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/_private.h"
  25 #include "asterisk/astobj2.h"
  26 #include "asterisk/utils.h"
  27 #include "asterisk/cli.h"
  28 #define REF_FILE "/tmp/refs"
  29
  30 /*!
  31  * astobj2 objects are always preceded by this data structure,
  32  * which contains a lock, a reference counter,
  33  * the flags and a pointer to a destructor.
  34  * The refcount is used to decide when it is time to
  35  * invoke the destructor.
  36  * The magic number is used for consistency check.
  37  * XXX the lock is not always needed, and its initialization may be
  38  * expensive. Consider making it external.
  39  */
  40 struct __priv_data {
  41         ast_mutex_t lock;
  42         int ref_counter;
  43         ao2_destructor_fn destructor_fn;
  44         /*! for stats */
  45         size_t data_size;
  46         /*! magic number.  This is used to verify that a pointer passed in is a
  47          *  valid astobj2 */
  48         uint32_t magic;
  49 };
  50
  51 #define AO2_MAGIC       0xa570b123
  52
  53 /*!
  54  * What an astobj2 object looks like: fixed-size private data
  55  * followed by variable-size user data.
  56  */
  57 struct astobj2 {
  58         struct __priv_data priv_data;
  59         void *user_data[0];
  60 };
  61
  62 #ifdef AST_DEVMODE
  63 #define AO2_DEBUG 1
  64 #endif
  65
  66 #ifdef AO2_DEBUG
  67 struct ao2_stats {
  68         volatile int total_objects;
  69         volatile int total_mem;
  70         volatile int total_containers;
  71         volatile int total_refs;
  72         volatile int total_locked;
  73 };
  74
  75 static struct ao2_stats ao2;
  76 #endif
  77
  78 #ifndef HAVE_BKTR       /* backtrace support */
  79 void ao2_bt(void) {}
  80 #else
  81 #include <execinfo.h>    /* for backtrace */
  82
  83 void ao2_bt(void)
  84 {
  85         int c, i;
  86 #define N1      20
  87         void *addresses[N1];
  88         char **strings;
  89
  90         c = backtrace(addresses, N1);
  91         strings = backtrace_symbols(addresses,c);
  92         ast_verbose("backtrace returned: %d\n", c);
  93         for(i = 0; i < c; i++) {
  94                 ast_verbose("%d: %p %s\n", i, addresses[i], strings[i]);
  95         }
  96         free(strings);
  97 }
  98 #endif
  99
 100 /*!
 101  * \brief convert from a pointer _p to a user-defined object
 102  *
 103  * \return the pointer to the astobj2 structure
 104  */
 105 static inline struct astobj2 *INTERNAL_OBJ(void *user_data)
 106 {
 107         struct astobj2 *p;
 108
 109         if (!user_data) {
 110                 ast_log(LOG_ERROR, "user_data is NULL\n");
 111                 return NULL;
 112         }
 113
 114         p = (struct astobj2 *) ((char *) user_data - sizeof(*p));
 115         if (AO2_MAGIC != (p->priv_data.magic) ) {
 116                 ast_log(LOG_ERROR, "bad magic number 0x%x for %p\n", p->priv_data.magic, p);
 117                 p = NULL;
 118         }
 119
 120         return p;
 121 }
 122
 123 /*!
 124  * \brief convert from a pointer _p to an astobj2 object
 125  *
 126  * \return the pointer to the user-defined portion.
