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 * To start, you should probably first look at the definitions of
60 * ::TALLOC_CTX, talloc_init(), talloc() and talloc_free().
62 * \section named_blocks Named blocks
64 * Every talloc chunk has a name that can be used as a dynamic type-checking
65 * system. If for some reason like a callback function you had to cast a
66 * "struct foo *" to a "void *" variable, later you can safely reassign the
67 * "void *" pointer to a "struct foo *" by using the talloc_get_type() or
68 * talloc_get_type_abort() macros.
71 * struct foo *X = talloc_get_type_abort(ptr, struct foo);
74 * This will abort if "ptr" does not contain a pointer that has been created
75 * with talloc(mem_ctx, struct foo).
77 * \section multi_threading Multi-Threading
79 * talloc itself does not deal with threads. It is thread-safe (assuming the
80 * underlying "malloc" is), as long as each thread uses different memory
83 * If two threads uses the same context then they need to synchronize in order
84 * to be safe. In particular:
87 * - when using talloc_enable_leak_report(), giving directly NULL as a
88 * parent context implicitly refers to a hidden "null context" global
89 * variable, so this should not be used in a multi-threaded environment
90 * without proper synchronization
91 * - the context returned by talloc_autofree_context() is also global so
92 * shouldn't be used by several threads simultaneously without
96 /** \defgroup talloc_basic Basic Talloc Routines
98 * This module contains the basic talloc routines that are used in everyday
102 /** \defgroup talloc_ref Talloc References
104 * This module contains the definitions around talloc references
107 /** \defgroup talloc_array Array routines
109 * Talloc contains some handy helpers for handling Arrays conveniently
112 /** \defgroup talloc_string String handling routines
114 * Talloc contains some handy string handling functions
117 /** \defgroup talloc_debug Debugging support routines
119 * To aid memory debugging, talloc contains routines to inspect the currently
120 * allocated memory hierarchy.
123 /** \defgroup todo Default group of undocumented stuff
125 * This should be empty...
131 * \typedef TALLOC_CTX
132 * \brief Define a talloc parent type
133 * \ingroup talloc_basic
135 * As talloc is a hierarchial memory allocator, every talloc chunk is a
136 * potential parent to other talloc chunks. So defining a separate type for a
137 * talloc chunk is not strictly necessary. TALLOC_CTX is defined nevertheless,
138 * as it provides an indicator for function arguments. You will frequently
142 * struct foo *foo_create(TALLOC_CTX *mem_ctx)
144 * struct foo *result;
145 * result = talloc(mem_ctx, struct foo);
146 * if (result == NULL) return NULL;
147 * ... initialize foo ...
152 * In this type of allocating functions it is handy to have a general
153 * TALLOC_CTX type to indicate which parent to put allocated structures on.
155 typedef void TALLOC_CTX;
158 this uses a little trick to allow __LINE__ to be stringified
161 #define __TALLOC_STRING_LINE1__(s) #s
162 #define __TALLOC_STRING_LINE2__(s) __TALLOC_STRING_LINE1__(s)
163 #define __TALLOC_STRING_LINE3__ __TALLOC_STRING_LINE2__(__LINE__)
164 #define __location__ __FILE__ ":" __TALLOC_STRING_LINE3__
167 #ifndef TALLOC_DEPRECATED
168 #define TALLOC_DEPRECATED 0
171 #ifndef PRINTF_ATTRIBUTE
173 /** Use gcc attribute to check printf fns. a1 is the 1-based index of
174 * the parameter containing the format, and a2 the index of the first
175 * argument. Note that some gcc 2.x versions don't handle this
177 #define PRINTF_ATTRIBUTE(a1, a2) __attribute__ ((format (__printf__, a1, a2)))
179 #define PRINTF_ATTRIBUTE(a1, a2)
184 * \def talloc_set_destructor
185 * \brief Assign a function to be called when a chunk is freed
186 * \param ptr The talloc chunk to add a destructor to
187 * \param function The destructor function to be called
188 * \ingroup talloc_basic
190 * The function talloc_set_destructor() sets the "destructor" for the pointer
191 * "ptr". A destructor is a function that is called when the memory used by a
192 * pointer is about to be released. The destructor receives the pointer as an
193 * argument, and should return 0 for success and -1 for failure.
195 * The destructor can do anything it wants to, including freeing other pieces
196 * of memory. A common use for destructors is to clean up operating system
197 * resources (such as open file descriptors) contained in the structure the
198 * destructor is placed on.
200 * You can only place one destructor on a pointer. If you need more than one
201 * destructor then you can create a zero-length child of the pointer and place
202 * an additional destructor on that.
204 * To remove a destructor call talloc_set_destructor() with NULL for the
207 * If your destructor attempts to talloc_free() the pointer that it is the
208 * destructor for then talloc_free() will return -1 and the free will be
209 * ignored. This would be a pointless operation anyway, as the destructor is
210 * only called when the memory is just about to go away.
214 * \def talloc_steal(ctx, ptr)
215 * \brief Change a talloc chunk's parent
216 * \param ctx The new parent context
217 * \param ptr The talloc chunk to move
219 * \ingroup talloc_basic
221 * The talloc_steal() function changes the parent context of a talloc
222 * pointer. It is typically used when the context that the pointer is
223 * currently a child of is going to be freed and you wish to keep the
224 * memory for a longer time.
