1 /* Licensed under BSD-MIT - see LICENSE file for details */
5 #include <ccan/compiler/compiler.h>
6 #include <ccan/likely/likely.h>
7 #include <ccan/typesafe_cb/typesafe_cb.h>
8 #include <ccan/str/str.h>
9 #include <ccan/take/take.h>
15 * tal_t - convenient alias for void to mark tal pointers.
17 * Since any pointer can be a tal-allocated pointer, it's often
18 * useful to use this typedef to mark them explicitly.
23 * tal - basic allocator function
24 * @ctx: NULL, or tal allocated object to be parent.
25 * @type: the type to allocate.
27 * Allocates a specific type, with a given parent context. The name
28 * of the object is a string of the type, but if CCAN_TAL_DEBUG is
29 * defined it also contains the file and line which allocated it.
32 * int *p = tal(NULL, int);
35 #define tal(ctx, type) \
36 ((type *)tal_alloc_((ctx), sizeof(type), false, false, TAL_LABEL(type, "")))
39 * talz - zeroing allocator function
40 * @ctx: NULL, or tal allocated object to be parent.
41 * @type: the type to allocate.
43 * Equivalent to tal() followed by memset() to zero.
46 * p = talz(NULL, int);
49 #define talz(ctx, type) \
50 ((type *)tal_alloc_((ctx), sizeof(type), true, false, TAL_LABEL(type, "")))
53 * tal_free - free a tal-allocated pointer.
54 * @p: NULL, or tal allocated object to free.
56 * This calls the destructors for p (if any), then does the same for all its
57 * children (recursively) before finally freeing the memory. It returns
58 * NULL, for convenience.
60 * Note: errno is preserved by this call, and also saved and restored
61 * for any destructors or notifiers.
66 void *tal_free(const tal_t *p);
69 * tal_arr - allocate an array of objects.
70 * @ctx: NULL, or tal allocated object to be parent.
71 * @type: the type to allocate.
72 * @count: the number to allocate.
74 * Note that an object allocated with tal_arr() has a length property;
78 * p = tal_arr(NULL, int, 2);
82 #define tal_arr(ctx, type, count) \
83 ((type *)tal_alloc_arr_((ctx), sizeof(type), (count), false, \
84 true, TAL_LABEL(type, "[]")))
87 * tal_arrz - allocate an array of zeroed objects.
88 * @ctx: NULL, or tal allocated object to be parent.
89 * @type: the type to allocate.
90 * @count: the number to allocate.
92 * Note that an object allocated with tal_arrz() has a length property;
96 * p = tal_arrz(NULL, int, 2);
97 * assert(p[0] == 0 && p[1] == 0);
99 #define tal_arrz(ctx, type, count) \
100 ((type *)tal_alloc_arr_((ctx), sizeof(type), (count), true, \
101 true, TAL_LABEL(type, "[]")))
104 * tal_resize - enlarge or reduce a tal_arr[z].
105 * @p: A pointer to the tal allocated array to resize.
106 * @count: the number to allocate.
108 * This returns true on success (and may move *@p), or false on failure.
109 * If @p has a length property, it is updated on success.
112 * tal_resize(&p, 100);
114 #define tal_resize(p, count) \
115 tal_resize_((void **)(p), sizeof**(p), (count), false)
118 * tal_resizez - enlarge or reduce a tal_arr[z]; zero out extra.
119 * @p: A pointer to the tal allocated array to resize.
120 * @count: the number to allocate.
122 * This returns true on success (and may move *@p), or false on failure.
123 * If @p has a length property, it is updated on success.
124 * On expand, new elements are memset to 0 bytes.
127 * tal_resizez(&p, 200);
129 #define tal_resizez(p, count) \
130 tal_resize_((void **)(p), sizeof**(p), (count), true)
133 * tal_steal - change the parent of a tal-allocated pointer.
134 * @ctx: The new parent.
135 * @ptr: The tal allocated object to move.
137 * This may need to perform an allocation, in which case it may fail; thus
138 * it can return NULL, otherwise returns @ptr.
140 #if HAVE_STATEMENT_EXPR
141 /* Weird macro avoids gcc's 'warning: value computed is not used'. */
142 #define tal_steal(ctx, ptr) \
143 ({ (tal_typeof(ptr) tal_steal_((ctx),(ptr))); })
145 #define tal_steal(ctx, ptr) \
146 (tal_typeof(ptr) tal_steal_((ctx),(ptr)))
150 * tal_add_destructor - add a callback function when this context is destroyed.