 127  */
 128 #define EXTERNAL_OBJ(_p)        ((_p) == NULL ? NULL : (_p)->user_data)
 129
 130 /* the underlying functions common to debug and non-debug versions */
 131
 132 static int __ao2_ref(void *user_data, const int delta);
 133 static void *__ao2_alloc(size_t data_size, ao2_destructor_fn destructor_fn);
 134 static struct ao2_container *__ao2_container_alloc(struct ao2_container *c, const uint n_buckets, ao2_hash_fn *hash_fn,
 135                                                                                         ao2_callback_fn *cmp_fn);
 136 static struct bucket_list *__ao2_link(struct ao2_container *c, void *user_data);
 137 static void *__ao2_callback(struct ao2_container *c,
 138         const enum search_flags flags, ao2_callback_fn *cb_fn, void *arg,
 139                                          char *tag, char *file, int line, const char *funcname);
 140 static void * __ao2_iterator_next(struct ao2_iterator *a, struct bucket_list **q);
 141
 142 int ao2_lock(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_lock(&p->priv_data.lock);
 154 }
 155
 156 int ao2_unlock(void *user_data)
 157 {
 158         struct astobj2 *p = INTERNAL_OBJ(user_data);
 159
 160         if (p == NULL)
 161                 return -1;
 162
 163 #ifdef AO2_DEBUG
 164         ast_atomic_fetchadd_int(&ao2.total_locked, -1);
 165 #endif
 166
 167         return ast_mutex_unlock(&p->priv_data.lock);
 168 }
 169
 170 int ao2_trylock(void *user_data)
 171 {
 172         struct astobj2 *p = INTERNAL_OBJ(user_data);
 173         int ret;
 174
 175         if (p == NULL)
 176                 return -1;
 177         ret =  ast_mutex_trylock(&p->priv_data.lock);
 178 #ifdef AO2_DEBUG
 179         if (!ret)
 180                 ast_atomic_fetchadd_int(&ao2.total_locked, 1);
 181 #endif
 182         return ret;
 183 }
 184
 185 void *ao2_object_get_lockaddr(void *obj)
 186 {
 187         struct astobj2 *p = INTERNAL_OBJ(obj);
 188
 189         if (p == NULL)
 190                 return NULL;
 191
 192         return &p->priv_data.lock;
 193 }
 194
 195 /*
 196  * The argument is a pointer to the user portion.
 197  */
 198
 199
 200 int _ao2_ref_debug(void *user_data, const int delta, char *tag, char *file, int line, const char *funcname)
 201 {
 202         struct astobj2 *obj = INTERNAL_OBJ(user_data);
 203
 204         if (obj == NULL)
 205                 return -1;
 206
 207         if (delta != 0) {
 208                 FILE *refo = fopen(REF_FILE,"a");
 209                 fprintf(refo, "%p %s%d   %s:%d:%s (%s) [@%d]\n", user_data, (delta<0? "":"+"), delta, file, line, funcname, tag, obj->priv_data.ref_counter);
 210                 fclose(refo);
 211         }
 212         if (obj->priv_data.ref_counter + delta == 0 && obj->priv_data.destructor_fn != NULL) { /* this isn't protected with lock; just for o/p */
 213                         FILE *refo = fopen(REF_FILE,"a");
 214                         fprintf(refo, "%p **call destructor** %s:%d:%s (%s)\n", user_data, file, line, funcname, tag);
 215                         fclose(refo);
 216         }
 217         return __ao2_ref(user_data, delta);
 218 }
 219
 220 int _ao2_ref(void *user_data, const int delta)
 221 {
 222         struct astobj2 *obj = INTERNAL_OBJ(user_data);
 223
 224         if (obj == NULL)
 225                 return -1;
 226
 227         return __ao2_ref(user_data, delta);
 228 }
 229
 230 static int __ao2_ref(void *user_data, const int delta)
 231 {
 232         struct astobj2 *obj = INTERNAL_OBJ(user_data);
 233         int current_value;
 234         int ret;
 235
 236         /* if delta is 0, just return the refcount */
 237         if (delta == 0)
 238                 return (obj->priv_data.ref_counter);
 239
 240         /* we modify with an atomic operation the reference counter */
 241         ret = ast_atomic_fetchadd_int(&obj->priv_data.ref_counter, delta);
 242         current_value = ret + delta;
 243
 244 #ifdef AO2_DEBUG
 245         ast_atomic_fetchadd_int(&ao2.total_refs, delta);
 246 #endif
 247
 248         /* this case must never happen */
 249         if (current_value < 0)
 250                 ast_log(LOG_ERROR, "refcount %d on object %p\n", current_value, user_data);
 251
 252         if (current_value <= 0) { /* last reference, destroy the object */
 253                 if (obj->priv_data.destructor_fn != NULL) {
 254                         obj->priv_data.destructor_fn(user_data);
 255                 }
 256
 257                 ast_mutex_destroy(&obj->priv_data.lock);
 258 #ifdef AO2_DEBUG
 259                 ast_atomic_fetchadd_int(&ao2.total_mem, - obj->priv_data.data_size);
 260                 ast_atomic_fetchadd_int(&ao2.total_objects, -1);
 261 #endif
 262                 /* for safety, zero-out the astobj2 header and also the
 263                  * first word of the user-data, which we make sure is always
 264                  * allocated. */
 265                 bzero(obj, sizeof(struct astobj2 *) + sizeof(void *) );
 266                 free(obj);
 267         }
 268
 269         return ret;
 270 }
 271
 272 /*
 273  * We always alloc at least the size of a void *,
 274  * for debugging purposes.
