4 Unix SMB/CIFS implementation.
5 Samba temporary memory allocation functions
7 Copyright (C) Andrew Tridgell 2004-2005
8 Copyright (C) Stefan Metzmacher 2006
10 ** NOTE! The following LGPL license applies to the talloc
11 ** library. This does NOT imply that all of Samba is released
14 This library is free software; you can redistribute it and/or
15 modify it under the terms of the GNU Lesser General Public
16 License as published by the Free Software Foundation; either
17 version 3 of the License, or (at your option) any later version.
19 This library is distributed in the hope that it will be useful,
20 but WITHOUT ANY WARRANTY; without even the implied warranty of
21 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
22 Lesser General Public License for more details.
24 You should have received a copy of the GNU Lesser General Public
25 License along with this library; if not, see <http://www.gnu.org/licenses/>.
34 * \section intro_sec Introduction
36 * Talloc is a hierarchical, reference counted memory pool system with
37 * destructors. Quite a mouthful really, but not too bad once you get used to
40 * Perhaps the biggest difference from other memory pool systems is that there
41 * is no distinction between a "talloc context" and a "talloc pointer". Any
42 * pointer returned from talloc() is itself a valid talloc context. This means
46 * struct foo *X = talloc(mem_ctx, struct foo);
47 * X->name = talloc_strdup(X, "foo");
50 * and the pointer X->name would be a "child" of the talloc context "X" which
51 * is itself a child of mem_ctx. So if you do talloc_free(mem_ctx) then it is
52 * all destroyed, whereas if you do talloc_free(X) then just X and X->name are
53 * destroyed, and if you do talloc_free(X->name) then just the name element of
56 * If you think about this, then what this effectively gives you is an n-ary
57 * tree, where you can free any part of the tree with talloc_free().
59 * \section named_blocks Named blocks
61 * Every talloc chunk has a name that can be used as a dynamic type-checking
62 * system. If for some reason like a callback function you had to cast a
63 * "struct foo *" to a "void *" variable, later you can safely reassign the
64 * "void *" pointer to a "struct foo *" by using the talloc_get_type() or
65 * talloc_get_type_abort() macros.
68 * struct foo *X = talloc_get_type_abort(ptr, struct foo);
71 * This will abort if "ptr" does not contain a pointer that has been created
72 * with talloc(mem_ctx, struct foo).
74 * \section multi_threading Multi-Threading
76 * talloc itself does not deal with threads. It is thread-safe (assuming the
77 * underlying "malloc" is), as long as each thread uses different memory
80 * If two threads uses the same context then they need to synchronize in order
81 * to be safe. In particular:
84 * - when using talloc_enable_leak_report(), giving directly NULL as a
85 * parent context implicitly refers to a hidden "null context" global
86 * variable, so this should not be used in a multi-threaded environment
87 * without proper synchronization
88 * - the context returned by talloc_autofree_context() is also global so
89 * shouldn't be used by several threads simultaneously without
93 /** \defgroup talloc_basic Basic Talloc Routines
95 * This module contains the basic talloc routines that are used in everyday
99 /** \defgroup talloc_ref Talloc References
101 * This module contains the definitions around talloc references
104 /** \defgroup talloc_array Array routines
106 * Talloc contains some handy helpers for handling Arrays conveniently
109 /** \defgroup talloc_string String handling routines
111 * Talloc contains some handy string handling functions
114 /** \defgroup talloc_debug Debugging support routines
116 * To aid memory debugging, talloc contains routines to inspect the currently
117 * allocated memory hierarchy.
120 /** \defgroup todo Default group of undocumented stuff
122 * This should be empty...
128 * \typedef TALLOC_CTX
129 * \brief Define a talloc parent type
130 * \ingroup talloc_basic
132 * As talloc is a hierarchial memory allocator, every talloc chunk is a
133 * potential parent to other talloc chunks. So defining a separate type for a
134 * talloc chunk is not strictly necessary. TALLOC_CTX is defined nevertheless,
135 * as it provides an indicator for function arguments. You will frequently
139 * struct foo *foo_create(TALLOC_CTX *mem_ctx)
141 * struct foo *result;
142 * result = talloc(mem_ctx, struct foo);
143 * if (result == NULL) return NULL;
144 * ... initialize foo ...
149 * In this type of allocating functions it is handy to have a general
150 * TALLOC_CTX type to indicate which parent to put allocated structures on.
152 typedef void TALLOC_CTX;
155 this uses a little trick to allow __LINE__ to be stringified
158 #define __TALLOC_STRING_LINE1__(s) #s
159 #define __TALLOC_STRING_LINE2__(s) __TALLOC_STRING_LINE1__(s)
160 #define __TALLOC_STRING_LINE3__ __TALLOC_STRING_LINE2__(__LINE__)
161 #define __location__ __FILE__ ":" __TALLOC_STRING_LINE3__
164 #ifndef TALLOC_DEPRECATED
165 #define TALLOC_DEPRECATED 0
168 #ifndef PRINTF_ATTRIBUTE
170 /** Use gcc attribute to check printf fns. a1 is the 1-based index of
171 * the parameter containing the format, and a2 the index of the first
172 * argument. Note that some gcc 2.x versions don't handle this
174 #define PRINTF_ATTRIBUTE(a1, a2) __attribute__ ((format (__printf__, a1, a2)))
176 #define PRINTF_ATTRIBUTE(a1, a2)
181 * \def talloc_set_destructor
182 * \brief Assign a function to be called when a chunk is freed
183 * \param ptr The talloc chunk to add a destructor to
184 * \param function The destructor function to be called
185 * \ingroup talloc_basic
187 * The function talloc_set_destructor() sets the "destructor" for the pointer
188 * "ptr". A destructor is a function that is called when the memory used by a
189 * pointer is about to be released. The destructor receives the pointer as an
190 * argument, and should return 0 for success and -1 for failure.
