~singpolyma/asterisk

ref: 51af79b42e4ae7d1831603633d73bf0df179720e asterisk/main/astobj2_container.c -rw-r--r-- 30.4 KiB
51af79b4Christopher Vollick Content Created By Initiator 2: Electric Boogaloo 9 months ago
                                                                                
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
/* astobj2 - replacement containers for asterisk data structures.
 *
 * Copyright (C) 2006 Marta Carbone, Luigi Rizzo - Univ. di Pisa, Italy
 *
 * See http://www.asterisk.org for more information about
 * the Asterisk project. Please do not directly contact
 * any of the maintainers of this project for assistance;
 * the project provides a web site, mailing lists and IRC
 * channels for your use.
 *
 * This program is free software, distributed under the terms of
 * the GNU General Public License Version 2. See the LICENSE file
 * at the top of the source tree.
 */

/*! \file
 *
 * \brief Functions implementing astobj2 objects.
 *
 * \author Richard Mudgett <rmudgett@digium.com>
 */

#include "asterisk.h"

#include "asterisk/_private.h"
#include "asterisk/astobj2.h"
#include "astobj2_private.h"
#include "astobj2_container_private.h"
#include "asterisk/cli.h"

/*!
 * return the number of elements in the container
 */
int ao2_container_count(struct ao2_container *c)
{
	return ast_atomic_fetchadd_int(&c->elements, 0);
}

int __container_unlink_node_debug(struct ao2_container_node *node, uint32_t flags,
	const char *tag, const char *file, int line, const char *func)
{
	struct ao2_container *container = node->my_container;

	if (container == NULL && (flags & AO2_UNLINK_NODE_DEC_COUNT)) {
		return 0;
	}

	if ((flags & AO2_UNLINK_NODE_UNLINK_OBJECT)
		&& !(flags & AO2_UNLINK_NODE_NOUNREF_OBJECT)) {
		__ao2_ref(node->obj, -1, tag ?: "Remove obj from container", file, line, func);
	}

	node->obj = NULL;

	if (flags & AO2_UNLINK_NODE_DEC_COUNT) {
		ast_atomic_fetchadd_int(&container->elements, -1);
#if defined(AO2_DEBUG)
		{
			int empty = container->nodes - container->elements;

			if (container->max_empty_nodes < empty) {
				container->max_empty_nodes = empty;
			}
			if (container->v_table->unlink_stat) {
				container->v_table->unlink_stat(container, node);
			}
		}
#endif	/* defined(AO2_DEBUG) */
	}

	if (flags & AO2_UNLINK_NODE_UNREF_NODE) {
		/* Remove node from container */
		ao2_t_ref(node, -1, NULL);
	}

	return 1;
}

/*!
 * \internal
 * \brief Link an object into this container.  (internal)
 *
 * \param self Container to operate upon.
 * \param obj_new Object to insert into the container.
 * \param flags search_flags to control linking the object.  (OBJ_NOLOCK)
 * \param tag used for debugging.
 * \param file Debug file name invoked from
 * \param line Debug line invoked from
 * \param func Debug function name invoked from
 *
 * \retval 0 on errors.
 * \retval 1 on success.
 */
int __ao2_link(struct ao2_container *self, void *obj_new, int flags,
	const char *tag, const char *file, int line, const char *func)
{
	int res;
	enum ao2_lock_req orig_lock;
	struct ao2_container_node *node;

	if (!__is_ao2_object(obj_new, file, line, func)
		|| !__is_ao2_object(self, file, line, func)) {
		return 0;
	}

	if (!self->v_table || !self->v_table->new_node || !self->v_table->insert) {
		/* Sanity checks. */
		__ast_assert_failed(0, "invalid container v_table", file, line, func);
		return 0;
	}

	if (flags & OBJ_NOLOCK) {
		orig_lock = __adjust_lock(self, AO2_LOCK_REQ_WRLOCK, 1);
	} else {
		ao2_wrlock(self);
		orig_lock = AO2_LOCK_REQ_MUTEX;
	}

	res = 0;
	node = self->v_table->new_node(self, obj_new, tag, file, line, func);
	if (node) {
#if defined(AO2_DEBUG)
		if (ao2_container_check(self, OBJ_NOLOCK)) {
			ast_log(LOG_ERROR, "Container integrity failed before insert.\n");
		}
#endif	/* defined(AO2_DEBUG) */