151 * @ptr: The tal allocated object.
152 * @function: the function to call before it's freed.
154 * This is a more convenient form of tal_add_notifier(@ptr,
155 * TAL_NOTIFY_FREE, ...), in that the function prototype takes only @ptr.
157 * Note that this can only fail if your allocfn fails and your errorfn returns.
159 #define tal_add_destructor(ptr, function) \
160 tal_add_destructor_((ptr), typesafe_cb(void, void *, (function), (ptr)))
163 * tal_del_destructor - remove a destructor callback function.
164 * @ptr: The tal allocated object.
165 * @function: the function to call before it's freed.
167 * If @function has not been successfully added as a destructor, this returns
170 #define tal_del_destructor(ptr, function) \
171 tal_del_destructor_((ptr), typesafe_cb(void, void *, (function), (ptr)))
174 * tal_add_destructor2 - add a 2-arg callback function when context is destroyed.
175 * @ptr: The tal allocated object.
176 * @function: the function to call before it's freed.
177 * @arg: the extra argument to the function.
179 * Sometimes an extra argument is required for a destructor; this
180 * saves the extra argument internally to avoid the caller having to
181 * do an extra allocation.
183 * Note that this can only fail if your allocfn fails and your errorfn returns.
185 #define tal_add_destructor2(ptr, function, arg) \
186 tal_add_destructor2_((ptr), \
187 typesafe_cb_cast(void (*)(tal_t *, void *), \
188 void (*)(__typeof__(ptr), \
194 * tal_del_destructor - remove a destructor callback function.
195 * @ptr: The tal allocated object.
196 * @function: the function to call before it's freed.
198 * If @function has not been successfully added as a destructor, this returns
201 #define tal_del_destructor(ptr, function) \
202 tal_del_destructor_((ptr), typesafe_cb(void, void *, (function), (ptr)))
205 * tal_del_destructor2 - remove 2-arg callback function.
206 * @ptr: The tal allocated object.
207 * @function: the function to call before it's freed.
208 * @arg: the extra argument to the function.
210 * If @function has not been successfully added as a destructor with
211 * @arg, this returns false.
213 #define tal_del_destructor2(ptr, function, arg) \
214 tal_del_destructor2_((ptr), \
215 typesafe_cb_cast(void (*)(tal_t *, void *), \
216 void (*)(__typeof__(ptr), \
220 enum tal_notify_type {
222 TAL_NOTIFY_STEAL = 2,
224 TAL_NOTIFY_RESIZE = 8,
225 TAL_NOTIFY_RENAME = 16,
226 TAL_NOTIFY_ADD_CHILD = 32,
227 TAL_NOTIFY_DEL_CHILD = 64,
228 TAL_NOTIFY_ADD_NOTIFIER = 128,
229 TAL_NOTIFY_DEL_NOTIFIER = 256
233 * tal_add_notifier - add a callback function when this context changes.
234 * @ptr: The tal allocated object.
235 * @types: Bitwise OR of the types the callback is interested in.
236 * @callback: the function to call.
238 * Note that this can only fail if your allocfn fails and your errorfn
239 * returns. Also note that notifiers are not reliable in the case
240 * where an allocation fails, as they may be called before any
241 * allocation is actually done.
243 * TAL_NOTIFY_FREE is called when @ptr is freed, either directly or
244 * because an ancestor is freed: @info is the argument to tal_free().
245 * It is exactly equivalent to a destructor, with more information.
246 * errno is set to the value it was at the call of tal_free().
248 * TAL_NOTIFY_STEAL is called when @ptr's parent changes: @info is the
251 * TAL_NOTIFY_MOVE is called when @ptr is realloced (via tal_resize)
252 * and moved. In this case, @ptr arg here is the new memory, and
253 * @info is the old pointer.
255 * TAL_NOTIFY_RESIZE is called when @ptr is realloced via tal_resize:
256 * @info is the new size, in bytes. If the pointer has moved,
257 * TAL_NOTIFY_MOVE callbacks are called first.
259 * TAL_NOTIFY_ADD_CHILD/TAL_NOTIFY_DEL_CHILD are called when @ptr is
260 * the context for a tal() allocating call, or a direct child is
261 * tal_free()d: @info is the child. Note that TAL_NOTIFY_DEL_CHILD is
262 * not called when this context is tal_free()d: TAL_NOTIFY_FREE is
263 * considered sufficient for that case.
