00001 /* 00002 * astobj2 - replacement containers for asterisk data structures. 00003 * 00004 * Copyright (C) 2006 Marta Carbone, Luigi Rizzo - Univ. di Pisa, Italy 00005 * 00006 * See http://www.asterisk.org for more information about 00007 * the Asterisk project. Please do not directly contact 00008 * any of the maintainers of this project for assistance; 00009 * the project provides a web site, mailing lists and IRC 00010 * channels for your use. 00011 * 00012 * This program is free software, distributed under the terms of 00013 * the GNU General Public License Version 2. See the LICENSE file 00014 * at the top of the source tree. 00015 */ 00016 00017 #ifndef _ASTERISK_ASTOBJ2_H 00018 #define _ASTERISK_ASTOBJ2_H 00019 00020 #include "asterisk/compat.h" 00021 #include "asterisk/linkedlists.h" 00022 00023 /*! \file 00024 * \ref AstObj2 00025 * 00026 * \page AstObj2 Object Model implementing objects and containers. 00027 00028 This module implements an abstraction for objects (with locks and 00029 reference counts), and containers for these user-defined objects, 00030 also supporting locking, reference counting and callbacks. 00031 00032 The internal implementation of objects and containers is opaque to the user, 00033 so we can use different data structures as needs arise. 00034 00035 \section AstObj2_UsageObjects USAGE - OBJECTS 00036 00037 An ao2 object is a block of memory that the user code can access, 00038 and for which the system keeps track (with a bit of help from the 00039 programmer) of the number of references around. When an object has 00040 no more references (refcount == 0), it is destroyed, by first 00041 invoking whatever 'destructor' function the programmer specifies 00042 (it can be NULL if none is necessary), and then freeing the memory. 00043 This way objects can be shared without worrying who is in charge 00044 of freeing them. 00045 As an additional feature, ao2 objects are associated to individual 00046 locks. 00047 00048 Creating an object requires the size of the object and 00049 and a pointer to the destructor function: 00050 00051 struct foo *o; 00052 00053 o = ao2_alloc(sizeof(struct foo), my_destructor_fn); 00054 00055 The value returned points to the user-visible portion of the objects 00056 (user-data), but is also used as an identifier for all object-related 00057 operations such as refcount and lock manipulations. 00058 00059 On return from ao2_alloc(): 00060 00061 - the object has a refcount = 1; 00062 - the memory for the object is allocated dynamically and zeroed; 00063 - we cannot realloc() the object itself; 00064 - we cannot call free(o) to dispose of the object. Rather, we 00065 tell the system that we do not need the reference anymore: 00066 00067 ao2_ref(o, -1) 00068 00069 causing the destructor to be called (and then memory freed) when 00070 the refcount goes to 0. 00071 00072 - ao2_ref(o, +1) can be used to modify the refcount on the 00073 object in case we want to pass it around. 00074 00075 - ao2_lock(obj), ao2_unlock(obj), ao2_trylock(obj) can be used 00076 to manipulate the lock associated with the object. 00077 00078 00079 \section AstObj2_UsageContainers USAGE - CONTAINERS 00080 00081 An ao2 container is an abstract data structure where we can store 00082 ao2 objects, search them (hopefully in an efficient way), and iterate 00083 or apply a callback function to them. A container is just an ao2 object 00084 itself. 00085 00086 A container must first be allocated, specifying the initial 00087 parameters. At the moment, this is done as follows: 00088 00089 <b>Sample Usage:</b> 00090 \code 00091 00092 struct ao2_container *c; 00093 00094 c = ao2_container_alloc(MAX_BUCKETS, my_hash_fn, my_cmp_fn); 00095 \endcode 00096 00097 where 00098 00099 - MAX_BUCKETS is the number of buckets in the hash table, 00100 - my_hash_fn() is the (user-supplied) function that returns a 00101 hash key for the object (further reduced modulo MAX_BUCKETS 00102 by the container's code); 00103 - my_cmp_fn() is the default comparison function used when doing 00104 searches on the container, 00105 00106 A container knows little or nothing about the objects it stores, 00107 other than the fact that they have been created by ao2_alloc(). 00108 All knowledge of the (user-defined) internals of the objects 00109 is left to the (user-supplied) functions passed as arguments 00110 to ao2_container_alloc(). 00111 00112 If we want to insert an object in a container, we should 00113 initialize its fields -- especially, those used by my_hash_fn() -- 00114 to compute the bucket to use. 00115 Once done, we can link an object to a container with 00116 00117 ao2_link(c, o); 00118 00119 The function returns NULL in case of errors (and the object 00120 is not inserted in the container). Other values mean success 00121 (we are not supposed to use the value as a pointer to anything). 00122 Linking an object to a container increases its refcount by 1 00123 automatically. 00124 00125 \note While an object o is in a container, we expect that 00126 my_hash_fn(o) will always return the same value. The function 00127 does not lock the object to be computed, so modifications of 00128 those fields that affect the computation of the hash should 00129 be done by extracting the object from the container, and 00130 reinserting it after the change (this is not terribly expensive). 00131 00132 \note A container with a single buckets is effectively a linked 00133 list. However there is no ordering among elements. 00134 00135 - \ref AstObj2_Containers 00136 - \ref astobj2.h All documentation for functions and data structures 00137 00138 */ 00139 00140 /* 00141 \note DEBUGGING REF COUNTS BIBLE: 00142 An interface to help debug refcounting is provided 00143 in this package. It is dependent on the REF_DEBUG macro being 00144 defined in a source file, before the #include of astobj2.h, 00145 and in using variants of the normal ao2_xxxx functions 00146 that are named ao2_t_xxxx instead, with an extra argument, a string, 00147 that will be printed out into /tmp/refs when the refcount for an 00148 object is changed. 