		/* Insert the new node. */
		switch (self->v_table->insert(self, node)) {
		case AO2_CONTAINER_INSERT_NODE_INSERTED:
			node->is_linked = 1;
			ast_atomic_fetchadd_int(&self->elements, 1);
#if defined(AO2_DEBUG)
			AO2_DEVMODE_STAT(++self->nodes);
			if (self->v_table->link_stat) {
				self->v_table->link_stat(self, node);
			}
#endif	/* defined(AO2_DEBUG) */
			/* Fall through */
		case AO2_CONTAINER_INSERT_NODE_OBJ_REPLACED:
#if defined(AO2_DEBUG)
			if (ao2_container_check(self, OBJ_NOLOCK)) {
				ast_log(LOG_ERROR, "Container integrity failed after insert or replace.\n");
			}
#endif	/* defined(AO2_DEBUG) */
			res = 1;
			break;
		case AO2_CONTAINER_INSERT_NODE_REJECTED:
			ao2_t_ref(node, -1, NULL);
			break;
		}
	}

	if (flags & OBJ_NOLOCK) {
		__adjust_lock(self, orig_lock, 0);
	} else {
		ao2_unlock(self);
	}

	return res;
}

/*!
 * \brief another convenience function is a callback that matches on address
 */
int ao2_match_by_addr(void *user_data, void *arg, int flags)
{
	return (user_data == arg) ? (CMP_MATCH | CMP_STOP) : 0;
}

/*
 * Unlink an object from the container
 * and destroy the associated * bucket_entry structure.
 */
void *__ao2_unlink(struct ao2_container *c, void *user_data, int flags,
	const char *tag, const char *file, int line, const char *func)
{
	if (!__is_ao2_object(user_data, file, line, func)) {
		/* Sanity checks. */
		return NULL;
	}

	flags &= ~OBJ_SEARCH_MASK;
	flags |= (OBJ_UNLINK | OBJ_SEARCH_OBJECT | OBJ_NODATA);
	__ao2_callback(c, flags, ao2_match_by_addr, user_data, tag, file, line, func);

	return NULL;
}

/*!
 * \brief special callback that matches all
 */
static int cb_true(void *user_data, void *arg, int flags)
{
	return CMP_MATCH;
}

/*!
 * \brief similar to cb_true, but is an ao2_callback_data_fn instead
 */
static int cb_true_data(void *user_data, void *arg, void *data, int flags)
{
	return CMP_MATCH;
}

/*!
 * \internal
 * \brief Traverse the container.  (internal)
 *
 * \param self Container to operate upon.
 * \param flags search_flags to control traversing the container
 * \param cb_fn Comparison callback function.
 * \param arg Comparison callback arg parameter.
 * \param data Data comparison callback data parameter.
 * \param type Type of comparison callback cb_fn.
 * \param tag used for debugging.
 * \param file Debug file name invoked from
 * \param line Debug line invoked from
 * \param func Debug function name invoked from
 *
 * \retval NULL on failure or no matching object found.
 *
 * \retval object found if OBJ_MULTIPLE is not set in the flags
 * parameter.
 *
 * \retval ao2_iterator pointer if OBJ_MULTIPLE is set in the
 * flags parameter.  The iterator must be destroyed with
 * ao2_iterator_destroy() when the caller no longer needs it.
 */
static void *internal_ao2_traverse(struct ao2_container *self, enum search_flags flags,
	void *cb_fn, void *arg, void *data, enum ao2_callback_type type,
	const char *tag, const char *file, int line, const char *func)
{
	void *ret;
	ao2_callback_fn *cb_default = NULL;
	ao2_callback_data_fn *cb_withdata = NULL;
	struct ao2_container_node *node;
	void *traversal_state;

	enum ao2_lock_req orig_lock;
	struct ao2_container *multi_container = NULL;
	struct ao2_iterator *multi_iterator = NULL;

	if (!__is_ao2_object(self, file, line, func)) {
		return NULL;
	}

	if (!self->v_table
		|| !self->v_table->traverse_first || !self->v_table->traverse_next) {
		/* Sanity checks. */
		__ast_assert_failed(0, "invalid container v_table", file, line, func);
		return NULL;
	}

	/*
	 * This logic is used so we can support OBJ_MULTIPLE with OBJ_NODATA
	 * turned off.  This if statement checks for the special condition
	 * where multiple items may need to be returned.
	 */
	if ((flags & (OBJ_MULTIPLE | OBJ_NODATA)) == OBJ_MULTIPLE) {
		/* we need to return an ao2_iterator with the results,
		 * as there could be more than one. the iterator will
		 * hold the only reference to a container that has all the
		 * matching objects linked into it, so when the iterator
		 * is destroyed, the container will be automatically
		 * destroyed as well.
		 */
		multi_container = ao2_t_container_alloc_list(AO2_ALLOC_OPT_LOCK_NOLOCK, 0, NULL,
			NULL, "OBJ_MULTIPLE return container creation");
		if (!multi_container) {
			return NULL;
		}
		if (!(multi_iterator = ast_calloc(1, sizeof(*multi_iterator)))) {
			ao2_t_ref(multi_container, -1, "OBJ_MULTIPLE interator creation failed.");
			return NULL;
		}
	}

	if (!cb_fn) {
		/* Match everything if no callback match function provided. */
		if (type == AO2_CALLBACK_WITH_DATA) {
			cb_withdata = cb_true_data;
		} else {
			cb_default = cb_true;
		}
	} else {
		/*
		 * We do this here to avoid the per object casting penalty (even
		 * though that is probably optimized away anyway).
		 */
		if (type == AO2_CALLBACK_WITH_DATA) {
			cb_withdata = cb_fn;
		} else {
			cb_default = cb_fn;
		}
	}