226 * The talloc_steal() function returns the pointer that you pass it. It
227 * does not have any failure modes.
229 * NOTE: It is possible to produce loops in the parent/child relationship
230 * if you are not careful with talloc_steal(). No guarantees are provided
231 * as to your sanity or the safety of your data if you do this.
233 * To make the changed hierarchy less error-prone, you might consider to use
236 * talloc_steal (ctx, NULL) will return NULL with no sideeffects.
239 /* try to make talloc_set_destructor() and talloc_steal() type safe,
240 if we have a recent gcc */
242 #define _TALLOC_TYPEOF(ptr) __typeof__(ptr)
243 #define talloc_set_destructor(ptr, function) \
245 int (*_talloc_destructor_fn)(_TALLOC_TYPEOF(ptr)) = (function); \
246 _talloc_set_destructor((ptr), (int (*)(void *))_talloc_destructor_fn); \
248 /* this extremely strange macro is to avoid some braindamaged warning
249 stupidity in gcc 4.1.x */
250 #define talloc_steal(ctx, ptr) ({ _TALLOC_TYPEOF(ptr) __talloc_steal_ret = (_TALLOC_TYPEOF(ptr))_talloc_steal((ctx),(ptr)); __talloc_steal_ret; })
252 #define talloc_set_destructor(ptr, function) \
253 _talloc_set_destructor((ptr), (int (*)(void *))(function))
254 #define _TALLOC_TYPEOF(ptr) void *
255 #define talloc_steal(ctx, ptr) (_TALLOC_TYPEOF(ptr))_talloc_steal((ctx),(ptr))
259 * \def talloc_reference(ctx, ptr)
260 * \brief Create an additional talloc parent to a pointer
261 * \param ctx The additional parent
262 * \param ptr The pointer you want to create an additional parent for
264 * \ingroup talloc_ref
266 * The talloc_reference() function makes "context" an additional parent of
269 * The return value of talloc_reference() is always the original pointer
270 * "ptr", unless talloc ran out of memory in creating the reference in which
271 * case it will return NULL (each additional reference consumes around 48
272 * bytes of memory on intel x86 platforms).
274 * If "ptr" is NULL, then the function is a no-op, and simply returns NULL.
276 * After creating a reference you can free it in one of the following ways:
278 * - you can talloc_free() any parent of the original pointer. That
279 * will reduce the number of parents of this pointer by 1, and will
280 * cause this pointer to be freed if it runs out of parents.
282 * - you can talloc_free() the pointer itself. That will destroy the
283 * most recently established parent to the pointer and leave the
284 * pointer as a child of its current parent.
286 * For more control on which parent to remove, see talloc_unlink()
288 #define talloc_reference(ctx, ptr) (_TALLOC_TYPEOF(ptr))_talloc_reference((ctx),(ptr))
292 * \def talloc_move(ctx, ptr)
293 * \brief Change a talloc chunk's parent
294 * \param ctx The new parent context
295 * \param ptr Pointer to the talloc chunk to move
297 * \ingroup talloc_basic
299 * talloc_move() has the same effect as talloc_steal(), and additionally sets
300 * the source pointer to NULL. You would use it like this:
303 * struct foo *X = talloc(tmp_ctx, struct foo);
305 * Y = talloc_move(new_ctx, &X);
308 #define talloc_move(ctx, ptr) (_TALLOC_TYPEOF(*(ptr)))_talloc_move((ctx),(void *)(ptr))
310 /* useful macros for creating type checked pointers */
313 * \def talloc(ctx, type)
314 * \brief Main entry point to allocate structures
315 * \param ctx The talloc context to hang the result off
316 * \param type The type that we want to allocate
317 * \return Pointer to a piece of memory, properly cast to "type *"
318 * \ingroup talloc_basic
320 * The talloc() macro is the core of the talloc library. It takes a memory
321 * context and a type, and returns a pointer to a new area of memory of the
324 * The returned pointer is itself a talloc context, so you can use it as the
325 * context argument to more calls to talloc if you wish.
327 * The returned pointer is a "child" of the supplied context. This means that
328 * if you talloc_free() the context then the new child disappears as
329 * well. Alternatively you can free just the child.
331 * The context argument to talloc() can be NULL, in which case a new top
332 * level context is created.
334 #define talloc(ctx, type) (type *)talloc_named_const(ctx, sizeof(type), #type)
337 * \def talloc_size(ctx, size)
338 * \brief Untyped allocation
339 * \param ctx The talloc context to hang the result off
340 * \param size Number of char's that you want to allocate
341 * \return The allocated memory chunk
342 * \ingroup talloc_basic
344 * The function talloc_size() should be used when you don't have a convenient
345 * type to pass to talloc(). Unlike talloc(), it is not type safe (as it
346 * returns a void *), so you are on your own for type checking.