00149 00150 these ao2_t_xxxx variants are provided: 00151 00152 ao2_t_alloc(arg1, arg2, arg3) 00153 ao2_t_ref(arg1,arg2,arg3) 00154 ao2_t_container_alloc(arg1,arg2,arg3,arg4) 00155 ao2_t_link(arg1, arg2, arg3) 00156 ao2_t_unlink(arg1, arg2, arg3) 00157 ao2_t_callback(arg1,arg2,arg3,arg4,arg5) 00158 ao2_t_find(arg1,arg2,arg3,arg4) 00159 ao2_t_iterator_next(arg1, arg2) 00160 00161 If you study each argument list, you will see that these functions all have 00162 one extra argument that their ao2_xxx counterpart. The last argument in 00163 each case is supposed to be a string pointer, a "tag", that should contain 00164 enough of an explanation, that you can pair operations that increment the 00165 ref count, with operations that are meant to decrement the refcount. 00166 00167 Each of these calls will generate at least one line of output in /tmp/refs. 00168 These lines look like this: 00169 ... 00170 0x8756f00 =1 chan_sip.c:22240:load_module (allocate users) 00171 0x86e3408 =1 chan_sip.c:22241:load_module (allocate peers) 00172 0x86dd380 =1 chan_sip.c:22242:load_module (allocate peers_by_ip) 00173 0x822d020 =1 chan_sip.c:22243:load_module (allocate dialogs) 00174 0x8930fd8 =1 chan_sip.c:20025:build_peer (allocate a peer struct) 00175 0x8930fd8 +1 chan_sip.c:21467:reload_config (link peer into peer table) [@1] 00176 0x8930fd8 -1 chan_sip.c:2370:unref_peer (unref_peer: from reload_config) [@2] 00177 0x89318b0 =1 chan_sip.c:20025:build_peer (allocate a peer struct) 00178 0x89318b0 +1 chan_sip.c:21467:reload_config (link peer into peer table) [@1] 00179 0x89318b0 -1 chan_sip.c:2370:unref_peer (unref_peer: from reload_config) [@2] 00180 0x8930218 =1 chan_sip.c:20025:build_peer (allocate a peer struct) 00181 0x8930218 +1 chan_sip.c:21539:reload_config (link peer into peers table) [@1] 00182 0x868c040 -1 chan_sip.c:2424:dialog_unlink_all (unset the relatedpeer->call field in tandem with relatedpeer field itself) [@2] 00183 0x868c040 -1 chan_sip.c:2443:dialog_unlink_all (Let's unbump the count in the unlink so the poor pvt can disappear if it is time) [@1] 00184 0x868c040 **call destructor** chan_sip.c:2443:dialog_unlink_all (Let's unbump the count in the unlink so the poor pvt can disappear if it is time) 00185 0x8cc07e8 -1 chan_sip.c:2370:unref_peer (unsetting a dialog relatedpeer field in sip_destroy) [@3] 00186 0x8cc07e8 +1 chan_sip.c:3876:find_peer (ao2_find in peers table) [@2] 00187 0x8cc07e8 -1 chan_sip.c:2370:unref_peer (unref_peer, from sip_devicestate, release ref from find_peer) [@3] 00188 ... 00189 00190 The first column is the object address. 00191 The second column reflects how the operation affected the ref count 00192 for that object. Creation sets the ref count to 1 (=1). 00193 increment or decrement and amount are specified (-1/+1). 00194 The remainder of the line specifies where in the file the call was made, 00195 and the function name, and the tag supplied in the function call. 00196 00197 The **call destructor** is specified when the the destroy routine is 00198 run for an object. It does not affect the ref count, but is important 00199 in debugging, because it is possible to have the astobj2 system run it 00200 multiple times on the same object, commonly fatal to asterisk. 00201 00202 Sometimes you have some helper functions to do object ref/unref 00203 operations. Using these normally hides the place where these 00204 functions were called. To get the location where these functions 00205 were called to appear in /tmp/refs, you can do this sort of thing: 00206 00207 #ifdef REF_DEBUG 00208 #define dialog_ref(arg1,arg2) dialog_ref_debug((arg1),(arg2), __FILE__, __LINE__, __PRETTY_FUNCTION__) 00209 #define dialog_unref(arg1,arg2) dialog_unref_debug((arg1),(arg2), __FILE__, __LINE__, __PRETTY_FUNCTION__) 00210 static struct sip_pvt *dialog_ref_debug(struct sip_pvt *p, char *tag, const char *file, int line, const char *func) 00211 { 00212 if (p) 00213 ao2_ref_debug(p, 1, tag, file, line, func); 00214 else 00215 ast_log(LOG_ERROR, "Attempt to Ref a null pointer\n"); 00216 return p; 00217 } 00218 00219 static struct sip_pvt *dialog_unref_debug(struct sip_pvt *p, char *tag, const char *file, int line, const char *func) 00220 { 00221 if (p) 00222 ao2_ref_debug(p, -1, tag, file, line, func); 00223 return NULL; 00224 } 00225 #else 00226 static struct sip_pvt *dialog_ref(struct sip_pvt *p, char *tag) 00227 { 00228 if (p) 00229 ao2_ref(p, 1); 00230 else 00231 ast_log(LOG_ERROR, "Attempt to Ref a null pointer\n"); 00232 return p; 00233 } 00234 00235 static struct sip_pvt *dialog_unref(struct sip_pvt *p, char *tag) 00236 { 00237 if (p) 00238 ao2_ref(p, -1); 00239 return NULL; 00240 } 00241 #endif 00242 00243 In the above code, note that the "normal" helper funcs call ao2_ref() as 00244 normal, and the "helper" functions call ao2_ref_debug directly with the 00245 file, function, and line number info provided. You might find this 00246 well worth the effort to help track these function calls in the code. 00247 00248 To find out why objects are not destroyed (a common bug), you can 00249 edit the source file to use the ao2_t_* variants, add the #define REF_DEBUG 1 00250 before the #include "asterisk/astobj2.h" line, and add a descriptive 00251 tag to each call. Recompile, and run Asterisk, exit asterisk with 00252 "stop gracefully", which should result in every object being destroyed. 00253 Then, you can "sort -k 1 /tmp/refs > x1" to get a sorted list of 00254 all the objects, or you can use "util/refcounter" to scan the file 00255 for you and output any problems it finds. 00256 00257 The above may seem astronomically more work than it is worth to debug 00258 reference counts, which may be true in "simple" situations, but for 00259 more complex situations, it is easily worth 100 times this effort to 00260 help find problems. 00261 00262 To debug, pair all calls so that each call that increments the 00263 refcount is paired with a corresponding call that decrements the 00264 count for the same reason. Hopefully, you will be left with one 00265 or more unpaired calls. This is where you start your search! 