entry++;
2309	i++;
2310	}
2311
2312	if (i == IFACE_ENTRIES_N_ENTRIES (entries))
2313	break;
2314
2315	type_iface_vtable_iface_init_Wm (iface: lookup_type_node_I (utype: entry->iface_type), node);
2316
2317	/* As in the loop above, additional initialized entries might be inserted
2318	* if the write lock is released, but that's harmless because the entries
2319	* we need to initialize only move higher in the list.
2320	*/
2321	i++;
2322	}
2323
2324	g_atomic_int_set (&node->data->class.init_state, INITIALIZED);
2325	}
2326
2327	static void
2328	type_data_finalize_class_ifaces_Wm (TypeNode *node)
2329	{
2330	guint i;
2331	IFaceEntries *entries;
2332
2333	g_assert (node->is_instantiatable && node->data && node->data->class.class && NODE_REFCOUNT (node) == 0);
2334
2335	reiterate:
2336	entries = CLASSED_NODE_IFACES_ENTRIES_LOCKED (node);
2337	for (i = 0; entries != NULL && i < IFACE_ENTRIES_N_ENTRIES (entries); i++)
2338	{
2339	IFaceEntry *entry = &entries->entry[i];
2340	if (entry->vtable)
2341	{
2342	if (type_iface_vtable_finalize_Wm (iface: lookup_type_node_I (utype: entry->iface_type), node, vtable: entry->vtable))
2343	{
2344	/* refetch entries, IFACES_ENTRIES might be modified */
2345	goto reiterate;
2346	}
2347	else
2348	{
2349	/* type_iface_vtable_finalize_Wm() doesn't modify write lock upon FALSE,
2350	* iface vtable came from parent
2351	*/
2352	entry->vtable = NULL;
2353	entry->init_state = UNINITIALIZED;
2354	}
2355	}
2356	}
2357	}
2358
2359	static void
2360	type_data_finalize_class_U (TypeNode *node,
2361	ClassData *cdata)
2362	{
2363	GTypeClass *class = cdata->class;
2364	TypeNode *bnode;
2365
2366	g_assert (cdata->class && NODE_REFCOUNT (node) == 0);
2367
2368	if (cdata->class_finalize)
2369	cdata->class_finalize (class, (gpointer) cdata->class_data);
2370
2371	/* call all base class destruction functions in descending order
2372	*/
2373	if (cdata->class_finalize_base)
2374	cdata->class_finalize_base (class);
2375	for (bnode = lookup_type_node_I (NODE_PARENT_TYPE (node)); bnode; bnode = lookup_type_node_I (NODE_PARENT_TYPE (bnode)))
2376	if (bnode->data->class.class_finalize_base)
2377	bnode->data->class.class_finalize_base (class);
2378
2379	g_free (mem: cdata->class);
2380	}
2381
2382	static void
2383	type_data_last_unref_Wm (TypeNode *node,
2384	gboolean uncached)
2385	{
2386	g_return_if_fail (node != NULL && node->plugin != NULL);
2387
2388	if (!node->data || NODE_REFCOUNT (node) == 0)
2389	{
2390	g_warning ("cannot drop last reference to unreferenced type '%s'",
2391	NODE_NAME (node));
2392	return;
2393	}
2394
2395	/* call class cache hooks */
2396	if (node->is_classed && node->data && node->data->class.class && static_n_class_cache_funcs && !uncached)
2397	{
2398	guint i;
2399
2400	G_WRITE_UNLOCK (&type_rw_lock);
2401	G_READ_LOCK (&type_rw_lock);
2402	for (i = 0; i < static_n_class_cache_funcs; i++)
2403	{
2404	GTypeClassCacheFunc cache_func = static_class_cache_funcs[i].cache_func;
2405	gpointer cache_data = static_class_cache_funcs[i].cache_data;
2406	gboolean need_break;
2407
2408	G_READ_UNLOCK (&type_rw_lock);
2409	need_break = cache_func (cache_data, node->data->class.class);
2410	G_READ_LOCK (&type_rw_lock);
2411	if (!node->data || NODE_REFCOUNT (node) == 0)
2412	INVALID_RECURSION ("GType class cache function ", cache_func, NODE_NAME (node));
2413	if (need_break)
2414	break;
2415	}
2416	G_READ_UNLOCK (&type_rw_lock);
2417	G_WRITE_LOCK (&type_rw_lock);
2418	}
2419
2420	/* may have been re-referenced meanwhile */
2421	if (g_atomic_int_dec_and_test ((int *) &node->ref_count))
2422	{
2423	GType ptype = NODE_PARENT_TYPE (node);
2424	TypeData *tdata;
2425
2426	if (node->is_instantiatable)
2427	{
2428	/* destroy node->data->instance.mem_chunk */
2429	}
2430
2431	tdata = node->data;
2432	if (node->is_classed && tdata->class.class)
2433	{
2434	if (CLASSED_NODE_IFACES_ENTRIES_LOCKED (node) != NULL)
2435	type_data_finalize_class_ifaces_Wm (node);
2436	node->mutatable_check_cache = FALSE;
2437	node->data = NULL;
2438	G_WRITE_UNLOCK (&type_rw_lock);
2439	type_data_finalize_class_U (node, cdata: &tdata->class);
2440	G_WRITE_LOCK (&type_rw_lock);
2441	}
2442	else if (NODE_IS_IFACE (node) && tdata->iface.dflt_vtable)
2443	{
2444	node->mutatable_check_cache = FALSE;
2445	node->data = NULL;
2446	if (tdata->iface.dflt_finalize || tdata->iface.vtable_finalize_base)
2447	{
2448	G_WRITE_UNLOCK (&type_rw_lock);
2449	if (tdata->iface.dflt_finalize)
2450	tdata->iface.dflt_finalize (tdata->iface.dflt_vtable, (gpointer) tdata->iface.dflt_data);
2451	if (tdata->iface.vtable_finalize_base)
2452	tdata->iface.vtable_finalize_base (tdata->iface.dflt_vtable);
2453	G_WRITE_LOCK (&type_rw_lock);
2454	}
2455	g_free (mem: tdata->iface.dflt_vtable);
2456	}
2457	else
2458	{
2459	node->mutatable_check_cache = FALSE;
2460	node->data = NULL;
2461	}
2462
2463	/* freeing tdata->common.value_table and its contents is taken care of
2464	* by allocating it in one chunk with tdata
2465	*/
2466	g_free (mem: tdata);
2467
2468	G_WRITE_UNLOCK (&type_rw_lock);
2469	g_type_plugin_unuse (plugin: node->plugin);
2470	if (ptype)
2471	type_data_unref_U (node: lookup_type_node_I (utype: ptype), FALSE);
2472	G_WRITE_LOCK (&type_rw_lock);
2473	}
2474	}
2475
2476	static inline void
2477	type_data_unref_U (TypeNode *node,
2478	gboolean uncached)
2479	{
2480	guint current;
2481
2482	do {
2483	current = NODE_REFCOUNT (node);
2484
2485	if (current <= 1)
2486	{
2487	if (!node->plugin)
2488	{
2489	g_warning ("static type '%s' unreferenced too often",
2490	NODE_NAME (node));
2491	return;
2492	}
2493	else
2494	{
2495	/* This is the last reference of a type from a plugin. We are
2496	* experimentally disabling support for unloading type
2497	* plugins, so don't allow the last ref to drop.
2498	*/
2499	return;
2500	}
2501
2502	g_assert (current > 0);
2503
2504	g_rec_mutex_lock (rec_mutex: &class_init_rec_mutex); /* required locking order: 1) class_init_rec_mutex, 2) type_rw_lock */
2505	G_WRITE_LOCK (&type_rw_lock);
2506	type_data_last_unref_Wm (node, uncached);
2507	G_WRITE_UNLOCK (&type_rw_lock);
2508	g_rec_mutex_unlock (rec_mutex: &class_init_rec_mutex);
2509	return;
2510	}
2511	} while (!g_atomic_int_compare_and_exchange ((int *) &node->ref_count, current, current - 1));
2512	}
2513
2514	/**
2515	* g_type_add_class_cache_func: (skip)
2516	* @cache_data: data to be passed to @cache_func
2517	* @cache_func: a #GTypeClassCacheFunc
2518	*
2519	* Adds a #GTypeClassCacheFunc to be called before the reference count of a
2520	* class goes from one to zero. This can be used to prevent premature class
2521	* destruction. All installed #GTypeClassCacheFunc functions will be chained
2522	* until one of them returns %TRUE. The functions have to check the class id
2523	* passed in to figure whether they actually want to cache the class of this
2524	* type, since all classes are routed through the same #GTypeClassCacheFunc
2525	* chain.
2526	*/
2527	void
2528	g_type_add_class_cache_func (gpointer cache_data,
2529	GTypeClassCacheFunc cache_func)
2530	{
2531	guint i;
2532
2533	g_return_if_fail (cache_func != NULL);
2534
2535	G_WRITE_LOCK (&type_rw_lock);
2536	i = static_n_class_cache_funcs++;
2537	static_class_cache_funcs = g_renew (ClassCacheFunc, static_class_cache_funcs, static_n_class_cache_funcs);
2538	static_class_cache_funcs[i].cache_data = cache_data;
2539	static_class_cache_funcs[i].cache_func = cache_func;
2540	G_WRITE_UNLOCK (&type_rw_lock);
2541	}
2542
2543	/**
2544	* g_type_remove_class_cache_func: (skip)
2545	* @cache_data: data that was given when adding @cache_func
2546	* @cache_func: a #GTypeClassCacheFunc
2547	*
2548	* Removes a previously installed #GTypeClassCacheFunc. The cache
2549	* maintained by @cache_func has to be empty when calling
2550	* g_type_remove_class_cache_func() to avoid leaks.
2551	*/
2552	void
2553	g_type_remove_class_cache_func (gpointer cache_data,
2554	GTypeClassCacheFunc cache_func)
2555	{
2556	gboolean found_it = FALSE;
2557	guint i;
2558
2559	g_return_if_fail (cache_func != NULL);
2560
2561	G_WRITE_LOCK (&type_rw_lock);
2562	for (i = 0; i < static_n_class_cache_funcs; i++)
2563	if (static_class_cache_funcs[i].cache_data == cache_data &&
2564	static_class_cache_funcs[i].cache_func == cache_func)
2565	{
2566	static_n_class_cache_funcs--;
2567	memmove (dest: static_class_cache_funcs + i,
2568	src: static_class_cache_funcs + i + 1,
2569	n: sizeof (static_class_cache_funcs[0]) * (static_n_class_cache_funcs - i));
2570	static_class_cache_funcs = g_renew (ClassCacheFunc, static_class_cache_funcs, static_n_class_cache_funcs);
2571	found_it = TRUE;
2572	break;
2573	}
2574	G_WRITE_UNLOCK (&type_rw_lock);
2575
2576	if (!found_it)
2577	g_warning (G_STRLOC ": cannot remove unregistered class cache func %p with data %p",
2578	cache_func, cache_data);
2579	}
2580
2581
2582	/**
2583	* g_type_add_interface_check: (skip)
2584	* @check_data: data to pass to @check_func
2585	* @check_func: function to be called after each interface
2586	* is initialized
2587	*
2588	* Adds a function to be called after an interface vtable is
2589	* initialized for any class (i.e. after the @interface_init
2590	* member of #GInterfaceInfo has been called).
2591	*
2592	* This function is useful when you want to check an invariant
2593	* that depends on the interfaces of a class. For instance, the
2594	* implementation of #GObject uses this facility to check that an
2595	* object implements all of the properties that are defined on its
2596	* interfaces.
2597	*
2598	* Since: 2.4
2599	*/
2600	void
2601	g_type_add_interface_check (gpointer check_data,
2602	GTypeInterfaceCheckFunc check_func)
2603	{
2604	guint i;
2605
2606	g_return_if_fail (check_func != NULL);
2607
2608	G_WRITE_LOCK (&type_rw_lock);
2609	i = static_n_iface_check_funcs++;
2610	static_iface_check_funcs = g_renew (IFaceCheckFunc, static_iface_check_funcs, static_n_iface_check_funcs);
2611	static_iface_check_funcs[i].check_data = check_data;
2612	static_iface_check_funcs[i].check_func = check_func;
2613	G_WRITE_UNLOCK (&type_rw_lock);
2614	}
2615
2616	/**
2617	* g_type_remove_interface_check: (skip)
2618	* @check_data: callback data passed to g_type_add_interface_check()
2619	* @check_func: callback function passed to g_type_add_interface_check()
2620	*
2621	* Removes an interface check function added with
2622	* g_type_add_interface_check().