192 * The destructor can do anything it wants to, including freeing other pieces
193 * of memory. A common use for destructors is to clean up operating system
194 * resources (such as open file descriptors) contained in the structure the
195 * destructor is placed on.
197 * You can only place one destructor on a pointer. If you need more than one
198 * destructor then you can create a zero-length child of the pointer and place
199 * an additional destructor on that.
201 * To remove a destructor call talloc_set_destructor() with NULL for the
204 * If your destructor attempts to talloc_free() the pointer that it is the
205 * destructor for then talloc_free() will return -1 and the free will be
206 * ignored. This would be a pointless operation anyway, as the destructor is
207 * only called when the memory is just about to go away.
211 * \def talloc_steal(ctx, ptr)
212 * \brief Change a talloc chunk's parent
213 * \param ctx The new parent context
214 * \param ptr The talloc chunk to move
216 * \ingroup talloc_basic
218 * The talloc_steal() function changes the parent context of a talloc
219 * pointer. It is typically used when the context that the pointer is
220 * currently a child of is going to be freed and you wish to keep the
221 * memory for a longer time.
223 * The talloc_steal() function returns the pointer that you pass it. It
224 * does not have any failure modes.
226 * NOTE: It is possible to produce loops in the parent/child relationship
227 * if you are not careful with talloc_steal(). No guarantees are provided
228 * as to your sanity or the safety of your data if you do this.
230 * To make the changed hierarchy less error-prone, you might consider to use
233 * talloc_steal (ctx, NULL) will return NULL with no sideeffects.
236 /* try to make talloc_set_destructor() and talloc_steal() type safe,
237 if we have a recent gcc */
239 #define _TALLOC_TYPEOF(ptr) __typeof__(ptr)
240 #define talloc_set_destructor(ptr, function) \
242 int (*_talloc_destructor_fn)(_TALLOC_TYPEOF(ptr)) = (function); \
243 _talloc_set_destructor((ptr), (int (*)(void *))_talloc_destructor_fn); \
245 /* this extremely strange macro is to avoid some braindamaged warning
246 stupidity in gcc 4.1.x */
247 #define talloc_steal(ctx, ptr) ({ _TALLOC_TYPEOF(ptr) __talloc_steal_ret = (_TALLOC_TYPEOF(ptr))_talloc_steal((ctx),(ptr)); __talloc_steal_ret; })
249 #define talloc_set_destructor(ptr, function) \
250 _talloc_set_destructor((ptr), (int (*)(void *))(function))
251 #define _TALLOC_TYPEOF(ptr) void *
252 #define talloc_steal(ctx, ptr) (_TALLOC_TYPEOF(ptr))_talloc_steal((ctx),(ptr))
256 * \def talloc_reference(ctx, ptr)
257 * \brief Create an additional talloc parent to a pointer
258 * \param ctx The additional parent
259 * \param ptr The pointer you want to create an additional parent for
261 * \ingroup talloc_ref
263 * The talloc_reference() function makes "context" an additional parent of
266 * The return value of talloc_reference() is always the original pointer
267 * "ptr", unless talloc ran out of memory in creating the reference in which
268 * case it will return NULL (each additional reference consumes around 48
269 * bytes of memory on intel x86 platforms).
271 * If "ptr" is NULL, then the function is a no-op, and simply returns NULL.
273 * After creating a reference you can free it in one of the following ways:
275 * - you can talloc_free() any parent of the original pointer. That
276 * will reduce the number of parents of this pointer by 1, and will
277 * cause this pointer to be freed if it runs out of parents.
279 * - you can talloc_free() the pointer itself. That will destroy the
280 * most recently established parent to the pointer and leave the
281 * pointer as a child of its current parent.
283 * For more control on which parent to remove, see talloc_unlink()
285 #define talloc_reference(ctx, ptr) (_TALLOC_TYPEOF(ptr))_talloc_reference((ctx),(ptr))
289 * \def talloc_move(ctx, ptr)
290 * \brief Change a talloc chunk's parent
291 * \param ctx The new parent context
292 * \param ptr Pointer to the talloc chunk to move
294 * \ingroup talloc_basic
296 * talloc_move() has the same effect as talloc_steal(), and additionally sets
297 * the source pointer to NULL. You would use it like this:
300 * struct foo *X = talloc(tmp_ctx, struct foo);
302 * Y = talloc_move(new_ctx, &X);
305 #define talloc_move(ctx, ptr) (_TALLOC_TYPEOF(*(ptr)))_talloc_move((ctx),(void *)(ptr))
307 /* useful macros for creating type checked pointers */
310 * \def talloc(ctx, type)
311 * \brief Main entry point to allocate structures
312 * \param ctx The talloc context to hang the result off
313 * \param type The type that we want to allocate
314 * \return Pointer to a piece of memory, properly cast to "type *"
315 * \ingroup talloc_basic
317 * The talloc() macro is the core of the talloc library. It takes a memory
318 * context and a type, and returns a pointer to a new area of memory of the
321 * The returned pointer is itself a talloc context, so you can use it as the
322 * context argument to more calls to talloc if you wish.