00266 00267 For instance, here is an example of this for a dialog object in 00268 chan_sip, that was not getting destroyed, after I moved the lines around 00269 to pair operations: 00270 00271 0x83787a0 =1 chan_sip.c:5733:sip_alloc (allocate a dialog(pvt) struct) 00272 0x83787a0 -1 chan_sip.c:19173:sip_poke_peer (unref dialog at end of sip_poke_peer, obtained from sip_alloc, just before it goes out of scope) [@4] 00273 00274 0x83787a0 +1 chan_sip.c:5854:sip_alloc (link pvt into dialogs table) [@1] 00275 0x83787a0 -1 chan_sip.c:19150:sip_poke_peer (About to change the callid -- remove the old name) [@3] 00276 0x83787a0 +1 chan_sip.c:19152:sip_poke_peer (Linking in under new name) [@2] 00277 0x83787a0 -1 chan_sip.c:2399:dialog_unlink_all (unlinking dialog via ao2_unlink) [@5] 00278 00279 0x83787a0 +1 chan_sip.c:19130:sip_poke_peer (copy sip alloc from p to peer->call) [@2] 00280 00281 00282 0x83787a0 +1 chan_sip.c:2996:__sip_reliable_xmit (__sip_reliable_xmit: setting pkt->owner) [@3] 00283 0x83787a0 -1 chan_sip.c:2425:dialog_unlink_all (remove all current packets in this dialog, and the pointer to the dialog too as part of __sip_destroy) [@4] 00284 00285 0x83787a0 +1 chan_sip.c:22356:unload_module (iterate thru dialogs) [@4] 00286 0x83787a0 -1 chan_sip.c:22359:unload_module (toss dialog ptr from iterator_next) [@5] 00287 00288 00289 0x83787a0 +1 chan_sip.c:22373:unload_module (iterate thru dialogs) [@3] 00290 0x83787a0 -1 chan_sip.c:22375:unload_module (throw away iterator result) [@2] 00291 00292 0x83787a0 +1 chan_sip.c:2397:dialog_unlink_all (Let's bump the count in the unlink so it doesn't accidentally become dead before we are done) [@4] 00293 0x83787a0 -1 chan_sip.c:2436:dialog_unlink_all (Let's unbump the count in the unlink so the poor pvt can disappear if it is time) [@3] 00294 00295 As you can see, only one unbalanced operation is in the list, a ref count increment when 00296 the peer->call was set, but no corresponding decrement was made... 00297 00298 Hopefully this helps you narrow your search and find those bugs. 00299 00300 THE ART OF REFERENCE COUNTING 00301 (by Steve Murphy) 00302 SOME TIPS for complicated code, and ref counting: 00303 00304 1. Theoretically, passing a refcounted object pointer into a function 00305 call is an act of copying the reference, and could be refcounted. 00306 But, upon examination, this sort of refcounting will explode the amount 00307 of code you have to enter, and for no tangible benefit, beyond 00308 creating more possible failure points/bugs. It will even 00309 complicate your code and make debugging harder, slow down your program 00310 doing useless increments and decrements of the ref counts. 00311 00312 2. It is better to track places where a ref counted pointer 00313 is copied into a structure or stored. Make sure to decrement the refcount 00314 of any previous pointer that might have been there, if setting 00315 this field might erase a previous pointer. ao2_find and iterate_next 00316 internally increment the ref count when they return a pointer, so 00317 you need to decrement the count before the pointer goes out of scope. 00318 00319 3. Any time you decrement a ref count, it may be possible that the 00320 object will be destroyed (freed) immediately by that call. If you 00321 are destroying a series of fields in a refcounted object, and 00322 any of the unref calls might possibly result in immediate destruction, 00323 you can first increment the count to prevent such behavior, then 00324 after the last test, decrement the pointer to allow the object 00325 to be destroyed, if the refcount would be zero. 00326 00327 Example: 00328 00329 dialog_ref(dialog, "Let's bump the count in the unlink so it doesn't accidentally become dead before we are done"); 00330 00331 ao2_t_unlink(dialogs, dialog, "unlinking dialog via ao2_unlink"); 00332 00333 *//* Unlink us from the owner (channel) if we have one *//* 00334 if (dialog->owner) { 00335 if (lockowner) 00336 ast_channel_lock(dialog->owner); 00337 ast_debug(1, "Detaching from channel %s\n", dialog->owner->name); 00338 dialog->owner->tech_pvt = dialog_unref(dialog->owner->tech_pvt, "resetting channel dialog ptr in unlink_all"); 00339 if (lockowner) 00340 ast_channel_unlock(dialog->owner); 00341 } 00342 if (dialog->registry) { 00343 if (dialog->registry->call == dialog) 00344 dialog->registry->call = dialog_unref(dialog->registry->call, "nulling out the registry's call dialog field in unlink_all"); 00345 dialog->registry = registry_unref(dialog->registry, "delete dialog->registry"); 00346 } 00347 ... 00348 dialog_unref(dialog, "Let's unbump the count in the unlink so the poor pvt can disappear if it is time"); 00349 00350 In the above code, the ao2_t_unlink could end up destroying the dialog 00351 object; if this happens, then the subsequent usages of the dialog 00352 pointer could result in a core dump. So, we 'bump' the 00353 count upwards before beginning, and then decrementing the count when 00354 we are finished. This is analogous to 'locking' or 'protecting' operations 00355 for a short while. 00356 00357 4. One of the most insidious problems I've run into when converting 00358 code to do ref counted automatic destruction, is in the destruction 00359 routines. Where a "destroy" routine had previously been called to 00360 get rid of an object in non-refcounted code, the new regime demands 00361 that you tear that "destroy" routine into two pieces, one that will 00362 tear down the links and 'unref' them, and the other to actually free 00363 and reset fields. A destroy routine that does any reference deletion 00364 for its own object, will never be called. Another insidious problem 00365 occurs in mutually referenced structures. As an example, a dialog contains 00366 a pointer to a peer, and a peer contains a pointer to a dialog. Watch 00367 out that the destruction of one doesn't depend on the destruction of the 00368 other, as in this case a dependency loop will result in neither being 00369 destroyed! 00370 00371 Given the above, you should be ready to do a good job! 00372 00373 murf 00374 00375 */ 00376 00377 00378 00379 /*! \brief 00380 * Typedef for an object destructor. This is called just before freeing 00381 * the memory for the object. It is passed a pointer to the user-defined 00382 * data of the object. 