348 #define talloc_size(ctx, size) talloc_named_const(ctx, size, __location__)
351 * \def talloc_ptrtype(ctx, ptr)
352 * \brief Allocate into a typed pointer
353 * \param ctx The talloc context to hang the result off
354 * \param ptr The pointer you want to assign the result to
355 * \result The allocated memory chunk, properly cast
356 * \ingroup talloc_basic
358 * The talloc_ptrtype() macro should be used when you have a pointer and
359 * want to allocate memory to point at with this pointer. When compiling
360 * with gcc >= 3 it is typesafe. Note this is a wrapper of talloc_size()
361 * and talloc_get_name() will return the current location in the source file.
364 #define talloc_ptrtype(ctx, ptr) (_TALLOC_TYPEOF(ptr))talloc_size(ctx, sizeof(*(ptr)))
367 * \def talloc_new(ctx)
368 * \brief Allocate a new 0-sized talloc chunk
369 * \param ctx The talloc parent context
370 * \return A new talloc chunk
371 * \ingroup talloc_basic
373 * This is a utility macro that creates a new memory context hanging off an
374 * exiting context, automatically naming it "talloc_new: __location__" where
375 * __location__ is the source line it is called from. It is particularly
376 * useful for creating a new temporary working context.
378 #define talloc_new(ctx) talloc_named_const(ctx, 0, "talloc_new: " __location__)
381 * \def talloc_zero(ctx, type)
382 * \brief Allocate a 0-initizialized structure
383 * \param ctx The talloc context to hang the result off
384 * \param type The type that we want to allocate
385 * \return Pointer to a piece of memory, properly cast to "type *"
386 * \ingroup talloc_basic
388 * The talloc_zero() macro is equivalent to:
391 * ptr = talloc(ctx, type);
392 * if (ptr) memset(ptr, 0, sizeof(type));
395 #define talloc_zero(ctx, type) (type *)_talloc_zero(ctx, sizeof(type), #type)
398 * \def talloc_zero_size(ctx, size)
399 * \brief Untyped, 0-initialized allocation
400 * \param ctx The talloc context to hang the result off
401 * \param size Number of char's that you want to allocate
402 * \return The allocated memory chunk
403 * \ingroup talloc_basic
405 * The talloc_zero_size() macro is equivalent to:
408 * ptr = talloc_size(ctx, size);
409 * if (ptr) memset(ptr, 0, size);
413 #define talloc_zero_size(ctx, size) _talloc_zero(ctx, size, __location__)
415 #define talloc_zero_array(ctx, type, count) (type *)_talloc_zero_array(ctx, sizeof(type), count, #type)
418 * \def talloc_array(ctx, type, count)
419 * \brief Allocate an array
420 * \param ctx The talloc context to hang the result off
421 * \param type The type that we want to allocate
422 * \param count The number of "type" elements you want to allocate
423 * \return The allocated result, properly cast to "type *"
424 * \ingroup talloc_array
426 * The talloc_array() macro is equivalent to::
429 * (type *)talloc_size(ctx, sizeof(type) * count);
432 * except that it provides integer overflow protection for the multiply,
433 * returning NULL if the multiply overflows.
435 #define talloc_array(ctx, type, count) (type *)_talloc_array(ctx, sizeof(type), count, #type)
438 * \def talloc_array_size(ctx, size, count)
439 * \brief Allocate an array
440 * \param ctx The talloc context to hang the result off
441 * \param size The size of an array element
442 * \param count The number of "type" elements you want to allocate
443 * \return The allocated result, properly cast to "type *"
444 * \ingroup talloc_array
446 * The talloc_array_size() function is useful when the type is not
447 * known. It operates in the same way as talloc_array(), but takes a size
450 #define talloc_array_size(ctx, size, count) _talloc_array(ctx, size, count, __location__)
453 * \def talloc_array_ptrtype(ctx, ptr, count)
454 * \brief Allocate an array into a typed pointer
455 * \param ctx The talloc context to hang the result off
456 * \param ptr The pointer you want to assign the result to
457 * \param count The number of elements you want to allocate
458 * \result The allocated memory chunk, properly cast
459 * \ingroup talloc_array
461 * The talloc_array_ptrtype() macro should be used when you have a pointer to
462 * an array and want to allocate memory of an array to point at with this
463 * pointer. When compiling with gcc >= 3 it is typesafe. Note this is a
464 * wrapper of talloc_array_size() and talloc_get_name() will return the
465 * current location in the source file. and not the type.
467 #define talloc_array_ptrtype(ctx, ptr, count) (_TALLOC_TYPEOF(ptr))talloc_array_size(ctx, sizeof(*(ptr)), count)
470 * \def talloc_array_length(ctx)
471 * \brief Return the number of elements in a talloc'ed array
472 * \param ctx The talloc'ed array
473 * \return The number of elements in ctx
474 * \ingroup talloc_array
476 * A talloc chunk carries its own size, so for talloc'ed arrays it is not
477 * necessary to store the number of elements explicitly.
479 #define talloc_array_length(ctx) ((ctx) ? talloc_get_size(ctx)/sizeof(*ctx) : 0)
482 * \def talloc_realloc(ctx, p, type, count)
483 * \brief Change the size of a talloc array
484 * \param ctx The parent context used if "p" is NULL
485 * \param p The chunk to be resized
486 * \param type The type of the array element inside p
487 * \param count The intended number of array elements
488 * \return The new array
489 * \ingroup talloc_array
491 * The talloc_realloc() macro changes the size of a talloc
492 * pointer. The "count" argument is the number of elements of type "type"
493 * that you want the resulting pointer to hold.
