main/astobj2.c

   1 /*
   2  * astobj2 - replacement containers for asterisk data structures.
   3  *
   4  * Copyright (C) 2006 Marta Carbone, Luigi Rizzo - Univ. di Pisa, Italy
   5  *
   6  * See http://www.asterisk.org for more information about
   7  * the Asterisk project. Please do not directly contact
   8  * any of the maintainers of this project for assistance;
   9  * the project provides a web site, mailing lists and IRC
  10  * channels for your use.
  11  *
  12  * This program is free software, distributed under the terms of
  13  * the GNU General Public License Version 2. See the LICENSE file
  14  * at the top of the source tree.
  15  */
  16
  17 /*
  18  * Function implementing astobj2 objects.
  19  */
  20 #include "asterisk.h"
  21
  22 ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
  23
  24 #include "asterisk/astobj2.h"
  25 #include "asterisk/utils.h"
  26 #include "asterisk/cli.h"
  27
  28 /*!
  29  * astobj2 objects are always prepended this data structure,
  30  * which contains a lock, a reference counter,
  31  * the flags and a pointer to a destructor.
  32  * The refcount is used to decide when it is time to
  33  * invoke the destructor.
  34  * The magic number is used for consistency check.
  35  * XXX the lock is not always needed, and its initialization may be
  36  * expensive. Consider making it external.
  37  */
  38 struct __priv_data {
  39         ast_mutex_t lock;
  40         int ref_counter;
  41         ao2_destructor_fn destructor_fn;
  42         /*! for stats */
  43         size_t data_size;
  44         /*! magic number.  This is used to verify that a pointer passed in is a
  45          *  valid astobj2 */
  46         uint32_t magic;
  47 };
  48
  49 #define AO2_MAGIC       0xa570b123
  50
  51 /*!
  52  * What an astobj2 object looks like: fixed-size private data
  53  * followed by variable-size user data.
  54  */
  55 struct astobj2 {
  56         struct __priv_data priv_data;
  57         void *user_data[0];
  58 };
  59
  60 #ifdef AST_DEVMODE
  61 #define AO2_DEBUG 1
  62 #endif
  63
  64 #ifdef AO2_DEBUG
  65 struct ao2_stats {
  66         volatile int total_objects;
  67         volatile int total_mem;
  68         volatile int total_containers;
  69         volatile int total_refs;
  70         volatile int total_locked;
  71 };
  72
  73 static struct ao2_stats ao2;
  74 #endif
  75
  76 #ifndef HAVE_BKTR       /* backtrace support */
  77 void ao2_bt(void) {}
  78 #else
  79 #include <execinfo.h>    /* for backtrace */
  80
  81 void ao2_bt(void)
  82 {
  83     int c, i;
  84 #define N1      20
  85     void *addresses[N1];
  86     char **strings;
  87
  88     c = backtrace(addresses, N1);
  89     strings = backtrace_symbols(addresses,c);
  90     ast_verbose("backtrace returned: %d\n", c);
  91     for(i = 0; i < c; i++) {
  92         ast_verbose("%d: %p %s\n", i, addresses[i], strings[i]);
  93     }
  94     free(strings);
  95 }
  96 #endif
  97
  98 /*!
  99  * \brief convert from a pointer _p to a user-defined object
 100  *
 101  * \return the pointer to the astobj2 structure
 102  */
 103 static inline struct astobj2 *INTERNAL_OBJ(void *user_data)
 104 {
 105         struct astobj2 *p;
 106
 107         if (!user_data) {
 108                 ast_log(LOG_ERROR, "user_data is NULL\n");
 109                 return NULL;
 110         }
 111
 112         p = (struct astobj2 *) ((char *) user_data - sizeof(*p));
 113         if (AO2_MAGIC != (p->priv_data.magic) ) {
 114                 ast_log(LOG_ERROR, "bad magic number 0x%x for %p\n", p->priv_data.magic, p);
 115                 p = NULL;
 116         }
 117
 118         return p;
 119 }
 120
 121 /*!
 122  * \brief convert from a pointer _p to an astobj2 object
 123  *
 124  * \return the pointer to the user-defined portion.