324 * The returned pointer is a "child" of the supplied context. This means that
325 * if you talloc_free() the context then the new child disappears as
326 * well. Alternatively you can free just the child.
328 * The context argument to talloc() can be NULL, in which case a new top
329 * level context is created.
331 #define talloc(ctx, type) (type *)talloc_named_const(ctx, sizeof(type), #type)
334 * \def talloc_size(ctx, size)
335 * \brief Untyped allocation
336 * \param ctx The talloc context to hang the result off
337 * \param size Number of char's that you want to allocate
338 * \return The allocated memory chunk
339 * \ingroup talloc_basic
341 * The function talloc_size() should be used when you don't have a convenient
342 * type to pass to talloc(). Unlike talloc(), it is not type safe (as it
343 * returns a void *), so you are on your own for type checking.
345 #define talloc_size(ctx, size) talloc_named_const(ctx, size, __location__)
348 * \def talloc_ptrtype(ctx, ptr)
349 * \brief Allocate into a typed pointer
350 * \param ctx The talloc context to hang the result off
351 * \param ptr The pointer you want to assign the result to
352 * \result The allocated memory chunk, properly cast
353 * \ingroup talloc_basic
355 * The talloc_ptrtype() macro should be used when you have a pointer and
356 * want to allocate memory to point at with this pointer. When compiling
357 * with gcc >= 3 it is typesafe. Note this is a wrapper of talloc_size()
358 * and talloc_get_name() will return the current location in the source file.
361 #define talloc_ptrtype(ctx, ptr) (_TALLOC_TYPEOF(ptr))talloc_size(ctx, sizeof(*(ptr)))
364 * \def talloc_new(ctx)
365 * \brief Allocate a new 0-sized talloc chunk
366 * \param ctx The talloc parent context
367 * \return A new talloc chunk
368 * \ingroup talloc_basic
370 * This is a utility macro that creates a new memory context hanging off an
371 * exiting context, automatically naming it "talloc_new: __location__" where
372 * __location__ is the source line it is called from. It is particularly
373 * useful for creating a new temporary working context.
375 #define talloc_new(ctx) talloc_named_const(ctx, 0, "talloc_new: " __location__)
378 * \def talloc_zero(ctx, type)
379 * \brief Allocate a 0-initizialized structure
380 * \param ctx The talloc context to hang the result off
381 * \param type The type that we want to allocate
382 * \return Pointer to a piece of memory, properly cast to "type *"
383 * \ingroup talloc_basic
385 * The talloc_zero() macro is equivalent to:
388 * ptr = talloc(ctx, type);
389 * if (ptr) memset(ptr, 0, sizeof(type));
392 #define talloc_zero(ctx, type) (type *)_talloc_zero(ctx, sizeof(type), #type)
395 * \def talloc_zero_size(ctx, size)
396 * \brief Untyped, 0-initialized allocation
397 * \param ctx The talloc context to hang the result off
398 * \param size Number of char's that you want to allocate
399 * \return The allocated memory chunk
400 * \ingroup talloc_basic
402 * The talloc_zero_size() macro is equivalent to:
405 * ptr = talloc_size(ctx, size);
406 * if (ptr) memset(ptr, 0, size);
410 #define talloc_zero_size(ctx, size) _talloc_zero(ctx, size, __location__)
412 #define talloc_zero_array(ctx, type, count) (type *)_talloc_zero_array(ctx, sizeof(type), count, #type)
415 * \def talloc_array(ctx, type, count)
416 * \brief Allocate an array
417 * \param ctx The talloc context to hang the result off
418 * \param type The type that we want to allocate
419 * \param count The number of "type" elements you want to allocate
420 * \return The allocated result, properly cast to "type *"
421 * \ingroup talloc_array
423 * The talloc_array() macro is equivalent to::
426 * (type *)talloc_size(ctx, sizeof(type) * count);
429 * except that it provides integer overflow protection for the multiply,
430 * returning NULL if the multiply overflows.
432 #define talloc_array(ctx, type, count) (type *)_talloc_array(ctx, sizeof(type), count, #type)
435 * \def talloc_array_size(ctx, size, count)
436 * \brief Allocate an array
437 * \param ctx The talloc context to hang the result off
438 * \param size The size of an array element
439 * \param count The number of "type" elements you want to allocate
440 * \return The allocated result, properly cast to "type *"
441 * \ingroup talloc_array
443 * The talloc_array_size() function is useful when the type is not
444 * known. It operates in the same way as talloc_array(), but takes a size
447 #define talloc_array_size(ctx, size, count) _talloc_array(ctx, size, count, __location__)
450 * \def talloc_array_ptrtype(ctx, ptr, count)
451 * \brief Allocate an array into a typed pointer
452 * \param ctx The talloc context to hang the result off
453 * \param ptr The pointer you want to assign the result to
454 * \param count The number of elements you want to allocate
455 * \result The allocated memory chunk, properly cast
456 * \ingroup talloc_array
458 * The talloc_array_ptrtype() macro should be used when you have a pointer to
459 * an array and want to allocate memory of an array to point at with this
460 * pointer. When compiling with gcc >= 3 it is typesafe. Note this is a
461 * wrapper of talloc_array_size() and talloc_get_name() will return the
462 * current location in the source file. and not the type.