265 * TAL_NOTIFY_ADD_NOTIFIER/TAL_NOTIFIER_DEL_NOTIFIER are called when a
266 * notifier is added or removed (not for this notifier): @info is the
267 * callback. This is also called for tal_add_destructor and
268 * tal_del_destructor.
270 #define tal_add_notifier(ptr, types, callback) \
271 tal_add_notifier_((ptr), (types), \
272 typesafe_cb_postargs(void, tal_t *, (callback), \
274 enum tal_notify_type, void *))
277 * tal_del_notifier - remove a notifier callback function.
278 * @ptr: The tal allocated object.
279 * @callback: the function to call.
281 #define tal_del_notifier(ptr, callback) \
282 tal_del_notifier_((ptr), \
283 typesafe_cb_postargs(void, void *, (callback), \
285 enum tal_notify_type, void *), \
289 * tal_set_name - attach a name to a tal pointer.
290 * @ptr: The tal allocated object.
291 * @name: The name to use.
293 * The name is copied, unless we're certain it's a string literal.
295 #define tal_set_name(ptr, name) \
296 tal_set_name_((ptr), (name), TAL_IS_LITERAL(name))
299 * tal_name - get the name for a tal pointer.
300 * @ptr: The tal allocated object.
302 * Returns NULL if no name has been set.
304 const char *tal_name(const tal_t *ptr);
307 * tal_count - get the count of objects in a tal_arr.
308 * @ptr: The tal allocated object array (or NULL)
310 * Returns 0 if @ptr has no length property or is NULL, but be aware
311 * that that is also a valid size!
313 #define tal_count(p) (tal_len(p) / sizeof(*p))
316 * tal_len - get the count of bytes in a tal_arr.
317 * @ptr: The tal allocated object array (or NULL)
319 * Returns 0 if @ptr has no length property or NULL, but be aware that that is
322 size_t tal_len(const tal_t *ptr);
325 * tal_first - get the first immediate tal object child.
326 * @root: The tal allocated object to start with, or NULL.
328 * Returns NULL if there are no children.
330 tal_t *tal_first(const tal_t *root);
333 * tal_next - get the next immediate tal object child.
334 * @prev: The return value from tal_first or tal_next.
336 * Returns NULL if there are no more immediate children. This should be safe to
337 * call on an altering tree unless @prev is no longer valid.
339 tal_t *tal_next(const tal_t *prev);
342 * tal_parent - get the parent of a tal object.
343 * @ctx: The tal allocated object.
345 * Returns the parent, which may be NULL. Returns NULL if @ctx is NULL.
347 tal_t *tal_parent(const tal_t *ctx);
350 * tal_dup - duplicate an object.
351 * @ctx: The tal allocated object to be parent of the result (may be NULL).
352 * @type: the type (should match type of @p!)
353 * @p: the object to copy (or reparented if take())
355 #define tal_dup(ctx, type, p) \
356 ((type *)tal_dup_((ctx), tal_typechk_(p, type *), \
357 sizeof(type), 1, 0, \
358 false, TAL_LABEL(type, "")))
361 * tal_dup_arr - duplicate an array.
362 * @ctx: The tal allocated object to be parent of the result (may be NULL).
363 * @type: the type (should match type of @p!)
364 * @p: the array to copy (or resized & reparented if take())
365 * @n: the number of sizeof(type) entries to copy.
366 * @extra: the number of extra sizeof(type) entries to allocate.
368 #define tal_dup_arr(ctx, type, p, n, extra) \
369 ((type *)tal_dup_((ctx), tal_typechk_(p, type *), \
370 sizeof(type), (n), (extra), \
371 true, TAL_LABEL(type, "[]")))
375 * tal_set_backend - set the allocation or error functions to use
376 * @alloc_fn: allocator or NULL (default is malloc)
377 * @resize_fn: re-allocator or NULL (default is realloc)
378 * @free_fn: free function or NULL (default is free)
379 * @error_fn: called on errors or NULL (default is abort)
381 * The defaults are set up so tal functions never return NULL, but you
382 * can override erorr_fn to change that. error_fn can return, and is
383 * called if alloc_fn or resize_fn fail.
385 * If any parameter is NULL, that function is unchanged.
387 void tal_set_backend(void *(*alloc_fn)(size_t size),
388 void *(*resize_fn)(void *, size_t size),
389 void (*free_fn)(void *),
390 void (*error_fn)(const char *msg));
393 * tal_expand - expand a tal array with contents.
394 * @a1p: a pointer to the tal array to expand.
395 * @a2: the second array (can be take()).