2623	*
2624	* Since: 2.4
2625	*/
2626	void
2627	g_type_remove_interface_check (gpointer check_data,
2628	GTypeInterfaceCheckFunc check_func)
2629	{
2630	gboolean found_it = FALSE;
2631	guint i;
2632
2633	g_return_if_fail (check_func != NULL);
2634
2635	G_WRITE_LOCK (&type_rw_lock);
2636	for (i = 0; i < static_n_iface_check_funcs; i++)
2637	if (static_iface_check_funcs[i].check_data == check_data &&
2638	static_iface_check_funcs[i].check_func == check_func)
2639	{
2640	static_n_iface_check_funcs--;
2641	memmove (dest: static_iface_check_funcs + i,
2642	src: static_iface_check_funcs + i + 1,
2643	n: sizeof (static_iface_check_funcs[0]) * (static_n_iface_check_funcs - i));
2644	static_iface_check_funcs = g_renew (IFaceCheckFunc, static_iface_check_funcs, static_n_iface_check_funcs);
2645	found_it = TRUE;
2646	break;
2647	}
2648	G_WRITE_UNLOCK (&type_rw_lock);
2649
2650	if (!found_it)
2651	g_warning (G_STRLOC ": cannot remove unregistered class check func %p with data %p",
2652	check_func, check_data);
2653	}
2654
2655	/* --- type registration --- */
2656	/**
2657	* g_type_register_fundamental:
2658	* @type_id: a predefined type identifier
2659	* @type_name: 0-terminated string used as the name of the new type
2660	* @info: #GTypeInfo structure for this type
2661	* @finfo: #GTypeFundamentalInfo structure for this type
2662	* @flags: bitwise combination of #GTypeFlags values
2663	*
2664	* Registers @type_id as the predefined identifier and @type_name as the
2665	* name of a fundamental type. If @type_id is already registered, or a
2666	* type named @type_name is already registered, the behaviour is undefined.
2667	* The type system uses the information contained in the #GTypeInfo structure
2668	* pointed to by @info and the #GTypeFundamentalInfo structure pointed to by
2669	* @finfo to manage the type and its instances. The value of @flags determines
2670	* additional characteristics of the fundamental type.
2671	*
2672	* Returns: the predefined type identifier
2673	*/
2674	GType
2675	g_type_register_fundamental (GType type_id,
2676	const gchar *type_name,
2677	const GTypeInfo *info,
2678	const GTypeFundamentalInfo *finfo,
2679	GTypeFlags flags)
2680	{
2681	TypeNode *node;
2682
2683	g_assert_type_system_initialized ();
2684	g_return_val_if_fail (type_id > 0, 0);
2685	g_return_val_if_fail (type_name != NULL, 0);
2686	g_return_val_if_fail (info != NULL, 0);
2687	g_return_val_if_fail (finfo != NULL, 0);
2688
2689	if (!check_type_name_I (type_name))
2690	return 0;
2691	if ((type_id & TYPE_ID_MASK) ||
2692	type_id > G_TYPE_FUNDAMENTAL_MAX)
2693	{
2694	g_warning ("attempt to register fundamental type '%s' with invalid type id (%" G_GSIZE_FORMAT ")",
2695	type_name,
2696	type_id);
2697	return 0;
2698	}
2699	if ((finfo->type_flags & G_TYPE_FLAG_INSTANTIATABLE) &&
2700	!(finfo->type_flags & G_TYPE_FLAG_CLASSED))
2701	{
2702	g_warning ("cannot register instantiatable fundamental type '%s' as non-classed",
2703	type_name);
2704	return 0;
2705	}
2706	if (lookup_type_node_I (utype: type_id))
2707	{
2708	g_warning ("cannot register existing fundamental type '%s' (as '%s')",
2709	type_descriptive_name_I (type_id),
2710	type_name);
2711	return 0;
2712	}
2713
2714	G_WRITE_LOCK (&type_rw_lock);
2715	node = type_node_fundamental_new_W (ftype: type_id, name: type_name, type_flags: finfo->type_flags);
2716	type_add_flags_W (node, flags);
2717
2718	if (check_type_info_I (NULL, NODE_FUNDAMENTAL_TYPE (node), type_name, info))
2719	type_data_make_W (node, info,
2720	value_table: check_value_table_I (type_name, value_table: info->value_table) ? info->value_table : NULL);
2721	G_WRITE_UNLOCK (&type_rw_lock);
2722
2723	return NODE_TYPE (node);
2724	}
2725
2726	/**
2727	* g_type_register_static_simple: (skip)
2728	* @parent_type: type from which this type will be derived
2729	* @type_name: 0-terminated string used as the name of the new type
2730	* @class_size: size of the class structure (see #GTypeInfo)
2731	* @class_init: location of the class initialization function (see #GTypeInfo)
2732	* @instance_size: size of the instance structure (see #GTypeInfo)
2733	* @instance_init: location of the instance initialization function (see #GTypeInfo)
2734	* @flags: bitwise combination of #GTypeFlags values
2735	*
2736	* Registers @type_name as the name of a new static type derived from
2737	* @parent_type. The value of @flags determines the nature (e.g.
2738	* abstract or not) of the type. It works by filling a #GTypeInfo
2739	* struct and calling g_type_register_static().
2740	*
2741	* Since: 2.12
2742	*
2743	* Returns: the new type identifier
2744	*/
2745	GType
2746	g_type_register_static_simple (GType parent_type,
2747	const gchar *type_name,
2748	guint class_size,
2749	GClassInitFunc class_init,
2750	guint instance_size,
2751	GInstanceInitFunc instance_init,
2752	GTypeFlags flags)
2753	{
2754	GTypeInfo info;
2755
2756	/* Instances are not allowed to be larger than this. If you have a big
2757	* fixed-length array or something, point to it instead.
2758	*/
2759	g_return_val_if_fail (class_size <= G_MAXUINT16, G_TYPE_INVALID);
2760	g_return_val_if_fail (instance_size <= G_MAXUINT16, G_TYPE_INVALID);
2761
2762	info.class_size = class_size;
2763	info.base_init = NULL;
2764	info.base_finalize = NULL;
2765	info.class_init = class_init;
2766	info.class_finalize = NULL;
2767	info.class_data = NULL;
2768	info.instance_size = instance_size;
2769	info.n_preallocs = 0;
2770	info.instance_init = instance_init;
2771	info.value_table = NULL;
2772
2773	return g_type_register_static (parent_type, type_name, info: &info, flags);
2774	}
2775
2776	/**
2777	* g_type_register_static:
2778	* @parent_type: type from which this type will be derived
2779	* @type_name: 0-terminated string used as the name of the new type
2780	* @info: #GTypeInfo structure for this type
2781	* @flags: bitwise combination of #GTypeFlags values
2782	*
2783	* Registers @type_name as the name of a new static type derived from
2784	* @parent_type. The type system uses the information contained in the
2785	* #GTypeInfo structure pointed to by @info to manage the type and its
2786	* instances (if not abstract). The value of @flags determines the nature
2787	* (e.g. abstract or not) of the type.
2788	*
2789	* Returns: the new type identifier
2790	*/
2791	GType
2792	g_type_register_static (GType parent_type,
2793	const gchar *type_name,
2794	const GTypeInfo *info,
2795	GTypeFlags flags)
2796	{
2797	TypeNode *pnode, *node;
2798	GType type = 0;
2799
2800	g_assert_type_system_initialized ();
2801	g_return_val_if_fail (parent_type > 0, 0);
2802	g_return_val_if_fail (type_name != NULL, 0);
2803	g_return_val_if_fail (info != NULL, 0);
2804
2805	if (!check_type_name_I (type_name) ||
2806	!check_derivation_I (parent_type, type_name))
2807	return 0;
2808	if (info->class_finalize)
2809	{
2810	g_warning ("class finalizer specified for static type '%s'",
2811	type_name);
2812	return 0;
2813	}
2814
2815	pnode = lookup_type_node_I (utype: parent_type);
2816	G_WRITE_LOCK (&type_rw_lock);
2817	type_data_ref_Wm (node: pnode);
2818	if (check_type_info_I (pnode, NODE_FUNDAMENTAL_TYPE (pnode), type_name, info))
2819	{
2820	node = type_node_new_W (pnode, name: type_name, NULL);
2821	type_add_flags_W (node, flags);
2822	type = NODE_TYPE (node);
2823	type_data_make_W (node, info,
2824	value_table: check_value_table_I (type_name, value_table: info->value_table) ? info->value_table : NULL);
2825	}
2826	G_WRITE_UNLOCK (&type_rw_lock);
2827
2828	return type;
2829	}
2830
2831	/**
2832	* g_type_register_dynamic:
2833	* @parent_type: type from which this type will be derived
2834	* @type_name: 0-terminated string used as the name of the new type
2835	* @plugin: #GTypePlugin structure to retrieve the #GTypeInfo from
2836	* @flags: bitwise combination of #GTypeFlags values
2837	*
2838	* Registers @type_name as the name of a new dynamic type derived from
2839	* @parent_type. The type system uses the information contained in the
2840	* #GTypePlugin structure pointed to by @plugin to manage the type and its
2841	* instances (if not abstract). The value of @flags determines the nature
2842	* (e.g. abstract or not) of the type.
2843	*
2844	* Returns: the new type identifier or #G_TYPE_INVALID if registration failed
2845	*/
2846	GType
2847	g_type_register_dynamic (GType parent_type,
2848	const gchar *type_name,
2849	GTypePlugin *plugin,
2850	GTypeFlags flags)
2851	{
2852	TypeNode *pnode, *node;
2853	GType type;
2854
2855	g_assert_type_system_initialized ();
2856	g_return_val_if_fail (parent_type > 0, 0);
2857	g_return_val_if_fail (type_name != NULL, 0);
2858	g_return_val_if_fail (plugin != NULL, 0);
2859
2860	if (!check_type_name_I (type_name) ||
2861	!check_derivation_I (parent_type, type_name) ||
2862	!check_plugin_U (plugin, TRUE, FALSE, type_name))
2863	return 0;
2864
2865	G_WRITE_LOCK (&type_rw_lock);
2866	pnode = lookup_type_node_I (utype: parent_type);
2867	node = type_node_new_W (pnode, name: type_name, plugin);
2868	type_add_flags_W (node, flags);
2869	type = NODE_TYPE (node);
2870	G_WRITE_UNLOCK (&type_rw_lock);
2871
2872	return type;
2873	}
2874
2875	/**
2876	* g_type_add_interface_static:
2877	* @instance_type: #GType value of an instantiatable type
2878	* @interface_type: #GType value of an interface type
2879	* @info: #GInterfaceInfo structure for this
2880	* (@instance_type, @interface_type) combination
2881	*
2882	* Adds @interface_type to the static @instance_type.
2883	* The information contained in the #GInterfaceInfo structure
2884	* pointed to by @info is used to manage the relationship.
2885	*/
2886	void
2887	g_type_add_interface_static (GType instance_type,
2888	GType interface_type,
2889	const GInterfaceInfo *info)
2890	{
2891	/* G_TYPE_IS_INSTANTIATABLE() is an external call: _U */
2892	g_return_if_fail (G_TYPE_IS_INSTANTIATABLE (instance_type));
2893	g_return_if_fail (g_type_parent (interface_type) == G_TYPE_INTERFACE);
2894
2895	/* we only need to lock class_init_rec_mutex if instance_type already has its
2896	* class initialized, however this function is rarely enough called to take
2897	* the simple route and always acquire class_init_rec_mutex.