495 * talloc_realloc() has the following equivalences::
498 * talloc_realloc(context, NULL, type, 1) ==> talloc(context, type);
499 * talloc_realloc(context, NULL, type, N) ==> talloc_array(context, type, N);
500 * talloc_realloc(context, ptr, type, 0) ==> talloc_free(ptr);
503 * The "context" argument is only used if "ptr" is NULL, otherwise it is
506 * talloc_realloc() returns the new pointer, or NULL on failure. The call
507 * will fail either due to a lack of memory, or because the pointer has
508 * more than one parent (see talloc_reference()).
510 #define talloc_realloc(ctx, p, type, count) (type *)_talloc_realloc_array(ctx, p, sizeof(type), count, #type)
513 * \def talloc_realloc_size(ctx, ptr, size)
514 * \brief Untyped realloc
515 * \param ctx The parent context used if "ptr" is NULL
516 * \param ptr The chunk to be resized
517 * \param size The new chunk size
518 * \return The new chunk
519 * \ingroup talloc_array
521 * The talloc_realloc_size() function is useful when the type is not known so
522 * the typesafe talloc_realloc() cannot be used.
524 #define talloc_realloc_size(ctx, ptr, size) _talloc_realloc(ctx, ptr, size, __location__)
527 * \def talloc_memdup(t, p, size)
528 * \brief Duplicate a memory area into a talloc chunk
529 * \param t The talloc context to hang the result off
530 * \param p The memory chunk you want to duplicate
531 * \param size Number of char's that you want copy
532 * \return The allocated memory chunk
533 * \ingroup talloc_basic
535 * The talloc_memdup() function is equivalent to::
538 * ptr = talloc_size(ctx, size);
539 * if (ptr) memcpy(ptr, p, size);
542 #define talloc_memdup(t, p, size) _talloc_memdup(t, p, size, __location__)
545 * \def talloc_set_type(ptr, type)
546 * \brief Assign a type to a talloc chunk
547 * \param ptr The talloc chunk to assign the type to
548 * \param type The type to assign
549 * \ingroup talloc_basic
551 * This macro allows you to force the name of a pointer to be a
552 * particular type. This can be used in conjunction with
553 * talloc_get_type() to do type checking on void* pointers.
555 * It is equivalent to this::
558 * talloc_set_name_const(ptr, #type)
561 #define talloc_set_type(ptr, type) talloc_set_name_const(ptr, #type)
564 * \def talloc_get_type(ptr, type)
565 * \brief Get a typed pointer out of a talloc pointer
566 * \param ptr The talloc pointer to check
567 * \param type The type to check against
568 * \return ptr, properly cast, or NULL
569 * \ingroup talloc_basic
571 * This macro allows you to do type checking on talloc pointers. It is
572 * particularly useful for void* private pointers. It is equivalent to
576 * (type *)talloc_check_name(ptr, #type)
580 #define talloc_get_type(ptr, type) (type *)talloc_check_name(ptr, #type)
583 * \def talloc_get_type_abort(ptr, type)
584 * \brief Helper macro to safely turn a void * into a typed pointer
585 * \param ptr The void * to convert
586 * \param type The type that this chunk contains
587 * \return Same value as ptr, type-checked and properly cast
588 * \ingroup talloc_basic
590 * This macro is used together with talloc(mem_ctx, struct foo). If you had to
591 * assing the talloc chunk pointer to some void * variable,
592 * talloc_get_type_abort() is the recommended way to get the convert the void
593 * pointer back to a typed pointer.
595 #define talloc_get_type_abort(ptr, type) (type *)_talloc_get_type_abort(ptr, #type, __location__)
598 * \def talloc_find_parent_bytype(ptr, type)
599 * \brief Find a parent context by type
600 * \param ptr The talloc chunk to start from
601 * \param type The type of the parent to look for
602 * \ingroup talloc_basic
604 * Find a parent memory context of the current context that has the given
605 * name. This can be very useful in complex programs where it may be
606 * difficult to pass all information down to the level you need, but you
607 * know the structure you want is a parent of another context.
609 * Like talloc_find_parent_byname() but takes a type, making it typesafe.
611 #define talloc_find_parent_bytype(ptr, type) (type *)talloc_find_parent_byname(ptr, #type)
613 #if TALLOC_DEPRECATED
614 #define talloc_zero_p(ctx, type) talloc_zero(ctx, type)
615 #define talloc_p(ctx, type) talloc(ctx, type)
616 #define talloc_array_p(ctx, type, count) talloc_array(ctx, type, count)
617 #define talloc_realloc_p(ctx, p, type, count) talloc_realloc(ctx, p, type, count)
618 #define talloc_destroy(ctx) talloc_free(ctx)
619 #define talloc_append_string(c, s, a) (s?talloc_strdup_append(s,a):talloc_strdup(c, a))
622 #define TALLOC_FREE(ctx) do { talloc_free(ctx); ctx=NULL; } while(0)
624 /* The following definitions come from talloc.c */
625 void *_talloc(const void *context, size_t size);
626 void *talloc_pool(const void *context, size_t size);
627 void _talloc_set_destructor(const void *ptr, int (*destructor)(void *));
630 * \brief Increase the reference count of a talloc chunk
633 * \ingroup talloc_ref
635 * The talloc_increase_ref_count(ptr) function is exactly equivalent to:
638 * talloc_reference(NULL, ptr);
641 * You can use either syntax, depending on which you think is clearer in
644 * It returns 0 on success and -1 on failure.