 275  */
 276 static void *__ao2_alloc(size_t data_size, ao2_destructor_fn destructor_fn)
 277 {
 278         /* allocation */
 279         struct astobj2 *obj;
 280
 281         if (data_size < sizeof(void *))
 282                 data_size = sizeof(void *);
 283
 284         obj = ast_calloc(1, sizeof(*obj) + data_size);
 285
 286         if (obj == NULL)
 287                 return NULL;
 288
 289         ast_mutex_init(&obj->priv_data.lock);
 290         obj->priv_data.magic = AO2_MAGIC;
 291         obj->priv_data.data_size = data_size;
 292         obj->priv_data.ref_counter = 1;
 293         obj->priv_data.destructor_fn = destructor_fn;   /* can be NULL */
 294
 295 #ifdef AO2_DEBUG
 296         ast_atomic_fetchadd_int(&ao2.total_objects, 1);
 297         ast_atomic_fetchadd_int(&ao2.total_mem, data_size);
 298         ast_atomic_fetchadd_int(&ao2.total_refs, 1);
 299 #endif
 300
 301         /* return a pointer to the user data */
 302         return EXTERNAL_OBJ(obj);
 303 }
 304
 305 void *_ao2_alloc_debug(size_t data_size, ao2_destructor_fn destructor_fn, char *tag, char *file, int line, const char *funcname)
 306 {
 307         /* allocation */
 308         void *obj;
 309         FILE *refo = fopen(REF_FILE,"a");
 310
 311         obj = __ao2_alloc(data_size, destructor_fn);
 312
 313         if (obj == NULL)
 314                 return NULL;
 315
 316         if (refo) {
 317                 fprintf(refo, "%p =1   %s:%d:%s (%s)\n", obj, file, line, funcname, tag);
 318                 fclose(refo);
 319         }
 320
 321         /* return a pointer to the user data */
 322         return obj;
 323 }
 324
 325 void *_ao2_alloc(size_t data_size, ao2_destructor_fn destructor_fn)
 326 {
 327         return __ao2_alloc(data_size, destructor_fn);
 328 }
 329
 330
 331 /* internal callback to destroy a container. */
 332 static void container_destruct(void *c);
 333
 334 /* internal callback to destroy a container. */
 335 static void container_destruct_debug(void *c);
 336
 337 /* each bucket in the container is a tailq. */
 338 AST_LIST_HEAD_NOLOCK(bucket, bucket_list);
 339
 340 /*!
 341  * A container; stores the hash and callback functions, information on
 342  * the size, the hash bucket heads, and a version number, starting at 0
 343  * (for a newly created, empty container)
 344  * and incremented every time an object is inserted or deleted.
 345  * The assumption is that an object is never moved in a container,
 346  * but removed and readded with the new number.
 347  * The version number is especially useful when implementing iterators.
 348  * In fact, we can associate a unique, monotonically increasing number to
 349  * each object, which means that, within an iterator, we can store the
 350  * version number of the current object, and easily look for the next one,
 351  * which is the next one in the list with a higher number.
 352  * Since all objects have a version >0, we can use 0 as a marker for
 353  * 'we need the first object in the bucket'.
 354  *
 355  * \todo Linking and unlink objects is typically expensive, as it
 356  * involves a malloc() of a small object which is very inefficient.
 357  * To optimize this, we allocate larger arrays of bucket_list's
 358  * when we run out of them, and then manage our own freelist.
 359  * This will be more efficient as we can do the freelist management while
 360  * we hold the lock (that we need anyways).
 361  */
 362 struct ao2_container {
 363         ao2_hash_fn *hash_fn;
 364         ao2_callback_fn *cmp_fn;
 365         int n_buckets;
 366         /*! Number of elements in the container */
 367         int elements;
 368         /*! described above */
 369         int version;
 370         /*! variable size */
 371         struct bucket buckets[0];
 372 };
 373
 374 /*!
 375  * \brief always zero hash function
 376  *
 377  * it is convenient to have a hash function that always returns 0.
 378  * This is basically used when we want to have a container that is
 379  * a simple linked list.
 380  *
 381  * \returns 0
 382  */
 383 static int hash_zero(const void *user_obj, const int flags)
 384 {
 385         return 0;
 386 }
 387
 388 /*
 389  * A container is just an object, after all!