00383 */ 00384 typedef void (*ao2_destructor_fn)(void *); 00385 00386 00387 /*! \brief 00388 * Allocate and initialize an object. 00389 * 00390 * \param data_size The sizeof() of the user-defined structure. 00391 * \param destructor_fn The destructor function (can be NULL) 00392 * \param debug_msg 00393 * \return A pointer to user-data. 00394 * 00395 * Allocates a struct astobj2 with sufficient space for the 00396 * user-defined structure. 00397 * \note 00398 * - storage is zeroed; XXX maybe we want a flag to enable/disable this. 00399 * - the refcount of the object just created is 1 00400 * - the returned pointer cannot be free()'d or realloc()'ed; 00401 * rather, we just call ao2_ref(o, -1); 00402 * 00403 * @{ 00404 */ 00405 00406 #if defined(REF_DEBUG) 00407 00408 #define ao2_t_alloc(data_size, destructor_fn, debug_msg) __ao2_alloc_debug((data_size), (destructor_fn), (debug_msg), __FILE__, __LINE__, __PRETTY_FUNCTION__, 1) 00409 #define ao2_alloc(data_size, destructor_fn) __ao2_alloc_debug((data_size), (destructor_fn), "", __FILE__, __LINE__, __PRETTY_FUNCTION__, 1) 00410 00411 #elif defined(__AST_DEBUG_MALLOC) 00412 00413 #define ao2_t_alloc(data_size, destructor_fn, debug_msg) __ao2_alloc_debug((data_size), (destructor_fn), (debug_msg), __FILE__, __LINE__, __PRETTY_FUNCTION__, 0) 00414 #define ao2_alloc(data_size, destructor_fn) __ao2_alloc_debug((data_size), (destructor_fn), "", __FILE__, __LINE__, __PRETTY_FUNCTION__, 0) 00415 00416 #else 00417 00418 #define ao2_t_alloc(data_size, destructor_fn, debug_msg) __ao2_alloc((data_size), (destructor_fn)) 00419 #define ao2_alloc(data_size, destructor_fn) __ao2_alloc((data_size), (destructor_fn)) 00420 00421 #endif 00422 00423 void *__ao2_alloc_debug(const size_t data_size, ao2_destructor_fn destructor_fn, char *tag, 00424 const char *file, int line, const char *funcname, int ref_debug); 00425 void *__ao2_alloc(const size_t data_size, ao2_destructor_fn destructor_fn); 00426 00427 /*! @} */ 00428 00429 /*! \brief 00430 * Reference/unreference an object and return the old refcount. 00431 * 00432 * \param o A pointer to the object 00433 * \param delta Value to add to the reference counter. 00434 * \param tag used for debugging 00435 * \return The value of the reference counter before the operation. 00436 * 00437 * Increase/decrease the reference counter according 00438 * the value of delta. 00439 * 00440 * If the refcount goes to zero, the object is destroyed. 00441 * 00442 * \note The object must not be locked by the caller of this function, as 00443 * it is invalid to try to unlock it after releasing the reference. 00444 * 00445 * \note if we know the pointer to an object, it is because we 00446 * have a reference count to it, so the only case when the object 00447 * can go away is when we release our reference, and it is 00448 * the last one in existence. 00449 * 00450 * @{ 00451 */ 00452 00453 #ifdef REF_DEBUG 00454 00455 #define ao2_t_ref(o,delta,tag) __ao2_ref_debug((o), (delta), (tag), __FILE__, __LINE__, __PRETTY_FUNCTION__) 00456 #define ao2_ref(o,delta) __ao2_ref_debug((o), (delta), "", __FILE__, __LINE__, __PRETTY_FUNCTION__) 00457 00458 #else 00459 00460 #define ao2_t_ref(o,delta,tag) __ao2_ref((o), (delta)) 00461 #define ao2_ref(o,delta) __ao2_ref((o), (delta)) 00462 00463 #endif 00464 00465 int __ao2_ref_debug(void *o, int delta, char *tag, char *file, int line, const char *funcname); 00466 int __ao2_ref(void *o, int delta); 00467 00468 /*! @} */ 00469 00470 /*! \brief 00471 * Lock an object. 00472 * 00473 * \param a A pointer to the object we want to lock. 00474 * \return 0 on success, other values on error. 00475 */ 00476 int __ao2_lock(void *a, const char *file, const char *func, int line, const char *var); 00477 #define ao2_lock(a) __ao2_lock(a, __FILE__, __PRETTY_FUNCTION__, __LINE__, #a) 00478 00479 /*! \brief 00480 * Unlock an object. 00481 * 00482 * \param a A pointer to the object we want unlock. 00483 * \return 0 on success, other values on error. 00484 */ 00485 int __ao2_unlock(void *a, const char *file, const char *func, int line, const char *var); 00486 #define ao2_unlock(a) __ao2_unlock(a, __FILE__, __PRETTY_FUNCTION__, __LINE__, #a) 00487 00488 /*! \brief 00489 * Try locking-- (don't block if fail) 00490 * 00491 * \param a A pointer to the object we want to lock. 00492 * \return 0 on success, other values on error. 00493 */ 00494 int __ao2_trylock(void *a, const char *file, const char *func, int line, const char *var); 00495 #define ao2_trylock(a) __ao2_trylock(a, __FILE__, __PRETTY_FUNCTION__, __LINE__, #a) 00496 00497 /*! 00498 * \brief Return the lock address of an object 00499 * 00500 * \param[in] obj A pointer to the object we want. 00501 * \return the address of the lock, else NULL. 00502 * 00503 * This function comes in handy mainly for debugging locking 00504 * situations, where the locking trace code reports the 00505 * lock address, this allows you to correlate against 00506 * object address, to match objects to reported locks. 00507 * 00508 * \since 1.6.1 00509 */ 00510 void *ao2_object_get_lockaddr(void *obj); 00511 00512 /*! 00513 \page AstObj2_Containers AstObj2 Containers 00514 00515 Containers are data structures meant to store several objects, 00516 and perform various operations on them. 00517 Internally, objects are stored in lists, hash tables or other 00518 data structures depending on the needs. 00519 00520 \note NOTA BENE: at the moment the only container we support is the 00521 hash table and its degenerate form, the list. 00522 00523 Operations on container include: 00524 00525 - c = \b ao2_container_alloc(size, hash_fn, cmp_fn) 00526 allocate a container with desired size and default compare 00527 and hash function 00528 -The compare function returns an int, which 00529 can be 0 for not found, CMP_STOP to stop end a traversal, 00530 or CMP_MATCH if they are equal 00531 -The hash function returns an int. The hash function 00532 takes two argument, the object pointer and a flags field, 00533 00534 - \b ao2_find(c, arg, flags) 00535 returns zero or more element matching a given criteria 00536 (specified as arg). 'c' is the container pointer. Flags 00537 can be: 00538 OBJ_UNLINK - to remove the object, once found, from the container. 