464 #define talloc_array_ptrtype(ctx, ptr, count) (_TALLOC_TYPEOF(ptr))talloc_array_size(ctx, sizeof(*(ptr)), count)
467 * \def talloc_array_length(ctx)
468 * \brief Return the number of elements in a talloc'ed array
469 * \param ctx The talloc'ed array
470 * \return The number of elements in ctx
471 * \ingroup talloc_array
473 * A talloc chunk carries its own size, so for talloc'ed arrays it is not
474 * necessary to store the number of elements explicitly.
476 #define talloc_array_length(ctx) ((ctx) ? talloc_get_size(ctx)/sizeof(*ctx) : 0)
479 * \def talloc_realloc(ctx, p, type, count)
480 * \brief Change the size of a talloc array
481 * \param ctx The parent context used if "p" is NULL
482 * \param p The chunk to be resized
483 * \param type The type of the array element inside p
484 * \param count The intended number of array elements
485 * \return The new array
486 * \ingroup talloc_array
488 * The talloc_realloc() macro changes the size of a talloc
489 * pointer. The "count" argument is the number of elements of type "type"
490 * that you want the resulting pointer to hold.
492 * talloc_realloc() has the following equivalences::
495 * talloc_realloc(context, NULL, type, 1) ==> talloc(context, type);
496 * talloc_realloc(context, NULL, type, N) ==> talloc_array(context, type, N);
497 * talloc_realloc(context, ptr, type, 0) ==> talloc_free(ptr);
500 * The "context" argument is only used if "ptr" is NULL, otherwise it is
503 * talloc_realloc() returns the new pointer, or NULL on failure. The call
504 * will fail either due to a lack of memory, or because the pointer has
505 * more than one parent (see talloc_reference()).
507 #define talloc_realloc(ctx, p, type, count) (type *)_talloc_realloc_array(ctx, p, sizeof(type), count, #type)
510 * \def talloc_realloc_size(ctx, ptr, size)
511 * \brief Untyped realloc
512 * \param ctx The parent context used if "ptr" is NULL
513 * \param ptr The chunk to be resized
514 * \param size The new chunk size
515 * \return The new chunk
516 * \ingroup talloc_array
518 * The talloc_realloc_size() function is useful when the type is not known so
519 * the typesafe talloc_realloc() cannot be used.
521 #define talloc_realloc_size(ctx, ptr, size) _talloc_realloc(ctx, ptr, size, __location__)
524 * \def talloc_memdup(t, p, size)
525 * \brief Duplicate a memory area into a talloc chunk
526 * \param t The talloc context to hang the result off
527 * \param p The memory chunk you want to duplicate
528 * \param size Number of char's that you want copy
529 * \return The allocated memory chunk
530 * \ingroup talloc_basic
532 * The talloc_memdup() function is equivalent to::
535 * ptr = talloc_size(ctx, size);
536 * if (ptr) memcpy(ptr, p, size);
539 #define talloc_memdup(t, p, size) _talloc_memdup(t, p, size, __location__)
542 * \def talloc_set_type(ptr, type)
543 * \brief Assign a type to a talloc chunk
544 * \param ptr The talloc chunk to assign the type to
545 * \param type The type to assign
546 * \ingroup talloc_basic
548 * This macro allows you to force the name of a pointer to be a
549 * particular type. This can be used in conjunction with
550 * talloc_get_type() to do type checking on void* pointers.
552 * It is equivalent to this::
555 * talloc_set_name_const(ptr, #type)
558 #define talloc_set_type(ptr, type) talloc_set_name_const(ptr, #type)
561 * \def talloc_get_type(ptr, type)
562 * \brief Get a typed pointer out of a talloc pointer
563 * \param ptr The talloc pointer to check
564 * \param type The type to check against
565 * \return ptr, properly cast, or NULL
566 * \ingroup talloc_basic
568 * This macro allows you to do type checking on talloc pointers. It is
569 * particularly useful for void* private pointers. It is equivalent to
573 * (type *)talloc_check_name(ptr, #type)
577 #define talloc_get_type(ptr, type) (type *)talloc_check_name(ptr, #type)
580 * \def talloc_get_type_abort(ptr, type)
581 * \brief Helper macro to safely turn a void * into a typed pointer
582 * \param ptr The void * to convert
583 * \param type The type that this chunk contains
584 * \return Same value as ptr, type-checked and properly cast
585 * \ingroup talloc_basic
587 * This macro is used together with talloc(mem_ctx, struct foo). If you had to
588 * assing the talloc chunk pointer to some void * variable,
589 * talloc_get_type_abort() is the recommended way to get the convert the void
590 * pointer back to a typed pointer.
592 #define talloc_get_type_abort(ptr, type) (type *)_talloc_get_type_abort(ptr, #type, __location__)
595 * \def talloc_find_parent_bytype(ptr, type)
596 * \brief Find a parent context by type
597 * \param ptr The talloc chunk to start from
598 * \param type The type of the parent to look for
599 * \ingroup talloc_basic
601 * Find a parent memory context of the current context that has the given
602 * name. This can be very useful in complex programs where it may be
603 * difficult to pass all information down to the level you need, but you
604 * know the structure you want is a parent of another context.
606 * Like talloc_find_parent_byname() but takes a type, making it typesafe.