 390  */
 391 static struct ao2_container *__ao2_container_alloc(struct ao2_container *c, const uint n_buckets, ao2_hash_fn *hash_fn,
 392                                                                                         ao2_callback_fn *cmp_fn)
 393 {
 394         /* XXX maybe consistency check on arguments ? */
 395         /* compute the container size */
 396
 397         if (!c)
 398                 return NULL;
 399
 400         c->version = 1; /* 0 is a reserved value here */
 401         c->n_buckets = n_buckets;
 402         c->hash_fn = hash_fn ? hash_fn : hash_zero;
 403         c->cmp_fn = cmp_fn;
 404
 405 #ifdef AO2_DEBUG
 406         ast_atomic_fetchadd_int(&ao2.total_containers, 1);
 407 #endif
 408
 409         return c;
 410 }
 411
 412 struct ao2_container *_ao2_container_alloc_debug(const uint n_buckets, ao2_hash_fn *hash_fn,
 413                 ao2_callback_fn *cmp_fn, char *tag, char *file, int line, const char *funcname)
 414 {
 415         /* XXX maybe consistency check on arguments ? */
 416         /* compute the container size */
 417         size_t container_size = sizeof(struct ao2_container) + n_buckets * sizeof(struct bucket);
 418         struct ao2_container *c = _ao2_alloc_debug(container_size, container_destruct_debug, tag, file, line, funcname);
 419
 420         return __ao2_container_alloc(c, n_buckets, hash_fn, cmp_fn);
 421 }
 422
 423 struct ao2_container *
 424 _ao2_container_alloc(const uint n_buckets, ao2_hash_fn *hash_fn,
 425                 ao2_callback_fn *cmp_fn)
 426 {
 427         /* XXX maybe consistency check on arguments ? */
 428         /* compute the container size */
 429
 430         size_t container_size = sizeof(struct ao2_container) + n_buckets * sizeof(struct bucket);
 431         struct ao2_container *c = _ao2_alloc(container_size, container_destruct);
 432
 433         return __ao2_container_alloc(c, n_buckets, hash_fn, cmp_fn);
 434 }
 435
 436 /*!
 437  * return the number of elements in the container
 438  */
 439 int ao2_container_count(struct ao2_container *c)
 440 {
 441         return c->elements;
 442 }
 443
 444 /*!
 445  * A structure to create a linked list of entries,
 446  * used within a bucket.
 447  * XXX \todo this should be private to the container code
 448  */
 449 struct bucket_list {
 450         AST_LIST_ENTRY(bucket_list) entry;
 451         int version;
 452         struct astobj2 *astobj;         /* pointer to internal data */
 453 };
 454
 455 /*
 456  * link an object to a container
 457  */
 458
 459 static struct bucket_list *__ao2_link(struct ao2_container *c, void *user_data)
 460 {
 461         int i;
 462         /* create a new list entry */
 463         struct bucket_list *p;
 464         struct astobj2 *obj = INTERNAL_OBJ(user_data);
 465
 466         if (!obj)
 467                 return NULL;
 468
 469         if (INTERNAL_OBJ(c) == NULL)
 470                 return NULL;
 471
 472         p = ast_calloc(1, sizeof(*p));
 473         if (!p)
 474                 return NULL;
 475
 476         i = c->hash_fn(user_data, OBJ_POINTER);
 477
 478         ao2_lock(c);
 479         i %= c->n_buckets;
 480         p->astobj = obj;
 481         p->version = ast_atomic_fetchadd_int(&c->version, 1);
 482         AST_LIST_INSERT_TAIL(&c->buckets[i], p, entry);
 483         ast_atomic_fetchadd_int(&c->elements, 1);
 484
 485         /* the last two operations (ao2_ref, ao2_unlock) must be done by the calling func */
 486         return p;
 487 }
 488
 489 void *_ao2_link_debug(struct ao2_container *c, void *user_data, char *tag, char *file, int line, const char *funcname)
 490 {
 491         struct bucket_list *p = __ao2_link(c, user_data);
 492
 493         if (p) {
 494                 _ao2_ref_debug(user_data, +1, tag, file, line, funcname);
 495                 ao2_unlock(c);
 496         }
 497         return p;
 498 }
 499
 500 void *_ao2_link(struct ao2_container *c, void *user_data)
 501 {
 502         struct bucket_list *p = __ao2_link(c, user_data);
 503
 504         if (p) {
 505                 _ao2_ref(user_data, +1);
 506                 ao2_unlock(c);
 507         }
 508         return p;
 509 }
 510
 511 /*!