00539 OBJ_NODATA - don't return the object if found (no ref count change) 00540 OBJ_MULTIPLE - don't stop at first match 00541 OBJ_POINTER - if set, 'arg' is an object pointer, and a hashtable 00542 search will be done. If not, a traversal is done. 00543 00544 - \b ao2_callback(c, flags, fn, arg) 00545 apply fn(obj, arg) to all objects in the container. 00546 Similar to find. fn() can tell when to stop, and 00547 do anything with the object including unlinking it. 00548 - c is the container; 00549 - flags can be 00550 OBJ_UNLINK - to remove the object, once found, from the container. 00551 OBJ_NODATA - don't return the object if found (no ref count change) 00552 OBJ_MULTIPLE - don't stop at first match 00553 OBJ_POINTER - if set, 'arg' is an object pointer, and a hashtable 00554 search will be done. If not, a traversal is done through 00555 all the hashtable 'buckets'.. 00556 - fn is a func that returns int, and takes 3 args: 00557 (void *obj, void *arg, int flags); 00558 obj is an object 00559 arg is the same as arg passed into ao2_callback 00560 flags is the same as flags passed into ao2_callback 00561 fn returns: 00562 0: no match, keep going 00563 CMP_STOP: stop search, no match 00564 CMP_MATCH: This object is matched. 00565 00566 Note that the entire operation is run with the container 00567 locked, so noone else can change its content while we work on it. 00568 However, we pay this with the fact that doing 00569 anything blocking in the callback keeps the container 00570 blocked. 00571 The mechanism is very flexible because the callback function fn() 00572 can do basically anything e.g. counting, deleting records, etc. 00573 possibly using arg to store the results. 00574 00575 - \b iterate on a container 00576 this is done with the following sequence 00577 00578 \code 00579 00580 struct ao2_container *c = ... // our container 00581 struct ao2_iterator i; 00582 void *o; 00583 00584 i = ao2_iterator_init(c, flags); 00585 00586 while ((o = ao2_iterator_next(&i))) { 00587 ... do something on o ... 00588 ao2_ref(o, -1); 00589 } 00590 00591 ao2_iterator_destroy(&i); 00592 \endcode 00593 00594 The difference with the callback is that the control 00595 on how to iterate is left to us. 00596 00597 - \b ao2_ref(c, -1) 00598 dropping a reference to a container destroys it, very simple! 00599 00600 Containers are ao2 objects themselves, and this is why their 00601 implementation is simple too. 00602 00603 Before declaring containers, we need to declare the types of the 00604 arguments passed to the constructor - in turn, this requires 00605 to define callback and hash functions and their arguments. 00606 00607 - \ref AstObj2 00608 - \ref astobj2.h 00609 */ 00610 00611 /*! \brief 00612 * Type of a generic callback function 00613 * \param obj pointer to the (user-defined part) of an object. 00614 * \param arg callback argument from ao2_callback() 00615 * \param flags flags from ao2_callback() 00616 * 00617 * The return values are a combination of enum _cb_results. 00618 * Callback functions are used to search or manipulate objects in a container. 00619 */ 00620 typedef int (ao2_callback_fn)(void *obj, void *arg, int flags); 00621 00622 /*! \brief 00623 * Type of a generic callback function 00624 * \param obj pointer to the (user-defined part) of an object. 00625 * \param arg callback argument from ao2_callback() 00626 * \param data arbitrary data from ao2_callback() 00627 * \param flags flags from ao2_callback() 00628 * 00629 * The return values are a combination of enum _cb_results. 00630 * Callback functions are used to search or manipulate objects in a container. 00631 */ 00632 typedef int (ao2_callback_data_fn)(void *obj, void *arg, void *data, int flags); 00633 00634 /*! \brief a very common callback is one that matches by address. */ 00635 ao2_callback_fn ao2_match_by_addr; 00636 00637 /*! \brief 00638 * A callback function will return a combination of CMP_MATCH and CMP_STOP. 00639 * The latter will terminate the search in a container. 00640 */ 00641 enum _cb_results { 00642 CMP_MATCH = 0x1, /*!< the object matches the request */ 00643 CMP_STOP = 0x2, /*!< stop the search now */ 00644 }; 00645 00646 /*! \brief 00647 * Flags passed to ao2_callback() and ao2_hash_fn() to modify its behaviour. 00648 */ 00649 enum search_flags { 00650 /*! Unlink the object for which the callback function 00651 * returned CMP_MATCH. 00652 */ 00653 OBJ_UNLINK = (1 << 0), 00654 /*! On match, don't return the object hence do not increase 00655 * its refcount. 00656 */ 00657 OBJ_NODATA = (1 << 1), 00658 /*! Don't stop at the first match in ao2_callback() unless the result of 00659 * of the callback function == (CMP_STOP | CMP_MATCH). 00660 */ 00661 OBJ_MULTIPLE = (1 << 2), 00662 /*! obj is an object of the same type as the one being searched for, 00663 * so use the object's hash function for optimized searching. 00664 * The search function is unaffected (i.e. use the one passed as 00665 * argument, or match_by_addr if none specified). 00666 */ 00667 OBJ_POINTER = (1 << 3), 00668 /*! 00669 * \brief Continue if a match is not found in the hashed out bucket 00670 * 00671 * This flag is to be used in combination with OBJ_POINTER. This tells 00672 * the ao2_callback() core to keep searching through the rest of the 00673 * buckets if a match is not found in the starting bucket defined by 00674 * the hash value on the argument. 00675 */ 00676 OBJ_CONTINUE = (1 << 4), 00677 }; 00678 00679 /*! 00680 * Type of a generic function to generate a hash value from an object. 00681 * flags is ignored at the moment. Eventually, it will include the 00682 * value of OBJ_POINTER passed to ao2_callback(). 00683 */ 00684 typedef int (ao2_hash_fn)(const void *obj, const int flags); 00685 00686 /*! \name Object Containers 00687 * Here start declarations of containers. 00688 */ 00689 /*@{ */ 00690 struct ao2_container; 00691 00692 /*! \brief 00693 * Allocate and initialize a container 00694 * with the desired number of buckets. 00695 * 00696 * We allocate space for a struct astobj_container, struct container 00697 * and the buckets[] array. 