608 #define talloc_find_parent_bytype(ptr, type) (type *)talloc_find_parent_byname(ptr, #type)
610 #if TALLOC_DEPRECATED
611 #define talloc_zero_p(ctx, type) talloc_zero(ctx, type)
612 #define talloc_p(ctx, type) talloc(ctx, type)
613 #define talloc_array_p(ctx, type, count) talloc_array(ctx, type, count)
614 #define talloc_realloc_p(ctx, p, type, count) talloc_realloc(ctx, p, type, count)
615 #define talloc_destroy(ctx) talloc_free(ctx)
616 #define talloc_append_string(c, s, a) (s?talloc_strdup_append(s,a):talloc_strdup(c, a))
619 #define TALLOC_FREE(ctx) do { talloc_free(ctx); ctx=NULL; } while(0)
621 /* The following definitions come from talloc.c */
622 void *_talloc(const void *context, size_t size);
623 void *talloc_pool(const void *context, size_t size);
624 void _talloc_set_destructor(const void *ptr, int (*destructor)(void *));
627 * \brief Increase the reference count of a talloc chunk
630 * \ingroup talloc_ref
632 * The talloc_increase_ref_count(ptr) function is exactly equivalent to:
635 * talloc_reference(NULL, ptr);
638 * You can use either syntax, depending on which you think is clearer in
641 * It returns 0 on success and -1 on failure.
643 int talloc_increase_ref_count(const void *ptr);
646 * \brief Return the number of references to a talloc chunk
647 * \param ptr The chunk you are interested in
648 * \return Number of refs
649 * \ingroup talloc_ref
651 size_t talloc_reference_count(const void *ptr);
652 void *_talloc_reference(const void *context, const void *ptr);
655 * \brief Remove a specific parent from a talloc chunk
656 * \param context The talloc parent to remove
657 * \param ptr The talloc ptr you want to remove the parent from
658 * \ingroup talloc_ref
660 * The talloc_unlink() function removes a specific parent from ptr. The
661 * context passed must either be a context used in talloc_reference() with
662 * this pointer, or must be a direct parent of ptr.
664 * Note that if the parent has already been removed using talloc_free() then
665 * this function will fail and will return -1. Likewise, if "ptr" is NULL,
666 * then the function will make no modifications and return -1.
668 * Usually you can just use talloc_free() instead of talloc_unlink(), but
669 * sometimes it is useful to have the additional control on which parent is
672 int talloc_unlink(const void *context, void *ptr);
675 * \brief Assign a name to a talloc chunk
676 * \param ptr The talloc chunk to assign a name to
677 * \param fmt Format string for the name
678 * \param ... printf-style additional arguments
679 * \return The assigned name
680 * \ingroup talloc_basic
682 * Each talloc pointer has a "name". The name is used principally for
683 * debugging purposes, although it is also possible to set and get the name on
684 * a pointer in as a way of "marking" pointers in your code.
686 * The main use for names on pointer is for "talloc reports". See
687 * talloc_report() and talloc_report_full() for details. Also see
688 * talloc_enable_leak_report() and talloc_enable_leak_report_full().
690 * The talloc_set_name() function allocates memory as a child of the
691 * pointer. It is logically equivalent to:
694 * talloc_set_name_const(ptr, talloc_asprintf(ptr, fmt, ...));
697 * Note that multiple calls to talloc_set_name() will allocate more memory
698 * without releasing the name. All of the memory is released when the ptr is
699 * freed using talloc_free().
701 const char *talloc_set_name(const void *ptr, const char *fmt, ...) PRINTF_ATTRIBUTE(2,3);
704 * \brief Assign a name to a talloc chunk
705 * \param ptr The talloc chunk to assign a name to
706 * \param name Format string for the name
707 * \ingroup talloc_basic
709 * The function talloc_set_name_const() is just like talloc_set_name(), but it
710 * takes a string constant, and is much faster. It is extensively used by the
711 * "auto naming" macros, such as talloc_p().
713 * This function does not allocate any memory. It just copies the supplied
714 * pointer into the internal representation of the talloc ptr. This means you
715 * must not pass a name pointer to memory that will disappear before the ptr
716 * is freed with talloc_free().
718 void talloc_set_name_const(const void *ptr, const char *name);
721 * \brief Create a named talloc chunk
722 * \param context The talloc context to hang the result off
723 * \param size Number of char's that you want to allocate
724 * \param fmt Format string for the name
725 * \param ... printf-style additional arguments
726 * \return The allocated memory chunk
727 * \ingroup talloc_basic
729 * The talloc_named() function creates a named talloc pointer. It is
733 * ptr = talloc_size(context, size);
734 * talloc_set_name(ptr, fmt, ....);
738 void *talloc_named(const void *context, size_t size,
739 const char *fmt, ...) PRINTF_ATTRIBUTE(3,4);
742 * \brief Basic routine to allocate a chunk of memory
743 * \param context The parent context
744 * \param size The number of char's that we want to allocate
745 * \param name The name the talloc block has
746 * \return The allocated chunk
747 * \ingroup talloc_basic
749 * This is equivalent to:
752 * ptr = talloc_size(context, size);
753 * talloc_set_name_const(ptr, name);
756 void *talloc_named_const(const void *context, size_t size, const char *name);
759 * \brief Return the name of a talloc chunk
760 * \param ptr The talloc chunk
762 * \ingroup talloc_basic
764 * This returns the current name for the given talloc pointer. See
765 * talloc_set_name() for details.
