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/>.
33 * @defgroup talloc The talloc API
35 * talloc is a hierarchical, reference counted memory pool system with
36 * destructors. It is the core memory allocator used in Samba.
41 #define TALLOC_VERSION_MAJOR 2
42 #define TALLOC_VERSION_MINOR 0
44 int talloc_version_major(void);
45 int talloc_version_minor(void);
48 * @brief Define a talloc parent type
50 * As talloc is a hierarchial memory allocator, every talloc chunk is a
51 * potential parent to other talloc chunks. So defining a separate type for a
52 * talloc chunk is not strictly necessary. TALLOC_CTX is defined nevertheless,
53 * as it provides an indicator for function arguments. You will frequently
57 * struct foo *foo_create(TALLOC_CTX *mem_ctx)
60 * result = talloc(mem_ctx, struct foo);
61 * if (result == NULL) return NULL;
62 * ... initialize foo ...
67 * In this type of allocating functions it is handy to have a general
68 * TALLOC_CTX type to indicate which parent to put allocated structures on.
70 typedef void TALLOC_CTX;
73 this uses a little trick to allow __LINE__ to be stringified
76 #define __TALLOC_STRING_LINE1__(s) #s
77 #define __TALLOC_STRING_LINE2__(s) __TALLOC_STRING_LINE1__(s)
78 #define __TALLOC_STRING_LINE3__ __TALLOC_STRING_LINE2__(__LINE__)
79 #define __location__ __FILE__ ":" __TALLOC_STRING_LINE3__
82 #ifndef TALLOC_DEPRECATED
83 #define TALLOC_DEPRECATED 0
86 #ifndef PRINTF_ATTRIBUTE
88 /** Use gcc attribute to check printf fns. a1 is the 1-based index of
89 * the parameter containing the format, and a2 the index of the first
90 * argument. Note that some gcc 2.x versions don't handle this
92 #define PRINTF_ATTRIBUTE(a1, a2) __attribute__ ((format (__printf__, a1, a2)))
94 #define PRINTF_ATTRIBUTE(a1, a2)
100 * @brief Create a new talloc context.
102 * The talloc() macro is the core of the talloc library. It takes a memory
103 * context and a type, and returns a pointer to a new area of memory of the
106 * The returned pointer is itself a talloc context, so you can use it as the
107 * context argument to more calls to talloc if you wish.
109 * The returned pointer is a "child" of the supplied context. This means that if
110 * you talloc_free() the context then the new child disappears as well.
111 * Alternatively you can free just the child.
113 * @param[in] ctx A talloc context to create a new reference on or NULL to
114 * create a new top level context.
116 * @param[in] type The type of memory to allocate.
118 * @return A type casted talloc context or NULL on error.
121 * unsigned int *a, *b;
123 * a = talloc(NULL, unsigned int);
124 * b = talloc(a, unsigned int);
132 void *talloc(const void *ctx, #type);
134 #define talloc(ctx, type) (type *)talloc_named_const(ctx, sizeof(type), #type)
135 void *_talloc(const void *context, size_t size);
139 * @brief Create a new top level talloc context.
141 * This function creates a zero length named talloc context as a top level
142 * context. It is equivalent to:
145 * talloc_named(NULL, 0, fmt, ...);
147 * @param[in] fmt Format string for the name.
149 * @param[in] ... Additional printf-style arguments.
151 * @return The allocated memory chunk, NULL on error.
153 * @see talloc_named()
155 void *talloc_init(const char *fmt, ...) PRINTF_ATTRIBUTE(1,2);
159 * @brief Free a chunk of talloc memory.
161 * The talloc_free() function frees a piece of talloc memory, and all its
162 * children. You can call talloc_free() on any pointer returned by
165 * The return value of talloc_free() indicates success or failure, with 0
166 * returned for success and -1 for failure. A possible failure condition
167 * is if the pointer had a destructor attached to it and the destructor
168 * returned -1. See talloc_set_destructor() for details on
169 * destructors. Likewise, if "ptr" is NULL, then the function will make
170 * no modifications and return -1.
172 * If this pointer has an additional parent when talloc_free() is called
173 * then the memory is not actually released, but instead the most
174 * recently established parent is destroyed. See talloc_reference() for
175 * details on establishing additional parents.
177 * For more control on which parent is removed, see talloc_unlink()
179 * talloc_free() operates recursively on its children.
181 * From the 2.0 version of talloc, as a special case, talloc_free() is
182 * refused on pointers that have more than one parent, as talloc would
183 * have no way of knowing which parent should be removed. To free a
184 * pointer that has more than one parent please use talloc_unlink().
186 * To help you find problems in your code caused by this behaviour, if
187 * you do try and free a pointer with more than one parent then the
188 * talloc logging function will be called to give output like this:
191 * ERROR: talloc_free with references at some_dir/source/foo.c:123
192 * reference at some_dir/source/other.c:325
193 * reference at some_dir/source/third.c:121
196 * Please see the documentation for talloc_set_log_fn() and
197 * talloc_set_log_stderr() for more information on talloc logging
200 * @param[in] ptr The chunk to be freed.
202 * @return Returns 0 on success and -1 on error. A possible
203 * failure condition is if the pointer had a destructor
204 * attached to it and the destructor returned -1. Likewise,
205 * if "ptr" is NULL, then the function will make no
206 * modifications and returns -1.
210 * unsigned int *a, *b;
211 * a = talloc(NULL, unsigned int);
212 * b = talloc(a, unsigned int);
214 * talloc_free(a); // Frees a and b
217 * @see talloc_set_destructor()
218 * @see talloc_unlink()
220 int talloc_free(void *ptr);
222 #define talloc_free(ctx) _talloc_free(ctx, __location__)
223 int _talloc_free(void *ptr, const char *location);
227 * @brief Free a talloc chunk's children.
229 * The function walks along the list of all children of a talloc context and
230 * talloc_free()s only the children, not the context itself.
232 * @param[in] ptr The chunk that you want to free the children of.
234 void talloc_free_children(void *ptr);
238 * @brief Assign a destructor function to be called when a chunk is freed.
240 * The function talloc_set_destructor() sets the "destructor" for the pointer
241 * "ptr". A destructor is a function that is called when the memory used by a
242 * pointer is about to be released. The destructor receives the pointer as an
243 * argument, and should return 0 for success and -1 for failure.