 125  */
 126 #define EXTERNAL_OBJ(_p)        ((_p) == NULL ? NULL : (_p)->user_data)
 127
 128 int ao2_lock(void *user_data)
 129 {
 130         struct astobj2 *p = INTERNAL_OBJ(user_data);
 131
 132         if (p == NULL)
 133                 return -1;
 134
 135 #ifdef AO2_DEBUG
 136         ast_atomic_fetchadd_int(&ao2.total_locked, 1);
 137 #endif
 138
 139         return ast_mutex_lock(&p->priv_data.lock);
 140 }
 141
 142 int ao2_unlock(void *user_data)
 143 {
 144         struct astobj2 *p = INTERNAL_OBJ(user_data);
 145
 146         if (p == NULL)
 147                 return -1;
 148
 149 #ifdef AO2_DEBUG
 150         ast_atomic_fetchadd_int(&ao2.total_locked, -1);
 151 #endif
 152
 153         return ast_mutex_unlock(&p->priv_data.lock);
 154 }
 155
 156 /*
 157  * The argument is a pointer to the user portion.
 158  */
 159 int ao2_ref(void *user_data, const int delta)
 160 {
 161         int current_value;
 162         int ret;
 163         struct astobj2 *obj = INTERNAL_OBJ(user_data);
 164
 165         if (obj == NULL)
 166                 return -1;
 167
 168         /* if delta is 0, just return the refcount */
 169         if (delta == 0)
 170                 return (obj->priv_data.ref_counter);
 171
 172         /* we modify with an atomic operation the reference counter */
 173         ret = ast_atomic_fetchadd_int(&obj->priv_data.ref_counter, delta);
 174         current_value = ret + delta;
 175
 176 #ifdef AO2_DEBUG
 177         ast_atomic_fetchadd_int(&ao2.total_refs, delta);
 178 #endif
 179
 180         /* this case must never happen */
 181         if (current_value < 0)
 182                 ast_log(LOG_ERROR, "refcount %d on object %p\n", current_value, user_data);
 183
 184         if (current_value <= 0) { /* last reference, destroy the object */
 185                 if (obj->priv_data.destructor_fn != NULL)
 186                         obj->priv_data.destructor_fn(user_data);
 187
 188                 ast_mutex_destroy(&obj->priv_data.lock);
 189 #ifdef AO2_DEBUG
 190                 ast_atomic_fetchadd_int(&ao2.total_mem, - obj->priv_data.data_size);
 191                 ast_atomic_fetchadd_int(&ao2.total_objects, -1);
 192 #endif
 193                 /* for safety, zero-out the astobj2 header and also the
 194                  * first word of the user-data, which we make sure is always
 195                  * allocated. */
 196                 bzero(obj, sizeof(struct astobj2 *) + sizeof(void *) );
 197                 free(obj);
 198         }
 199
 200         return ret;
 201 }
 202
 203 /*
 204  * We always alloc at least the size of a void *,
 205  * for debugging purposes.
 206  */
 207 void *ao2_alloc(size_t data_size, ao2_destructor_fn destructor_fn)
 208 {
 209         /* allocation */
 210         struct astobj2 *obj;
 211
 212         if (data_size < sizeof(void *))
 213                 data_size = sizeof(void *);
 214
 215         obj = ast_calloc(1, sizeof(*obj) + data_size);
 216
 217         if (obj == NULL)
 218                 return NULL;
 219
 220         ast_mutex_init(&obj->priv_data.lock);
 221         obj->priv_data.magic = AO2_MAGIC;
 222         obj->priv_data.data_size = data_size;
 223         obj->priv_data.ref_counter = 1;
 224         obj->priv_data.destructor_fn = destructor_fn;   /* can be NULL */
 225
 226 #ifdef AO2_DEBUG
 227         ast_atomic_fetchadd_int(&ao2.total_objects, 1);
 228         ast_atomic_fetchadd_int(&ao2.total_mem, data_size);
 229         ast_atomic_fetchadd_int(&ao2.total_refs, 1);
 230 #endif
 231
 232         /* return a pointer to the user data */
 233         return EXTERNAL_OBJ(obj);
 234 }
 235
 236 /* internal callback to destroy a container. */
 237 static void container_destruct(void *c);
 238
 239 /* each bucket in the container is a tailq. */
 240 AST_LIST_HEAD_NOLOCK(bucket, bucket_list);
 241
 242 /*!
 243  * A container; stores the hash and callback functions, information on
 244  * the size, the hash bucket heads, and a version number, starting at 0
 245  * (for a newly created, empty container)
 246  * and incremented every time an object is inserted or deleted.
 247  * The assumption is that an object is never moved in a container,
 248  * but removed and readded with the new number.
 249  * The version number is especially useful when implementing iterators.