2898	*/
2899	g_rec_mutex_lock (rec_mutex: &class_init_rec_mutex); /* required locking order: 1) class_init_rec_mutex, 2) type_rw_lock */
2900	G_WRITE_LOCK (&type_rw_lock);
2901	if (check_add_interface_L (instance_type, iface_type: interface_type))
2902	{
2903	TypeNode *node = lookup_type_node_I (utype: instance_type);
2904	TypeNode *iface = lookup_type_node_I (utype: interface_type);
2905	if (check_interface_info_I (iface, NODE_TYPE (node), info))
2906	type_add_interface_Wm (node, iface, info, NULL);
2907	}
2908	G_WRITE_UNLOCK (&type_rw_lock);
2909	g_rec_mutex_unlock (rec_mutex: &class_init_rec_mutex);
2910	}
2911
2912	/**
2913	* g_type_add_interface_dynamic:
2914	* @instance_type: #GType value of an instantiatable type
2915	* @interface_type: #GType value of an interface type
2916	* @plugin: #GTypePlugin structure to retrieve the #GInterfaceInfo from
2917	*
2918	* Adds @interface_type to the dynamic @instance_type. The information
2919	* contained in the #GTypePlugin structure pointed to by @plugin
2920	* is used to manage the relationship.
2921	*/
2922	void
2923	g_type_add_interface_dynamic (GType instance_type,
2924	GType interface_type,
2925	GTypePlugin *plugin)
2926	{
2927	TypeNode *node;
2928	/* G_TYPE_IS_INSTANTIATABLE() is an external call: _U */
2929	g_return_if_fail (G_TYPE_IS_INSTANTIATABLE (instance_type));
2930	g_return_if_fail (g_type_parent (interface_type) == G_TYPE_INTERFACE);
2931
2932	node = lookup_type_node_I (utype: instance_type);
2933	if (!check_plugin_U (plugin, FALSE, TRUE, NODE_NAME (node)))
2934	return;
2935
2936	/* see comment in g_type_add_interface_static() about class_init_rec_mutex */
2937	g_rec_mutex_lock (rec_mutex: &class_init_rec_mutex); /* required locking order: 1) class_init_rec_mutex, 2) type_rw_lock */
2938	G_WRITE_LOCK (&type_rw_lock);
2939	if (check_add_interface_L (instance_type, iface_type: interface_type))
2940	{
2941	TypeNode *iface = lookup_type_node_I (utype: interface_type);
2942	type_add_interface_Wm (node, iface, NULL, plugin);
2943	}
2944	G_WRITE_UNLOCK (&type_rw_lock);
2945	g_rec_mutex_unlock (rec_mutex: &class_init_rec_mutex);
2946	}
2947
2948
2949	/* --- public API functions --- */
2950	/**
2951	* g_type_class_ref:
2952	* @type: type ID of a classed type
2953	*
2954	* Increments the reference count of the class structure belonging to
2955	* @type. This function will demand-create the class if it doesn't
2956	* exist already.
2957	*
2958	* Returns: (type GObject.TypeClass) (transfer none): the #GTypeClass
2959	* structure for the given type ID
2960	*/
2961	gpointer
2962	g_type_class_ref (GType type)
2963	{
2964	TypeNode *node;
2965	GType ptype;
2966	gboolean holds_ref;
2967	GTypeClass *pclass;
2968
2969	/* optimize for common code path */
2970	node = lookup_type_node_I (utype: type);
2971	if (!node || !node->is_classed)
2972	{
2973	g_warning ("cannot retrieve class for invalid (unclassed) type '%s'",
2974	type_descriptive_name_I (type));
2975	return NULL;
2976	}
2977
2978	if (G_LIKELY (type_data_ref_U (node)))
2979	{
2980	if (G_LIKELY (g_atomic_int_get (&node->data->class.init_state) == INITIALIZED))
2981	return node->data->class.class;
2982	holds_ref = TRUE;
2983	}
2984	else
2985	holds_ref = FALSE;
2986
2987	/* here, we either have node->data->class.class == NULL, or a recursive
2988	* call to g_type_class_ref() with a partly initialized class, or
2989	* node->data->class.init_state == INITIALIZED, because any
2990	* concurrently running initialization was guarded by class_init_rec_mutex.
2991	*/
2992	g_rec_mutex_lock (rec_mutex: &class_init_rec_mutex); /* required locking order: 1) class_init_rec_mutex, 2) type_rw_lock */
2993
2994	/* we need an initialized parent class for initializing derived classes */
2995	ptype = NODE_PARENT_TYPE (node);
2996	pclass = ptype ? g_type_class_ref (type: ptype) : NULL;
2997
2998	G_WRITE_LOCK (&type_rw_lock);
2999
3000	if (!holds_ref)
3001	type_data_ref_Wm (node);
3002
3003	if (!node->data->class.class) /* class uninitialized */
3004	type_class_init_Wm (node, pclass);
3005
3006	G_WRITE_UNLOCK (&type_rw_lock);
3007
3008	if (pclass)
3009	g_type_class_unref (g_class: pclass);
3010
3011	g_rec_mutex_unlock (rec_mutex: &class_init_rec_mutex);
3012
3013	return node->data->class.class;
3014	}
3015
3016	/**
3017	* g_type_class_unref:
3018	* @g_class: (type GObject.TypeClass): a #GTypeClass structure to unref
3019	*
3020	* Decrements the reference count of the class structure being passed in.
3021	* Once the last reference count of a class has been released, classes
3022	* may be finalized by the type system, so further dereferencing of a
3023	* class pointer after g_type_class_unref() are invalid.
3024	*/
3025	void
3026	g_type_class_unref (gpointer g_class)
3027	{
3028	TypeNode *node;
3029	GTypeClass *class = g_class;
3030
3031	g_return_if_fail (g_class != NULL);
3032
3033	node = lookup_type_node_I (utype: class->g_type);
3034	if (node && node->is_classed && NODE_REFCOUNT (node))
3035	type_data_unref_U (node, FALSE);
3036	else
3037	g_warning ("cannot unreference class of invalid (unclassed) type '%s'",
3038	type_descriptive_name_I (class->g_type));
3039	}
3040
3041	/**
3042	* g_type_class_unref_uncached: (skip)
3043	* @g_class: (type GObject.TypeClass): a #GTypeClass structure to unref
3044	*
3045	* A variant of g_type_class_unref() for use in #GTypeClassCacheFunc
3046	* implementations. It unreferences a class without consulting the chain
3047	* of #GTypeClassCacheFuncs, avoiding the recursion which would occur
3048	* otherwise.
3049	*/
3050	void
3051	g_type_class_unref_uncached (gpointer g_class)
3052	{
3053	TypeNode *node;
3054	GTypeClass *class = g_class;
3055
3056	g_return_if_fail (g_class != NULL);
3057
3058	node = lookup_type_node_I (utype: class->g_type);
3059	if (node && node->is_classed && NODE_REFCOUNT (node))
3060	type_data_unref_U (node, TRUE);
3061	else
3062	g_warning ("cannot unreference class of invalid (unclassed) type '%s'",
3063	type_descriptive_name_I (class->g_type));
3064	}
3065
3066	/**
3067	* g_type_class_peek:
3068	* @type: type ID of a classed type
3069	*
3070	* This function is essentially the same as g_type_class_ref(),
3071	* except that the classes reference count isn't incremented.
3072	* As a consequence, this function may return %NULL if the class
3073	* of the type passed in does not currently exist (hasn't been
3074	* referenced before).
3075	*
3076	* Returns: (type GObject.TypeClass) (transfer none): the #GTypeClass
3077	* structure for the given type ID or %NULL if the class does not
3078	* currently exist
3079	*/
3080	gpointer
3081	g_type_class_peek (GType type)
3082	{
3083	TypeNode *node;
3084	gpointer class;
3085
3086	node = lookup_type_node_I (utype: type);
3087	if (node && node->is_classed && NODE_REFCOUNT (node) &&
3088	g_atomic_int_get (&node->data->class.init_state) == INITIALIZED)
3089	/* ref_count _may_ be 0 */
3090	class = node->data->class.class;
3091	else
3092	class = NULL;
3093
3094	return class;
3095	}
3096
3097	/**
3098	* g_type_class_peek_static:
3099	* @type: type ID of a classed type
3100	*
3101	* A more efficient version of g_type_class_peek() which works only for
3102	* static types.
3103	*
3104	* Returns: (type GObject.TypeClass) (transfer none): the #GTypeClass
3105	* structure for the given type ID or %NULL if the class does not
3106	* currently exist or is dynamically loaded
3107	*
3108	* Since: 2.4
3109	*/
3110	gpointer
3111	g_type_class_peek_static (GType type)
3112	{
3113	TypeNode *node;
3114	gpointer class;
3115
3116	node = lookup_type_node_I (utype: type);
3117	if (node && node->is_classed && NODE_REFCOUNT (node) &&
3118	/* peek only static types: */ node->plugin == NULL &&
3119	g_atomic_int_get (&node->data->class.init_state) == INITIALIZED)
3120	/* ref_count _may_ be 0 */
3121	class = node->data->class.class;
3122	else
3123	class = NULL;
3124
3125	return class;
3126	}
3127
3128	/**
3129	* g_type_class_peek_parent:
3130	* @g_class: (type GObject.TypeClass): the #GTypeClass structure to
3131	* retrieve the parent class for
3132	*
3133	* This is a convenience function often needed in class initializers.
3134	* It returns the class structure of the immediate parent type of the
3135	* class passed in. Since derived classes hold a reference count on
3136	* their parent classes as long as they are instantiated, the returned
3137	* class will always exist.
3138	*
3139	* This function is essentially equivalent to:
3140	* g_type_class_peek (g_type_parent (G_TYPE_FROM_CLASS (g_class)))
3141	*
3142	* Returns: (type GObject.TypeClass) (transfer none): the parent class
3143	* of @g_class
3144	*/
3145	gpointer
3146	g_type_class_peek_parent (gpointer g_class)
3147	{
3148	TypeNode *node;
3149	gpointer class = NULL;
3150
3151	g_return_val_if_fail (g_class != NULL, NULL);
3152
3153	node = lookup_type_node_I (G_TYPE_FROM_CLASS (g_class));
3154	/* We used to acquire a read lock here. That is not necessary, since
3155	* parent->data->class.class is constant as long as the derived class
3156	* exists.
3157	*/
3158	if (node && node->is_classed && node->data && NODE_PARENT_TYPE (node))
3159	{
3160	node = lookup_type_node_I (NODE_PARENT_TYPE (node));
3161	class = node->data->class.class;
3162	}
3163	else if (NODE_PARENT_TYPE (node))
3164	g_warning (G_STRLOC ": invalid class pointer '%p'", g_class);
3165
3166	return class;
3167	}
3168
3169	/**
3170	* g_type_interface_peek:
3171	* @instance_class: (type GObject.TypeClass): a #GTypeClass structure
3172	* @iface_type: an interface ID which this class conforms to
3173	*
3174	* Returns the #GTypeInterface structure of an interface to which the
3175	* passed in class conforms.
3176	*
3177	* Returns: (type GObject.TypeInterface) (transfer none): the #GTypeInterface
3178	* structure of @iface_type if implemented by @instance_class, %NULL
3179	* otherwise
3180	*/
3181	gpointer
3182	g_type_interface_peek (gpointer instance_class,
3183	GType iface_type)
3184	{
3185	TypeNode *node;
3186	TypeNode *iface;
3187	gpointer vtable = NULL;
3188	GTypeClass *class = instance_class;
3189
3190	g_return_val_if_fail (instance_class != NULL, NULL);
3191
3192	node = lookup_type_node_I (utype: class->g_type);
3193	iface = lookup_type_node_I (utype: iface_type);
3194	if (node && node->is_instantiatable && iface)
3195	type_lookup_iface_vtable_I (node, iface_node: iface, vtable_ptr: &vtable);
3196	else
3197	g_warning (G_STRLOC ": invalid class pointer '%p'", class);
3198
3199	return vtable;
3200	}
3201
3202	/**
3203	* g_type_interface_peek_parent:
3204	* @g_iface: (type GObject.TypeInterface): a #GTypeInterface structure
3205	*
3206	* Returns the corresponding #GTypeInterface structure of the parent type
3207	* of the instance type to which @g_iface belongs. This is useful when
3208	* deriving the implementation of an interface from the parent type and
3209	* then possibly overriding some methods.