245 * The destructor can do anything it wants to, including freeing other pieces
246 * of memory. A common use for destructors is to clean up operating system
247 * resources (such as open file descriptors) contained in the structure the
248 * destructor is placed on.
250 * You can only place one destructor on a pointer. If you need more than one
251 * destructor then you can create a zero-length child of the pointer and place
252 * an additional destructor on that.
254 * To remove a destructor call talloc_set_destructor() with NULL for the
257 * If your destructor attempts to talloc_free() the pointer that it is the
258 * destructor for then talloc_free() will return -1 and the free will be
259 * ignored. This would be a pointless operation anyway, as the destructor is
260 * only called when the memory is just about to go away.
262 * @param[in] ptr The talloc chunk to add a destructor to.
264 * @param[in] destructor The destructor function to be called. NULL to remove
269 * static int destroy_fd(int *fd) {
274 * int *open_file(const char *filename) {
275 * int *fd = talloc(NULL, int);
276 * *fd = open(filename, O_RDONLY);
281 * // Whenever they free this, we close the file.
282 * talloc_set_destructor(fd, destroy_fd);
290 void talloc_set_destructor(const void *ptr, int (*destructor)(void *));
293 * @brief Change a talloc chunk's parent.
295 * The talloc_steal() function changes the parent context of a talloc
296 * pointer. It is typically used when the context that the pointer is
297 * currently a child of is going to be freed and you wish to keep the
298 * memory for a longer time.
300 * To make the changed hierarchy less error-prone, you might consider to use
303 * If you try and call talloc_steal() on a pointer that has more than one
304 * parent then the result is ambiguous. Talloc will choose to remove the
305 * parent that is currently indicated by talloc_parent() and replace it with
306 * the chosen parent. You will also get a message like this via the talloc
310 * WARNING: talloc_steal with references at some_dir/source/foo.c:123
311 * reference at some_dir/source/other.c:325
312 * reference at some_dir/source/third.c:121
315 * To unambiguously change the parent of a pointer please see the function
316 * talloc_reparent(). See the talloc_set_log_fn() documentation for more
317 * information on talloc logging.
319 * @param[in] new_ctx The new parent context.
321 * @param[in] ptr The talloc chunk to move.
323 * @return Returns the pointer that you pass it. It does not have
326 * @note It is possible to produce loops in the parent/child relationship
327 * if you are not careful with talloc_steal(). No guarantees are provided
328 * as to your sanity or the safety of your data if you do this.
330 void *talloc_steal(const void *new_ctx, const void *ptr);
332 /* try to make talloc_set_destructor() and talloc_steal() type safe,
333 if we have a recent gcc */
335 #define _TALLOC_TYPEOF(ptr) __typeof__(ptr)
336 #define talloc_set_destructor(ptr, function) \
338 int (*_talloc_destructor_fn)(_TALLOC_TYPEOF(ptr)) = (function); \
339 _talloc_set_destructor((ptr), (int (*)(void *))_talloc_destructor_fn); \
341 /* this extremely strange macro is to avoid some braindamaged warning
342 stupidity in gcc 4.1.x */
343 #define talloc_steal(ctx, ptr) ({ _TALLOC_TYPEOF(ptr) __talloc_steal_ret = (_TALLOC_TYPEOF(ptr))_talloc_steal_loc((ctx),(ptr), __location__); __talloc_steal_ret; })
344 #else /* __GNUC__ >= 3 */
345 #define talloc_set_destructor(ptr, function) \
346 _talloc_set_destructor((ptr), (int (*)(void *))(function))
347 #define _TALLOC_TYPEOF(ptr) void *
348 #define talloc_steal(ctx, ptr) (_TALLOC_TYPEOF(ptr))_talloc_steal_loc((ctx),(ptr), __location__)
349 #endif /* __GNUC__ >= 3 */
350 void _talloc_set_destructor(const void *ptr, int (*_destructor)(void *));
351 void *_talloc_steal_loc(const void *new_ctx, const void *ptr, const char *location);
355 * @brief Assign a name to a talloc chunk.
357 * Each talloc pointer has a "name". The name is used principally for
358 * debugging purposes, although it is also possible to set and get the name on
359 * a pointer in as a way of "marking" pointers in your code.
361 * The main use for names on pointer is for "talloc reports". See
362 * talloc_report() and talloc_report_full() for details. Also see
363 * talloc_enable_leak_report() and talloc_enable_leak_report_full().
365 * The talloc_set_name() function allocates memory as a child of the
366 * pointer. It is logically equivalent to:
369 * talloc_set_name_const(ptr, talloc_asprintf(ptr, fmt, ...));
372 * @param[in] ptr The talloc chunk to assign a name to.
374 * @param[in] fmt Format string for the name.
376 * @param[in] ... Add printf-style additional arguments.
378 * @return The assigned name, NULL on error.
380 * @note Multiple calls to talloc_set_name() will allocate more memory without
381 * releasing the name. All of the memory is released when the ptr is freed
382 * using talloc_free().
384 const char *talloc_set_name(const void *ptr, const char *fmt, ...) PRINTF_ATTRIBUTE(2,3);
388 * @brief Change a talloc chunk's parent.
390 * This function has the same effect as talloc_steal(), and additionally sets
391 * the source pointer to NULL. You would use it like this:
394 * struct foo *X = talloc(tmp_ctx, struct foo);
396 * Y = talloc_move(new_ctx, &X);
399 * @param[in] new_ctx The new parent context.
401 * @param[in] ptr Pointer to the talloc chunk to move.
403 * @return The pointer of the talloc chunk it has been moved to,
406 void *talloc_move(const void *new_ctx, const void *ptr);
408 #define talloc_move(ctx, ptr) (_TALLOC_TYPEOF(*(ptr)))_talloc_move((ctx),(void *)(ptr))
409 void *_talloc_move(const void *new_ctx, const void *pptr);
413 * @brief Assign a name to a talloc chunk.
415 * The function is just like talloc_set_name(), but it takes a string constant,
416 * and is much faster. It is extensively used by the "auto naming" macros, such
419 * This function does not allocate any memory. It just copies the supplied
420 * pointer into the internal representation of the talloc ptr. This means you
421 * must not pass a name pointer to memory that will disappear before the ptr
422 * is freed with talloc_free().