 250  * In fact, we can associate a unique, monotonically increasing number to
 251  * each object, which means that, within an iterator, we can store the
 252  * version number of the current object, and easily look for the next one,
 253  * which is the next one in the list with a higher number.
 254  * Since all objects have a version >0, we can use 0 as a marker for
 255  * 'we need the first object in the bucket'.
 256  *
 257  * \todo Linking and unlink objects is typically expensive, as it
 258  * involves a malloc() of a small object which is very inefficient.
 259  * To optimize this, we allocate larger arrays of bucket_list's
 260  * when we run out of them, and then manage our own freelist.
 261  * This will be more efficient as we can do the freelist management while
 262  * we hold the lock (that we need anyways).
 263  */
 264 struct ao2_container {
 265         ao2_hash_fn hash_fn;
 266         ao2_callback_fn cmp_fn;
 267         int n_buckets;
 268         /*! Number of elements in the container */
 269         int elements;
 270         /*! described above */
 271         int version;
 272         /*! variable size */
 273         struct bucket buckets[0];
 274 };
 275
 276 /*!
 277  * \brief always zero hash function
 278  *
 279  * it is convenient to have a hash function that always returns 0.
 280  * This is basically used when we want to have a container that is
 281  * a simple linked list.
 282  *
 283  * \returns 0
 284  */
 285 static int hash_zero(const void *user_obj, const int flags)
 286 {
 287         return 0;
 288 }
 289
 290 /*
 291  * A container is just an object, after all!
 292  */
 293 struct ao2_container *
 294 ao2_container_alloc(const uint n_buckets, ao2_hash_fn hash_fn,
 295                 ao2_callback_fn cmp_fn)
 296 {
 297         /* XXX maybe consistency check on arguments ? */
 298         /* compute the container size */
 299         size_t container_size = sizeof(struct ao2_container) + n_buckets * sizeof(struct bucket);
 300
 301         struct ao2_container *c = ao2_alloc(container_size, container_destruct);
 302
 303         if (!c)
 304                 return NULL;
 305
 306         c->version = 1; /* 0 is a reserved value here */
 307         c->n_buckets = n_buckets;
 308         c->hash_fn = hash_fn ? hash_fn : hash_zero;
 309         c->cmp_fn = cmp_fn;
 310
 311 #ifdef AO2_DEBUG
 312         ast_atomic_fetchadd_int(&ao2.total_containers, 1);
 313 #endif
 314
 315         return c;
 316 }
 317
 318 /*!
 319  * return the number of elements in the container
 320  */
 321 int ao2_container_count(struct ao2_container *c)
 322 {
 323         return c->elements;
 324 }
 325
 326 /*!
 327  * A structure to create a linked list of entries,
 328  * used within a bucket.
 329  * XXX \todo this should be private to the container code
 330  */
 331 struct bucket_list {
 332         AST_LIST_ENTRY(bucket_list) entry;
 333         int version;
 334         struct astobj2 *astobj;         /* pointer to internal data */
 335 };
 336
 337 /*
 338  * link an object to a container
 339  */
 340 void *__ao2_link(struct ao2_container *c, void *user_data, int iax2_hack)
 341 {
 342         int i;
 343         /* create a new list entry */
 344         struct bucket_list *p;
 345         struct astobj2 *obj = INTERNAL_OBJ(user_data);
 346
 347         if (!obj)
 348                 return NULL;
 349
 350         if (INTERNAL_OBJ(c) == NULL)
 351                 return NULL;
 352
 353         p = ast_calloc(1, sizeof(*p));
 354         if (!p)
 355                 return NULL;
 356
 357         i = c->hash_fn(user_data, OBJ_POINTER);
 358
 359         ao2_lock(c);
 360         i %= c->n_buckets;
 361         p->astobj = obj;
 362         p->version = ast_atomic_fetchadd_int(&c->version, 1);
 363         if (iax2_hack)
 364                 AST_LIST_INSERT_HEAD(&c->buckets[i], p, entry);
 365         else
 366                 AST_LIST_INSERT_TAIL(&c->buckets[i], p, entry);
 367         ast_atomic_fetchadd_int(&c->elements, 1);
 368         ao2_ref(user_data, +1);
 369         ao2_unlock(c);
 370
 371         return p;
 372 }
 373
 374 /*!
 375  * \brief another convenience function is a callback that matches on address
 376  */
 377 int ao2_match_by_addr(void *user_data, void *arg, int flags)
 378 {
 379         return (user_data == arg) ? (CMP_MATCH | CMP_STOP) : 0;
 380 }
 381
 382 /*
 383  * Unlink an object from the container
 384  * and destroy the associated * ao2_bucket_list structure.