646 int talloc_increase_ref_count(const void *ptr);
649 * \brief Return the number of references to a talloc chunk
650 * \param ptr The chunk you are interested in
651 * \return Number of refs
652 * \ingroup talloc_ref
654 size_t talloc_reference_count(const void *ptr);
655 void *_talloc_reference(const void *context, const void *ptr);
658 * \brief Remove a specific parent from a talloc chunk
659 * \param context The talloc parent to remove
660 * \param ptr The talloc ptr you want to remove the parent from
661 * \ingroup talloc_ref
663 * The talloc_unlink() function removes a specific parent from ptr. The
664 * context passed must either be a context used in talloc_reference() with
665 * this pointer, or must be a direct parent of ptr.
667 * Note that if the parent has already been removed using talloc_free() then
668 * this function will fail and will return -1. Likewise, if "ptr" is NULL,
669 * then the function will make no modifications and return -1.
671 * Usually you can just use talloc_free() instead of talloc_unlink(), but
672 * sometimes it is useful to have the additional control on which parent is
675 int talloc_unlink(const void *context, void *ptr);
678 * \brief Assign a name to a talloc chunk
679 * \param ptr The talloc chunk to assign a name to
680 * \param fmt Format string for the name
681 * \param ... printf-style additional arguments
682 * \return The assigned name
683 * \ingroup talloc_basic
685 * Each talloc pointer has a "name". The name is used principally for
686 * debugging purposes, although it is also possible to set and get the name on
687 * a pointer in as a way of "marking" pointers in your code.
689 * The main use for names on pointer is for "talloc reports". See
690 * talloc_report() and talloc_report_full() for details. Also see
691 * talloc_enable_leak_report() and talloc_enable_leak_report_full().
693 * The talloc_set_name() function allocates memory as a child of the
694 * pointer. It is logically equivalent to:
697 * talloc_set_name_const(ptr, talloc_asprintf(ptr, fmt, ...));
700 * Note that multiple calls to talloc_set_name() will allocate more memory
701 * without releasing the name. All of the memory is released when the ptr is
702 * freed using talloc_free().
704 const char *talloc_set_name(const void *ptr, const char *fmt, ...) PRINTF_ATTRIBUTE(2,3);
707 * \brief Assign a name to a talloc chunk
708 * \param ptr The talloc chunk to assign a name to
709 * \param name Format string for the name
710 * \ingroup talloc_basic
712 * The function talloc_set_name_const() is just like talloc_set_name(), but it
713 * takes a string constant, and is much faster. It is extensively used by the
714 * "auto naming" macros, such as talloc_p().
716 * This function does not allocate any memory. It just copies the supplied
717 * pointer into the internal representation of the talloc ptr. This means you
718 * must not pass a name pointer to memory that will disappear before the ptr
719 * is freed with talloc_free().
721 void talloc_set_name_const(const void *ptr, const char *name);
724 * \brief Create a named talloc chunk
725 * \param context The talloc context to hang the result off
726 * \param size Number of char's that you want to allocate
727 * \param fmt Format string for the name
728 * \param ... printf-style additional arguments
729 * \return The allocated memory chunk
730 * \ingroup talloc_basic
732 * The talloc_named() function creates a named talloc pointer. It is
736 * ptr = talloc_size(context, size);
737 * talloc_set_name(ptr, fmt, ....);
741 void *talloc_named(const void *context, size_t size,
742 const char *fmt, ...) PRINTF_ATTRIBUTE(3,4);
745 * \brief Basic routine to allocate a chunk of memory
746 * \param context The parent context
747 * \param size The number of char's that we want to allocate
748 * \param name The name the talloc block has
749 * \return The allocated chunk
750 * \ingroup talloc_basic
752 * This is equivalent to:
755 * ptr = talloc_size(context, size);
756 * talloc_set_name_const(ptr, name);
759 void *talloc_named_const(const void *context, size_t size, const char *name);
762 * \brief Return the name of a talloc chunk
763 * \param ptr The talloc chunk
765 * \ingroup talloc_basic
767 * This returns the current name for the given talloc pointer. See
768 * talloc_set_name() for details.
770 const char *talloc_get_name(const void *ptr);
773 * \brief Verify that a talloc chunk carries a specified name
774 * \param ptr The talloc chunk to check
775 * \param name The name to check agains
776 * \ingroup talloc_basic
778 * This function checks if a pointer has the specified name. If it does
779 * then the pointer is returned. It it doesn't then NULL is returned.