3210	*
3211	* Returns: (transfer none) (type GObject.TypeInterface): the
3212	* corresponding #GTypeInterface structure of the parent type of the
3213	* instance type to which @g_iface belongs, or %NULL if the parent
3214	* type doesn't conform to the interface
3215	*/
3216	gpointer
3217	g_type_interface_peek_parent (gpointer g_iface)
3218	{
3219	TypeNode *node;
3220	TypeNode *iface;
3221	gpointer vtable = NULL;
3222	GTypeInterface *iface_class = g_iface;
3223
3224	g_return_val_if_fail (g_iface != NULL, NULL);
3225
3226	iface = lookup_type_node_I (utype: iface_class->g_type);
3227	node = lookup_type_node_I (utype: iface_class->g_instance_type);
3228	if (node)
3229	node = lookup_type_node_I (NODE_PARENT_TYPE (node));
3230	if (node && node->is_instantiatable && iface)
3231	type_lookup_iface_vtable_I (node, iface_node: iface, vtable_ptr: &vtable);
3232	else if (node)
3233	g_warning (G_STRLOC ": invalid interface pointer '%p'", g_iface);
3234
3235	return vtable;
3236	}
3237
3238	/**
3239	* g_type_default_interface_ref:
3240	* @g_type: an interface type
3241	*
3242	* Increments the reference count for the interface type @g_type,
3243	* and returns the default interface vtable for the type.
3244	*
3245	* If the type is not currently in use, then the default vtable
3246	* for the type will be created and initialized by calling
3247	* the base interface init and default vtable init functions for
3248	* the type (the @base_init and @class_init members of #GTypeInfo).
3249	* Calling g_type_default_interface_ref() is useful when you
3250	* want to make sure that signals and properties for an interface
3251	* have been installed.
3252	*
3253	* Since: 2.4
3254	*
3255	* Returns: (type GObject.TypeInterface) (transfer none): the default
3256	* vtable for the interface; call g_type_default_interface_unref()
3257	* when you are done using the interface.
3258	*/
3259	gpointer
3260	g_type_default_interface_ref (GType g_type)
3261	{
3262	TypeNode *node;
3263	gpointer dflt_vtable;
3264
3265	G_WRITE_LOCK (&type_rw_lock);
3266
3267	node = lookup_type_node_I (utype: g_type);
3268	if (!node || !NODE_IS_IFACE (node) ||
3269	(node->data && NODE_REFCOUNT (node) == 0))
3270	{
3271	G_WRITE_UNLOCK (&type_rw_lock);
3272	g_warning ("cannot retrieve default vtable for invalid or non-interface type '%s'",
3273	type_descriptive_name_I (g_type));
3274	return NULL;
3275	}
3276
3277	if (!node->data || !node->data->iface.dflt_vtable)
3278	{
3279	G_WRITE_UNLOCK (&type_rw_lock);
3280	g_rec_mutex_lock (rec_mutex: &class_init_rec_mutex); /* required locking order: 1) class_init_rec_mutex, 2) type_rw_lock */
3281	G_WRITE_LOCK (&type_rw_lock);
3282	node = lookup_type_node_I (utype: g_type);
3283	type_data_ref_Wm (node);
3284	type_iface_ensure_dflt_vtable_Wm (iface: node);
3285	g_rec_mutex_unlock (rec_mutex: &class_init_rec_mutex);
3286	}
3287	else
3288	type_data_ref_Wm (node); /* ref_count >= 1 already */
3289
3290	dflt_vtable = node->data->iface.dflt_vtable;
3291	G_WRITE_UNLOCK (&type_rw_lock);
3292
3293	return dflt_vtable;
3294	}
3295
3296	/**
3297	* g_type_default_interface_peek:
3298	* @g_type: an interface type
3299	*
3300	* If the interface type @g_type is currently in use, returns its
3301	* default interface vtable.
3302	*
3303	* Since: 2.4
3304	*
3305	* Returns: (type GObject.TypeInterface) (transfer none): the default
3306	* vtable for the interface, or %NULL if the type is not currently
3307	* in use
3308	*/
3309	gpointer
3310	g_type_default_interface_peek (GType g_type)
3311	{
3312	TypeNode *node;
3313	gpointer vtable;
3314
3315	node = lookup_type_node_I (utype: g_type);
3316	if (node && NODE_IS_IFACE (node) && NODE_REFCOUNT (node))
3317	vtable = node->data->iface.dflt_vtable;
3318	else
3319	vtable = NULL;
3320
3321	return vtable;
3322	}
3323
3324	/**
3325	* g_type_default_interface_unref:
3326	* @g_iface: (type GObject.TypeInterface): the default vtable
3327	* structure for an interface, as returned by g_type_default_interface_ref()
3328	*
3329	* Decrements the reference count for the type corresponding to the
3330	* interface default vtable @g_iface. If the type is dynamic, then
3331	* when no one is using the interface and all references have
3332	* been released, the finalize function for the interface's default
3333	* vtable (the @class_finalize member of #GTypeInfo) will be called.
3334	*
3335	* Since: 2.4
3336	*/
3337	void
3338	g_type_default_interface_unref (gpointer g_iface)
3339	{
3340	TypeNode *node;
3341	GTypeInterface *vtable = g_iface;
3342
3343	g_return_if_fail (g_iface != NULL);
3344
3345	node = lookup_type_node_I (utype: vtable->g_type);
3346	if (node && NODE_IS_IFACE (node))
3347	type_data_unref_U (node, FALSE);
3348	else
3349	g_warning ("cannot unreference invalid interface default vtable for '%s'",
3350	type_descriptive_name_I (vtable->g_type));
3351	}
3352
3353	/**
3354	* g_type_name:
3355	* @type: type to return name for
3356	*
3357	* Get the unique name that is assigned to a type ID. Note that this
3358	* function (like all other GType API) cannot cope with invalid type
3359	* IDs. %G_TYPE_INVALID may be passed to this function, as may be any
3360	* other validly registered type ID, but randomized type IDs should
3361	* not be passed in and will most likely lead to a crash.
3362	*
3363	* Returns: static type name or %NULL
3364	*/
3365	const gchar *
3366	g_type_name (GType type)
3367	{
3368	TypeNode *node;
3369
3370	g_assert_type_system_initialized ();
3371
3372	node = lookup_type_node_I (utype: type);
3373
3374	return node ? NODE_NAME (node) : NULL;
3375	}
3376
3377	/**
3378	* g_type_qname:
3379	* @type: type to return quark of type name for
3380	*
3381	* Get the corresponding quark of the type IDs name.
3382	*
3383	* Returns: the type names quark or 0
3384	*/
3385	GQuark
3386	g_type_qname (GType type)
3387	{
3388	TypeNode *node;
3389
3390	node = lookup_type_node_I (utype: type);
3391
3392	return node ? node->qname : 0;
3393	}
3394
3395	/**
3396	* g_type_from_name:
3397	* @name: type name to look up
3398	*
3399	* Look up the type ID from a given type name, returning 0 if no type
3400	* has been registered under this name (this is the preferred method
3401	* to find out by name whether a specific type has been registered
3402	* yet).
3403	*
3404	* Returns: corresponding type ID or 0
3405	*/
3406	GType
3407	g_type_from_name (const gchar *name)
3408	{
3409	GType type = 0;
3410
3411	g_return_val_if_fail (name != NULL, 0);
3412
3413	G_READ_LOCK (&type_rw_lock);
3414	type = (GType) g_hash_table_lookup (hash_table: static_type_nodes_ht, key: name);
3415	G_READ_UNLOCK (&type_rw_lock);
3416
3417	return type;
3418	}
3419
3420	/**
3421	* g_type_parent:
3422	* @type: the derived type
3423	*
3424	* Return the direct parent type of the passed in type. If the passed
3425	* in type has no parent, i.e. is a fundamental type, 0 is returned.
3426	*
3427	* Returns: the parent type
3428	*/
3429	GType
3430	g_type_parent (GType type)
3431	{
3432	TypeNode *node;
3433
3434	node = lookup_type_node_I (utype: type);
3435
3436	return node ? NODE_PARENT_TYPE (node) : 0;
3437	}
3438
3439	/**
3440	* g_type_depth:
3441	* @type: a #GType
3442	*
3443	* Returns the length of the ancestry of the passed in type. This
3444	* includes the type itself, so that e.g. a fundamental type has depth 1.
3445	*
3446	* Returns: the depth of @type
3447	*/
3448	guint
3449	g_type_depth (GType type)
3450	{
3451	TypeNode *node;
3452
3453	node = lookup_type_node_I (utype: type);
3454
3455	return node ? node->n_supers + 1 : 0;
3456	}
3457
3458	/**
3459	* g_type_next_base:
3460	* @leaf_type: descendant of @root_type and the type to be returned
3461	* @root_type: immediate parent of the returned type
3462	*
3463	* Given a @leaf_type and a @root_type which is contained in its
3464	* ancestry, return the type that @root_type is the immediate parent
3465	* of. In other words, this function determines the type that is
3466	* derived directly from @root_type which is also a base class of
3467	* @leaf_type. Given a root type and a leaf type, this function can
3468	* be used to determine the types and order in which the leaf type is
3469	* descended from the root type.
3470	*
3471	* Returns: immediate child of @root_type and ancestor of @leaf_type
3472	*/
3473	GType
3474	g_type_next_base (GType type,
3475	GType base_type)
3476	{
3477	GType atype = 0;
3478	TypeNode *node;
3479
3480	node = lookup_type_node_I (utype: type);
3481	if (node)
3482	{
3483	TypeNode *base_node = lookup_type_node_I (utype: base_type);
3484
3485	if (base_node && base_node->n_supers < node->n_supers)
3486	{
3487	guint n = node->n_supers - base_node->n_supers;
3488
3489	if (node->supers[n] == base_type)
3490	atype = node->supers[n - 1];
3491	}
3492	}
3493
3494	return atype;
3495	}
3496
3497	static inline gboolean
3498	type_node_check_conformities_UorL (TypeNode *node,
3499	TypeNode *iface_node,
3500	/* support_inheritance */
3501	gboolean support_interfaces,
3502	gboolean support_prerequisites,
3503	gboolean have_lock)
3504	{
3505	gboolean match;
3506
3507	if (/* support_inheritance && */
3508	NODE_IS_ANCESTOR (iface_node, node))
3509	return TRUE;
3510
3511	support_interfaces = support_interfaces && node->is_instantiatable && NODE_IS_IFACE (iface_node);
3512	support_prerequisites = support_prerequisites && NODE_IS_IFACE (node);
3513	match = FALSE;
3514	if (support_interfaces)
3515	{
3516	if (have_lock)
3517	{
3518	if (type_lookup_iface_entry_L (node, iface_node))
3519	match = TRUE;
3520	}
3521	else
3522	{
3523	if (type_lookup_iface_vtable_I (node, iface_node, NULL))
3524	match = TRUE;
3525	}
3526	}
3527	if (!match &&
3528	support_prerequisites)
3529	{
3530	if (!have_lock)
3531	G_READ_LOCK (&type_rw_lock);
3532	if (support_prerequisites && type_lookup_prerequisite_L (iface: node, NODE_TYPE (iface_node)))
3533	match = TRUE;
3534	if (!have_lock)
3535	G_READ_UNLOCK (&type_rw_lock);
3536	}
3537	return match;
3538	}
3539
3540	static gboolean
3541	type_node_is_a_L (TypeNode *node,
3542	TypeNode *iface_node)
3543	{
3544	return type_node_check_conformities_UorL (node, iface_node, TRUE, TRUE, TRUE);
3545	}
3546
3547	static inline gboolean
3548	type_node_conforms_to_U (TypeNode *node,
3549	TypeNode *iface_node,
3550	gboolean support_interfaces,
3551	gboolean support_prerequisites)
3552	{
3553	return type_node_check_conformities_UorL (node, iface_node, support_interfaces, support_prerequisites, FALSE);
3554	}
3555
3556	/**
3557	* g_type_is_a:
3558	* @type: type to check ancestry for
3559	* @is_a_type: possible ancestor of @type or interface that @type
3560	* could conform to
3561	*
3562	* If @is_a_type is a derivable type, check whether @type is a
3563	* descendant of @is_a_type. If @is_a_type is an interface, check
3564	* whether @type conforms to it.