	/* avoid modifications to the content */
	if (flags & OBJ_NOLOCK) {
		if (flags & OBJ_UNLINK) {
			orig_lock = __adjust_lock(self, AO2_LOCK_REQ_WRLOCK, 1);
		} else {
			orig_lock = __adjust_lock(self, AO2_LOCK_REQ_RDLOCK, 1);
		}
	} else {
		orig_lock = AO2_LOCK_REQ_MUTEX;
		if (flags & OBJ_UNLINK) {
			ao2_wrlock(self);
		} else {
			ao2_rdlock(self);
		}
	}

	/* Create a buffer for the traversal state. */
	traversal_state = alloca(AO2_TRAVERSAL_STATE_SIZE);

	ret = NULL;
	for (node = self->v_table->traverse_first(self, flags, arg, traversal_state);
		node;
		node = self->v_table->traverse_next(self, traversal_state, node)) {
		int match;

		/* Visit the current node. */
		match = (CMP_MATCH | CMP_STOP);
		if (type == AO2_CALLBACK_WITH_DATA) {
			match &= cb_withdata(node->obj, arg, data, flags);
		} else {
			match &= cb_default(node->obj, arg, flags);
		}
		if (match == 0) {
			/* no match, no stop, continue */
			continue;
		}
		if (match == CMP_STOP) {
			/* no match but stop, we are done */
			break;
		}

		/*
		 * CMP_MATCH is set here
		 *
		 * we found the object, performing operations according to flags
		 */
		if (node->obj) {
			/* The object is still in the container. */
			if (!(flags & OBJ_NODATA)) {
				/*
				 * We are returning the object, record the value.  It is
				 * important to handle this case before the unlink.
				 */
				if (multi_container) {
					/*
					 * Link the object into the container that will hold the
					 * results.
					 */
					__ao2_link(multi_container, node->obj, flags, tag, file, line, func);
				} else {
					ret = node->obj;
					/* Returning a single object. */
					if (!(flags & OBJ_UNLINK)) {
						/*
						 * Bump the ref count since we are not going to unlink and
						 * transfer the container's object ref to the returned object.
						 */
						__ao2_ref(ret, 1, tag ?: "Traversal found object", file, line, func);
					}
				}
			}

			if (flags & OBJ_UNLINK) {
				int ulflag = AO2_UNLINK_NODE_UNREF_NODE | AO2_UNLINK_NODE_DEC_COUNT;
				if (multi_container || (flags & OBJ_NODATA)) {
					ulflag |= AO2_UNLINK_NODE_UNLINK_OBJECT;
				}
				__container_unlink_node_debug(node, ulflag, tag, file, line, func);
			}
		}

		if ((match & CMP_STOP) || !(flags & OBJ_MULTIPLE)) {
			/* We found our only (or last) match, so we are done */
			break;
		}
	}
	if (self->v_table->traverse_cleanup) {
		self->v_table->traverse_cleanup(traversal_state);
	}
	if (node) {
		/* Unref the node from self->v_table->traverse_first/traverse_next() */
		ao2_t_ref(node, -1, NULL);
	}

	if (flags & OBJ_NOLOCK) {
		__adjust_lock(self, orig_lock, 0);
	} else {
		ao2_unlock(self);
	}

	/* if multi_container was created, we are returning multiple objects */
	if (multi_container) {
		*multi_iterator = ao2_iterator_init(multi_container,
			AO2_ITERATOR_UNLINK | AO2_ITERATOR_MALLOCD);
		ao2_t_ref(multi_container, -1,
			"OBJ_MULTIPLE for multiple objects traversal complete.");
		return multi_iterator;
	} else {
		return ret;
	}
}

void *__ao2_callback(struct ao2_container *c, enum search_flags flags,
	ao2_callback_fn *cb_fn, void *arg, const char *tag, const char *file, int line,
	const char *func)
{
	return internal_ao2_traverse(c, flags, cb_fn, arg, NULL, AO2_CALLBACK_DEFAULT, tag, file, line, func);
}

void *__ao2_callback_data(struct ao2_container *c, enum search_flags flags,
	ao2_callback_data_fn *cb_fn, void *arg, void *data, const char *tag, const char *file,
	int line, const char *func)
{
	return internal_ao2_traverse(c, flags, cb_fn, arg, data, AO2_CALLBACK_WITH_DATA, tag, file, line, func);
}