781 void *talloc_check_name(const void *ptr, const char *name);
783 void *_talloc_get_type_abort(const void *ptr, const char *name, const char *location);
784 void *talloc_parent(const void *ptr);
785 const char *talloc_parent_name(const void *ptr);
788 * \brief Create a new top level talloc context
789 * \param fmt Format string for the name
790 * \param ... printf-style additional arguments
791 * \return The allocated memory chunk
792 * \ingroup talloc_basic
794 * This function creates a zero length named talloc context as a top level
795 * context. It is equivalent to:
798 * talloc_named(NULL, 0, fmt, ...);
801 void *talloc_init(const char *fmt, ...) PRINTF_ATTRIBUTE(1,2);
804 * \brief Free a chunk of talloc memory
805 * \param ptr The chunk to be freed
807 * \ingroup talloc_basic
809 * The talloc_free() function frees a piece of talloc memory, and all its
810 * children. You can call talloc_free() on any pointer returned by talloc().
812 * The return value of talloc_free() indicates success or failure, with 0
813 * returned for success and -1 for failure. The only possible failure
814 * condition is if the pointer had a destructor attached to it and the
815 * destructor returned -1. See talloc_set_destructor() for details on
818 * If this pointer has an additional parent when talloc_free() is called
819 * then the memory is not actually released, but instead the most
820 * recently established parent is destroyed. See talloc_reference() for
821 * details on establishing additional parents.
823 * For more control on which parent is removed, see talloc_unlink()
825 * talloc_free() operates recursively on its children.
827 int talloc_free(void *ptr);
830 * \brief Free a talloc chunk's children
831 * \param ptr The chunk that you want to free the children of
833 * \ingroup talloc_basic
835 * The talloc_free_children() walks along the list of all children of a talloc
836 * context and talloc_free()s only the children, not the context itself.
838 void talloc_free_children(void *ptr);
839 void *_talloc_realloc(const void *context, void *ptr, size_t size, const char *name);
840 void *_talloc_steal(const void *new_ctx, const void *ptr);
841 void *_talloc_move(const void *new_ctx, const void *pptr);
844 * \brief Return the total size of a talloc chunk including its children
845 * \param ptr The talloc chunk
846 * \return The total size
847 * \ingroup talloc_basic
849 * The talloc_total_size() function returns the total size in bytes used
850 * by this pointer and all child pointers. Mostly useful for debugging.
852 * Passing NULL is allowed, but it will only give a meaningful result if
853 * talloc_enable_leak_report() or talloc_enable_leak_report_full() has
856 size_t talloc_total_size(const void *ptr);
859 * \brief Return the number of talloc chunks hanging off a chunk
860 * \param ptr The talloc chunk
861 * \return The total size
862 * \ingroup talloc_basic
864 * The talloc_total_blocks() function returns the total memory block
865 * count used by this pointer and all child pointers. Mostly useful for
868 * Passing NULL is allowed, but it will only give a meaningful result if
869 * talloc_enable_leak_report() or talloc_enable_leak_report_full() has
872 size_t talloc_total_blocks(const void *ptr);
875 * \brief Walk a complete talloc hierarchy
876 * \param ptr The talloc chunk
877 * \param depth Internal parameter to control recursion. Call with 0.
878 * \param max_depth Maximum recursion level.
879 * \param callback Function to be called on every chunk
880 * \param private_data Private pointer passed to callback
881 * \ingroup talloc_debug
883 * This provides a more flexible reports than talloc_report(). It
884 * will recursively call the callback for the entire tree of memory
885 * referenced by the pointer. References in the tree are passed with
886 * is_ref = 1 and the pointer that is referenced.
888 * You can pass NULL for the pointer, in which case a report is
889 * printed for the top level memory context, but only if
890 * talloc_enable_leak_report() or talloc_enable_leak_report_full()
893 * The recursion is stopped when depth >= max_depth.
894 * max_depth = -1 means only stop at leaf nodes.
896 void talloc_report_depth_cb(const void *ptr, int depth, int max_depth,
897 void (*callback)(const void *ptr,
898 int depth, int max_depth,
904 * \brief Print a talloc hierarchy
905 * \param ptr The talloc chunk
906 * \param depth Internal parameter to control recursion. Call with 0.
907 * \param max_depth Maximum recursion level.
908 * \param f The file handle to print to
909 * \ingroup talloc_debug
911 * This provides a more flexible reports than talloc_report(). It
912 * will let you specify the depth and max_depth.
914 void talloc_report_depth_file(const void *ptr, int depth, int max_depth, FILE *f);
917 * \brief Print a summary report of all memory used by ptr
918 * \param ptr The talloc chunk
919 * \param f The file handle to print to
920 * \ingroup talloc_debug
922 * This provides a more detailed report than talloc_report(). It will
923 * recursively print the ensire tree of memory referenced by the
924 * pointer. References in the tree are shown by giving the name of the
925 * pointer that is referenced.
927 * You can pass NULL for the pointer, in which case a report is printed
928 * for the top level memory context, but only if
929 * talloc_enable_leak_report() or talloc_enable_leak_report_full() has
932 void talloc_report_full(const void *ptr, FILE *f);
935 * \brief Print a summary report of all memory used by ptr
936 * \param ptr The talloc chunk
937 * \param f The file handle to print to
938 * \ingroup talloc_debug
940 * The talloc_report() function prints a summary report of all memory
941 * used by ptr. One line of report is printed for each immediate child of
942 * ptr, showing the total memory and number of blocks used by that child.