424 * @param[in] ptr The talloc chunk to assign a name to.
426 * @param[in] name Format string for the name.
428 void talloc_set_name_const(const void *ptr, const char *name);
431 * @brief Create a named talloc chunk.
433 * The talloc_named() function creates a named talloc pointer. It is
437 * ptr = talloc_size(context, size);
438 * talloc_set_name(ptr, fmt, ....);
441 * @param[in] context The talloc context to hang the result off.
443 * @param[in] size Number of char's that you want to allocate.
445 * @param[in] fmt Format string for the name.
447 * @param[in] ... Additional printf-style arguments.
449 * @return The allocated memory chunk, NULL on error.
451 * @see talloc_set_name()
453 void *talloc_named(const void *context, size_t size,
454 const char *fmt, ...) PRINTF_ATTRIBUTE(3,4);
457 * @brief Basic routine to allocate a chunk of memory.
459 * This is equivalent to:
462 * ptr = talloc_size(context, size);
463 * talloc_set_name_const(ptr, name);
466 * @param[in] context The parent context.
468 * @param[in] size The number of char's that we want to allocate.
470 * @param[in] name The name the talloc block has.
472 * @return The allocated memory chunk, NULL on error.
474 void *talloc_named_const(const void *context, size_t size, const char *name);
478 * @brief Untyped allocation.
480 * The function should be used when you don't have a convenient type to pass to
481 * talloc(). Unlike talloc(), it is not type safe (as it returns a void *), so
482 * you are on your own for type checking.
484 * Best to use talloc() or talloc_array() instead.
486 * @param[in] ctx The talloc context to hang the result off.
488 * @param[in] size Number of char's that you want to allocate.
490 * @return The allocated memory chunk, NULL on error.
494 * void *mem = talloc_size(NULL, 100);
497 void *talloc_size(const void *ctx, size_t size);
499 #define talloc_size(ctx, size) talloc_named_const(ctx, size, __location__)
504 * @brief Allocate into a typed pointer.
506 * The talloc_ptrtype() macro should be used when you have a pointer and want
507 * to allocate memory to point at with this pointer. When compiling with
508 * gcc >= 3 it is typesafe. Note this is a wrapper of talloc_size() and
509 * talloc_get_name() will return the current location in the source file and
512 * @param[in] ctx The talloc context to hang the result off.
514 * @param[in] type The pointer you want to assign the result to.
516 * @return The properly casted allocated memory chunk, NULL on
521 * unsigned int *a = talloc_ptrtype(NULL, a);
524 void *talloc_ptrtype(const void *ctx, #type);
526 #define talloc_ptrtype(ctx, ptr) (_TALLOC_TYPEOF(ptr))talloc_size(ctx, sizeof(*(ptr)))
531 * @brief Allocate a new 0-sized talloc chunk.
533 * This is a utility macro that creates a new memory context hanging off an
534 * existing context, automatically naming it "talloc_new: __location__" where
535 * __location__ is the source line it is called from. It is particularly
536 * useful for creating a new temporary working context.
538 * @param[in] ctx The talloc parent context.
540 * @return A new talloc chunk, NULL on error.
542 void *talloc_new(const void *ctx);
544 #define talloc_new(ctx) talloc_named_const(ctx, 0, "talloc_new: " __location__)
549 * @brief Allocate a 0-initizialized structure.
551 * The macro is equivalent to:
554 * ptr = talloc(ctx, type);
555 * if (ptr) memset(ptr, 0, sizeof(type));
558 * @param[in] ctx The talloc context to hang the result off.
560 * @param[in] type The type that we want to allocate.
562 * @return Pointer to a piece of memory, properly cast to 'type *',
567 * unsigned int *a, *b;
568 * a = talloc_zero(NULL, unsigned int);
569 * b = talloc_zero(a, unsigned int);
573 * @see talloc_zero_size()
574 * @see talloc_zero_array()
576 void *talloc_zero(const void *ctx, #type);
579 * @brief Allocate untyped, 0-initialized memory.
581 * @param[in] ctx The talloc context to hang the result off.
583 * @param[in] size Number of char's that you want to allocate.
585 * @return The allocated memory chunk.
587 void *talloc_zero_size(const void *ctx, size_t size);
589 #define talloc_zero(ctx, type) (type *)_talloc_zero(ctx, sizeof(type), #type)
590 #define talloc_zero_size(ctx, size) _talloc_zero(ctx, size, __location__)
591 void *_talloc_zero(const void *ctx, size_t size, const char *name);
595 * @brief Return the name of a talloc chunk.
597 * @param[in] ptr The talloc chunk.
599 * @return The current name for the given talloc pointer.
601 * @see talloc_set_name()
603 const char *talloc_get_name(const void *ptr);
606 * @brief Verify that a talloc chunk carries a specified name.
608 * This function checks if a pointer has the specified name. If it does
609 * then the pointer is returned.
611 * @param[in] ptr The talloc chunk to check.
613 * @param[in] name The name to check against.
615 * @return The pointer if the name matches, NULL if it doesn't.
617 void *talloc_check_name(const void *ptr, const char *name);
620 * @brief Get the parent chunk of a pointer.
622 * @param[in] ptr The talloc pointer to inspect.
624 * @return The talloc parent of ptr, NULL on error.
626 void *talloc_parent(const void *ptr);
629 * @brief Get a talloc chunk's parent name.
631 * @param[in] ptr The talloc pointer to inspect.
633 * @return The name of ptr's parent chunk.
635 const char *talloc_parent_name(const void *ptr);
638 * @brief Get the total size of a talloc chunk including its children.
640 * The function returns the total size in bytes used by this pointer and all
641 * child pointers. Mostly useful for debugging.
643 * Passing NULL is allowed, but it will only give a meaningful result if
644 * talloc_enable_leak_report() or talloc_enable_leak_report_full() has
647 * @param[in] ptr The talloc chunk.
649 * @return The total size.
651 size_t talloc_total_size(const void *ptr);
654 * @brief Get the number of talloc chunks hanging off a chunk.
656 * The talloc_total_blocks() function returns the total memory block
657 * count used by this pointer and all child pointers. Mostly useful for
660 * Passing NULL is allowed, but it will only give a meaningful result if
661 * talloc_enable_leak_report() or talloc_enable_leak_report_full() has
664 * @param[in] ptr The talloc chunk.