3565	*
3566	* Returns: %TRUE if @type is a @is_a_type
3567	*/
3568	gboolean
3569	g_type_is_a (GType type,
3570	GType iface_type)
3571	{
3572	TypeNode *node, *iface_node;
3573	gboolean is_a;
3574
3575	if (type == iface_type)
3576	return TRUE;
3577
3578	node = lookup_type_node_I (utype: type);
3579	iface_node = lookup_type_node_I (utype: iface_type);
3580	is_a = node && iface_node && type_node_conforms_to_U (node, iface_node, TRUE, TRUE);
3581
3582	return is_a;
3583	}
3584
3585	/**
3586	* g_type_children:
3587	* @type: the parent type
3588	* @n_children: (out) (optional): location to store the length of
3589	* the returned array, or %NULL
3590	*
3591	* Return a newly allocated and 0-terminated array of type IDs, listing
3592	* the child types of @type.
3593	*
3594	* Returns: (array length=n_children) (transfer full): Newly allocated
3595	* and 0-terminated array of child types, free with g_free()
3596	*/
3597	GType*
3598	g_type_children (GType type,
3599	guint *n_children)
3600	{
3601	TypeNode *node;
3602
3603	node = lookup_type_node_I (utype: type);
3604	if (node)
3605	{
3606	GType *children;
3607
3608	G_READ_LOCK (&type_rw_lock); /* ->children is relocatable */
3609	children = g_new (GType, node->n_children + 1);
3610	if (node->n_children != 0)
3611	memcpy (dest: children, src: node->children, n: sizeof (GType) * node->n_children);
3612	children[node->n_children] = 0;
3613
3614	if (n_children)
3615	*n_children = node->n_children;
3616	G_READ_UNLOCK (&type_rw_lock);
3617
3618	return children;
3619	}
3620	else
3621	{
3622	if (n_children)
3623	*n_children = 0;
3624
3625	return NULL;
3626	}
3627	}
3628
3629	/**
3630	* g_type_interfaces:
3631	* @type: the type to list interface types for
3632	* @n_interfaces: (out) (optional): location to store the length of
3633	* the returned array, or %NULL
3634	*
3635	* Return a newly allocated and 0-terminated array of type IDs, listing
3636	* the interface types that @type conforms to.
3637	*
3638	* Returns: (array length=n_interfaces) (transfer full): Newly allocated
3639	* and 0-terminated array of interface types, free with g_free()
3640	*/
3641	GType*
3642	g_type_interfaces (GType type,
3643	guint *n_interfaces)
3644	{
3645	TypeNode *node;
3646
3647	node = lookup_type_node_I (utype: type);
3648	if (node && node->is_instantiatable)
3649	{
3650	IFaceEntries *entries;
3651	GType *ifaces;
3652	guint i;
3653
3654	G_READ_LOCK (&type_rw_lock);
3655	entries = CLASSED_NODE_IFACES_ENTRIES_LOCKED (node);
3656	if (entries)
3657	{
3658	ifaces = g_new (GType, IFACE_ENTRIES_N_ENTRIES (entries) + 1);
3659	for (i = 0; i < IFACE_ENTRIES_N_ENTRIES (entries); i++)
3660	ifaces[i] = entries->entry[i].iface_type;
3661	}
3662	else
3663	{
3664	ifaces = g_new (GType, 1);
3665	i = 0;
3666	}
3667	ifaces[i] = 0;
3668
3669	if (n_interfaces)
3670	*n_interfaces = i;
3671	G_READ_UNLOCK (&type_rw_lock);
3672
3673	return ifaces;
3674	}
3675	else
3676	{
3677	if (n_interfaces)
3678	*n_interfaces = 0;
3679
3680	return NULL;
3681	}
3682	}
3683
3684	typedef struct _QData QData;
3685	struct _GData
3686	{
3687	guint n_qdatas;
3688	QData *qdatas;
3689	};
3690	struct _QData
3691	{
3692	GQuark quark;
3693	gpointer data;
3694	};
3695
3696	static inline gpointer
3697	type_get_qdata_L (TypeNode *node,
3698	GQuark quark)
3699	{
3700	GData *gdata = node->global_gdata;
3701
3702	if (quark && gdata && gdata->n_qdatas)
3703	{
3704	QData *qdatas = gdata->qdatas - 1;
3705	guint n_qdatas = gdata->n_qdatas;
3706
3707	do
3708	{
3709	guint i;
3710	QData *check;
3711
3712	i = (n_qdatas + 1) / 2;
3713	check = qdatas + i;
3714	if (quark == check->quark)
3715	return check->data;
3716	else if (quark > check->quark)
3717	{
3718	n_qdatas -= i;
3719	qdatas = check;
3720	}
3721	else /* if (quark < check->quark) */
3722	n_qdatas = i - 1;
3723	}
3724	while (n_qdatas);
3725	}
3726	return NULL;
3727	}
3728
3729	/**
3730	* g_type_get_qdata:
3731	* @type: a #GType
3732	* @quark: a #GQuark id to identify the data
3733	*
3734	* Obtains data which has previously been attached to @type
3735	* with g_type_set_qdata().
3736	*
3737	* Note that this does not take subtyping into account; data
3738	* attached to one type with g_type_set_qdata() cannot
3739	* be retrieved from a subtype using g_type_get_qdata().
3740	*
3741	* Returns: (transfer none): the data, or %NULL if no data was found
3742	*/
3743	gpointer
3744	g_type_get_qdata (GType type,
3745	GQuark quark)
3746	{
3747	TypeNode *node;
3748	gpointer data;
3749
3750	node = lookup_type_node_I (utype: type);
3751	if (node)
3752	{
3753	G_READ_LOCK (&type_rw_lock);
3754	data = type_get_qdata_L (node, quark);
3755	G_READ_UNLOCK (&type_rw_lock);
3756	}
3757	else
3758	{
3759	g_return_val_if_fail (node != NULL, NULL);
3760	data = NULL;
3761	}
3762	return data;
3763	}
3764
3765	static inline void
3766	type_set_qdata_W (TypeNode *node,
3767	GQuark quark,
3768	gpointer data)
3769	{
3770	GData *gdata;
3771	QData *qdata;
3772	guint i;
3773
3774	/* setup qdata list if necessary */
3775	if (!node->global_gdata)
3776	node->global_gdata = g_new0 (GData, 1);
3777	gdata = node->global_gdata;
3778
3779	/* try resetting old data */
3780	qdata = gdata->qdatas;
3781	for (i = 0; i < gdata->n_qdatas; i++)
3782	if (qdata[i].quark == quark)
3783	{
3784	qdata[i].data = data;
3785	return;
3786	}
3787
3788	/* add new entry */
3789	gdata->n_qdatas++;
3790	gdata->qdatas = g_renew (QData, gdata->qdatas, gdata->n_qdatas);
3791	qdata = gdata->qdatas;
3792	for (i = 0; i < gdata->n_qdatas - 1; i++)
3793	if (qdata[i].quark > quark)
3794	break;
3795	memmove (dest: qdata + i + 1, src: qdata + i, n: sizeof (qdata[0]) * (gdata->n_qdatas - i - 1));
3796	qdata[i].quark = quark;
3797	qdata[i].data = data;
3798	}
3799
3800	/**
3801	* g_type_set_qdata:
3802	* @type: a #GType
3803	* @quark: a #GQuark id to identify the data
3804	* @data: the data
3805	*
3806	* Attaches arbitrary data to a type.
3807	*/
3808	void
3809	g_type_set_qdata (GType type,
3810	GQuark quark,
3811	gpointer data)
3812	{
3813	TypeNode *node;
3814
3815	g_return_if_fail (quark != 0);
3816
3817	node = lookup_type_node_I (utype: type);
3818	if (node)
3819	{
3820	G_WRITE_LOCK (&type_rw_lock);
3821	type_set_qdata_W (node, quark, data);
3822	G_WRITE_UNLOCK (&type_rw_lock);
3823	}
3824	else
3825	g_return_if_fail (node != NULL);
3826	}
3827
3828	static void
3829	type_add_flags_W (TypeNode *node,
3830	GTypeFlags flags)
3831	{
3832	guint dflags;
3833
3834	g_return_if_fail ((flags & ~TYPE_FLAG_MASK) == 0);
3835	g_return_if_fail (node != NULL);
3836
3837	if ((flags & TYPE_FLAG_MASK) && node->is_classed && node->data && node->data->class.class)
3838	g_warning ("tagging type '%s' as abstract after class initialization", NODE_NAME (node));
3839	dflags = GPOINTER_TO_UINT (type_get_qdata_L (node, static_quark_type_flags));
3840	dflags |= flags;
3841	type_set_qdata_W (node, quark: static_quark_type_flags, GUINT_TO_POINTER (dflags));
3842	}
3843
3844	/**
3845	* g_type_query:
3846	* @type: #GType of a static, classed type
3847	* @query: (out caller-allocates): a user provided structure that is
3848	* filled in with constant values upon success
3849	*
3850	* Queries the type system for information about a specific type.
3851	* This function will fill in a user-provided structure to hold
3852	* type-specific information. If an invalid #GType is passed in, the
3853	* @type member of the #GTypeQuery is 0. All members filled into the
3854	* #GTypeQuery structure should be considered constant and have to be
3855	* left untouched.
3856	*/
3857	void
3858	g_type_query (GType type,
3859	GTypeQuery *query)
3860	{
3861	TypeNode *node;
3862
3863	g_return_if_fail (query != NULL);
3864
3865	/* if node is not static and classed, we won't allow query */
3866	query->type = 0;
3867	node = lookup_type_node_I (utype: type);
3868	if (node && node->is_classed && !node->plugin)
3869	{
3870	/* type is classed and probably even instantiatable */
3871	G_READ_LOCK (&type_rw_lock);
3872	if (node->data) /* type is static or referenced */
3873	{
3874	query->type = NODE_TYPE (node);
3875	query->type_name = NODE_NAME (node);
3876	query->class_size = node->data->class.class_size;
3877	query->instance_size = node->is_instantiatable ? node->data->instance.instance_size : 0;
3878	}
3879	G_READ_UNLOCK (&type_rw_lock);
3880	}
3881	}
3882
3883	/**
3884	* g_type_get_instance_count:
3885	* @type: a #GType
3886	*
3887	* Returns the number of instances allocated of the particular type;
3888	* this is only available if GLib is built with debugging support and
3889	* the instance_count debug flag is set (by setting the GOBJECT_DEBUG
3890	* variable to include instance-count).
3891	*
3892	* Returns: the number of instances allocated of the given type;
3893	* if instance counts are not available, returns 0.
3894	*
3895	* Since: 2.44
3896	*/
3897	int
3898	g_type_get_instance_count (GType type)
3899	{
3900	#ifdef G_ENABLE_DEBUG
3901	TypeNode *node;
3902
3903	node = lookup_type_node_I (utype: type);
3904	g_return_val_if_fail (node != NULL, 0);
3905
3906	return g_atomic_int_get (&node->instance_count);
3907	#else
3908	return 0;
3909	#endif
3910	}
3911
3912	/* --- implementation details --- */
3913	gboolean
3914	g_type_test_flags (GType type,
3915	guint flags)
3916	{
3917	TypeNode *node;
3918	gboolean result = FALSE;
3919
3920	node = lookup_type_node_I (utype: type);
3921	if (node)
3922	{
3923	guint fflags = flags & TYPE_FUNDAMENTAL_FLAG_MASK;
3924	guint tflags = flags & TYPE_FLAG_MASK;
3925
3926	if (fflags)
3927	{
3928	GTypeFundamentalInfo *finfo = type_node_fundamental_info_I (node);
3929
3930	fflags = (finfo->type_flags & fflags) == fflags;
3931	}
3932	else
3933	fflags = TRUE;
3934
3935	if (tflags)
3936	{
3937	G_READ_LOCK (&type_rw_lock);
3938	tflags = (tflags & GPOINTER_TO_UINT (type_get_qdata_L (node, static_quark_type_flags))) == tflags;
3939	G_READ_UNLOCK (&type_rw_lock);
3940	}
3941	else
3942	tflags = TRUE;
3943
3944	result = tflags && fflags;
3945	}
3946
3947	return result;
3948	}
3949
3950	/**
3951	* g_type_get_plugin:
3952	* @type: #GType to retrieve the plugin for
3953	*
3954	* Returns the #GTypePlugin structure for @type.