767 const char *talloc_get_name(const void *ptr);
770 * \brief Verify that a talloc chunk carries a specified name
771 * \param ptr The talloc chunk to check
772 * \param name The name to check agains
773 * \ingroup talloc_basic
775 * This function checks if a pointer has the specified name. If it does
776 * then the pointer is returned. It it doesn't then NULL is returned.
778 void *talloc_check_name(const void *ptr, const char *name);
780 void *_talloc_get_type_abort(const void *ptr, const char *name, const char *location);
781 void *talloc_parent(const void *ptr);
782 const char *talloc_parent_name(const void *ptr);
785 * \brief Create a new top level talloc context
786 * \param fmt Format string for the name
787 * \param ... printf-style additional arguments
788 * \return The allocated memory chunk
789 * \ingroup talloc_basic
791 * This function creates a zero length named talloc context as a top level
792 * context. It is equivalent to:
795 * talloc_named(NULL, 0, fmt, ...);
798 void *talloc_init(const char *fmt, ...) PRINTF_ATTRIBUTE(1,2);
801 * \brief Free a chunk of talloc memory
802 * \param ptr The chunk to be freed
804 * \ingroup talloc_basic
806 * The talloc_free() function frees a piece of talloc memory, and all its
807 * children. You can call talloc_free() on any pointer returned by talloc().
809 * The return value of talloc_free() indicates success or failure, with 0
810 * returned for success and -1 for failure. The only possible failure
811 * condition is if the pointer had a destructor attached to it and the
812 * destructor returned -1. See talloc_set_destructor() for details on
815 * If this pointer has an additional parent when talloc_free() is called
816 * then the memory is not actually released, but instead the most
817 * recently established parent is destroyed. See talloc_reference() for
818 * details on establishing additional parents.
820 * For more control on which parent is removed, see talloc_unlink()
822 * talloc_free() operates recursively on its children.
824 int talloc_free(void *ptr);
827 * \brief Free a talloc chunk's children
828 * \param ptr The chunk that you want to free the children of
830 * \ingroup talloc_basic
832 * The talloc_free_children() walks along the list of all children of a talloc
833 * context and talloc_free()s only the children, not the context itself.
835 void talloc_free_children(void *ptr);
836 void *_talloc_realloc(const void *context, void *ptr, size_t size, const char *name);
837 void *_talloc_steal(const void *new_ctx, const void *ptr);
838 void *_talloc_move(const void *new_ctx, const void *pptr);
841 * \brief Return the total size of a talloc chunk including its children
842 * \param ptr The talloc chunk
843 * \return The total size
844 * \ingroup talloc_basic
846 * The talloc_total_size() function returns the total size in bytes used
847 * by this pointer and all child pointers. Mostly useful for debugging.
849 * Passing NULL is allowed, but it will only give a meaningful result if
850 * talloc_enable_leak_report() or talloc_enable_leak_report_full() has
853 size_t talloc_total_size(const void *ptr);
856 * \brief Return the number of talloc chunks hanging off a chunk
857 * \param ptr The talloc chunk
858 * \return The total size
859 * \ingroup talloc_basic
861 * The talloc_total_blocks() function returns the total memory block
862 * count used by this pointer and all child pointers. Mostly useful for
865 * Passing NULL is allowed, but it will only give a meaningful result if
866 * talloc_enable_leak_report() or talloc_enable_leak_report_full() has
869 size_t talloc_total_blocks(const void *ptr);
872 * \brief Walk a complete talloc hierarchy
873 * \param ptr The talloc chunk
874 * \param depth Internal parameter to control recursion. Call with 0.
875 * \param max_depth Maximum recursion level.
876 * \param callback Function to be called on every chunk
877 * \param private_data Private pointer passed to callback
878 * \ingroup talloc_debug
880 * This provides a more flexible reports than talloc_report(). It
881 * will recursively call the callback for the entire tree of memory
882 * referenced by the pointer. References in the tree are passed with
883 * is_ref = 1 and the pointer that is referenced.
885 * You can pass NULL for the pointer, in which case a report is
886 * printed for the top level memory context, but only if
887 * talloc_enable_leak_report() or talloc_enable_leak_report_full()
890 * The recursion is stopped when depth >= max_depth.
891 * max_depth = -1 means only stop at leaf nodes.
893 void talloc_report_depth_cb(const void *ptr, int depth, int max_depth,
894 void (*callback)(const void *ptr,
895 int depth, int max_depth,
901 * \brief Print a talloc hierarchy
902 * \param ptr The talloc chunk
903 * \param depth Internal parameter to control recursion. Call with 0.
904 * \param max_depth Maximum recursion level.
905 * \param f The file handle to print to
906 * \ingroup talloc_debug
908 * This provides a more flexible reports than talloc_report(). It
909 * will let you specify the depth and max_depth.
911 void talloc_report_depth_file(const void *ptr, int depth, int max_depth, FILE *f);
914 * \brief Print a summary report of all memory used by ptr
915 * \param ptr The talloc chunk
916 * \param f The file handle to print to
917 * \ingroup talloc_debug
919 * This provides a more detailed report than talloc_report(). It will
920 * recursively print the ensire tree of memory referenced by the
921 * pointer. References in the tree are shown by giving the name of the
922 * pointer that is referenced.