944 * You can pass NULL for the pointer, in which case a report is printed
945 * for the top level memory context, but only if
946 * talloc_enable_leak_report() or talloc_enable_leak_report_full() has
949 void talloc_report(const void *ptr, FILE *f);
952 * \brief Enable tracking the use of NULL memory contexts
953 * \ingroup talloc_debug
955 * This enables tracking of the NULL memory context without enabling leak
956 * reporting on exit. Useful for when you want to do your own leak
957 * reporting call via talloc_report_null_full();
959 void talloc_enable_null_tracking(void);
962 * \brief Disable tracking of the NULL memory context
963 * \ingroup talloc_debug
965 * This disables tracking of the NULL memory context.
968 void talloc_disable_null_tracking(void);
971 * \brief Enable calling of talloc_report(NULL, stderr) when a program exits
972 * \ingroup talloc_debug
974 * This enables calling of talloc_report(NULL, stderr) when the program
975 * exits. In Samba4 this is enabled by using the --leak-report command
978 * For it to be useful, this function must be called before any other
979 * talloc function as it establishes a "null context" that acts as the
980 * top of the tree. If you don't call this function first then passing
981 * NULL to talloc_report() or talloc_report_full() won't give you the
982 * full tree printout.
984 * Here is a typical talloc report:
987 talloc report on 'null_context' (total 267 bytes in 15 blocks)
988 libcli/auth/spnego_parse.c:55 contains 31 bytes in 2 blocks
989 libcli/auth/spnego_parse.c:55 contains 31 bytes in 2 blocks
990 iconv(UTF8,CP850) contains 42 bytes in 2 blocks
991 libcli/auth/spnego_parse.c:55 contains 31 bytes in 2 blocks
992 iconv(CP850,UTF8) contains 42 bytes in 2 blocks
993 iconv(UTF8,UTF-16LE) contains 45 bytes in 2 blocks
994 iconv(UTF-16LE,UTF8) contains 45 bytes in 2 blocks
997 void talloc_enable_leak_report(void);
1000 * \brief Enable calling of talloc_report(NULL, stderr) when a program exits
1001 * \ingroup talloc_debug
1003 * This enables calling of talloc_report_full(NULL, stderr) when the
1004 * program exits. In Samba4 this is enabled by using the
1005 * --leak-report-full command line option.
1007 * For it to be useful, this function must be called before any other
1008 * talloc function as it establishes a "null context" that acts as the
1009 * top of the tree. If you don't call this function first then passing
1010 * NULL to talloc_report() or talloc_report_full() won't give you the
1011 * full tree printout.
1013 * Here is a typical full report:
1015 full talloc report on 'root' (total 18 bytes in 8 blocks)
1016 p1 contains 18 bytes in 7 blocks (ref 0)
1017 r1 contains 13 bytes in 2 blocks (ref 0)
1019 p2 contains 1 bytes in 1 blocks (ref 1)
1020 x3 contains 1 bytes in 1 blocks (ref 0)
1021 x2 contains 1 bytes in 1 blocks (ref 0)
1022 x1 contains 1 bytes in 1 blocks (ref 0)
1025 void talloc_enable_leak_report_full(void);
1026 void *_talloc_zero(const void *ctx, size_t size, const char *name);
1027 void *_talloc_memdup(const void *t, const void *p, size_t size, const char *name);
1028 void *_talloc_array(const void *ctx, size_t el_size, unsigned count, const char *name);
1029 void *_talloc_zero_array(const void *ctx, size_t el_size, unsigned count, const char *name);
1030 void *_talloc_realloc_array(const void *ctx, void *ptr, size_t el_size, unsigned count, const char *name);
1033 * \brief Provide a function version of talloc_realloc_size
1034 * \param context The parent context used if "ptr" is NULL
1035 * \param ptr The chunk to be resized
1036 * \param size The new chunk size
1037 * \return The new chunk
1038 * \ingroup talloc_array
1040 * This is a non-macro version of talloc_realloc(), which is useful as
1041 * libraries sometimes want a ralloc function pointer. A realloc()
1042 * implementation encapsulates the functionality of malloc(), free() and
1043 * realloc() in one call, which is why it is useful to be able to pass around
1044 * a single function pointer.
1046 void *talloc_realloc_fn(const void *context, void *ptr, size_t size);
1049 * \brief Provide a talloc context that is freed at program exit
1050 * \return A talloc context
1051 * \ingroup talloc_basic
1053 * This is a handy utility function that returns a talloc context
1054 * which will be automatically freed on program exit. This can be used
1055 * to reduce the noise in memory leak reports.
1057 void *talloc_autofree_context(void);
1060 * \brief Get the size of a talloc chunk
1061 * \param ctx The talloc chunk
1063 * \ingroup talloc_basic
1065 * This function lets you know the amount of memory alloced so far by
1066 * this context. It does NOT account for subcontext memory.
1067 * This can be used to calculate the size of an array.