3955	*
3956	* Returns: (transfer none): the corresponding plugin
3957	* if @type is a dynamic type, %NULL otherwise
3958	*/
3959	GTypePlugin*
3960	g_type_get_plugin (GType type)
3961	{
3962	TypeNode *node;
3963
3964	node = lookup_type_node_I (utype: type);
3965
3966	return node ? node->plugin : NULL;
3967	}
3968
3969	/**
3970	* g_type_interface_get_plugin:
3971	* @instance_type: #GType of an instantiatable type
3972	* @interface_type: #GType of an interface type
3973	*
3974	* Returns the #GTypePlugin structure for the dynamic interface
3975	* @interface_type which has been added to @instance_type, or %NULL
3976	* if @interface_type has not been added to @instance_type or does
3977	* not have a #GTypePlugin structure. See g_type_add_interface_dynamic().
3978	*
3979	* Returns: (transfer none): the #GTypePlugin for the dynamic
3980	* interface @interface_type of @instance_type
3981	*/
3982	GTypePlugin*
3983	g_type_interface_get_plugin (GType instance_type,
3984	GType interface_type)
3985	{
3986	TypeNode *node;
3987	TypeNode *iface;
3988
3989	g_return_val_if_fail (G_TYPE_IS_INTERFACE (interface_type), NULL); /* G_TYPE_IS_INTERFACE() is an external call: _U */
3990
3991	node = lookup_type_node_I (utype: instance_type);
3992	iface = lookup_type_node_I (utype: interface_type);
3993	if (node && iface)
3994	{
3995	IFaceHolder *iholder;
3996	GTypePlugin *plugin;
3997
3998	G_READ_LOCK (&type_rw_lock);
3999
4000	iholder = iface_node_get_holders_L (iface);
4001	while (iholder && iholder->instance_type != instance_type)
4002	iholder = iholder->next;
4003	plugin = iholder ? iholder->plugin : NULL;
4004
4005	G_READ_UNLOCK (&type_rw_lock);
4006
4007	return plugin;
4008	}
4009
4010	g_return_val_if_fail (node == NULL, NULL);
4011	g_return_val_if_fail (iface == NULL, NULL);
4012
4013	g_warning (G_STRLOC ": attempt to look up plugin for invalid instance/interface type pair.");
4014
4015	return NULL;
4016	}
4017
4018	/**
4019	* g_type_fundamental_next:
4020	*
4021	* Returns the next free fundamental type id which can be used to
4022	* register a new fundamental type with g_type_register_fundamental().
4023	* The returned type ID represents the highest currently registered
4024	* fundamental type identifier.
4025	*
4026	* Returns: the next available fundamental type ID to be registered,
4027	* or 0 if the type system ran out of fundamental type IDs
4028	*/
4029	GType
4030	g_type_fundamental_next (void)
4031	{
4032	GType type;
4033
4034	G_READ_LOCK (&type_rw_lock);
4035	type = static_fundamental_next;
4036	G_READ_UNLOCK (&type_rw_lock);
4037	type = G_TYPE_MAKE_FUNDAMENTAL (type);
4038	return type <= G_TYPE_FUNDAMENTAL_MAX ? type : 0;
4039	}
4040
4041	/**
4042	* g_type_fundamental:
4043	* @type_id: valid type ID
4044	*
4045	* Internal function, used to extract the fundamental type ID portion.
4046	* Use G_TYPE_FUNDAMENTAL() instead.
4047	*
4048	* Returns: fundamental type ID
4049	*/
4050	GType
4051	g_type_fundamental (GType type_id)
4052	{
4053	TypeNode *node = lookup_type_node_I (utype: type_id);
4054
4055	return node ? NODE_FUNDAMENTAL_TYPE (node) : 0;
4056	}
4057
4058	gboolean
4059	g_type_check_instance_is_a (GTypeInstance *type_instance,
4060	GType iface_type)
4061	{
4062	TypeNode *node, *iface;
4063	gboolean check;
4064
4065	if (!type_instance || !type_instance->g_class)
4066	return FALSE;
4067
4068	node = lookup_type_node_I (utype: type_instance->g_class->g_type);
4069	iface = lookup_type_node_I (utype: iface_type);
4070	check = node && node->is_instantiatable && iface && type_node_conforms_to_U (node, iface_node: iface, TRUE, FALSE);
4071
4072	return check;
4073	}
4074
4075	gboolean
4076	g_type_check_instance_is_fundamentally_a (GTypeInstance *type_instance,
4077	GType fundamental_type)
4078	{
4079	TypeNode *node;
4080	if (!type_instance || !type_instance->g_class)
4081	return FALSE;
4082	node = lookup_type_node_I (utype: type_instance->g_class->g_type);
4083	return node && (NODE_FUNDAMENTAL_TYPE(node) == fundamental_type);
4084	}
4085
4086	gboolean
4087	g_type_check_class_is_a (GTypeClass *type_class,
4088	GType is_a_type)
4089	{
4090	TypeNode *node, *iface;
4091	gboolean check;
4092
4093	if (!type_class)
4094	return FALSE;
4095
4096	node = lookup_type_node_I (utype: type_class->g_type);
4097	iface = lookup_type_node_I (utype: is_a_type);
4098	check = node && node->is_classed && iface && type_node_conforms_to_U (node, iface_node: iface, FALSE, FALSE);
4099
4100	return check;
4101	}
4102
4103	GTypeInstance*
4104	g_type_check_instance_cast (GTypeInstance *type_instance,
4105	GType iface_type)
4106	{
4107	if (type_instance)
4108	{
4109	if (type_instance->g_class)
4110	{
4111	TypeNode *node, *iface;
4112	gboolean is_instantiatable, check;
4113
4114	node = lookup_type_node_I (utype: type_instance->g_class->g_type);
4115	is_instantiatable = node && node->is_instantiatable;
4116	iface = lookup_type_node_I (utype: iface_type);
4117	check = is_instantiatable && iface && type_node_conforms_to_U (node, iface_node: iface, TRUE, FALSE);
4118	if (check)
4119	return type_instance;
4120
4121	if (is_instantiatable)
4122	g_warning ("invalid cast from '%s' to '%s'",
4123	type_descriptive_name_I (type_instance->g_class->g_type),
4124	type_descriptive_name_I (iface_type));
4125	else
4126	g_warning ("invalid uninstantiatable type '%s' in cast to '%s'",
4127	type_descriptive_name_I (type_instance->g_class->g_type),
4128	type_descriptive_name_I (iface_type));
4129	}
4130	else
4131	g_warning ("invalid unclassed pointer in cast to '%s'",
4132	type_descriptive_name_I (iface_type));
4133	}
4134
4135	return type_instance;
4136	}
4137
4138	GTypeClass*
4139	g_type_check_class_cast (GTypeClass *type_class,
4140	GType is_a_type)
4141	{
4142	if (type_class)
4143	{
4144	TypeNode *node, *iface;
4145	gboolean is_classed, check;
4146
4147	node = lookup_type_node_I (utype: type_class->g_type);
4148	is_classed = node && node->is_classed;
4149	iface = lookup_type_node_I (utype: is_a_type);
4150	check = is_classed && iface && type_node_conforms_to_U (node, iface_node: iface, FALSE, FALSE);
4151	if (check)
4152	return type_class;
4153
4154	if (is_classed)
4155	g_warning ("invalid class cast from '%s' to '%s'",
4156	type_descriptive_name_I (type_class->g_type),
4157	type_descriptive_name_I (is_a_type));
4158	else
4159	g_warning ("invalid unclassed type '%s' in class cast to '%s'",
4160	type_descriptive_name_I (type_class->g_type),
4161	type_descriptive_name_I (is_a_type));
4162	}
4163	else
4164	g_warning ("invalid class cast from (NULL) pointer to '%s'",
4165	type_descriptive_name_I (is_a_type));
4166	return type_class;
4167	}
4168
4169	/**
4170	* g_type_check_instance:
4171	* @instance: a valid #GTypeInstance structure
4172	*
4173	* Private helper function to aid implementation of the
4174	* G_TYPE_CHECK_INSTANCE() macro.
4175	*
4176	* Returns: %TRUE if @instance is valid, %FALSE otherwise
4177	*/
4178	gboolean
4179	g_type_check_instance (GTypeInstance *type_instance)
4180	{
4181	/* this function is just here to make the signal system
4182	* conveniently elaborated on instance checks
4183	*/
4184	if (type_instance)
4185	{
4186	if (type_instance->g_class)
4187	{
4188	TypeNode *node = lookup_type_node_I (utype: type_instance->g_class->g_type);
4189
4190	if (node && node->is_instantiatable)
4191	return TRUE;
4192
4193	g_warning ("instance of invalid non-instantiatable type '%s'",
4194	type_descriptive_name_I (type_instance->g_class->g_type));
4195	}
4196	else
4197	g_warning ("instance with invalid (NULL) class pointer");
4198	}
4199	else
4200	g_warning ("invalid (NULL) pointer instance");
4201
4202	return FALSE;
4203	}
4204
4205	static inline gboolean
4206	type_check_is_value_type_U (GType type)
4207	{
4208	GTypeFlags tflags = G_TYPE_FLAG_VALUE_ABSTRACT;
4209	TypeNode *node;
4210
4211	/* common path speed up */
4212	node = lookup_type_node_I (utype: type);
4213	if (node && node->mutatable_check_cache)
4214	return TRUE;
4215
4216	G_READ_LOCK (&type_rw_lock);
4217	restart_check:
4218	if (node)
4219	{
4220	if (node->data && NODE_REFCOUNT (node) > 0 &&
4221	node->data->common.value_table->value_init)
4222	tflags = GPOINTER_TO_UINT (type_get_qdata_L (node, static_quark_type_flags));
4223	else if (NODE_IS_IFACE (node))
4224	{
4225	guint i;
4226
4227	for (i = 0; i < IFACE_NODE_N_PREREQUISITES (node); i++)
4228	{
4229	GType prtype = IFACE_NODE_PREREQUISITES (node)[i];
4230	TypeNode *prnode = lookup_type_node_I (utype: prtype);
4231
4232	if (prnode->is_instantiatable)
4233	{
4234	type = prtype;
4235	node = lookup_type_node_I (utype: type);
4236	goto restart_check;
4237	}
4238	}
4239	}
4240	}
4241	G_READ_UNLOCK (&type_rw_lock);
4242
4243	return !(tflags & G_TYPE_FLAG_VALUE_ABSTRACT);
4244	}
4245
4246	gboolean
4247	g_type_check_is_value_type (GType type)
4248	{
4249	return type_check_is_value_type_U (type);
4250	}
4251
4252	gboolean
4253	g_type_check_value (const GValue *value)
4254	{
4255	return value && type_check_is_value_type_U (type: value->g_type);
4256	}
4257
4258	gboolean
4259	g_type_check_value_holds (const GValue *value,
4260	GType type)
4261	{
4262	return value && type_check_is_value_type_U (type: value->g_type) && g_type_is_a (type: value->g_type, iface_type: type);
4263	}
4264
4265	/**
4266	* g_type_value_table_peek: (skip)
4267	* @type: a #GType
4268	*
4269	* Returns the location of the #GTypeValueTable associated with @type.
4270	*
4271	* Note that this function should only be used from source code
4272	* that implements or has internal knowledge of the implementation of
4273	* @type.