 385  */
 386 void *ao2_unlink(struct ao2_container *c, void *user_data)
 387 {
 388         if (INTERNAL_OBJ(user_data) == NULL)    /* safety check on the argument */
 389                 return NULL;
 390
 391         ao2_callback(c, OBJ_UNLINK | OBJ_POINTER | OBJ_NODATA, ao2_match_by_addr, user_data);
 392
 393         return NULL;
 394 }
 395
 396 /*!
 397  * \brief special callback that matches all
 398  */
 399 static int cb_true(void *user_data, void *arg, int flags)
 400 {
 401         return CMP_MATCH;
 402 }
 403
 404 /*!
 405  * Browse the container using different stategies accoding the flags.
 406  * \return Is a pointer to an object or to a list of object if OBJ_MULTIPLE is
 407  * specified.
 408  */
 409 void *ao2_callback(struct ao2_container *c,
 410         const enum search_flags flags,
 411         ao2_callback_fn cb_fn, void *arg)
 412 {
 413         int i, last;    /* search boundaries */
 414         void *ret = NULL;
 415
 416         if (INTERNAL_OBJ(c) == NULL)    /* safety check on the argument */
 417                 return NULL;
 418
 419         if ((flags & (OBJ_MULTIPLE | OBJ_NODATA)) == OBJ_MULTIPLE) {
 420                 ast_log(LOG_WARNING, "multiple data return not implemented yet (flags %x)\n", flags);
 421                 return NULL;
 422         }
 423
 424         /* override the match function if necessary */
 425 #if 0
 426         /* Removing this slightly changes the meaning of OBJ_POINTER, but makes it
 427          * do what I want it to.  I'd like to hint to ao2_callback that the arg is
 428          * of the same object type, so it can be passed to the hash function.
 429          * However, I don't want to imply that this is the object being searched for. */
 430         if (flags & OBJ_POINTER)
 431                 cb_fn = match_by_addr;
 432         else
 433 #endif
 434         if (cb_fn == NULL)      /* if NULL, match everything */
 435                 cb_fn = cb_true;
 436         /*
 437          * XXX this can be optimized.
 438          * If we have a hash function and lookup by pointer,
 439          * run the hash function. Otherwise, scan the whole container
 440          * (this only for the time being. We need to optimize this.)
 441          */
 442         if ((flags & OBJ_POINTER))      /* we know hash can handle this case */
 443                 i = c->hash_fn(arg, flags & OBJ_POINTER) % c->n_buckets;
 444         else                    /* don't know, let's scan all buckets */
 445                 i = -1;         /* XXX this must be fixed later. */
 446
 447         /* determine the search boundaries: i..last-1 */
 448         if (i < 0) {
 449                 i = 0;
 450                 last = c->n_buckets;
 451         } else {
 452                 last = i + 1;
 453         }
 454
 455         ao2_lock(c);    /* avoid modifications to the content */
 456
 457         for (; i < last ; i++) {
 458                 /* scan the list with prev-cur pointers */
 459                 struct bucket_list *cur;
 460
 461                 AST_LIST_TRAVERSE_SAFE_BEGIN(&c->buckets[i], cur, entry) {
 462                         int match = cb_fn(EXTERNAL_OBJ(cur->astobj), arg, flags) & (CMP_MATCH | CMP_STOP);
 463
 464                         /* we found the object, performing operations according flags */
 465                         if (match == 0) {       /* no match, no stop, continue */
 466                                 continue;
 467                         } else if (match == CMP_STOP) { /* no match but stop, we are done */
 468                                 i = last;
 469                                 break;
 470                         }
 471                         /* we have a match (CMP_MATCH) here */
 472                         if (!(flags & OBJ_NODATA)) {    /* if must return the object, record the value */
 473                                 /* it is important to handle this case before the unlink */
 474                                 ret = EXTERNAL_OBJ(cur->astobj);
 475                                 ao2_ref(ret, 1);
 476                         }
 477
 478                         if (flags & OBJ_UNLINK) {       /* must unlink */
 479                                 struct bucket_list *x = cur;
 480
 481                                 /* we are going to modify the container, so update version */
 482                                 ast_atomic_fetchadd_int(&c->version, 1);
 483                                 AST_LIST_REMOVE_CURRENT(&c->buckets[i], entry);
 484                                 /* update number of elements and version */
 485                                 ast_atomic_fetchadd_int(&c->elements, -1);
 486                                 ao2_ref(EXTERNAL_OBJ(x->astobj), -1);
 487                                 free(x);        /* free the link record */
 488                         }
 489
 490                         if ((match & CMP_STOP) || (flags & OBJ_MULTIPLE) == 0) {
 491                                 /* We found the only match we need */
 492                                 i = last;       /* force exit from outer loop */
 493                                 break;
 494                         }
 495                         if (!(flags & OBJ_NODATA)) {
 496 #if 0   /* XXX to be completed */
 497                                 /*
 498                                  * This is the multiple-return case. We need to link
 499                                  * the object in a list. The refcount is already increased.