/*!
 * the find function just invokes the default callback with some reasonable flags.
 */
void *__ao2_find(struct ao2_container *c, const void *arg, enum search_flags flags,
	const char *tag, const char *file, int line, const char *func)
{
	void *arged = (void *) arg;/* Done to avoid compiler const warning */

	if (!c) {
		/* Sanity checks. */
		ast_assert(0);
		return NULL;
	}
	return __ao2_callback(c, flags, c->cmp_fn, arged, tag, file, line, func);
}

void *__ao2_weakproxy_find(struct ao2_container *c, const void *arg, enum search_flags flags,
	const char *tag, const char *file, int line, const char *func)
{
	void *proxy;
	void *obj = NULL;
	enum ao2_lock_req orig_lock;

	ast_assert(!!c);
	ast_assert(flags & OBJ_SEARCH_MASK);
	ast_assert(!(flags & ~(OBJ_SEARCH_MASK | OBJ_NOLOCK)));

	if (flags & OBJ_NOLOCK) {
		orig_lock = __adjust_lock(c, AO2_LOCK_REQ_RDLOCK, 1);
	} else {
		orig_lock = AO2_LOCK_REQ_RDLOCK;
		ao2_rdlock(c);
	}

	while ((proxy = ao2_find(c, arg, flags | OBJ_NOLOCK))) {
		obj = __ao2_weakproxy_get_object(proxy, 0, tag ?: __PRETTY_FUNCTION__, file, line, func);

		if (obj) {
			ao2_ref(proxy, -1);
			break;
		}

		/* Upgrade to a write lock */
		__adjust_lock(c, AO2_LOCK_REQ_WRLOCK, 1);
		ao2_unlink_flags(c, proxy, OBJ_NOLOCK);
		ao2_ref(proxy, -1);
	}

	if (flags & OBJ_NOLOCK) {
		/* We'll keep any upgraded lock */
		__adjust_lock(c, orig_lock, 1);
	} else {
		ao2_unlock(c);
	}

	return obj;
}

/*!
 * initialize an iterator so we start from the first object
 */
struct ao2_iterator ao2_iterator_init(struct ao2_container *c, int flags)
{
	struct ao2_iterator a = {
		.c = c,
		.flags = flags
	};

	ao2_t_ref(c, +1, "Init iterator with container.");

	return a;
}

void ao2_iterator_restart(struct ao2_iterator *iter)
{
	if (!is_ao2_object(iter->c)) {
		/* Sanity check. */
		return;
	}

	/* Release the last container node reference if we have one. */
	if (iter->last_node) {
		enum ao2_lock_req orig_lock;

		/*
		 * Do a read lock in case the container node unref does not
		 * destroy the node.  If the container node is destroyed then
		 * the lock will be upgraded to a write lock.
		 */
		if (iter->flags & AO2_ITERATOR_DONTLOCK) {
			orig_lock = __adjust_lock(iter->c, AO2_LOCK_REQ_RDLOCK, 1);
		} else {
			orig_lock = AO2_LOCK_REQ_MUTEX;
			ao2_rdlock(iter->c);
		}

		ao2_t_ref(iter->last_node, -1, NULL);
		iter->last_node = NULL;

		if (iter->flags & AO2_ITERATOR_DONTLOCK) {
			__adjust_lock(iter->c, orig_lock, 0);
		} else {
			ao2_unlock(iter->c);
		}
	}

	/* The iteration is no longer complete. */
	iter->complete = 0;
}

void ao2_iterator_destroy(struct ao2_iterator *iter)
{
	/* Release any last container node reference. */
	ao2_iterator_restart(iter);

	/* Release the iterated container reference. */
	ao2_t_ref(iter->c, -1, "Unref iterator in ao2_iterator_destroy");
	iter->c = NULL;

	/* Free the malloced iterator. */
	if (iter->flags & AO2_ITERATOR_MALLOCD) {
		ast_free(iter);
	}
}

void ao2_iterator_cleanup(struct ao2_iterator *iter)
{
	if (iter) {
		ao2_iterator_destroy(iter);
	}
}

void *__ao2_iterator_next(struct ao2_iterator *iter,
	const char *tag, const char *file, int line, const char *func)
{
	enum ao2_lock_req orig_lock;
	struct ao2_container_node *node;
	void *ret;

	if (!__is_ao2_object(iter->c, file, line, func)) {
		return NULL;
	}

	if (!iter->c->v_table || !iter->c->v_table->iterator_next) {
		/* Sanity checks. */
		__ast_assert_failed(0, "invalid iterator container v_table", file, line, func);
		return NULL;
	}

	if (iter->complete) {
		/* Don't return any more objects. */
		return NULL;
	}

	if (iter->flags & AO2_ITERATOR_DONTLOCK) {
		if (iter->flags & AO2_ITERATOR_UNLINK) {
			orig_lock = __adjust_lock(iter->c, AO2_LOCK_REQ_WRLOCK, 1);
		} else {
			orig_lock = __adjust_lock(iter->c, AO2_LOCK_REQ_RDLOCK, 1);
		}
	} else {
		orig_lock = AO2_LOCK_REQ_MUTEX;
		if (iter->flags & AO2_ITERATOR_UNLINK) {
			ao2_wrlock(iter->c);
		} else {
			ao2_rdlock(iter->c);
		}
	}

	node = iter->c->v_table->iterator_next(iter->c, iter->last_node, iter->flags);
	if (node) {
		ret = node->obj;

		if (iter->flags & AO2_ITERATOR_UNLINK) {
			/* Transfer the object ref from the container to the returned object. */
			__container_unlink_node_debug(node, AO2_UNLINK_NODE_DEC_COUNT, tag, file, line, func);