4274	*
4275	* Returns: location of the #GTypeValueTable associated with @type or
4276	* %NULL if there is no #GTypeValueTable associated with @type
4277	*/
4278	GTypeValueTable*
4279	g_type_value_table_peek (GType type)
4280	{
4281	GTypeValueTable *vtable = NULL;
4282	TypeNode *node = lookup_type_node_I (utype: type);
4283	gboolean has_refed_data, has_table;
4284
4285	if (node && NODE_REFCOUNT (node) && node->mutatable_check_cache)
4286	return node->data->common.value_table;
4287
4288	G_READ_LOCK (&type_rw_lock);
4289
4290	restart_table_peek:
4291	has_refed_data = node && node->data && NODE_REFCOUNT (node) > 0;
4292	has_table = has_refed_data && node->data->common.value_table->value_init;
4293	if (has_refed_data)
4294	{
4295	if (has_table)
4296	vtable = node->data->common.value_table;
4297	else if (NODE_IS_IFACE (node))
4298	{
4299	guint i;
4300
4301	for (i = 0; i < IFACE_NODE_N_PREREQUISITES (node); i++)
4302	{
4303	GType prtype = IFACE_NODE_PREREQUISITES (node)[i];
4304	TypeNode *prnode = lookup_type_node_I (utype: prtype);
4305
4306	if (prnode->is_instantiatable)
4307	{
4308	type = prtype;
4309	node = lookup_type_node_I (utype: type);
4310	goto restart_table_peek;
4311	}
4312	}
4313	}
4314	}
4315
4316	G_READ_UNLOCK (&type_rw_lock);
4317
4318	if (vtable)
4319	return vtable;
4320
4321	if (!node)
4322	g_warning (G_STRLOC ": type id '%" G_GSIZE_FORMAT "' is invalid", type);
4323	if (!has_refed_data)
4324	g_warning ("can't peek value table for type '%s' which is not currently referenced",
4325	type_descriptive_name_I (type));
4326
4327	return NULL;
4328	}
4329
4330	const gchar *
4331	g_type_name_from_instance (GTypeInstance *instance)
4332	{
4333	if (!instance)
4334	return "<NULL-instance>";
4335	else
4336	return g_type_name_from_class (g_class: instance->g_class);
4337	}
4338
4339	const gchar *
4340	g_type_name_from_class (GTypeClass *g_class)
4341	{
4342	if (!g_class)
4343	return "<NULL-class>";
4344	else
4345	return g_type_name (type: g_class->g_type);
4346	}
4347
4348
4349	/* --- private api for gboxed.c --- */
4350	gpointer
4351	_g_type_boxed_copy (GType type, gpointer value)
4352	{
4353	TypeNode *node = lookup_type_node_I (utype: type);
4354
4355	return node->data->boxed.copy_func (value);
4356	}
4357
4358	void
4359	_g_type_boxed_free (GType type, gpointer value)
4360	{
4361	TypeNode *node = lookup_type_node_I (utype: type);
4362
4363	node->data->boxed.free_func (value);
4364	}
4365
4366	void
4367	_g_type_boxed_init (GType type,
4368	GBoxedCopyFunc copy_func,
4369	GBoxedFreeFunc free_func)
4370	{
4371	TypeNode *node = lookup_type_node_I (utype: type);
4372
4373	node->data->boxed.copy_func = copy_func;
4374	node->data->boxed.free_func = free_func;
4375	}
4376
4377	/* --- initialization --- */
4378	/**
4379	* g_type_init_with_debug_flags:
4380	* @debug_flags: bitwise combination of #GTypeDebugFlags values for
4381	* debugging purposes
4382	*
4383	* This function used to initialise the type system with debugging
4384	* flags. Since GLib 2.36, the type system is initialised automatically
4385	* and this function does nothing.
4386	*
4387	* If you need to enable debugging features, use the GOBJECT_DEBUG
4388	* environment variable.
4389	*
4390	* Deprecated: 2.36: the type system is now initialised automatically
4391	*/
4392	G_GNUC_BEGIN_IGNORE_DEPRECATIONS
4393	void
4394	g_type_init_with_debug_flags (GTypeDebugFlags debug_flags)
4395	{
4396	g_assert_type_system_initialized ();
4397
4398	if (debug_flags)
4399	g_message ("g_type_init_with_debug_flags() is no longer supported. Use the GOBJECT_DEBUG environment variable.");
4400	}
4401	G_GNUC_END_IGNORE_DEPRECATIONS
4402
4403	/**
4404	* g_type_init:
4405	*
4406	* This function used to initialise the type system. Since GLib 2.36,
4407	* the type system is initialised automatically and this function does
4408	* nothing.
4409	*
4410	* Deprecated: 2.36: the type system is now initialised automatically
4411	*/
4412	void
4413	g_type_init (void)
4414	{
4415	g_assert_type_system_initialized ();
4416	}
4417
4418	static void
4419	gobject_init (void)
4420	{
4421	const gchar *env_string;
4422	GTypeInfo info;
4423	TypeNode *node;
4424	GType type G_GNUC_UNUSED /* when compiling with G_DISABLE_ASSERT */;
4425
4426	/* Ensure GLib is initialized first, see
4427	* https://bugzilla.gnome.org/show_bug.cgi?id=756139
4428	*/
4429	GLIB_PRIVATE_CALL (glib_init) ();
4430
4431	G_WRITE_LOCK (&type_rw_lock);
4432
4433	/* setup GObject library wide debugging flags */
4434	env_string = g_getenv (variable: "GOBJECT_DEBUG");
4435	if (env_string != NULL)
4436	{
4437	GDebugKey debug_keys[] = {
4438	{ "objects", G_TYPE_DEBUG_OBJECTS },
4439	{ "instance-count", G_TYPE_DEBUG_INSTANCE_COUNT },
4440	{ "signals", G_TYPE_DEBUG_SIGNALS },
4441	};
4442
4443	_g_type_debug_flags = g_parse_debug_string (string: env_string, keys: debug_keys, G_N_ELEMENTS (debug_keys));
4444	}
4445
4446	/* quarks */
4447	static_quark_type_flags = g_quark_from_static_string (string: "-g-type-private--GTypeFlags");
4448	static_quark_iface_holder = g_quark_from_static_string (string: "-g-type-private--IFaceHolder");
4449	static_quark_dependants_array = g_quark_from_static_string (string: "-g-type-private--dependants-array");
4450
4451	/* type qname hash table */
4452	static_type_nodes_ht = g_hash_table_new (hash_func: g_str_hash, key_equal_func: g_str_equal);
4453
4454	/* invalid type G_TYPE_INVALID (0)
4455	*/
4456	static_fundamental_type_nodes[0] = NULL;
4457
4458	/* void type G_TYPE_NONE
4459	*/
4460	node = type_node_fundamental_new_W (G_TYPE_NONE, name: g_intern_static_string (string: "void"), type_flags: 0);
4461	type = NODE_TYPE (node);
4462	g_assert (type == G_TYPE_NONE);
4463
4464	/* interface fundamental type G_TYPE_INTERFACE (!classed)
4465	*/
4466	memset (s: &info, c: 0, n: sizeof (info));
4467	node = type_node_fundamental_new_W (G_TYPE_INTERFACE, name: g_intern_static_string (string: "GInterface"), type_flags: G_TYPE_FLAG_DERIVABLE);
4468	type = NODE_TYPE (node);
4469	type_data_make_W (node, info: &info, NULL);
4470	g_assert (type == G_TYPE_INTERFACE);
4471
4472	G_WRITE_UNLOCK (&type_rw_lock);
4473
4474	_g_value_c_init ();
4475
4476	/* G_TYPE_TYPE_PLUGIN
4477	*/
4478	g_type_ensure (type: g_type_plugin_get_type ());
4479
4480	/* G_TYPE_* value types
4481	*/
4482	_g_value_types_init ();
4483
4484	/* G_TYPE_ENUM & G_TYPE_FLAGS
4485	*/
4486	_g_enum_types_init ();
4487
4488	/* G_TYPE_BOXED
4489	*/
4490	_g_boxed_type_init ();
4491
4492	/* G_TYPE_PARAM
4493	*/
4494	_g_param_type_init ();
4495
4496	/* G_TYPE_OBJECT
4497	*/
4498	_g_object_type_init ();
4499
4500	/* G_TYPE_PARAM_* pspec types
4501	*/
4502	_g_param_spec_types_init ();
4503
4504	/* Value Transformations
4505	*/
4506	_g_value_transforms_init ();
4507
4508	/* Signal system
4509	*/
4510	_g_signal_init ();
4511	}
4512
4513	#if defined (G_OS_WIN32)
4514
4515	BOOL WINAPI DllMain (HINSTANCE hinstDLL,
4516	DWORD fdwReason,
4517	LPVOID lpvReserved);
4518
4519	BOOL WINAPI
4520	DllMain (HINSTANCE hinstDLL,
4521	DWORD fdwReason,
4522	LPVOID lpvReserved)
4523	{
4524	switch (fdwReason)
4525	{
4526	case DLL_PROCESS_ATTACH:
4527	gobject_init ();
4528	break;
4529
4530	default:
4531	/* do nothing */
4532	;
4533	}
4534
4535	return TRUE;
4536	}
4537
4538	#elif defined (G_HAS_CONSTRUCTORS)
4539	#ifdef G_DEFINE_CONSTRUCTOR_NEEDS_PRAGMA
4540	#pragma G_DEFINE_CONSTRUCTOR_PRAGMA_ARGS(gobject_init_ctor)
4541	#endif
4542	G_DEFINE_CONSTRUCTOR(gobject_init_ctor)
4543
4544	static void
4545	gobject_init_ctor (void)
4546	{
4547	gobject_init ();
4548	}
4549
4550	#else
4551	# error Your platform/compiler is missing constructor support
4552	#endif
4553
4554	/**
4555	* g_type_class_add_private:
4556	* @g_class: (type GObject.TypeClass): class structure for an instantiatable
4557	* type
4558	* @private_size: size of private structure
4559	*
4560	* Registers a private structure for an instantiatable type.
4561	*
4562	* When an object is allocated, the private structures for
4563	* the type and all of its parent types are allocated
4564	* sequentially in the same memory block as the public
4565	* structures, and are zero-filled.
4566	*
4567	* Note that the accumulated size of the private structures of
4568	* a type and all its parent types cannot exceed 64 KiB.
4569	*
4570	* This function should be called in the type's class_init() function.
4571	* The private structure can be retrieved using the
4572	* G_TYPE_INSTANCE_GET_PRIVATE() macro.
4573	*
4574	* The following example shows attaching a private structure
4575	* MyObjectPrivate to an object MyObject defined in the standard
4576	* GObject fashion in the type's class_init() function.
4577	*
4578	* Note the use of a structure member "priv" to avoid the overhead
4579	* of repeatedly calling MY_OBJECT_GET_PRIVATE().
4580	*
4581	* |[<!-- language="C" -->
4582	* typedef struct _MyObject MyObject;
4583	* typedef struct _MyObjectPrivate MyObjectPrivate;
4584	*
4585	* struct _MyObject {
4586	* GObject parent;
4587	*
4588	* MyObjectPrivate *priv;
4589	* };
4590	*
4591	* struct _MyObjectPrivate {
4592	* int some_field;
4593	* };
4594	*
4595	* static void
4596	* my_object_class_init (MyObjectClass *klass)
4597	* {
4598	* g_type_class_add_private (klass, sizeof (MyObjectPrivate));
4599	* }
4600	*
4601	* static void
4602	* my_object_init (MyObject *my_object)
4603	* {
4604	* my_object->priv = G_TYPE_INSTANCE_GET_PRIVATE (my_object,
4605	* MY_TYPE_OBJECT,
4606	* MyObjectPrivate);
4607	* // my_object->priv->some_field will be automatically initialised to 0
4608	* }
4609	*
4610	* static int
4611	* my_object_get_some_field (MyObject *my_object)
4612	* {
4613	* MyObjectPrivate *priv;
4614	*
4615	* g_return_val_if_fail (MY_IS_OBJECT (my_object), 0);
4616	*
4617	* priv = my_object->priv;
4618	*
4619	* return priv->some_field;
4620	* }
4621	* ]|
4622	*
4623	* Since: 2.4
4624	* Deprecated: 2.58: Use the G_ADD_PRIVATE() macro with the `G_DEFINE_*`
4625	* family of macros to add instance private data to a type
4626	*/
4627	void
4628	g_type_class_add_private (gpointer g_class,
4629	gsize private_size)
4630	{
4631	GType instance_type = ((GTypeClass *)g_class)->g_type;
4632	TypeNode *node = lookup_type_node_I (utype: instance_type);
4633
4634	g_return_if_fail (private_size > 0);
4635	g_return_if_fail (private_size <= 0xffff);
4636
4637	if (!node || !node->is_instantiatable || !node->data || node->data->class.class != g_class)
4638	{
4639	g_warning ("cannot add private field to invalid (non-instantiatable) type '%s'",
4640	type_descriptive_name_I (instance_type));
4641	return;
4642	}
4643
4644	if (NODE_PARENT_TYPE (node))
4645	{
4646	TypeNode *pnode = lookup_type_node_I (NODE_PARENT_TYPE (node));
4647	if (node->data->instance.private_size != pnode->data->instance.private_size)
4648	{
4649	g_warning ("g_type_class_add_private() called multiple times for the same type");
4650	return;
4651	}
4652	}
4653
4654	G_WRITE_LOCK (&type_rw_lock);
4655
4656	private_size = ALIGN_STRUCT (node->data->instance.private_size + private_size);
4657	g_assert (private_size <= 0xffff);
4658	node->data->instance.private_size = private_size;
4659
4660	G_WRITE_UNLOCK (&type_rw_lock);
4661	}
4662
4663	/* semi-private, called only by the G_ADD_PRIVATE macro */
4664	gint
4665	g_type_add_instance_private (GType class_gtype,
4666	gsize private_size)
4667	{
4668	TypeNode *node = lookup_type_node_I (utype: class_gtype);
4669
4670	g_return_val_if_fail (private_size > 0, 0);
4671	g_return_val_if_fail (private_size <= 0xffff, 0);
4672
4673	if (!node || !node->is_classed || !node->is_instantiatable || !node->data)
4674	{
4675	g_warning ("cannot add private field to invalid (non-instantiatable) type '%s'",
4676	type_descriptive_name_I (class_gtype));
4677	return 0;
4678	}
4679
4680	if (node->plugin != NULL)
4681	{
4682	g_warning ("cannot use g_type_add_instance_private() with dynamic type '%s'",
4683	type_descriptive_name_I (class_gtype));
4684	return 0;
4685	}
4686
4687	/* in the future, we want to register the private data size of a type
4688	* directly from the get_type() implementation so that we can take full
4689	* advantage of the type definition macros that we already have.