 512  * \brief another convenience function is a callback that matches on address
 513  */
 514 int ao2_match_by_addr(void *user_data, void *arg, int flags)
 515 {
 516         return (user_data == arg) ? (CMP_MATCH | CMP_STOP) : 0;
 517 }
 518
 519 /*
 520  * Unlink an object from the container
 521  * and destroy the associated * ao2_bucket_list structure.
 522  */
 523 void *_ao2_unlink_debug(struct ao2_container *c, void *user_data, char *tag,
 524                                            char *file, int line, const char *funcname)
 525 {
 526         if (INTERNAL_OBJ(user_data) == NULL)    /* safety check on the argument */
 527                 return NULL;
 528
 529         _ao2_callback_debug(c, OBJ_UNLINK | OBJ_POINTER | OBJ_NODATA, ao2_match_by_addr, user_data, tag, file, line, funcname);
 530
 531         return NULL;
 532 }
 533
 534 void *_ao2_unlink(struct ao2_container *c, void *user_data)
 535 {
 536         if (INTERNAL_OBJ(user_data) == NULL)    /* safety check on the argument */
 537                 return NULL;
 538
 539         _ao2_callback(c, OBJ_UNLINK | OBJ_POINTER | OBJ_NODATA, ao2_match_by_addr, user_data);
 540
 541         return NULL;
 542 }
 543
 544 /*!
 545  * \brief special callback that matches all
 546  */
 547 static int cb_true(void *user_data, void *arg, int flags)
 548 {
 549         ast_log(LOG_ERROR,"If you see this, something is strange!\n");
 550         return CMP_MATCH;
 551 }
 552
 553 /*!
 554  * Browse the container using different stategies accoding the flags.
 555  * \return Is a pointer to an object or to a list of object if OBJ_MULTIPLE is
 556  * specified.
 557  * Luckily, for debug purposes, the added args (tag, file, line, funcname)
 558  * aren't an excessive load to the system, as the callback should not be
 559  * called as often as, say, the ao2_ref func is called.
 560  */
 561 static void *__ao2_callback(struct ao2_container *c,
 562         const enum search_flags flags, ao2_callback_fn *cb_fn, void *arg,
 563         char *tag, char *file, int line, const char *funcname)
 564 {
 565         int i, last;    /* search boundaries */
 566         void *ret = NULL;
 567
 568         if (INTERNAL_OBJ(c) == NULL)    /* safety check on the argument */
 569                 return NULL;
 570
 571         if ((flags & (OBJ_MULTIPLE | OBJ_NODATA)) == OBJ_MULTIPLE) {
 572                 ast_log(LOG_WARNING, "multiple data return not implemented yet (flags %x)\n", flags);
 573                 return NULL;
 574         }
 575
 576         /* override the match function if necessary */
 577         if (cb_fn == NULL)      /* if NULL, match everything */
 578                 cb_fn = cb_true;
 579         /*
 580          * XXX this can be optimized.
 581          * If we have a hash function and lookup by pointer,
 582          * run the hash function. Otherwise, scan the whole container
 583          * (this only for the time being. We need to optimize this.)
 584          */
 585         if ((flags & OBJ_POINTER))      /* we know hash can handle this case */
 586                 i = c->hash_fn(arg, flags & OBJ_POINTER) % c->n_buckets;
 587         else                    /* don't know, let's scan all buckets */
 588                 i = -1;         /* XXX this must be fixed later. */
 589
 590         /* determine the search boundaries: i..last-1 */
 591         if (i < 0) {
 592                 i = 0;
 593                 last = c->n_buckets;
 594         } else {
 595                 last = i + 1;
 596         }
 597
 598         ao2_lock(c);    /* avoid modifications to the content */
 599
 600         for (; i < last ; i++) {
 601                 /* scan the list with prev-cur pointers */
 602                 struct bucket_list *cur;
 603
 604                 AST_LIST_TRAVERSE_SAFE_BEGIN(&c->buckets[i], cur, entry) {
 605                         int match = cb_fn(EXTERNAL_OBJ(cur->astobj), arg, flags) & (CMP_MATCH | CMP_STOP);
 606
 607                         /* we found the object, performing operations according flags */
 608                         if (match == 0) {       /* no match, no stop, continue */
 609                                 continue;
 610                         } else if (match == CMP_STOP) { /* no match but stop, we are done */
 611                                 i = last;
 612                                 break;
 613                         }
 614                         /* we have a match (CMP_MATCH) here */
 615                         if (!(flags & OBJ_NODATA)) {    /* if must return the object, record the value */
 616                                 /* it is important to handle this case before the unlink */
 617                                 ret = EXTERNAL_OBJ(cur->astobj);