			/* Transfer the container's node ref to the iterator. */
		} else {
			/* Bump ref of returned object */
			__ao2_ref(ret, +1, tag ?: "Next iterator object.", file, line, func);

			/* Bump the container's node ref for the iterator. */
			ao2_t_ref(node, +1, NULL);
		}
	} else {
		/* The iteration has completed. */
		iter->complete = 1;
		ret = NULL;
	}

	/* Replace the iterator's node */
	if (iter->last_node) {
		ao2_t_ref(iter->last_node, -1, NULL);
	}
	iter->last_node = node;

	if (iter->flags & AO2_ITERATOR_DONTLOCK) {
		__adjust_lock(iter->c, orig_lock, 0);
	} else {
		ao2_unlock(iter->c);
	}

	return ret;
}

int ao2_iterator_count(struct ao2_iterator *iter)
{
	return ao2_container_count(iter->c);
}

void container_destruct(void *_c)
{
	struct ao2_container *c = _c;

	/* Unlink any stored objects in the container. */
	c->destroying = 1;
	ao2_t_callback(c, OBJ_UNLINK | OBJ_NODATA | OBJ_MULTIPLE, NULL, NULL,
		"container_destruct called");

	/* Perform any extra container cleanup. */
	if (c->v_table && c->v_table->destroy) {
		c->v_table->destroy(c);
	}

#if defined(AO2_DEBUG)
	ast_atomic_fetchadd_int(&ao2.total_containers, -1);
#endif
}

/*!
 * \internal
 * \brief Put obj into the arg container.
 * \since 11.0
 *
 * \param obj  pointer to the (user-defined part) of an object.
 * \param arg callback argument from ao2_callback()
 * \param flags flags from ao2_callback()
 *
 * \retval 0 on success.
 * \retval CMP_STOP|CMP_MATCH on error.
 */
static int dup_obj_cb(void *obj, void *arg, int flags)
{
	struct ao2_container *dest = arg;

	return ao2_t_link_flags(dest, obj, OBJ_NOLOCK, NULL) ? 0 : (CMP_MATCH | CMP_STOP);
}

int ao2_container_dup(struct ao2_container *dest, struct ao2_container *src, enum search_flags flags)
{
	void *obj;
	int res = 0;

	if (!(flags & OBJ_NOLOCK)) {
		ao2_rdlock(src);
		ao2_wrlock(dest);
	}
	obj = ao2_callback(src, OBJ_NOLOCK, dup_obj_cb, dest);
	if (obj) {
		/* Failed to put this obj into the dest container. */
		ao2_t_ref(obj, -1, "Failed to put this object into the dest container.");

		/* Remove all items from the dest container. */
		ao2_t_callback(dest, OBJ_NOLOCK | OBJ_UNLINK | OBJ_NODATA | OBJ_MULTIPLE, NULL,
			NULL, NULL);
		res = -1;
	}
	if (!(flags & OBJ_NOLOCK)) {
		ao2_unlock(dest);
		ao2_unlock(src);
	}

	return res;
}

/*!
 * \brief Copy obj associated with a weakproxy into the arg container.
 *
 * \param proxy pointer to the weakproxy.
 * \param arg callback argument from ao2_callback()
 * \param flags flags from ao2_callback()
 *
 * \retval 0 on success.
 * \retval CMP_STOP|CMP_MATCH on error.
 */
static int dup_weakproxy_cb(void *proxy, void *arg, int flags)
{
	void *obj = ao2_weakproxy_get_object(proxy, 0);
	struct ao2_container *dest = arg;
	int ret;

	if (!obj) {
		return 0;
	}

	ret = ao2_t_link_flags(dest, obj, OBJ_NOLOCK, NULL) ? 0 : (CMP_MATCH | CMP_STOP);
	ao2_ref(obj, -1);

	return ret;
}

int ao2_container_dup_weakproxy_objs(struct ao2_container *dest, struct ao2_container *src, enum search_flags flags)
{
	void *obj;
	int res = 0;

	if (!(flags & OBJ_NOLOCK)) {
		ao2_rdlock(src);
		ao2_wrlock(dest);
	}
	obj = ao2_callback(src, OBJ_NOLOCK, dup_weakproxy_cb, dest);
	if (obj) {
		/* Failed to put this obj into the dest container. */
		ao2_t_ref(obj, -1, "Failed to put this object into the dest container.");