 500                                  */
 501 #endif
 502                         }
 503                 }
 504                 AST_LIST_TRAVERSE_SAFE_END
 505         }
 506         ao2_unlock(c);
 507         return ret;
 508 }
 509
 510 /*!
 511  * the find function just invokes the default callback with some reasonable flags.
 512  */
 513 void *ao2_find(struct ao2_container *c, void *arg, enum search_flags flags)
 514 {
 515         return ao2_callback(c, flags, c->cmp_fn, arg);
 516 }
 517
 518 /*!
 519  * initialize an iterator so we start from the first object
 520  */
 521 struct ao2_iterator ao2_iterator_init(struct ao2_container *c, int flags)
 522 {
 523         struct ao2_iterator a = {
 524                 .c = c,
 525                 .flags = flags
 526         };
 527
 528         return a;
 529 }
 530
 531 /*
 532  * move to the next element in the container.
 533  */
 534 void * ao2_iterator_next(struct ao2_iterator *a)
 535 {
 536         int lim;
 537         struct bucket_list *p = NULL;
 538         void *ret = NULL;
 539
 540         if (INTERNAL_OBJ(a->c) == NULL)
 541                 return NULL;
 542
 543         if (!(a->flags & F_AO2I_DONTLOCK))
 544                 ao2_lock(a->c);
 545
 546         /* optimization. If the container is unchanged and
 547          * we have a pointer, try follow it
 548          */
 549         if (a->c->version == a->c_version && (p = a->obj) ) {
 550                 if ( (p = AST_LIST_NEXT(p, entry)) )
 551                         goto found;
 552                 /* nope, start from the next bucket */
 553                 a->bucket++;
 554                 a->version = 0;
 555                 a->obj = NULL;
 556         }
 557
 558         lim = a->c->n_buckets;
 559
 560         /* Browse the buckets array, moving to the next
 561          * buckets if we don't find the entry in the current one.
 562          * Stop when we find an element with version number greater
 563          * than the current one (we reset the version to 0 when we
 564          * switch buckets).
 565          */
 566         for (; a->bucket < lim; a->bucket++, a->version = 0) {
 567                 /* scan the current bucket */
 568                 AST_LIST_TRAVERSE(&a->c->buckets[a->bucket], p, entry) {
 569                         if (p->version > a->version)
 570                                 goto found;
 571                 }
 572         }
 573
 574 found:
 575         if (p) {
 576                 a->version = p->version;
 577                 a->obj = p;
 578                 a->c_version = a->c->version;
 579                 ret = EXTERNAL_OBJ(p->astobj);
 580                 /* inc refcount of returned object */
 581                 ao2_ref(ret, 1);
 582         }
 583
 584         if (!(a->flags & F_AO2I_DONTLOCK))
 585                 ao2_unlock(a->c);
 586
 587         return ret;
 588 }
 589
 590 /* callback for destroying container.