1069 size_t talloc_get_size(const void *ctx);
1072 * \brief Find a parent context by name
1073 * \param ctx The talloc chunk to start from
1074 * \param name The name of the parent we look for
1075 * \ingroup talloc_basic
1077 * Find a parent memory context of the current context that has the given
1078 * name. This can be very useful in complex programs where it may be
1079 * difficult to pass all information down to the level you need, but you
1080 * know the structure you want is a parent of another context.
1082 void *talloc_find_parent_byname(const void *ctx, const char *name);
1083 void talloc_show_parents(const void *context, FILE *file);
1084 int talloc_is_parent(const void *context, const void *ptr);
1087 * \brief Duplicate a string into a talloc chunk
1088 * \param t The talloc context to hang the result off
1089 * \param p The string you want to duplicate
1090 * \return The duplicated string
1091 * \ingroup talloc_string
1093 * The talloc_strdup() function is equivalent to:
1096 * ptr = talloc_size(ctx, strlen(p)+1);
1097 * if (ptr) memcpy(ptr, p, strlen(p)+1);
1100 * This functions sets the name of the new pointer to the passed
1101 * string. This is equivalent to:
1104 * talloc_set_name_const(ptr, ptr)
1107 char *talloc_strdup(const void *t, const char *p);
1108 char *talloc_strdup_append(char *s, const char *a);
1109 char *talloc_strdup_append_buffer(char *s, const char *a);
1112 * \brief Duplicate a length-limited string into a talloc chunk
1113 * \param t The talloc context to hang the result off
1114 * \param p The string you want to duplicate
1115 * \param n The maximum string length to duplicate
1116 * \return The duplicated string
1117 * \ingroup talloc_string
1119 * The talloc_strndup() function is the talloc equivalent of the C
1120 * library function strndup()
1122 * This functions sets the name of the new pointer to the passed
1123 * string. This is equivalent to:
1126 * talloc_set_name_const(ptr, ptr)
1129 char *talloc_strndup(const void *t, const char *p, size_t n);
1130 char *talloc_strndup_append(char *s, const char *a, size_t n);
1131 char *talloc_strndup_append_buffer(char *s, const char *a, size_t n);
1134 * \brief Format a string given a va_list
1135 * \param t The talloc context to hang the result off
1136 * \param fmt The format string
1137 * \param ap The parameters used to fill fmt
1138 * \return The formatted string
1139 * \ingroup talloc_string
1141 * The talloc_vasprintf() function is the talloc equivalent of the C
1142 * library function vasprintf()
1144 * This functions sets the name of the new pointer to the new
1145 * string. This is equivalent to:
1148 * talloc_set_name_const(ptr, ptr)
1151 char *talloc_vasprintf(const void *t, const char *fmt, va_list ap) PRINTF_ATTRIBUTE(2,0);
1152 char *talloc_vasprintf_append(char *s, const char *fmt, va_list ap) PRINTF_ATTRIBUTE(2,0);
1153 char *talloc_vasprintf_append_buffer(char *s, const char *fmt, va_list ap) PRINTF_ATTRIBUTE(2,0);
1156 * \brief Format a string
1157 * \param t The talloc context to hang the result off
1158 * \param fmt The format string
1159 * \param ... The parameters used to fill fmt
1160 * \return The formatted string
1161 * \ingroup talloc_string
1163 * The talloc_asprintf() function is the talloc equivalent of the C
1164 * library function asprintf()
1166 * This functions sets the name of the new pointer to the new
1167 * string. This is equivalent to:
1170 * talloc_set_name_const(ptr, ptr)
1173 char *talloc_asprintf(const void *t, const char *fmt, ...) PRINTF_ATTRIBUTE(2,3);
1176 * \brief Append a formatted string to another string
1177 * \param s The string to append to
1178 * \param fmt The format string
1179 * \param ... The parameters used to fill fmt
1180 * \return The formatted string
1181 * \ingroup talloc_string
1183 * The talloc_asprintf_append() function appends the given formatted string to
1184 * the given string. Use this varient when the string in the current talloc
1185 * buffer may have been truncated in length.
1187 * This functions sets the name of the new pointer to the new
1188 * string. This is equivalent to:
1191 * talloc_set_name_const(ptr, ptr)
1194 char *talloc_asprintf_append(char *s, const char *fmt, ...) PRINTF_ATTRIBUTE(2,3);
1197 * \brief Append a formatted string to another string
1198 * \param s The string to append to
1199 * \param fmt The format string
1200 * \param ... The parameters used to fill fmt
1201 * \return The formatted string
1202 * \ingroup talloc_string
1204 * The talloc_asprintf_append() function appends the given formatted string to
1205 * the end of the currently allocated talloc buffer. This routine should be
1206 * used if you create a large string step by step. talloc_asprintf() or
1207 * talloc_asprintf_append() call strlen() at every
1208 * step. talloc_asprintf_append_buffer() uses the existing buffer size of the
1209 * talloc chunk to calculate where to append the string.
1211 * This functions sets the name of the new pointer to the new
1212 * string. This is equivalent to:
1215 * talloc_set_name_const(ptr, ptr)
1218 char *talloc_asprintf_append_buffer(char *s, const char *fmt, ...) PRINTF_ATTRIBUTE(2,3);
1220 void talloc_set_abort_fn(void (*abort_fn)(const char *reason));