666 * @return The total size.
668 size_t talloc_total_blocks(const void *ptr);
672 * @brief Duplicate a memory area into a talloc chunk.
674 * The function is equivalent to:
677 * ptr = talloc_size(ctx, size);
678 * if (ptr) memcpy(ptr, p, size);
681 * @param[in] t The talloc context to hang the result off.
683 * @param[in] p The memory chunk you want to duplicate.
685 * @param[in] size Number of char's that you want copy.
687 * @return The allocated memory chunk.
691 void *talloc_memdup(const void *t, const void *p, size_t size);
693 #define talloc_memdup(t, p, size) _talloc_memdup(t, p, size, __location__)
694 void *_talloc_memdup(const void *t, const void *p, size_t size, const char *name);
699 * @brief Assign a type to a talloc chunk.
701 * This macro allows you to force the name of a pointer to be a particular type.
702 * This can be used in conjunction with talloc_get_type() to do type checking on
705 * It is equivalent to this:
708 * talloc_set_name_const(ptr, #type)
711 * @param[in] ptr The talloc chunk to assign the type to.
713 * @param[in] type The type to assign.
715 void talloc_set_type(const char *ptr, #type);
718 * @brief Get a typed pointer out of a talloc pointer.
720 * This macro allows you to do type checking on talloc pointers. It is
721 * particularly useful for void* private pointers. It is equivalent to
725 * (type *)talloc_check_name(ptr, #type)
728 * @param[in] ptr The talloc pointer to check.
730 * @param[in] type The type to check against.
732 * @return The properly casted pointer given by ptr, NULL on error.
734 type *talloc_get_type(const void *ptr, #type);
736 #define talloc_set_type(ptr, type) talloc_set_name_const(ptr, #type)
737 #define talloc_get_type(ptr, type) (type *)talloc_check_name(ptr, #type)
742 * @brief Safely turn a void pointer into a typed pointer.
744 * This macro is used together with talloc(mem_ctx, struct foo). If you had to
745 * assing the talloc chunk pointer to some void pointer variable,
746 * talloc_get_type_abort() is the recommended way to get the convert the void
747 * pointer back to a typed pointer.
749 * @param[in] ptr The void pointer to convert.
751 * @param[in] type The type that this chunk contains
753 * @return The same value as ptr, type-checked and properly cast.
755 void *talloc_get_type_abort(const void *ptr, #type);
757 #define talloc_get_type_abort(ptr, type) (type *)_talloc_get_type_abort(ptr, #type, __location__)
758 void *_talloc_get_type_abort(const void *ptr, const char *name, const char *location);
762 * @brief Find a parent context by name.
764 * Find a parent memory context of the current context that has the given
765 * name. This can be very useful in complex programs where it may be
766 * difficult to pass all information down to the level you need, but you
767 * know the structure you want is a parent of another context.
769 * @param[in] ctx The talloc chunk to start from.
771 * @param[in] name The name of the parent we look for.
773 * @return The memory context we are looking for, NULL if not
776 void *talloc_find_parent_byname(const void *ctx, const char *name);
780 * @brief Find a parent context by type.
782 * Find a parent memory context of the current context that has the given
783 * name. This can be very useful in complex programs where it may be
784 * difficult to pass all information down to the level you need, but you
785 * know the structure you want is a parent of another context.
787 * Like talloc_find_parent_byname() but takes a type, making it typesafe.
789 * @param[in] ptr The talloc chunk to start from.
791 * @param[in] type The type of the parent to look for.
793 * @return The memory context we are looking for, NULL if not
796 void *talloc_find_parent_bytype(const void *ptr, #type);
798 #define talloc_find_parent_bytype(ptr, type) (type *)talloc_find_parent_byname(ptr, #type)
802 * @brief Allocate a talloc pool.
804 * A talloc pool is a pure optimization for specific situations. In the
805 * release process for Samba 3.2 we found out that we had become considerably
806 * slower than Samba 3.0 was. Profiling showed that malloc(3) was a large CPU
807 * consumer in benchmarks. For Samba 3.2 we have internally converted many
808 * static buffers to dynamically allocated ones, so malloc(3) being beaten
809 * more was no surprise. But it made us slower.
811 * talloc_pool() is an optimization to call malloc(3) a lot less for the use
812 * pattern Samba has: The SMB protocol is mainly a request/response protocol
813 * where we have to allocate a certain amount of memory per request and free
814 * that after the SMB reply is sent to the client.
816 * talloc_pool() creates a talloc chunk that you can use as a talloc parent
817 * exactly as you would use any other ::TALLOC_CTX. The difference is that
818 * when you talloc a child of this pool, no malloc(3) is done. Instead, talloc
819 * just increments a pointer inside the talloc_pool. This also works
820 * recursively. If you use the child of the talloc pool as a parent for
821 * grand-children, their memory is also taken from the talloc pool.
823 * If you talloc_free() children of a talloc pool, the memory is not given
824 * back to the system. Instead, free(3) is only called if the talloc_pool()
825 * itself is released with talloc_free().
827 * The downside of a talloc pool is that if you talloc_move() a child of a
828 * talloc pool to a talloc parent outside the pool, the whole pool memory is
829 * not free(3)'ed until that moved chunk is also talloc_free()ed.
831 * @param[in] context The talloc context to hang the result off.
833 * @param[in] size Size of the talloc pool.
835 * @return The allocated talloc pool, NULL on error.
837 void *talloc_pool(const void *context, size_t size);
840 * @brief Free a talloc chunk and NULL out the pointer.
842 * TALLOC_FREE() frees a pointer and sets it to NULL. Use this if you want
843 * immediate feedback (i.e. crash) if you use a pointer after having free'ed
846 * @param[in] ctx The chunk to be freed.
848 #define TALLOC_FREE(ctx) do { talloc_free(ctx); ctx=NULL; } while(0)
850 /* @} ******************************************************************/
853 * \defgroup talloc_ref The talloc reference function.
856 * This module contains the definitions around talloc references
862 * @brief Increase the reference count of a talloc chunk.
864 * The talloc_increase_ref_count(ptr) function is exactly equivalent to:
867 * talloc_reference(NULL, ptr);
870 * You can use either syntax, depending on which you think is clearer in
873 * @param[in] ptr The pointer to increase the reference count.