4690	*
4691	* unfortunately, this does not behave correctly if a class in the middle
4692	* of the type hierarchy uses the "old style" of private data registration
4693	* from the class_init() implementation, as the private data offset is not
4694	* going to be known until the full class hierarchy is initialized.
4695	*
4696	* in order to transition our code to the Glorious New Future™, we proceed
4697	* with a two-step implementation: first, we provide this new function to
4698	* register the private data size in the get_type() implementation and we
4699	* hide it behind a macro. the function will return the private size, instead
4700	* of the offset, which will be stored inside a static variable defined by
4701	* the G_DEFINE_TYPE_EXTENDED macro. the G_DEFINE_TYPE_EXTENDED macro will
4702	* check the variable and call g_type_class_add_instance_private(), which
4703	* will use the data size and actually register the private data, then
4704	* return the computed offset of the private data, which will be stored
4705	* inside the static variable, so we can use it to retrieve the pointer
4706	* to the private data structure.
4707	*
4708	* once all our code has been migrated to the new idiomatic form of private
4709	* data registration, we will change the g_type_add_instance_private()
4710	* function to actually perform the registration and return the offset
4711	* of the private data; g_type_class_add_instance_private() already checks
4712	* if the passed argument is negative (meaning that it's an offset in the
4713	* GTypeInstance allocation) and becomes a no-op if that's the case. this
4714	* should make the migration fully transparent even if we're effectively
4715	* copying this macro into everybody's code.
4716	*/
4717	return private_size;
4718	}
4719
4720	/* semi-private function, should only be used by G_DEFINE_TYPE_EXTENDED */
4721	void
4722	g_type_class_adjust_private_offset (gpointer g_class,
4723	gint *private_size_or_offset)
4724	{
4725	GType class_gtype = ((GTypeClass *) g_class)->g_type;
4726	TypeNode *node = lookup_type_node_I (utype: class_gtype);
4727	gssize private_size;
4728
4729	g_return_if_fail (private_size_or_offset != NULL);
4730
4731	/* if we have been passed the offset instead of the private data size,
4732	* then we consider this as a no-op, and just return the value. see the
4733	* comment in g_type_add_instance_private() for the full explanation.
4734	*/
4735	if (*private_size_or_offset > 0)
4736	g_return_if_fail (*private_size_or_offset <= 0xffff);
4737	else
4738	return;
4739
4740	if (!node || !node->is_classed || !node->is_instantiatable || !node->data)
4741	{
4742	g_warning ("cannot add private field to invalid (non-instantiatable) type '%s'",
4743	type_descriptive_name_I (class_gtype));
4744	*private_size_or_offset = 0;
4745	return;
4746	}
4747
4748	if (NODE_PARENT_TYPE (node))
4749	{
4750	TypeNode *pnode = lookup_type_node_I (NODE_PARENT_TYPE (node));
4751	if (node->data->instance.private_size != pnode->data->instance.private_size)
4752	{
4753	g_warning ("g_type_add_instance_private() called multiple times for the same type");
4754	*private_size_or_offset = 0;
4755	return;
4756	}
4757	}
4758
4759	G_WRITE_LOCK (&type_rw_lock);
4760
4761	private_size = ALIGN_STRUCT (node->data->instance.private_size + *private_size_or_offset);
4762	g_assert (private_size <= 0xffff);
4763	node->data->instance.private_size = private_size;
4764
4765	*private_size_or_offset = -(gint) node->data->instance.private_size;
4766
4767	G_WRITE_UNLOCK (&type_rw_lock);
4768	}
4769
4770	gpointer
4771	g_type_instance_get_private (GTypeInstance *instance,
4772	GType private_type)
4773	{
4774	TypeNode *node;
4775
4776	g_return_val_if_fail (instance != NULL && instance->g_class != NULL, NULL);
4777
4778	node = lookup_type_node_I (utype: private_type);
4779	if (G_UNLIKELY (!node || !node->is_instantiatable))
4780	{
4781	g_warning ("instance of invalid non-instantiatable type '%s'",
4782	type_descriptive_name_I (instance->g_class->g_type));
4783	return NULL;
4784	}
4785
4786	return ((gchar *) instance) - node->data->instance.private_size;
4787	}
4788
4789	/**
4790	* g_type_class_get_instance_private_offset: (skip)
4791	* @g_class: (type GObject.TypeClass): a #GTypeClass
4792	*
4793	* Gets the offset of the private data for instances of @g_class.
4794	*
4795	* This is how many bytes you should add to the instance pointer of a
4796	* class in order to get the private data for the type represented by
4797	* @g_class.
4798	*
4799	* You can only call this function after you have registered a private
4800	* data area for @g_class using g_type_class_add_private().
4801	*
4802	* Returns: the offset, in bytes
4803	*
4804	* Since: 2.38
4805	**/
4806	gint
4807	g_type_class_get_instance_private_offset (gpointer g_class)
4808	{
4809	GType instance_type;
4810	guint16 parent_size;
4811	TypeNode *node;
4812
4813	g_assert (g_class != NULL);
4814
4815	instance_type = ((GTypeClass *) g_class)->g_type;
4816	node = lookup_type_node_I (utype: instance_type);
4817
4818	g_assert (node != NULL);
4819	g_assert (node->is_instantiatable);
4820
4821	if (NODE_PARENT_TYPE (node))
4822	{
4823	TypeNode *pnode = lookup_type_node_I (NODE_PARENT_TYPE (node));
4824
4825	parent_size = pnode->data->instance.private_size;
4826	}
4827	else
4828	parent_size = 0;
4829
4830	if (node->data->instance.private_size == parent_size)
4831	g_error ("g_type_class_get_instance_private_offset() called on class %s but it has no private data",
4832	g_type_name (instance_type));
4833
4834	return -(gint) node->data->instance.private_size;
4835	}
4836
4837	/**
4838	* g_type_add_class_private:
4839	* @class_type: GType of a classed type
4840	* @private_size: size of private structure
4841	*
4842	* Registers a private class structure for a classed type;
4843	* when the class is allocated, the private structures for
4844	* the class and all of its parent types are allocated
4845	* sequentially in the same memory block as the public
4846	* structures, and are zero-filled.
4847	*
4848	* This function should be called in the
4849	* type's get_type() function after the type is registered.
4850	* The private structure can be retrieved using the
4851	* G_TYPE_CLASS_GET_PRIVATE() macro.
4852	*
4853	* Since: 2.24
4854	*/
4855	void
4856	g_type_add_class_private (GType class_type,
4857	gsize private_size)
4858	{
4859	TypeNode *node = lookup_type_node_I (utype: class_type);
4860	gsize offset;
4861
4862	g_return_if_fail (private_size > 0);
4863
4864	if (!node || !node->is_classed || !node->data)
4865	{
4866	g_warning ("cannot add class private field to invalid type '%s'",
4867	type_descriptive_name_I (class_type));
4868	return;
4869	}
4870
4871	if (NODE_PARENT_TYPE (node))
4872	{
4873	TypeNode *pnode = lookup_type_node_I (NODE_PARENT_TYPE (node));
4874	if (node->data->class.class_private_size != pnode->data->class.class_private_size)
4875	{
4876	g_warning ("g_type_add_class_private() called multiple times for the same type");
4877	return;
4878	}
4879	}
4880
4881	G_WRITE_LOCK (&type_rw_lock);
4882
4883	offset = ALIGN_STRUCT (node->data->class.class_private_size);
4884	node->data->class.class_private_size = offset + private_size;
4885
4886	G_WRITE_UNLOCK (&type_rw_lock);
4887	}
4888
4889	gpointer
4890	g_type_class_get_private (GTypeClass *klass,
4891	GType private_type)
4892	{
4893	TypeNode *class_node;
4894	TypeNode *private_node;
4895	TypeNode *parent_node;
4896	gsize offset;
4897
4898	g_return_val_if_fail (klass != NULL, NULL);
4899
4900	class_node = lookup_type_node_I (utype: klass->g_type);
4901	if (G_UNLIKELY (!class_node || !class_node->is_classed))
4902	{
4903	g_warning ("class of invalid type '%s'",
4904	type_descriptive_name_I (klass->g_type));
4905	return NULL;
4906	}
4907
4908	private_node = lookup_type_node_I (utype: private_type);
4909	if (G_UNLIKELY (!private_node || !NODE_IS_ANCESTOR (private_node, class_node)))
4910	{
4911	g_warning ("attempt to retrieve private data for invalid type '%s'",
4912	type_descriptive_name_I (private_type));
4913	return NULL;
4914	}
4915
4916	offset = ALIGN_STRUCT (class_node->data->class.class_size);
4917
4918	if (NODE_PARENT_TYPE (private_node))
4919	{
4920	parent_node = lookup_type_node_I (NODE_PARENT_TYPE (private_node));
4921	g_assert (parent_node->data && NODE_REFCOUNT (parent_node) > 0);
4922
4923	if (G_UNLIKELY (private_node->data->class.class_private_size == parent_node->data->class.class_private_size))
4924	{
4925	g_warning ("g_type_instance_get_class_private() requires a prior call to g_type_add_class_private()");
4926	return NULL;
4927	}
4928
4929	offset += ALIGN_STRUCT (parent_node->data->class.class_private_size);
4930	}
4931
4932	return G_STRUCT_MEMBER_P (klass, offset);
4933	}
4934
4935	/**
4936	* g_type_ensure:
4937	* @type: a #GType
4938	*
4939	* Ensures that the indicated @type has been registered with the
4940	* type system, and its _class_init() method has been run.
4941	*
4942	* In theory, simply calling the type's _get_type() method (or using
4943	* the corresponding macro) is supposed take care of this. However,
4944	* _get_type() methods are often marked %G_GNUC_CONST for performance
4945	* reasons, even though this is technically incorrect (since
4946	* %G_GNUC_CONST requires that the function not have side effects,
4947	* which _get_type() methods do on the first call). As a result, if
4948	* you write a bare call to a _get_type() macro, it may get optimized
4949	* out by the compiler. Using g_type_ensure() guarantees that the
4950	* type's _get_type() method is called.
4951	*
4952	* Since: 2.34
4953	*/
4954	void
4955	g_type_ensure (GType type)
4956	{
4957	/* In theory, @type has already been resolved and so there's nothing
4958	* to do here. But this protects us in the case where the function
4959	* gets inlined (as it might in gobject_init_ctor() above).
4960	*/
4961	if (G_UNLIKELY (type == (GType)-1))
4962	g_error ("can't happen");
4963	}
4964