 618                                 if (tag)
 619                                         _ao2_ref_debug(ret, 1, tag, file, line, funcname);
 620                                 else
 621                                         _ao2_ref(ret, 1);
 622                         }
 623
 624                         if (flags & OBJ_UNLINK) {       /* must unlink */
 625                                 struct bucket_list *x = cur;
 626
 627                                 /* we are going to modify the container, so update version */
 628                                 ast_atomic_fetchadd_int(&c->version, 1);
 629                                 AST_LIST_REMOVE_CURRENT(entry);
 630                                 /* update number of elements and version */
 631                                 ast_atomic_fetchadd_int(&c->elements, -1);
 632                                 if (tag)
 633                                         _ao2_ref_debug(EXTERNAL_OBJ(x->astobj), -1, tag, file, line, funcname);
 634                                 else
 635                                         _ao2_ref(EXTERNAL_OBJ(x->astobj), -1);
 636                                 free(x);        /* free the link record */
 637                         }
 638
 639                         if ((match & CMP_STOP) || (flags & OBJ_MULTIPLE) == 0) {
 640                                 /* We found the only match we need */
 641                                 i = last;       /* force exit from outer loop */
 642                                 break;
 643                         }
 644                         if (!(flags & OBJ_NODATA)) {
 645 #if 0   /* XXX to be completed */
 646                                 /*
 647                                  * This is the multiple-return case. We need to link
 648                                  * the object in a list. The refcount is already increased.
 649                                  */
 650 #endif
 651                         }
 652                 }
 653                 AST_LIST_TRAVERSE_SAFE_END;
 654         }
 655         ao2_unlock(c);
 656         return ret;
 657 }
 658
 659 void *_ao2_callback_debug(struct ao2_container *c,
 660                                                  const enum search_flags flags,
 661                                                  ao2_callback_fn *cb_fn, void *arg,
 662                                                  char *tag, char *file, int line, const char *funcname)
 663 {
 664         return __ao2_callback(c,flags, cb_fn, arg, tag, file, line, funcname);
 665 }
 666
 667 void *_ao2_callback(struct ao2_container *c,const enum search_flags flags,
 668                     ao2_callback_fn *cb_fn, void *arg)
 669 {
 670         return __ao2_callback(c,flags, cb_fn, arg, NULL, NULL, 0, NULL);
 671 }
 672
 673 /*!
 674  * the find function just invokes the default callback with some reasonable flags.
 675  */
 676 void *_ao2_find_debug(struct ao2_container *c, void *arg, enum search_flags flags, char *tag, char *file, int line, const char *funcname)
 677 {
 678         return _ao2_callback_debug(c, flags, c->cmp_fn, arg, tag, file, line, funcname);
 679 }
 680
 681 void *_ao2_find(struct ao2_container *c, void *arg, enum search_flags flags)
 682 {
 683         return _ao2_callback(c, flags, c->cmp_fn, arg);
 684 }
 685
 686 /*!
 687  * initialize an iterator so we start from the first object
 688  */
 689 struct ao2_iterator ao2_iterator_init(struct ao2_container *c, int flags)
 690 {
 691         struct ao2_iterator a = {
 692                 .c = c,
 693                 .flags = flags
 694         };
 695
 696         return a;
 697 }
 698
 699 /*
 700  * move to the next element in the container.
 701  */
 702 static void * __ao2_iterator_next(struct ao2_iterator *a, struct bucket_list **q)
 703 {
 704         int lim;
 705         struct bucket_list *p = NULL;
 706         void *ret = NULL;
 707
 708         *q = NULL;
 709
 710         if (INTERNAL_OBJ(a->c) == NULL)
 711                 return NULL;
 712
 713         if (!(a->flags & F_AO2I_DONTLOCK))
 714                 ao2_lock(a->c);
 715
 716         /* optimization. If the container is unchanged and
 717          * we have a pointer, try follow it
 718          */
 719         if (a->c->version == a->c_version && (p = a->obj) ) {
 720                 if ( (p = AST_LIST_NEXT(p, entry)) )
 721                         goto found;
 722                 /* nope, start from the next bucket */
 723                 a->bucket++;
 724                 a->version = 0;
 725                 a->obj = NULL;
 726         }
 727
 728         lim = a->c->n_buckets;
 729
 730         /* Browse the buckets array, moving to the next
 731          * buckets if we don't find the entry in the current one.