875 * @return 0 on success, -1 on error.
877 int talloc_increase_ref_count(const void *ptr);
880 * @brief Get the number of references to a talloc chunk.
882 * @param[in] ptr The pointer to retrieve the reference count from.
884 * @return The number of references.
886 size_t talloc_reference_count(const void *ptr);
890 * @brief Create an additional talloc parent to a pointer.
892 * The talloc_reference() function makes "context" an additional parent of
893 * ptr. Each additional reference consumes around 48 bytes of memory on intel
896 * If ptr is NULL, then the function is a no-op, and simply returns NULL.
898 * After creating a reference you can free it in one of the following ways:
900 * - you can talloc_free() any parent of the original pointer. That
901 * will reduce the number of parents of this pointer by 1, and will
902 * cause this pointer to be freed if it runs out of parents.
904 * - you can talloc_free() the pointer itself. That will destroy the
905 * most recently established parent to the pointer and leave the
906 * pointer as a child of its current parent.
908 * For more control on which parent to remove, see talloc_unlink()
909 * @param[in] ctx The additional parent.
911 * @param[in] ptr The pointer you want to create an additional parent for.
913 * @return The original pointer 'ptr', NULL if talloc ran out of
914 * memory in creating the reference.
918 * unsigned int *a, *b, *c;
919 * a = talloc(NULL, unsigned int);
920 * b = talloc(NULL, unsigned int);
921 * c = talloc(a, unsigned int);
922 * // b also serves as a parent of c.
923 * talloc_reference(b, c);
926 * @see talloc_unlink()
928 void *talloc_reference(const void *ctx, const void *ptr);
930 #define talloc_reference(ctx, ptr) (_TALLOC_TYPEOF(ptr))_talloc_reference_loc((ctx),(ptr), __location__)
931 void *_talloc_reference_loc(const void *context, const void *ptr, const char *location);
935 * @brief Remove a specific parent from a talloc chunk.
937 * The function removes a specific parent from ptr. The context passed must
938 * either be a context used in talloc_reference() with this pointer, or must be
939 * a direct parent of ptr.
941 * Usually you can just use talloc_free() instead of talloc_unlink(), but
942 * sometimes it is useful to have the additional control on which parent is
945 * @param[in] context The talloc parent to remove.
947 * @param[in] ptr The talloc ptr you want to remove the parent from.
949 * @return 0 on success, -1 on error.
951 * @note If the parent has already been removed using talloc_free() then
952 * this function will fail and will return -1. Likewise, if ptr is NULL,
953 * then the function will make no modifications and return -1.
957 * unsigned int *a, *b, *c;
958 * a = talloc(NULL, unsigned int);
959 * b = talloc(NULL, unsigned int);
960 * c = talloc(a, unsigned int);
961 * // b also serves as a parent of c.
962 * talloc_reference(b, c);
963 * talloc_unlink(b, c);
966 int talloc_unlink(const void *context, void *ptr);
969 * @brief Provide a talloc context that is freed at program exit.
971 * This is a handy utility function that returns a talloc context
972 * which will be automatically freed on program exit. This can be used
973 * to reduce the noise in memory leak reports.
975 * Never use this in code that might be used in objects loaded with
976 * dlopen and unloaded with dlclose. talloc_autofree_context()
977 * internally uses atexit(3). Some platforms like modern Linux handles
978 * this fine, but for example FreeBSD does not deal well with dlopen()
979 * and atexit() used simultaneously: dlclose() does not clean up the
980 * list of atexit-handlers, so when the program exits the code that
981 * was registered from within talloc_autofree_context() is gone, the
982 * program crashes at exit.
984 * @return A talloc context, NULL on error.
986 void *talloc_autofree_context(void);
989 * @brief Get the size of a talloc chunk.
991 * This function lets you know the amount of memory alloced so far by
992 * this context. It does NOT account for subcontext memory.
993 * This can be used to calculate the size of an array.
995 * @param[in] ctx The talloc chunk.
997 * @return The size of the talloc chunk.
999 size_t talloc_get_size(const void *ctx);
1002 * @brief Show the parentage of a context.
1004 * @param[in] context The talloc context to look at.
1006 * @param[in] file The output to use, a file, stdout or stderr.
1008 void talloc_show_parents(const void *context, FILE *file);
1011 * @brief Check if a context is parent of a talloc chunk.
1013 * This checks if context is referenced in the talloc hierarchy above ptr.
1015 * @param[in] context The assumed talloc context.
1017 * @param[in] ptr The talloc chunk to check.
1019 * @return Return 1 if this is the case, 0 if not.
1021 int talloc_is_parent(const void *context, const void *ptr);
1024 * @brief Change the parent context of a talloc pointer.
1026 * The function changes the parent context of a talloc pointer. It is typically
1027 * used when the context that the pointer is currently a child of is going to be
1028 * freed and you wish to keep the memory for a longer time.
1030 * The difference between talloc_reparent() and talloc_steal() is that
1031 * talloc_reparent() can specify which parent you wish to change. This is
1032 * useful when a pointer has multiple parents via references.
1034 * @param[in] old_parent
1035 * @param[in] new_parent
1038 * @return Return the pointer you passed. It does not have any
1041 void *talloc_reparent(const void *old_parent, const void *new_parent, const void *ptr);
1043 /* @} ******************************************************************/
1046 * @defgroup talloc_array The talloc array functions
1049 * Talloc contains some handy helpers for handling Arrays conveniently
1056 * @brief Allocate an array.
1058 * The macro is equivalent to:
1061 * (type *)talloc_size(ctx, sizeof(type) * count);
1064 * except that it provides integer overflow protection for the multiply,
1065 * returning NULL if the multiply overflows.
1067 * @param[in] ctx The talloc context to hang the result off.
1069 * @param[in] type The type that we want to allocate.
1071 * @param[in] count The number of 'type' elements you want to allocate.
1073 * @return The allocated result, properly cast to 'type *', NULL on
1078 * unsigned int *a, *b;
1079 * a = talloc_zero(NULL, unsigned int);
1080 * b = talloc_array(a, unsigned int, 100);
1084 * @see talloc_array_zero()
1086 void *talloc_array(const void *ctx, #type, unsigned count);
1088 #define talloc_array(ctx, type, count) (type *)_talloc_array(ctx, sizeof(type), count, #type)
1089 void *_talloc_array(const void *ctx, size_t el_size, unsigned count, const char *name);
1094 * @brief Allocate an array.