		/* Remove all items from the dest container. */
		ao2_t_callback(dest, OBJ_NOLOCK | OBJ_UNLINK | OBJ_NODATA | OBJ_MULTIPLE, NULL,
			NULL, NULL);
		res = -1;
	}
	if (!(flags & OBJ_NOLOCK)) {
		ao2_unlock(dest);
		ao2_unlock(src);
	}

	return res;
}

struct ao2_container *__ao2_container_clone(struct ao2_container *orig, enum search_flags flags, const char *tag, const char *file, int line, const char *func)
{
	struct ao2_container *clone;
	int failed;

	/* Create the clone container with the same properties as the original. */
	if (!__is_ao2_object(orig, file, line, func)) {
		return NULL;
	}

	if (!orig->v_table || !orig->v_table->alloc_empty_clone) {
		/* Sanity checks. */
		__ast_assert_failed(0, "invalid container v_table", file, line, func);
		return NULL;
	}

	clone = orig->v_table->alloc_empty_clone(orig, tag, file, line, func);
	if (!clone) {
		return NULL;
	}

	/* This test is correct.  clone must be locked before calling
	 * ao2_container_dup when the OBJ_NOLOCK flag is set, otherwise
	 * we could have errors in __adjust_lock. */
	if (flags & OBJ_NOLOCK) {
		ao2_wrlock(clone);
	}
	failed = ao2_container_dup(clone, orig, flags);
	if (flags & OBJ_NOLOCK) {
		ao2_unlock(clone);
	}
	if (failed) {
		/* Object copy into the clone container failed. */
		__ao2_ref(clone, -1, tag ?: "Clone creation failed", file, line, func);
		clone = NULL;
	}
	return clone;
}

void ao2_container_dump(struct ao2_container *self, enum search_flags flags, const char *name, void *where, ao2_prnt_fn *prnt, ao2_prnt_obj_fn *prnt_obj)
{
	if (!is_ao2_object(self) || !self->v_table) {
		prnt(where, "Invalid container\n");
		ast_assert(0);
		return;
	}

	if (!(flags & OBJ_NOLOCK)) {
		ao2_rdlock(self);
	}
	if (name) {
		prnt(where, "Container name: %s\n", name);
	}
#if defined(AO2_DEBUG)
	if (self->v_table->dump) {
		self->v_table->dump(self, where, prnt, prnt_obj);
	} else
#endif	/* defined(AO2_DEBUG) */
	{
		prnt(where, "Container dump not available.\n");
	}
	if (!(flags & OBJ_NOLOCK)) {
		ao2_unlock(self);
	}
}

void ao2_container_stats(struct ao2_container *self, enum search_flags flags, const char *name, void *where, ao2_prnt_fn *prnt)
{
	if (!is_ao2_object(self) || !self->v_table) {
		prnt(where, "Invalid container\n");
		ast_assert(0);
		return;
	}

	if (!(flags & OBJ_NOLOCK)) {
		ao2_rdlock(self);
	}
	if (name) {
		prnt(where, "Container name: %s\n", name);
	}
	prnt(where, "Number of objects: %d\n", self->elements);
#if defined(AO2_DEBUG)
	prnt(where, "Number of nodes: %d\n", self->nodes);
	prnt(where, "Number of empty nodes: %d\n", self->nodes - self->elements);
	/*
	 * XXX
	 * If the max_empty_nodes count gets out of single digits you
	 * likely have a code path where ao2_iterator_destroy() is not
	 * called.
	 *
	 * Empty nodes do not harm the container but they do make
	 * container operations less efficient.
	 */
	prnt(where, "Maximum empty nodes: %d\n", self->max_empty_nodes);
	if (self->v_table->stats) {
		self->v_table->stats(self, where, prnt);
	}
#endif	/* defined(AO2_DEBUG) */
	if (!(flags & OBJ_NOLOCK)) {
		ao2_unlock(self);
	}
}

int ao2_container_check(struct ao2_container *self, enum search_flags flags)
{
	int res = 0;

	if (!is_ao2_object(self) || !self->v_table) {
		/* Sanity checks. */
		ast_assert(0);
		return -1;
	}
#if defined(AO2_DEBUG)
	if (!self->v_table->integrity) {
		/* No ingetrigy check available.  Assume container is ok. */
		return 0;
	}

	if (!(flags & OBJ_NOLOCK)) {
		ao2_rdlock(self);
	}
	res = self->v_table->integrity(self);
	if (!(flags & OBJ_NOLOCK)) {
		ao2_unlock(self);
	}
#endif	/* defined(AO2_DEBUG) */
	return res;
}