 732          * Stop when we find an element with version number greater
 733          * than the current one (we reset the version to 0 when we
 734          * switch buckets).
 735          */
 736         for (; a->bucket < lim; a->bucket++, a->version = 0) {
 737                 /* scan the current bucket */
 738                 AST_LIST_TRAVERSE(&a->c->buckets[a->bucket], p, entry) {
 739                         if (p->version > a->version)
 740                                 goto found;
 741                 }
 742         }
 743
 744 found:
 745         if (p) {
 746                 a->version = p->version;
 747                 a->obj = p;
 748                 a->c_version = a->c->version;
 749                 ret = EXTERNAL_OBJ(p->astobj);
 750                 /* inc refcount of returned object */
 751                 *q = p;
 752         }
 753
 754         return ret;
 755 }
 756
 757 void * _ao2_iterator_next_debug(struct ao2_iterator *a, char *tag, char *file, int line, const char *funcname)
 758 {
 759         struct bucket_list *p;
 760         void *ret = NULL;
 761
 762         ret = __ao2_iterator_next(a, &p);
 763
 764         if (p) {
 765                 /* inc refcount of returned object */
 766                 _ao2_ref_debug(ret, 1, tag, file, line, funcname);
 767         }
 768
 769         if (!(a->flags & F_AO2I_DONTLOCK))
 770                 ao2_unlock(a->c);
 771
 772         return ret;
 773 }
 774
 775 void * _ao2_iterator_next(struct ao2_iterator *a)
 776 {
 777         struct bucket_list *p = NULL;
 778         void *ret = NULL;
 779
 780         ret = __ao2_iterator_next(a, &p);
 781
 782         if (p) {
 783                 /* inc refcount of returned object */
 784                 _ao2_ref(ret, 1);
 785         }
 786
 787         if (!(a->flags & F_AO2I_DONTLOCK))
 788                 ao2_unlock(a->c);
 789
 790         return ret;
 791 }
 792
 793 /* callback for destroying container.
 794  * we can make it simple as we know what it does
 795  */
 796 static int cd_cb(void *obj, void *arg, int flag)
 797 {
 798         _ao2_ref(obj, -1);
 799         return 0;
 800 }
 801
 802 static int cd_cb_debug(void *obj, void *arg, int flag)
 803 {
 804         _ao2_ref_debug(obj, -1, "deref object via container destroy",  __FILE__, __LINE__, __PRETTY_FUNCTION__);
 805         return 0;
 806 }
 807
 808 static void container_destruct(void *_c)
 809 {
 810         struct ao2_container *c = _c;
 811
 812         _ao2_callback(c, OBJ_UNLINK, cd_cb, NULL);
 813
 814 #ifdef AO2_DEBUG
 815         ast_atomic_fetchadd_int(&ao2.total_containers, -1);
 816 #endif
 817 }
 818
 819 static void container_destruct_debug(void *_c)
 820 {
 821         struct ao2_container *c = _c;
 822
 823         _ao2_callback_debug(c, OBJ_UNLINK, cd_cb_debug, NULL, "container_destruct_debug called", __FILE__, __LINE__, __PRETTY_FUNCTION__);
 824
 825 #ifdef AO2_DEBUG
 826         ast_atomic_fetchadd_int(&ao2.total_containers, -1);
 827 #endif
 828 }
 829
 830 #ifdef AO2_DEBUG
 831 static int print_cb(void *obj, void *arg, int flag)
 832 {
 833         int *fd = arg;
 834         char *s = (char *)obj;
 835
 836         ast_cli(*fd, "string <%s>\n", s);
 837         return 0;
 838 }
 839
 840 /*
 841  * Print stats
 842  */
 843 static char *handle_astobj2_stats(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
 844 {
 845         switch (cmd) {
 846         case CLI_INIT:
 847                 e->command = "astobj2 stats";
 848                 e->usage = "Usage: astobj2 stats\n"
 849                            "       Show astobj2 stats\n";
 850                 return NULL;
 851         case CLI_GENERATE:
 852                 return NULL;
 853         }
 854         ast_cli(a->fd, "Objects    : %d\n", ao2.total_objects);
 855         ast_cli(a->fd, "Containers : %d\n", ao2.total_containers);
 856         ast_cli(a->fd, "Memory     : %d\n", ao2.total_mem);
 857         ast_cli(a->fd, "Locked     : %d\n", ao2.total_locked);
 858         ast_cli(a->fd, "Refs       : %d\n", ao2.total_refs);
 859         return CLI_SUCCESS;
 860 }
 861
 862 /*
 863  * This is testing code for astobj