1096 * @param[in] ctx The talloc context to hang the result off.
1098 * @param[in] size The size of an array element.
1100 * @param[in] count The number of elements you want to allocate.
1102 * @return The allocated result, NULL on error.
1104 void *talloc_array_size(const void *ctx, size_t size, unsigned count);
1106 #define talloc_array_size(ctx, size, count) _talloc_array(ctx, size, count, __location__)
1111 * @brief Allocate an array into a typed pointer.
1113 * The macro should be used when you have a pointer to an array and want to
1114 * allocate memory of an array to point at with this pointer. When compiling
1115 * with gcc >= 3 it is typesafe. Note this is a wrapper of talloc_array_size()
1116 * and talloc_get_name() will return the current location in the source file
1119 * @param[in] ctx The talloc context to hang the result off.
1121 * @param[in] ptr The pointer you want to assign the result to.
1123 * @param[in] count The number of elements you want to allocate.
1125 * @return The allocated memory chunk, properly casted. NULL on
1128 void *talloc_array_ptrtype(const void *ctx, const void *ptr, unsigned count);
1130 #define talloc_array_ptrtype(ctx, ptr, count) (_TALLOC_TYPEOF(ptr))talloc_array_size(ctx, sizeof(*(ptr)), count)
1135 * @brief Get the number of elements in a talloc'ed array.
1137 * A talloc chunk carries its own size, so for talloc'ed arrays it is not
1138 * necessary to store the number of elements explicitly.
1140 * @param[in] ctx The allocated array.
1142 * @return The number of elements in ctx.
1144 size_t talloc_array_length(const void *ctx);
1146 #define talloc_array_length(ctx) (talloc_get_size(ctx)/sizeof(*ctx))
1151 * @brief Allocate a zero-initialized array
1153 * @param[in] ctx The talloc context to hang the result off.
1155 * @param[in] type The type that we want to allocate.
1157 * @param[in] count The number of "type" elements you want to allocate.
1159 * @return The allocated result casted to "type *", NULL on error.
1161 * The talloc_zero_array() macro is equivalent to:
1164 * ptr = talloc_array(ctx, type, count);
1165 * if (ptr) memset(ptr, sizeof(type) * count);
1168 void *talloc_zero_array(const void *ctx, #type, unsigned count);
1170 #define talloc_zero_array(ctx, type, count) (type *)_talloc_zero_array(ctx, sizeof(type), count, #type)
1171 void *_talloc_zero_array(const void *ctx,
1179 * @brief Change the size of a talloc array.
1181 * The macro changes the size of a talloc pointer. The 'count' argument is the
1182 * number of elements of type 'type' that you want the resulting pointer to
1185 * talloc_realloc() has the following equivalences:
1188 * talloc_realloc(ctx, NULL, type, 1) ==> talloc(ctx, type);
1189 * talloc_realloc(ctx, NULL, type, N) ==> talloc_array(ctx, type, N);
1190 * talloc_realloc(ctx, ptr, type, 0) ==> talloc_free(ptr);
1193 * The "context" argument is only used if "ptr" is NULL, otherwise it is
1196 * @param[in] ctx The parent context used if ptr is NULL.
1198 * @param[in] ptr The chunk to be resized.
1200 * @param[in] type The type of the array element inside ptr.
1202 * @param[in] count The intended number of array elements.
1204 * @return The new array, NULL on error. The call will fail either
1205 * due to a lack of memory, or because the pointer has more
1206 * than one parent (see talloc_reference()).
1208 void *talloc_realloc(const void *ctx, void *ptr, #type, size_t count);
1210 #define talloc_realloc(ctx, p, type, count) (type *)_talloc_realloc_array(ctx, p, sizeof(type), count, #type)
1211 void *_talloc_realloc_array(const void *ctx, void *ptr, size_t el_size, unsigned count, const char *name);
1216 * @brief Untyped realloc to change the size of a talloc array.
1218 * The macro is useful when the type is not known so the typesafe
1219 * talloc_realloc() cannot be used.
1221 * @param[in] ctx The parent context used if 'ptr' is NULL.
1223 * @param[in] ptr The chunk to be resized.
1225 * @param[in] size The new chunk size.
1227 * @return The new array, NULL on error.
1229 void *talloc_realloc_size(const void *ctx, void *ptr, size_t size);
1231 #define talloc_realloc_size(ctx, ptr, size) _talloc_realloc(ctx, ptr, size, __location__)
1232 void *_talloc_realloc(const void *context, void *ptr, size_t size, const char *name);
1236 * @brief Provide a function version of talloc_realloc_size.
1238 * This is a non-macro version of talloc_realloc(), which is useful as
1239 * libraries sometimes want a ralloc function pointer. A realloc()
1240 * implementation encapsulates the functionality of malloc(), free() and
1241 * realloc() in one call, which is why it is useful to be able to pass around
1242 * a single function pointer.
1244 * @param[in] context The parent context used if ptr is NULL.
1246 * @param[in] ptr The chunk to be resized.
1248 * @param[in] size The new chunk size.
1250 * @return The new chunk, NULL on error.
1252 void *talloc_realloc_fn(const void *context, void *ptr, size_t size);
1254 /* @} ******************************************************************/
1257 * @defgroup talloc_string The talloc string functions.
1260 * talloc string allocation and manipulation functions.
1265 * @brief Duplicate a string into a talloc chunk.
1267 * This function is equivalent to:
1270 * ptr = talloc_size(ctx, strlen(p)+1);
1271 * if (ptr) memcpy(ptr, p, strlen(p)+1);
1274 * This functions sets the name of the new pointer to the passed
1275 * string. This is equivalent to:
1278 * talloc_set_name_const(ptr, ptr)
1281 * @param[in] t The talloc context to hang the result off.
1283 * @param[in] p The string you want to duplicate.
1285 * @return The duplicated string, NULL on error.
1287 char *talloc_strdup(const void *t, const char *p);
1290 * @brief Append a string to given string and duplicate the result.
1292 * @param[in] s The destination to append to.