924 * You can pass NULL for the pointer, in which case a report is printed
925 * for the top level memory context, but only if
926 * talloc_enable_leak_report() or talloc_enable_leak_report_full() has
929 void talloc_report_full(const void *ptr, FILE *f);
932 * \brief Print a summary report of all memory used by ptr
933 * \param ptr The talloc chunk
934 * \param f The file handle to print to
935 * \ingroup talloc_debug
937 * The talloc_report() function prints a summary report of all memory
938 * used by ptr. One line of report is printed for each immediate child of
939 * ptr, showing the total memory and number of blocks used by that child.
941 * You can pass NULL for the pointer, in which case a report is printed
942 * for the top level memory context, but only if
943 * talloc_enable_leak_report() or talloc_enable_leak_report_full() has
946 void talloc_report(const void *ptr, FILE *f);
949 * \brief Enable tracking the use of NULL memory contexts
950 * \ingroup talloc_debug
952 * This enables tracking of the NULL memory context without enabling leak
953 * reporting on exit. Useful for when you want to do your own leak
954 * reporting call via talloc_report_null_full();
956 void talloc_enable_null_tracking(void);
959 * \brief Disable tracking of the NULL memory context
960 * \ingroup talloc_debug
962 * This disables tracking of the NULL memory context.
965 void talloc_disable_null_tracking(void);
968 * \brief Enable calling of talloc_report(NULL, stderr) when a program exits
969 * \ingroup talloc_debug
971 * This enables calling of talloc_report(NULL, stderr) when the program
972 * exits. In Samba4 this is enabled by using the --leak-report command
975 * For it to be useful, this function must be called before any other
976 * talloc function as it establishes a "null context" that acts as the
977 * top of the tree. If you don't call this function first then passing
978 * NULL to talloc_report() or talloc_report_full() won't give you the
979 * full tree printout.
981 * Here is a typical talloc report:
984 talloc report on 'null_context' (total 267 bytes in 15 blocks)
985 libcli/auth/spnego_parse.c:55 contains 31 bytes in 2 blocks
986 libcli/auth/spnego_parse.c:55 contains 31 bytes in 2 blocks
987 iconv(UTF8,CP850) contains 42 bytes in 2 blocks
988 libcli/auth/spnego_parse.c:55 contains 31 bytes in 2 blocks
989 iconv(CP850,UTF8) contains 42 bytes in 2 blocks
990 iconv(UTF8,UTF-16LE) contains 45 bytes in 2 blocks
991 iconv(UTF-16LE,UTF8) contains 45 bytes in 2 blocks
994 void talloc_enable_leak_report(void);
997 * \brief Enable calling of talloc_report(NULL, stderr) when a program exits
998 * \ingroup talloc_debug
1000 * This enables calling of talloc_report_full(NULL, stderr) when the
1001 * program exits. In Samba4 this is enabled by using the
1002 * --leak-report-full command line option.
1004 * For it to be useful, this function must be called before any other
1005 * talloc function as it establishes a "null context" that acts as the
1006 * top of the tree. If you don't call this function first then passing
1007 * NULL to talloc_report() or talloc_report_full() won't give you the
1008 * full tree printout.
1010 * Here is a typical full report:
1012 full talloc report on 'root' (total 18 bytes in 8 blocks)
1013 p1 contains 18 bytes in 7 blocks (ref 0)
1014 r1 contains 13 bytes in 2 blocks (ref 0)
1016 p2 contains 1 bytes in 1 blocks (ref 1)
1017 x3 contains 1 bytes in 1 blocks (ref 0)
1018 x2 contains 1 bytes in 1 blocks (ref 0)
1019 x1 contains 1 bytes in 1 blocks (ref 0)
1022 void talloc_enable_leak_report_full(void);
1023 void *_talloc_zero(const void *ctx, size_t size, const char *name);
1024 void *_talloc_memdup(const void *t, const void *p, size_t size, const char *name);
1025 void *_talloc_array(const void *ctx, size_t el_size, unsigned count, const char *name);
1026 void *_talloc_zero_array(const void *ctx, size_t el_size, unsigned count, const char *name);
1027 void *_talloc_realloc_array(const void *ctx, void *ptr, size_t el_size, unsigned count, const char *name);
1030 * \brief Provide a function version of talloc_realloc_size
1031 * \param context The parent context used if "ptr" is NULL
1032 * \param ptr The chunk to be resized
1033 * \param size The new chunk size
1034 * \return The new chunk
1035 * \ingroup talloc_array
1037 * This is a non-macro version of talloc_realloc(), which is useful as
1038 * libraries sometimes want a ralloc function pointer. A realloc()
1039 * implementation encapsulates the functionality of malloc(), free() and
1040 * realloc() in one call, which is why it is useful to be able to pass around
1041 * a single function pointer.
1043 void *talloc_realloc_fn(const void *context, void *ptr, size_t size);
1046 * \brief Provide a talloc context that is freed at program exit
1047 * \return A talloc context
1048 * \ingroup talloc_basic
1050 * This is a handy utility function that returns a talloc context
1051 * which will be automatically freed on program exit. This can be used
1052 * to reduce the noise in memory leak reports.
1054 void *talloc_autofree_context(void);
1057 * \brief Get the size of a talloc chunk
1058 * \param ctx The talloc chunk
1060 * \ingroup talloc_basic
1062 * This function lets you know the amount of memory alloced so far by
1063 * this context. It does NOT account for subcontext memory.