 864  */
 865 static char *handle_astobj2_test(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
 866 {
 867         struct ao2_container *c1;
 868         int i, lim;
 869         char *obj;
 870         static int prof_id = -1;
 871         struct ast_cli_args fake_args = { a->fd, 0, NULL };
 872
 873         switch (cmd) {
 874         case CLI_INIT:
 875                 e->command = "astobj2 test";
 876                 e->usage = "Usage: astobj2 test <num>\n"
 877                            "       Runs astobj2 test. Creates 'num' objects,\n"
 878                            "       and test iterators, callbacks and may be other stuff\n";
 879                 return NULL;
 880         case CLI_GENERATE:
 881                 return NULL;
 882         }
 883
 884         if (a->argc != 3) {
 885                 return CLI_SHOWUSAGE;
 886         }
 887
 888         if (prof_id == -1)
 889                 prof_id = ast_add_profile("ao2_alloc", 0);
 890
 891         ast_cli(a->fd, "argc %d argv %s %s %s\n", a->argc, a->argv[0], a->argv[1], a->argv[2]);
 892         lim = atoi(a->argv[2]);
 893         ast_cli(a->fd, "called astobj_test\n");
 894
 895         handle_astobj2_stats(e, CLI_HANDLER, &fake_args);
 896         /*
 897          * allocate a container with no default callback, and no hash function.
 898          * No hash means everything goes in the same bucket.
 899          */
 900         c1 = ao2_t_container_alloc(100, NULL /* no callback */, NULL /* no hash */,"test");
 901         ast_cli(a->fd, "container allocated as %p\n", c1);
 902
 903         /*
 904          * fill the container with objects.
 905          * ao2_alloc() gives us a reference which we pass to the
 906          * container when we do the insert.
 907          */
 908         for (i = 0; i < lim; i++) {
 909                 ast_mark(prof_id, 1 /* start */);
 910                 obj = ao2_t_alloc(80, NULL,"test");
 911                 ast_mark(prof_id, 0 /* stop */);
 912                 ast_cli(a->fd, "object %d allocated as %p\n", i, obj);
 913                 sprintf(obj, "-- this is obj %d --", i);
 914                 ao2_link(c1, obj);
 915         }
 916         ast_cli(a->fd, "testing callbacks\n");
 917         ao2_t_callback(c1, 0, print_cb, &a->fd,"test callback");
 918         ast_cli(a->fd, "testing iterators, remove every second object\n");
 919         {
 920                 struct ao2_iterator ai;
 921                 int x = 0;
 922
 923                 ai = ao2_iterator_init(c1, 0);
 924                 while ( (obj = ao2_t_iterator_next(&ai,"test")) ) {
 925                         ast_cli(a->fd, "iterator on <%s>\n", obj);
 926                         if (x++ & 1)
 927                                 ao2_t_unlink(c1, obj,"test");
 928                         ao2_t_ref(obj, -1,"test");
 929                 }
 930                 ast_cli(a->fd, "testing iterators again\n");
 931                 ai = ao2_iterator_init(c1, 0);
 932                 while ( (obj = ao2_t_iterator_next(&ai,"test")) ) {
 933                         ast_cli(a->fd, "iterator on <%s>\n", obj);
 934                         ao2_t_ref(obj, -1,"test");
 935                 }
 936         }
 937         ast_cli(a->fd, "testing callbacks again\n");
 938         ao2_t_callback(c1, 0, print_cb, &a->fd,"test callback");
 939
 940         ast_verbose("now you should see an error message:\n");
 941         ao2_t_ref(&i, -1, "");  /* i is not a valid object so we print an error here */
 942
 943         ast_cli(a->fd, "destroy container\n");
 944         ao2_t_ref(c1, -1, "");  /* destroy container */
 945         handle_astobj2_stats(e, CLI_HANDLER, &fake_args);
 946         return CLI_SUCCESS;
 947 }
 948
 949 static struct ast_cli_entry cli_astobj2[] = {
 950         AST_CLI_DEFINE(handle_astobj2_stats, "Print astobj2 statistics"),
 951         AST_CLI_DEFINE(handle_astobj2_test, "Test astobj2"),
 952 };
 953 #endif /* AO2_DEBUG */
 954
 955 int astobj2_init(void)
 956 {
 957 #ifdef AO2_DEBUG
 958         ast_cli_register_multiple(cli_astobj2, ARRAY_LEN(cli_astobj2));
 959 #endif
 960
 961         return 0;
 962 }