1294 * @param[in] a The string you want to append.
1296 * @return The duplicated string, NULL on error.
1298 * @see talloc_strdup()
1300 char *talloc_strdup_append(char *s, const char *a);
1303 * @brief Append a string to a given buffer and duplicate the result.
1305 * @param[in] s The destination buffer to append to.
1307 * @param[in] a The string you want to append.
1309 * @return The duplicated string, NULL on error.
1311 * @see talloc_strdup()
1313 char *talloc_strdup_append_buffer(char *s, const char *a);
1316 * @brief Duplicate a length-limited string into a talloc chunk.
1318 * This function is the talloc equivalent of the C library function strndup(3).
1320 * This functions sets the name of the new pointer to the passed string. This is
1324 * talloc_set_name_const(ptr, ptr)
1327 * @param[in] t The talloc context to hang the result off.
1329 * @param[in] p The string you want to duplicate.
1331 * @param[in] n The maximum string length to duplicate.
1333 * @return The duplicated string, NULL on error.
1335 char *talloc_strndup(const void *t, const char *p, size_t n);
1338 * @brief Append at most n characters of a string to given string and duplicate
1341 * @param[in] s The destination string to append to.
1343 * @param[in] a The source string you want to append.
1345 * @param[in] n The number of characters you want to append from the
1348 * @return The duplicated string, NULL on error.
1350 * @see talloc_strndup()
1352 char *talloc_strndup_append(char *s, const char *a, size_t n);
1355 * @brief Append at most n characters of a string to given buffer and duplicate
1358 * @param[in] s The destination buffer to append to.
1360 * @param[in] a The source string you want to append.
1362 * @param[in] n The number of characters you want to append from the
1365 * @return The duplicated string, NULL on error.
1367 * @see talloc_strndup()
1369 char *talloc_strndup_append_buffer(char *s, const char *a, size_t n);
1372 * @brief Format a string given a va_list.
1374 * This function is the talloc equivalent of the C library function
1377 * This functions sets the name of the new pointer to the new string. This is
1381 * talloc_set_name_const(ptr, ptr)
1384 * @param[in] t The talloc context to hang the result off.
1386 * @param[in] fmt The format string.
1388 * @param[in] ap The parameters used to fill fmt.
1390 * @return The formatted string, NULL on error.
1392 char *talloc_vasprintf(const void *t, const char *fmt, va_list ap) PRINTF_ATTRIBUTE(2,0);
1395 * @brief Format a string given a va_list and append it to the given destination
1398 * @param[in] s The destination string to append to.
1400 * @param[in] fmt The format string.
1402 * @param[in] ap The parameters used to fill fmt.
1404 * @return The formatted string, NULL on error.
1406 * @see talloc_vasprintf()
1408 char *talloc_vasprintf_append(char *s, const char *fmt, va_list ap) PRINTF_ATTRIBUTE(2,0);
1411 * @brief Format a string given a va_list and append it to the given destination
1414 * @param[in] s The destination buffer to append to.
1416 * @param[in] fmt The format string.
1418 * @param[in] ap The parameters used to fill fmt.
1420 * @return The formatted string, NULL on error.
1422 * @see talloc_vasprintf()
1424 char *talloc_vasprintf_append_buffer(char *s, const char *fmt, va_list ap) PRINTF_ATTRIBUTE(2,0);
1427 * @brief Format a string.
1429 * This function is the talloc equivalent of the C library function asprintf(3).
1431 * This functions sets the name of the new pointer to the new string. This is
1435 * talloc_set_name_const(ptr, ptr)
1438 * @param[in] t The talloc context to hang the result off.
1440 * @param[in] fmt The format string.
1442 * @param[in] ... The parameters used to fill fmt.
1444 * @return The formatted string, NULL on error.
1446 char *talloc_asprintf(const void *t, const char *fmt, ...) PRINTF_ATTRIBUTE(2,3);
1449 * @brief Append a formatted string to another string.
1451 * This function appends the given formatted string to the given string. Use
1452 * this varient when the string in the current talloc buffer may have been
1453 * truncated in length.
1455 * This functions sets the name of the new pointer to the new
1456 * string. This is equivalent to:
1459 * talloc_set_name_const(ptr, ptr)
1462 * @param[in] s The string to append to.
1464 * @param[in] fmt The format string.
1466 * @param[in] ... The parameters used to fill fmt.
1468 * @return The formatted string, NULL on error.
1470 char *talloc_asprintf_append(char *s, const char *fmt, ...) PRINTF_ATTRIBUTE(2,3);
1473 * @brief Append a formatted string to another string.
1475 * @param[in] s The string to append to
1477 * @param[in] fmt The format string.
1479 * @param[in] ... The parameters used to fill fmt.
1481 * @return The formatted string, NULL on error.
1483 char *talloc_asprintf_append_buffer(char *s, const char *fmt, ...) PRINTF_ATTRIBUTE(2,3);
1485 /* @} ******************************************************************/
1488 * @defgroup talloc_debug The talloc debugging support functions
1491 * To aid memory debugging, talloc contains routines to inspect the currently
1492 * allocated memory hierarchy.
1498 * @brief Walk a complete talloc hierarchy.
1500 * This provides a more flexible reports than talloc_report(). It
1501 * will recursively call the callback for the entire tree of memory
1502 * referenced by the pointer. References in the tree are passed with
1503 * is_ref = 1 and the pointer that is referenced.
1505 * You can pass NULL for the pointer, in which case a report is
1506 * printed for the top level memory context, but only if
1507 * talloc_enable_leak_report() or talloc_enable_leak_report_full()
1510 * The recursion is stopped when depth >= max_depth.
1511 * max_depth = -1 means only stop at leaf nodes.
1513 * @param[in] ptr The talloc chunk.
1515 * @param[in] depth Internal parameter to control recursion. Call with 0.
1517 * @param[in] max_depth Maximum recursion level.
1519 * @param[in] callback Function to be called on every chunk.
1521 * @param[in] private_data Private pointer passed to callback.
1523 void talloc_report_depth_cb(const void *ptr, int depth, int max_depth,
1524 void (*callback)(const void *ptr,
1525 int depth, int max_depth,
1527 void *private_data),
1528 void *private_data);
1531 * @brief Print a talloc hierarchy.