1064 * This can be used to calculate the size of an array.
1066 size_t talloc_get_size(const void *ctx);
1069 * \brief Find a parent context by name
1070 * \param ctx The talloc chunk to start from
1071 * \param name The name of the parent we look for
1072 * \ingroup talloc_basic
1074 * Find a parent memory context of the current context that has the given
1075 * name. This can be very useful in complex programs where it may be
1076 * difficult to pass all information down to the level you need, but you
1077 * know the structure you want is a parent of another context.
1079 void *talloc_find_parent_byname(const void *ctx, const char *name);
1080 void talloc_show_parents(const void *context, FILE *file);
1081 int talloc_is_parent(const void *context, const void *ptr);
1084 * \brief Duplicate a string into a talloc chunk
1085 * \param t The talloc context to hang the result off
1086 * \param p The string you want to duplicate
1087 * \return The duplicated string
1088 * \ingroup talloc_string
1090 * The talloc_strdup() function is equivalent to:
1093 * ptr = talloc_size(ctx, strlen(p)+1);
1094 * if (ptr) memcpy(ptr, p, strlen(p)+1);
1097 * This functions sets the name of the new pointer to the passed
1098 * string. This is equivalent to:
1101 * talloc_set_name_const(ptr, ptr)
1104 char *talloc_strdup(const void *t, const char *p);
1105 char *talloc_strdup_append(char *s, const char *a);
1106 char *talloc_strdup_append_buffer(char *s, const char *a);
1109 * \brief Duplicate a length-limited string into a talloc chunk
1110 * \param t The talloc context to hang the result off
1111 * \param p The string you want to duplicate
1112 * \param n The maximum string length to duplicate
1113 * \return The duplicated string
1114 * \ingroup talloc_string
1116 * The talloc_strndup() function is the talloc equivalent of the C
1117 * library function strndup()
1119 * This functions sets the name of the new pointer to the passed
1120 * string. This is equivalent to:
1123 * talloc_set_name_const(ptr, ptr)
1126 char *talloc_strndup(const void *t, const char *p, size_t n);
1127 char *talloc_strndup_append(char *s, const char *a, size_t n);
1128 char *talloc_strndup_append_buffer(char *s, const char *a, size_t n);
1131 * \brief Format a string given a va_list
1132 * \param t The talloc context to hang the result off
1133 * \param fmt The format string
1134 * \param ap The parameters used to fill fmt
1135 * \return The formatted string
1136 * \ingroup talloc_string
1138 * The talloc_vasprintf() function is the talloc equivalent of the C
1139 * library function vasprintf()
1141 * This functions sets the name of the new pointer to the new
1142 * string. This is equivalent to:
1145 * talloc_set_name_const(ptr, ptr)
1148 char *talloc_vasprintf(const void *t, const char *fmt, va_list ap) PRINTF_ATTRIBUTE(2,0);
1149 char *talloc_vasprintf_append(char *s, const char *fmt, va_list ap) PRINTF_ATTRIBUTE(2,0);
1150 char *talloc_vasprintf_append_buffer(char *s, const char *fmt, va_list ap) PRINTF_ATTRIBUTE(2,0);
1153 * \brief Format a string
1154 * \param t The talloc context to hang the result off
1155 * \param fmt The format string
1156 * \param ... The parameters used to fill fmt
1157 * \return The formatted string
1158 * \ingroup talloc_string
1160 * The talloc_asprintf() function is the talloc equivalent of the C
1161 * library function asprintf()
1163 * This functions sets the name of the new pointer to the new
1164 * string. This is equivalent to:
1167 * talloc_set_name_const(ptr, ptr)
1170 char *talloc_asprintf(const void *t, const char *fmt, ...) PRINTF_ATTRIBUTE(2,3);
1173 * \brief Append a formatted string to another string
1174 * \param s The string to append to
1175 * \param fmt The format string
1176 * \param ... The parameters used to fill fmt
1177 * \return The formatted string
1178 * \ingroup talloc_string
1180 * The talloc_asprintf_append() function appends the given formatted string to
1181 * the given string. Use this varient when the string in the current talloc
1182 * buffer may have been truncated in length.
1184 * This functions sets the name of the new pointer to the new
1185 * string. This is equivalent to:
1188 * talloc_set_name_const(ptr, ptr)
1191 char *talloc_asprintf_append(char *s, const char *fmt, ...) PRINTF_ATTRIBUTE(2,3);
1194 * \brief Append a formatted string to another string
1195 * \param s The string to append to
1196 * \param fmt The format string
1197 * \param ... The parameters used to fill fmt
1198 * \return The formatted string
1199 * \ingroup talloc_string
1201 * The talloc_asprintf_append() function appends the given formatted string to
1202 * the end of the currently allocated talloc buffer. This routine should be
1203 * used if you create a large string step by step. talloc_asprintf() or
1204 * talloc_asprintf_append() call strlen() at every
1205 * step. talloc_asprintf_append_buffer() uses the existing buffer size of the
1206 * talloc chunk to calculate where to append the string.
1208 * This functions sets the name of the new pointer to the new
1209 * string. This is equivalent to:
1212 * talloc_set_name_const(ptr, ptr)
1215 char *talloc_asprintf_append_buffer(char *s, const char *fmt, ...) PRINTF_ATTRIBUTE(2,3);
1217 void talloc_set_abort_fn(void (*abort_fn)(const char *reason));