#if defined(AO2_DEBUG)
static struct ao2_container *reg_containers;

struct ao2_reg_container {
	/*! Registered container pointer. */
	struct ao2_container *registered;
	/*! Callback function to print the given object's key. (NULL if not available) */
	ao2_prnt_obj_fn *prnt_obj;
	/*! Name container registered under. */
	char name[1];
};

struct ao2_reg_partial_key {
	/*! Length of partial key match. */
	int len;
	/*! Registration partial key name. */
	const char *name;
};

struct ao2_reg_match {
	/*! The nth match to find. */
	int find_nth;
	/*! Count of the matches already found. */
	int count;
};
#endif	/* defined(AO2_DEBUG) */

#if defined(AO2_DEBUG)
static int ao2_reg_sort_cb(const void *obj_left, const void *obj_right, int flags)
{
	const struct ao2_reg_container *reg_left = obj_left;
	int cmp;

	switch (flags & OBJ_SEARCH_MASK) {
	case OBJ_SEARCH_OBJECT:
		{
			const struct ao2_reg_container *reg_right = obj_right;

			cmp = strcasecmp(reg_left->name, reg_right->name);
		}
		break;
	case OBJ_SEARCH_KEY:
		{
			const char *name = obj_right;

			cmp = strcasecmp(reg_left->name, name);
		}
		break;
	case OBJ_SEARCH_PARTIAL_KEY:
		{
			const struct ao2_reg_partial_key *partial_key = obj_right;

			cmp = strncasecmp(reg_left->name, partial_key->name, partial_key->len);
		}
		break;
	default:
		/* Sort can only work on something with a full or partial key. */
		ast_assert(0);
		cmp = 0;
		break;
	}
	return cmp;
}
#endif	/* defined(AO2_DEBUG) */

#if defined(AO2_DEBUG)
static void ao2_reg_destructor(void *v_doomed)
{
	struct ao2_reg_container *doomed = v_doomed;

	if (doomed->registered) {
		ao2_t_ref(doomed->registered, -1, "Releasing registered container.");
	}
}
#endif	/* defined(AO2_DEBUG) */

int ao2_container_register(const char *name, struct ao2_container *self, ao2_prnt_obj_fn *prnt_obj)
{
	int res = 0;
#if defined(AO2_DEBUG)
	struct ao2_reg_container *reg;

	reg = ao2_t_alloc_options(sizeof(*reg) + strlen(name), ao2_reg_destructor,
		AO2_ALLOC_OPT_LOCK_NOLOCK, "Container registration object.");
	if (!reg) {
		return -1;
	}

	/* Fill in registered entry */
	ao2_t_ref(self, +1, "Registering container.");
	reg->registered = self;
	reg->prnt_obj = prnt_obj;
	strcpy(reg->name, name);/* safe */

	if (!ao2_t_link(reg_containers, reg, "Save registration object.")) {
		res = -1;
	}

	ao2_t_ref(reg, -1, "Done registering container.");
#endif	/* defined(AO2_DEBUG) */
	return res;
}

void ao2_container_unregister(const char *name)
{
#if defined(AO2_DEBUG)
	ao2_t_find(reg_containers, name, OBJ_UNLINK | OBJ_NODATA | OBJ_SEARCH_KEY,
		"Unregister container");
#endif	/* defined(AO2_DEBUG) */
}

#if defined(AO2_DEBUG)
static int ao2_complete_reg_cb(void *obj, void *arg, int flags)
{
	struct ao2_reg_container *reg = obj;

	if (ast_cli_completion_add(ast_strdup(reg->name))) {
		return CMP_STOP;
	}

	return 0;
}
#endif	/* defined(AO2_DEBUG) */

#if defined(AO2_DEBUG)
static char *complete_container_names(struct ast_cli_args *a)
{
	struct ao2_reg_partial_key partial_key;

	if (a->pos != 3) {
		return NULL;
	}

	partial_key.len = strlen(a->word);
	partial_key.name = a->word;
	ao2_callback(reg_containers, partial_key.len ? OBJ_SEARCH_PARTIAL_KEY : 0,
		ao2_complete_reg_cb, &partial_key);

	return NULL;
}
#endif	/* defined(AO2_DEBUG) */

#if defined(AO2_DEBUG)
AST_THREADSTORAGE(ao2_out_buf);

/*!
 * \brief Print CLI output.
 * \since 12.0.0
 *
 * \param where User data pointer needed to determine where to put output.
 * \param fmt printf type format string.
 *
 * \return Nothing
 */
static void cli_output(void *where, const char *fmt, ...) __attribute__((format(printf, 2, 3)));
static void cli_output(void *where, const char *fmt, ...)
{
	int res;
	struct ast_str *buf;
	va_list ap;

	buf = ast_str_thread_get(&ao2_out_buf, 256);
	if (!buf) {
		return;
	}

	va_start(ap, fmt);
	res = ast_str_set_va(&buf, 0, fmt, ap);
	va_end(ap);

	if (res != AST_DYNSTR_BUILD_FAILED) {
		ast_cli(*(int *) where, "%s", ast_str_buffer(buf));
	}
}
#endif	/* defined(AO2_DEBUG) */