1533 * This provides a more flexible reports than talloc_report(). It
1534 * will let you specify the depth and max_depth.
1536 * @param[in] ptr The talloc chunk.
1538 * @param[in] depth Internal parameter to control recursion. Call with 0.
1540 * @param[in] max_depth Maximum recursion level.
1542 * @param[in] f The file handle to print to.
1544 void talloc_report_depth_file(const void *ptr, int depth, int max_depth, FILE *f);
1547 * @brief Print a summary report of all memory used by ptr.
1549 * This provides a more detailed report than talloc_report(). It will
1550 * recursively print the ensire tree of memory referenced by the
1551 * pointer. References in the tree are shown by giving the name of the
1552 * pointer that is referenced.
1554 * You can pass NULL for the pointer, in which case a report is printed
1555 * for the top level memory context, but only if
1556 * talloc_enable_leak_report() or talloc_enable_leak_report_full() has
1559 * @param[in] ptr The talloc chunk.
1561 * @param[in] f The file handle to print to.
1565 * unsigned int *a, *b;
1566 * a = talloc(NULL, unsigned int);
1567 * b = talloc(a, unsigned int);
1568 * fprintf(stderr, "Dumping memory tree for a:\n");
1569 * talloc_report_full(a, stderr);
1572 * @see talloc_report()
1574 void talloc_report_full(const void *ptr, FILE *f);
1577 * @brief Print a summary report of all memory used by ptr.
1579 * This function prints a summary report of all memory used by ptr. One line of
1580 * report is printed for each immediate child of ptr, showing the total memory
1581 * and number of blocks used by that child.
1583 * You can pass NULL for the pointer, in which case a report is printed
1584 * for the top level memory context, but only if talloc_enable_leak_report()
1585 * or talloc_enable_leak_report_full() has been called.
1587 * @param[in] ptr The talloc chunk.
1589 * @param[in] f The file handle to print to.
1593 * unsigned int *a, *b;
1594 * a = talloc(NULL, unsigned int);
1595 * b = talloc(a, unsigned int);
1596 * fprintf(stderr, "Summary of memory tree for a:\n");
1597 * talloc_report(a, stderr);
1600 * @see talloc_report_full()
1602 void talloc_report(const void *ptr, FILE *f);
1605 * @brief Enable tracking the use of NULL memory contexts.
1607 * This enables tracking of the NULL memory context without enabling leak
1608 * reporting on exit. Useful for when you want to do your own leak
1609 * reporting call via talloc_report_null_full();
1611 void talloc_enable_null_tracking(void);
1614 * @brief Enable tracking the use of NULL memory contexts.
1616 * This enables tracking of the NULL memory context without enabling leak
1617 * reporting on exit. Useful for when you want to do your own leak
1618 * reporting call via talloc_report_null_full();
1620 void talloc_enable_null_tracking_no_autofree(void);
1623 * @brief Disable tracking of the NULL memory context.
1625 * This disables tracking of the NULL memory context.
1627 void talloc_disable_null_tracking(void);
1630 * @brief Enable leak report when a program exits.
1632 * This enables calling of talloc_report(NULL, stderr) when the program
1633 * exits. In Samba4 this is enabled by using the --leak-report command
1636 * For it to be useful, this function must be called before any other
1637 * talloc function as it establishes a "null context" that acts as the
1638 * top of the tree. If you don't call this function first then passing
1639 * NULL to talloc_report() or talloc_report_full() won't give you the
1640 * full tree printout.
1642 * Here is a typical talloc report:
1645 * talloc report on 'null_context' (total 267 bytes in 15 blocks)
1646 * libcli/auth/spnego_parse.c:55 contains 31 bytes in 2 blocks
1647 * libcli/auth/spnego_parse.c:55 contains 31 bytes in 2 blocks
1648 * iconv(UTF8,CP850) contains 42 bytes in 2 blocks
1649 * libcli/auth/spnego_parse.c:55 contains 31 bytes in 2 blocks
1650 * iconv(CP850,UTF8) contains 42 bytes in 2 blocks
1651 * iconv(UTF8,UTF-16LE) contains 45 bytes in 2 blocks
1652 * iconv(UTF-16LE,UTF8) contains 45 bytes in 2 blocks
1655 void talloc_enable_leak_report(void);
1658 * @brief Enable full leak report when a program exits.
1660 * This enables calling of talloc_report_full(NULL, stderr) when the
1661 * program exits. In Samba4 this is enabled by using the
1662 * --leak-report-full command line option.
1664 * For it to be useful, this function must be called before any other
1665 * talloc function as it establishes a "null context" that acts as the
1666 * top of the tree. If you don't call this function first then passing
1667 * NULL to talloc_report() or talloc_report_full() won't give you the
1668 * full tree printout.
1670 * Here is a typical full report:
1673 * full talloc report on 'root' (total 18 bytes in 8 blocks)
1674 * p1 contains 18 bytes in 7 blocks (ref 0)
1675 * r1 contains 13 bytes in 2 blocks (ref 0)
1677 * p2 contains 1 bytes in 1 blocks (ref 1)
1678 * x3 contains 1 bytes in 1 blocks (ref 0)
1679 * x2 contains 1 bytes in 1 blocks (ref 0)
1680 * x1 contains 1 bytes in 1 blocks (ref 0)
1683 void talloc_enable_leak_report_full(void);
1685 /* @} ******************************************************************/
1687 void talloc_set_abort_fn(void (*abort_fn)(const char *reason));
1688 void talloc_set_log_fn(void (*log_fn)(const char *message));
1689 void talloc_set_log_stderr(void);
1691 #if TALLOC_DEPRECATED
1692 #define talloc_zero_p(ctx, type) talloc_zero(ctx, type)
1693 #define talloc_p(ctx, type) talloc(ctx, type)
1694 #define talloc_array_p(ctx, type, count) talloc_array(ctx, type, count)
1695 #define talloc_realloc_p(ctx, p, type, count) talloc_realloc(ctx, p, type, count)
1696 #define talloc_destroy(ctx) talloc_free(ctx)
1697 #define talloc_append_string(c, s, a) (s?talloc_strdup_append(s,a):talloc_strdup(c, a))
1700 #ifndef TALLOC_MAX_DEPTH
1701 #define TALLOC_MAX_DEPTH 10000