00698 * 00699 * \param arg1 Number of buckets for hash 00700 * \param arg2 Pointer to a function computing a hash value. 00701 * \param arg3 Pointer to a function comparating key-value 00702 * with a string. (can be NULL) 00703 * \param arg4 00704 * 00705 * \return A pointer to a struct container. 00706 * 00707 * \note Destructor is set implicitly. 00708 */ 00709 00710 #if defined(REF_DEBUG) 00711 00712 #define ao2_t_container_alloc(arg1,arg2,arg3,arg4) __ao2_container_alloc_debug((arg1), (arg2), (arg3), (arg4), __FILE__, __LINE__, __PRETTY_FUNCTION__, 1) 00713 #define ao2_container_alloc(arg1,arg2,arg3) __ao2_container_alloc_debug((arg1), (arg2), (arg3), "", __FILE__, __LINE__, __PRETTY_FUNCTION__, 1) 00714 00715 #elif defined(__AST_DEBUG_MALLOC) 00716 00717 #define ao2_t_container_alloc(arg1,arg2,arg3,arg4) __ao2_container_alloc_debug((arg1), (arg2), (arg3), (arg4), __FILE__, __LINE__, __PRETTY_FUNCTION__, 0) 00718 #define ao2_container_alloc(arg1,arg2,arg3) __ao2_container_alloc_debug((arg1), (arg2), (arg3), "", __FILE__, __LINE__, __PRETTY_FUNCTION__, 0) 00719 00720 #else 00721 00722 #define ao2_t_container_alloc(arg1,arg2,arg3,arg4) __ao2_container_alloc((arg1), (arg2), (arg3)) 00723 #define ao2_container_alloc(arg1,arg2,arg3) __ao2_container_alloc((arg1), (arg2), (arg3)) 00724 00725 #endif 00726 00727 struct ao2_container *__ao2_container_alloc(const unsigned int n_buckets, 00728 ao2_hash_fn *hash_fn, ao2_callback_fn *cmp_fn); 00729 struct ao2_container *__ao2_container_alloc_debug(const unsigned int n_buckets, 00730 ao2_hash_fn *hash_fn, ao2_callback_fn *cmp_fn, 00731 char *tag, char *file, int line, const char *funcname, 00732 int ref_debug); 00733 00734 /*! \brief 00735 * Returns the number of elements in a container. 00736 */ 00737 int ao2_container_count(struct ao2_container *c); 00738 00739 /*@} */ 00740 00741 /*! \name Object Management 00742 * Here we have functions to manage objects. 00743 * 00744 * We can use the functions below on any kind of 00745 * object defined by the user. 00746 */ 00747 /*@{ */ 00748 00749 /*! 00750 * \brief Add an object to a container. 00751 * 00752 * \param arg1 the container to operate on. 00753 * \param arg2 the object to be added. 00754 * \param arg3 used for debuging. 00755 * 00756 * \retval NULL on errors. 00757 * \retval newobj on success. 00758 * 00759 * This function inserts an object in a container according its key. 00760 * 00761 * \note Remember to set the key before calling this function. 00762 * 00763 * \note This function automatically increases the reference count to account 00764 * for the reference that the container now holds to the object. 00765 */ 00766 #ifdef REF_DEBUG 00767 00768 #define ao2_t_link(arg1, arg2, arg3) __ao2_link_debug((arg1), (arg2), (arg3), __FILE__, __LINE__, __PRETTY_FUNCTION__) 00769 #define ao2_link(arg1, arg2) __ao2_link_debug((arg1), (arg2), "", __FILE__, __LINE__, __PRETTY_FUNCTION__) 00770 00771 #else 00772 00773 #define ao2_t_link(arg1, arg2, arg3) __ao2_link((arg1), (arg2)) 00774 #define ao2_link(arg1, arg2) __ao2_link((arg1), (arg2)) 00775 00776 #endif 00777 00778 void *__ao2_link_debug(struct ao2_container *c, void *new_obj, char *tag, char *file, int line, const char *funcname); 00779 void *__ao2_link(struct ao2_container *c, void *newobj); 00780 00781 /*! 00782 * \brief Remove an object from a container 00783 * 00784 * \param arg1 the container 00785 * \param arg2 the object to unlink 00786 * \param arg3 tag for debugging 00787 * 00788 * \retval NULL, always 00789 * 00790 * \note The object requested to be unlinked must be valid. However, if it turns 00791 * out that it is not in the container, this function is still safe to 00792 * be called. 00793 * 00794 * \note If the object gets unlinked from the container, the container's 00795 * reference to the object will be automatically released. (The 00796 * refcount will be decremented). 00797 */ 00798 #ifdef REF_DEBUG 00799 00800 #define ao2_t_unlink(arg1, arg2, arg3) __ao2_unlink_debug((arg1), (arg2), (arg3), __FILE__, __LINE__, __PRETTY_FUNCTION__) 00801 #define ao2_unlink(arg1, arg2) __ao2_unlink_debug((arg1), (arg2), "", __FILE__, __LINE__, __PRETTY_FUNCTION__) 00802 00803 #else 00804 00805 #define ao2_t_unlink(arg1, arg2, arg3) __ao2_unlink((arg1), (arg2)) 00806 #define ao2_unlink(arg1, arg2) __ao2_unlink((arg1), (arg2)) 00807 00808 #endif 00809 00810 void *__ao2_unlink_debug(struct ao2_container *c, void *obj, char *tag, char *file, int line, const char *funcname); 00811 void *__ao2_unlink(struct ao2_container *c, void *obj); 00812 00813 00814 /*@} */ 00815 00816 /*! \brief 00817 * ao2_callback() is a generic function that applies cb_fn() to all objects 00818 * in a container, as described below. 00819 * 00820 * \param c A pointer to the container to operate on. 00821 * \param flags A set of flags specifying the operation to perform, 00822 partially used by the container code, but also passed to 00823 the callback. 00824 - If OBJ_NODATA is set, ao2_callback will return NULL. No refcounts 00825 of any of the traversed objects will be incremented. 00826 On the converse, if it is NOT set (the default), The ref count 00827 of each object for which CMP_MATCH was set will be incremented, 00828 and you will have no way of knowing which those are, until 00829 the multiple-object-return functionality is implemented. 00830 - If OBJ_POINTER is set, the traversed items will be restricted 00831 to the objects in the bucket that the object key hashes to. 00832 * \param cb_fn A function pointer, that will be called on all 00833 objects, to see if they match. This function returns CMP_MATCH 00834 if the object is matches the criteria; CMP_STOP if the traversal 00835 should immediately stop, or both (via bitwise ORing), if you find a 00836 match and want to end the traversal, and 0 if the object is not a match, 00837 but the traversal should continue. This is the function that is applied 00838 to each object traversed. Its arguments are: 00839 (void *obj, void *arg, int flags), where: 00840 obj is an object 00841 arg is the same as arg passed into ao2_callback 00842 flags is the same as flags passed into ao2_callback (flags are 00843 also used by ao2_callback). 