 591  * we can make it simple as we know what it does
 592  */
 593 static int cd_cb(void *obj, void *arg, int flag)
 594 {
 595         ao2_ref(obj, -1);
 596         return 0;
 597 }
 598
 599 static void container_destruct(void *_c)
 600 {
 601         struct ao2_container *c = _c;
 602         int i;
 603
 604         ao2_callback(c, OBJ_UNLINK, cd_cb, NULL);
 605
 606         for (i = 0; i < c->n_buckets; i++) {
 607                 struct bucket_list *cur;
 608
 609                 while ((cur = AST_LIST_REMOVE_HEAD(&c->buckets[i], entry))) {
 610                         ast_free(cur);
 611                 }
 612         }
 613
 614 #ifdef AO2_DEBUG
 615         ast_atomic_fetchadd_int(&ao2.total_containers, -1);
 616 #endif
 617 }
 618
 619 #ifdef AO2_DEBUG
 620 static int print_cb(void *obj, void *arg, int flag)
 621 {
 622         int *fd = arg;
 623         char *s = (char *)obj;
 624
 625         ast_cli(*fd, "string <%s>\n", s);
 626         return 0;
 627 }
 628
 629 /*
 630  * Print stats
 631  */
 632 static int handle_astobj2_stats(int fd, int argc, char *argv[])
 633 {
 634         ast_cli(fd, "Objects    : %d\n", ao2.total_objects);
 635         ast_cli(fd, "Containers : %d\n", ao2.total_containers);
 636         ast_cli(fd, "Memory     : %d\n", ao2.total_mem);
 637         ast_cli(fd, "Locked     : %d\n", ao2.total_locked);
 638         ast_cli(fd, "Refs       : %d\n", ao2.total_refs);
 639         return 0;
 640 }
 641
 642 /*
 643  * This is testing code for astobj
 644  */
 645 static int handle_astobj2_test(int fd, int argc, char *argv[])
 646 {
 647         struct ao2_container *c1;
 648         int i, lim;
 649         char *obj;
 650         static int prof_id = -1;
 651
 652         if (prof_id == -1)
 653                 prof_id = ast_add_profile("ao2_alloc", 0);
 654
 655         ast_cli(fd, "argc %d argv %s %s %s\n", argc, argv[0], argv[1], argv[2]);
 656         lim = atoi(argv[2]);
 657         ast_cli(fd, "called astobj_test\n");
 658
 659         handle_astobj2_stats(fd, 0, NULL);
 660         /*
 661          * allocate a container with no default callback, and no hash function.
 662          * No hash means everything goes in the same bucket.
 663          */
 664         c1 = ao2_container_alloc(100, NULL /* no callback */, NULL /* no hash */);
 665         ast_cli(fd, "container allocated as %p\n", c1);
 666
 667         /*
 668          * fill the container with objects.
 669          * ao2_alloc() gives us a reference which we pass to the
 670          * container when we do the insert.
 671          */
 672         for (i = 0; i < lim; i++) {
 673                 ast_mark(prof_id, 1 /* start */);
 674                 obj = ao2_alloc(80, NULL);
 675                 ast_mark(prof_id, 0 /* stop */);
 676                 ast_cli(fd, "object %d allocated as %p\n", i, obj);
 677                 sprintf(obj, "-- this is obj %d --", i);
 678                 ao2_link(c1, obj);
 679         }
 680         ast_cli(fd, "testing callbacks\n");
 681         ao2_callback(c1, 0, print_cb, &fd);
 682
 683         ast_cli(fd, "testing iterators, remove every second object\n");
 684         {
 685                 struct ao2_iterator ai;
 686                 int x = 0;
 687
 688                 ai = ao2_iterator_init(c1, 0);
 689                 while ( (obj = ao2_iterator_next(&ai)) ) {
 690                         ast_cli(fd, "iterator on <%s>\n", obj);
 691                         if (x++ & 1)
 692                                 ao2_unlink(c1, obj);
 693                         ao2_ref(obj, -1);
 694                 }
 695                 ast_cli(fd, "testing iterators again\n");
 696                 ai = ao2_iterator_init(c1, 0);
 697                 while ( (obj = ao2_iterator_next(&ai)) ) {
 698                         ast_cli(fd, "iterator on <%s>\n", obj);
 699                         ao2_ref(obj, -1);
 700                 }
 701         }
 702         ast_cli(fd, "testing callbacks again\n");
 703         ao2_callback(c1, 0, print_cb, &fd);
 704
 705         ast_verbose("now you should see an error message:\n");
 706         ao2_ref(&i, -1);        /* i is not a valid object so we print an error here */
 707
 708         ast_cli(fd, "destroy container\n");
 709         ao2_ref(c1, -1);        /* destroy container */
 710         handle_astobj2_stats(fd, 0, NULL);
 711         return 0;
 712 }
 713
 714 static struct ast_cli_entry cli_astobj2[] = {
 715         { { "astobj2", "stats", NULL },
 716         handle_astobj2_stats, "Print astobj2 statistics", },
 717         { { "astobj2", "test", NULL } , handle_astobj2_test, "Test astobj2", },
 718 };
 719 #endif /* AO2_DEBUG */
 720
 721 int astobj2_init(void)
 722 {
 723 #ifdef AO2_DEBUG
 724         ast_cli_register_multiple(cli_astobj2, ARRAY_LEN(cli_astobj2));
 725 #endif
 726
 727         return 0;
 728 }