396 * @num2: the number of elements in the second array.
398 * Note that *@a1 and @a2 should be the same type. tal_count(@a1) will
399 * be increased by @num2.
402 * int *arr1 = tal_arrz(NULL, int, 2);
403 * int arr2[2] = { 1, 3 };
405 * tal_expand(&arr1, arr2, 2);
406 * assert(tal_count(arr1) == 4);
407 * assert(arr1[2] == 1);
408 * assert(arr1[3] == 3);
410 #define tal_expand(a1p, a2, num2) \
411 tal_expand_((void **)(a1p), (a2), sizeof**(a1p), \
412 (num2) + 0*sizeof(*(a1p) == (a2)))
415 * tal_cleanup - remove pointers from NULL node
417 * Internally, tal keeps a list of nodes allocated from @ctx NULL; this
418 * prevents valgrind from noticing memory leaks. This re-initializes
419 * that list to empty.
421 * It also calls take_cleanup() for you.
423 void tal_cleanup(void);
427 * tal_check - sanity check a tal context and its children.
428 * @ctx: a tal context, or NULL.
429 * @errorstr: a string to prepend calls to error_fn, or NULL.
431 * This sanity-checks a tal tree (unless NDEBUG is defined, in which case
432 * it simply returns true). If errorstr is not null, error_fn is called
433 * when a problem is found, otherwise it is not.
438 bool tal_check(const tal_t *ctx, const char *errorstr);
440 #ifdef CCAN_TAL_DEBUG
442 * tal_dump - dump entire tal tree.
444 * This is a helper for debugging tal itself, which dumps all the tal internal
450 /* Internal support functions */
452 #ifdef CCAN_TAL_NO_LABELS
453 #define TAL_LABEL(type, arr) NULL
455 #ifdef CCAN_TAL_DEBUG
456 #define TAL_LABEL(type, arr) \
457 __FILE__ ":" stringify(__LINE__) ":" stringify(type) arr
459 #define TAL_LABEL(type, arr) stringify(type) arr
460 #endif /* CCAN_TAL_DEBUG */
464 #if HAVE_BUILTIN_CONSTANT_P
465 #define TAL_IS_LITERAL(str) __builtin_constant_p(str)
467 #define TAL_IS_LITERAL(str) (sizeof(&*(str)) != sizeof(char *))
470 bool tal_set_name_(tal_t *ctx, const char *name, bool literal);
473 #define tal_typeof(ptr) (__typeof__(ptr))
474 #if HAVE_STATEMENT_EXPR
475 /* Careful: ptr can be const foo *, ptype is foo *. Also, ptr could
476 * be an array, eg "hello". */
477 #define tal_typechk_(ptr, ptype) ({ __typeof__((ptr)+0) _p = (ptype)(ptr); _p; })
479 #define tal_typechk_(ptr, ptype) (ptr)
481 #else /* !HAVE_TYPEOF */
482 #define tal_typeof(ptr)
483 #define tal_typechk_(ptr, ptype) (ptr)
486 void *tal_alloc_(const tal_t *ctx, size_t bytes, bool clear,
487 bool add_length, const char *label);
488 void *tal_alloc_arr_(const tal_t *ctx, size_t bytes, size_t count, bool clear,
489 bool add_length, const char *label);
491 void *tal_dup_(const tal_t *ctx, const void *p TAKES, size_t size,
492 size_t n, size_t extra, bool add_length,
495 tal_t *tal_steal_(const tal_t *new_parent, const tal_t *t);
497 bool tal_resize_(tal_t **ctxp, size_t size, size_t count, bool clear);
498 bool tal_expand_(tal_t **ctxp, const void *src TAKES, size_t size, size_t count);
500 bool tal_add_destructor_(const tal_t *ctx, void (*destroy)(void *me));
501 bool tal_add_destructor2_(const tal_t *ctx, void (*destroy)(void *me, void *arg),
503 bool tal_del_destructor_(const tal_t *ctx, void (*destroy)(void *me));
504 bool tal_del_destructor2_(const tal_t *ctx, void (*destroy)(void *me, void *arg),
507 bool tal_add_notifier_(const tal_t *ctx, enum tal_notify_type types,
508 void (*notify)(tal_t *ctx, enum tal_notify_type,
510 bool tal_del_notifier_(const tal_t *ctx,
511 void (*notify)(tal_t *ctx, enum tal_notify_type,
513 bool match_extra_arg, void *arg);
514 #endif /* CCAN_TAL_H */