00844 * \param arg passed to the callback. 00845 * \param tag used for debuging. 00846 * \return when OBJ_MULTIPLE is not included in the flags parameter, 00847 * the return value will be either the object found or NULL if no 00848 * no matching object was found. if OBJ_MULTIPLE is included, 00849 * the return value will be a pointer to an ao2_iterator object, 00850 * which must be destroyed with ao2_iterator_destroy() when the 00851 * caller no longer needs it. 00852 * 00853 * If the function returns any objects, their refcount is incremented, 00854 * and the caller is in charge of decrementing them once done. 00855 * 00856 * Typically, ao2_callback() is used for two purposes: 00857 * - to perform some action (including removal from the container) on one 00858 * or more objects; in this case, cb_fn() can modify the object itself, 00859 * and to perform deletion should set CMP_MATCH on the matching objects, 00860 * and have OBJ_UNLINK set in flags. 00861 * - to look for a specific object in a container; in this case, cb_fn() 00862 * should not modify the object, but just return a combination of 00863 * CMP_MATCH and CMP_STOP on the desired object. 00864 * Other usages are also possible, of course. 00865 00866 * This function searches through a container and performs operations 00867 * on objects according on flags passed. 00868 * XXX describe better 00869 * The comparison is done calling the compare function set implicitly. 00870 * The p pointer can be a pointer to an object or to a key, 00871 * we can say this looking at flags value. 00872 * If p points to an object we will search for the object pointed 00873 * by this value, otherwise we serch for a key value. 00874 * If the key is not unique we only find the first matching valued. 00875 * 00876 * The use of flags argument is the follow: 00877 * 00878 * OBJ_UNLINK unlinks the object found 00879 * OBJ_NODATA on match, do return an object 00880 * Callbacks use OBJ_NODATA as a default 00881 * functions such as find() do 00882 * OBJ_MULTIPLE return multiple matches 00883 * Default is no. 00884 * OBJ_POINTER the pointer is an object pointer 00885 * 00886 * \note When the returned object is no longer in use, ao2_ref() should 00887 * be used to free the additional reference possibly created by this function. 00888 * 00889 * @{ 00890 */ 00891 #ifdef REF_DEBUG 00892 00893 #define ao2_t_callback(c,flags,cb_fn,arg,tag) __ao2_callback_debug((c), (flags), (cb_fn), (arg), (tag), __FILE__, __LINE__, __PRETTY_FUNCTION__) 00894 #define ao2_callback(c,flags,cb_fn,arg) __ao2_callback_debug((c), (flags), (cb_fn), (arg), "", __FILE__, __LINE__, __PRETTY_FUNCTION__) 00895 00896 #else 00897 00898 #define ao2_t_callback(c,flags,cb_fn,arg,tag) __ao2_callback((c), (flags), (cb_fn), (arg)) 00899 #define ao2_callback(c,flags,cb_fn,arg) __ao2_callback((c), (flags), (cb_fn), (arg)) 00900 00901 #endif 00902 00903 void *__ao2_callback_debug(struct ao2_container *c, enum search_flags flags, ao2_callback_fn *cb_fn, 00904 void *arg, char *tag, char *file, int line, const char *funcname); 00905 void *__ao2_callback(struct ao2_container *c, enum search_flags flags, ao2_callback_fn *cb_fn, void *arg); 00906 00907 /*! @} */ 00908 00909 /*! \brief 00910 * ao2_callback_data() is a generic function that applies cb_fn() to all objects 00911 * in a container. It is functionally identical to ao2_callback() except that 00912 * instead of taking an ao2_callback_fn *, it takes an ao2_callback_data_fn *, and 00913 * allows the caller to pass in arbitrary data. 00914 * 00915 * This call would be used instead of ao2_callback() when the caller needs to pass 00916 * OBJ_POINTER as part of the flags argument (which in turn requires passing in a 00917 * prototype ao2 object for 'arg') and also needs access to other non-global data 00918 * to complete it's comparison or task. 00919 * 00920 * See the documentation for ao2_callback() for argument descriptions. 00921 * 00922 * \see ao2_callback() 00923 */ 00924 #ifdef REF_DEBUG 00925 00926 #define ao2_t_callback_data(arg1,arg2,arg3,arg4,arg5,arg6) __ao2_callback_data_debug((arg1), (arg2), (arg3), (arg4), (arg5), (arg6), __FILE__, __LINE__, __PRETTY_FUNCTION__) 00927 #define ao2_callback_data(arg1,arg2,arg3,arg4,arg5) __ao2_callback_data_debug((arg1), (arg2), (arg3), (arg4), (arg5), "", __FILE__, __LINE__, __PRETTY_FUNCTION__) 00928 00929 #else 00930 00931 #define ao2_t_callback_data(arg1,arg2,arg3,arg4,arg5,arg6) __ao2_callback_data((arg1), (arg2), (arg3), (arg4), (arg5)) 00932 #define ao2_callback_data(arg1,arg2,arg3,arg4,arg5) __ao2_callback_data((arg1), (arg2), (arg3), (arg4), (arg5)) 00933 00934 #endif 00935 00936 void *__ao2_callback_data_debug(struct ao2_container *c, enum search_flags flags, 00937 ao2_callback_data_fn *cb_fn, void *arg, void *data, char *tag, 00938 char *file, int line, const char *funcname); 00939 void *__ao2_callback_data(struct ao2_container *c, enum search_flags flags, 00940 ao2_callback_data_fn *cb_fn, void *arg, void *data); 00941 00942 /*! ao2_find() is a short hand for ao2_callback(c, flags, c->cmp_fn, arg) 00943 * XXX possibly change order of arguments ? 00944 */ 00945 #ifdef REF_DEBUG 00946 00947 #define ao2_t_find(arg1,arg2,arg3,arg4) __ao2_find_debug((arg1), (arg2), (arg3), (arg4), __FILE__, __LINE__, __PRETTY_FUNCTION__) 00948 #define ao2_find(arg1,arg2,arg3) __ao2_find_debug((arg1), (arg2), (arg3), "", __FILE__, __LINE__, __PRETTY_FUNCTION__) 00949 00950 #else 00951 00952 #define ao2_t_find(arg1,arg2,arg3,arg4) __ao2_find((arg1), (arg2), (arg3)) 00953 #define ao2_find(arg1,arg2,arg3) __ao2_find((arg1), (arg2), (arg3)) 00954 00955 #endif 00956 00957 void *__ao2_find_debug(struct ao2_container *c, void *arg, enum search_flags flags, char *tag, 00958 char *file, int line, const char *funcname); 00959 void *__ao2_find(struct ao2_container *c, void *arg, enum search_flags flags); 00960 00961 /*! \brief 00962 * 00963 * 00964 * When we need to walk through a container, we use an 00965 * ao2_iterator to keep track of the current position. 