#if defined(AO2_DEBUG)
/*! \brief Show container contents - CLI command */
static char *handle_cli_astobj2_container_dump(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
{
	const char *name;
	struct ao2_reg_container *reg;

	switch (cmd) {
	case CLI_INIT:
		e->command = "astobj2 container dump";
		e->usage =
			"Usage: astobj2 container dump <name>\n"
			"	Show contents of the container <name>.\n";
		return NULL;
	case CLI_GENERATE:
		return complete_container_names(a);
	}

	if (a->argc != 4) {
		return CLI_SHOWUSAGE;
	}

	name = a->argv[3];
	reg = ao2_t_find(reg_containers, name, OBJ_SEARCH_KEY, "Find registered container");
	if (reg) {
		ao2_container_dump(reg->registered, 0, name, (void *) &a->fd, cli_output,
			reg->prnt_obj);
		ao2_t_ref(reg, -1, "Done with registered container object.");
	} else {
		ast_cli(a->fd, "Container '%s' not found.\n", name);
	}

	return CLI_SUCCESS;
}
#endif	/* defined(AO2_DEBUG) */

#if defined(AO2_DEBUG)
/*! \brief Show container statistics - CLI command */
static char *handle_cli_astobj2_container_stats(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
{
	const char *name;
	struct ao2_reg_container *reg;

	switch (cmd) {
	case CLI_INIT:
		e->command = "astobj2 container stats";
		e->usage =
			"Usage: astobj2 container stats <name>\n"
			"	Show statistics about the specified container <name>.\n";
		return NULL;
	case CLI_GENERATE:
		return complete_container_names(a);
	}

	if (a->argc != 4) {
		return CLI_SHOWUSAGE;
	}

	name = a->argv[3];
	reg = ao2_t_find(reg_containers, name, OBJ_SEARCH_KEY, "Find registered container");
	if (reg) {
		ao2_container_stats(reg->registered, 0, name, (void *) &a->fd, cli_output);
		ao2_t_ref(reg, -1, "Done with registered container object.");
	} else {
		ast_cli(a->fd, "Container '%s' not found.\n", name);
	}

	return CLI_SUCCESS;
}
#endif	/* defined(AO2_DEBUG) */

#if defined(AO2_DEBUG)
/*! \brief Show container check results - CLI command */
static char *handle_cli_astobj2_container_check(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
{
	const char *name;
	struct ao2_reg_container *reg;

	switch (cmd) {
	case CLI_INIT:
		e->command = "astobj2 container check";
		e->usage =
			"Usage: astobj2 container check <name>\n"
			"	Perform a container integrity check on <name>.\n";
		return NULL;
	case CLI_GENERATE:
		return complete_container_names(a);
	}

	if (a->argc != 4) {
		return CLI_SHOWUSAGE;
	}

	name = a->argv[3];
	reg = ao2_t_find(reg_containers, name, OBJ_SEARCH_KEY, "Find registered container");
	if (reg) {
		ast_cli(a->fd, "Container check of '%s': %s.\n", name,
			ao2_container_check(reg->registered, 0) ? "failed" : "OK");
		ao2_t_ref(reg, -1, "Done with registered container object.");
	} else {
		ast_cli(a->fd, "Container '%s' not found.\n", name);
	}

	return CLI_SUCCESS;
}
#endif	/* defined(AO2_DEBUG) */

#if defined(AO2_DEBUG)
static struct ast_cli_entry cli_astobj2[] = {
	AST_CLI_DEFINE(handle_cli_astobj2_container_dump, "Show container contents"),
	AST_CLI_DEFINE(handle_cli_astobj2_container_stats, "Show container statistics"),
	AST_CLI_DEFINE(handle_cli_astobj2_container_check, "Perform a container integrity check"),
};
#endif	/* defined(AO2_DEBUG) */

#if defined(AO2_DEBUG)
static void container_cleanup(void)
{
	ao2_t_ref(reg_containers, -1, "Releasing container registration container");
	reg_containers = NULL;

	ast_cli_unregister_multiple(cli_astobj2, ARRAY_LEN(cli_astobj2));
}
#endif	/* defined(AO2_DEBUG) */

int container_init(void)
{
#if defined(AO2_DEBUG)
	reg_containers = ao2_t_container_alloc_list(AO2_ALLOC_OPT_LOCK_RWLOCK,
		AO2_CONTAINER_ALLOC_OPT_DUPS_REPLACE, ao2_reg_sort_cb, NULL,
		"Container registration container.");
	if (!reg_containers) {
		return -1;
	}

	ast_cli_register_multiple(cli_astobj2, ARRAY_LEN(cli_astobj2));
	ast_register_cleanup(container_cleanup);
#endif	/* defined(AO2_DEBUG) */

	return 0;
}