00966 * 00967 * Because the navigation is typically done without holding the 00968 * lock on the container across the loop, objects can be inserted or deleted 00969 * or moved while we work. As a consequence, there is no guarantee that 00970 * we manage to touch all the elements in the container, and it is possible 00971 * that we touch the same object multiple times. 00972 * 00973 * However, within the current hash table container, the following is true: 00974 * - It is not possible to miss an object in the container while iterating 00975 * unless it gets added after the iteration begins and is added to a bucket 00976 * that is before the one the current object is in. In this case, even if 00977 * you locked the container around the entire iteration loop, you still would 00978 * not see this object, because it would still be waiting on the container 00979 * lock so that it can be added. 00980 * - It would be extremely rare to see an object twice. The only way this can 00981 * happen is if an object got unlinked from the container and added again 00982 * during the same iteration. Furthermore, when the object gets added back, 00983 * it has to be in the current or later bucket for it to be seen again. 00984 * 00985 * An iterator must be first initialized with ao2_iterator_init(), 00986 * then we can use o = ao2_iterator_next() to move from one 00987 * element to the next. Remember that the object returned by 00988 * ao2_iterator_next() has its refcount incremented, 00989 * and the reference must be explicitly released when done with it. 00990 * 00991 * In addition, ao2_iterator_init() will hold a reference to the container 00992 * being iterated, which will be freed when ao2_iterator_destroy() is called 00993 * to free up the resources used by the iterator (if any). 00994 * 00995 * Example: 00996 * 00997 * \code 00998 * 00999 * struct ao2_container *c = ... // the container we want to iterate on 01000 * struct ao2_iterator i; 01001 * struct my_obj *o; 01002 * 01003 * i = ao2_iterator_init(c, flags); 01004 * 01005 * while ((o = ao2_iterator_next(&i))) { 01006 * ... do something on o ... 01007 * ao2_ref(o, -1); 01008 * } 01009 * 01010 * ao2_iterator_destroy(&i); 01011 * 01012 * \endcode 01013 * 01014 */ 01015 01016 /*! \brief 01017 * The astobj2 iterator 01018 * 01019 * \note You are not supposed to know the internals of an iterator! 01020 * We would like the iterator to be opaque, unfortunately 01021 * its size needs to be known if we want to store it around 01022 * without too much trouble. 01023 * Anyways... 01024 * The iterator has a pointer to the container, and a flags 01025 * field specifying various things e.g. whether the container 01026 * should be locked or not while navigating on it. 01027 * The iterator "points" to the current object, which is identified 01028 * by three values: 01029 * 01030 * - a bucket number; 01031 * - the object_id, which is also the container version number 01032 * when the object was inserted. This identifies the object 01033 * uniquely, however reaching the desired object requires 01034 * scanning a list. 01035 * - a pointer, and a container version when we saved the pointer. 01036 * If the container has not changed its version number, then we 01037 * can safely follow the pointer to reach the object in constant time. 01038 * 01039 * Details are in the implementation of ao2_iterator_next() 01040 * A freshly-initialized iterator has bucket=0, version=0. 01041 */ 01042 struct ao2_iterator { 01043 /*! the container */ 01044 struct ao2_container *c; 01045 /*! operation flags */ 01046 int flags; 01047 /*! current bucket */ 01048 int bucket; 01049 /*! container version */ 01050 unsigned int c_version; 01051 /*! pointer to the current object */ 01052 void *obj; 01053 /*! container version when the object was created */ 01054 unsigned int version; 01055 }; 01056 01057 /*! Flags that can be passed to ao2_iterator_init() to modify the behavior 01058 * of the iterator. 01059 */ 01060 enum ao2_iterator_flags { 01061 /*! Prevents ao2_iterator_next() from locking the container 01062 * while retrieving the next object from it. 01063 */ 01064 AO2_ITERATOR_DONTLOCK = (1 << 0), 01065 /*! Indicates that the iterator was dynamically allocated by 01066 * astobj2 API and should be freed by ao2_iterator_destroy(). 01067 */ 01068 AO2_ITERATOR_MALLOCD = (1 << 1), 01069 /*! Indicates that before the iterator returns an object from 01070 * the container being iterated, the object should be unlinked 01071 * from the container. 01072 */ 01073 AO2_ITERATOR_UNLINK = (1 << 2), 01074 }; 01075 01076 /*! 01077 * \brief Create an iterator for a container 01078 * 01079 * \param c the container 01080 * \param flags one or more flags from ao2_iterator_flags 01081 * 01082 * \retval the constructed iterator 01083 * 01084 * \note This function does \b not take a pointer to an iterator; 01085 * rather, it returns an iterator structure that should be 01086 * assigned to (overwriting) an existing iterator structure 01087 * allocated on the stack or on the heap. 01088 * 01089 * This function will take a reference on the container being iterated. 01090 * 01091 */ 01092 struct ao2_iterator ao2_iterator_init(struct ao2_container *c, int flags); 01093 01094 /*! 01095 * \brief Destroy a container iterator 01096 * 01097 * \param i the iterator to destroy 01098 * 01099 * \retval none 01100 * 01101 * This function will release the container reference held by the iterator 01102 * and any other resources it may be holding. 01103 * 01104 */ 01105 void ao2_iterator_destroy(struct ao2_iterator *i); 01106 01107 #ifdef REF_DEBUG 01108 01109 #define ao2_t_iterator_next(arg1, arg2) __ao2_iterator_next_debug((arg1), (arg2), __FILE__, __LINE__, __PRETTY_FUNCTION__) 01110 #define ao2_iterator_next(arg1) __ao2_iterator_next_debug((arg1), "", __FILE__, __LINE__, __PRETTY_FUNCTION__) 01111 01112 #else 01113 01114 #define ao2_t_iterator_next(arg1, arg2) __ao2_iterator_next((arg1)) 01115 #define ao2_iterator_next(arg1) __ao2_iterator_next((arg1)) 01116 01117 #endif 01118 01119 void *__ao2_iterator_next_debug(struct ao2_iterator *a, char *tag, char *file, int line, const char *funcname); 01120 void *__ao2_iterator_next(struct ao2_iterator *a); 01121 01122 /* extra functions */ 01123 void ao2_bt(void); /* backtrace */ 01124 01125 #endif /* _ASTERISK_ASTOBJ2_H */