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.
31 * tal_count() of the return will be 1.
34 * int *p = tal(NULL, int);
37 #define tal(ctx, type) \
38 tal_label(ctx, type, TAL_LABEL(type, ""))
41 * talz - zeroing allocator function
42 * @ctx: NULL, or tal allocated object to be parent.
43 * @type: the type to allocate.
45 * Equivalent to tal() followed by memset() to zero.
48 * p = talz(NULL, int);
51 #define talz(ctx, type) \
52 talz_label(ctx, type, TAL_LABEL(type, ""))
55 * tal_free - free a tal-allocated pointer.
56 * @p: NULL, or tal allocated object to free.
58 * This calls the destructors for p (if any), then does the same for all its
59 * children (recursively) before finally freeing the memory. It returns
60 * NULL, for convenience.
62 * Note: errno is preserved by this call, and also saved and restored
63 * for any destructors or notifiers.
68 void *tal_free(const tal_t *p);
71 * tal_arr - allocate an array of objects.
72 * @ctx: NULL, or tal allocated object to be parent.
73 * @type: the type to allocate.
74 * @count: the number to allocate.
76 * tal_count() of the returned pointer will be @count.
79 * p = tal_arr(NULL, int, 2);
83 #define tal_arr(ctx, type, count) \
84 tal_arr_label(ctx, type, count, 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 * Equivalent to tal_arr() followed by memset() to zero.
95 * p = tal_arrz(NULL, int, 2);
96 * assert(p[0] == 0 && p[1] == 0);
98 #define tal_arrz(ctx, type, count) \
99 tal_arrz_label(ctx, type, count, TAL_LABEL(type, "[]"))
102 * tal_resize - enlarge or reduce a tal object.
103 * @p: A pointer to the tal allocated array to resize.
104 * @count: the number to allocate.
106 * This returns true on success (and may move *@p), or false on failure.
107 * On success, tal_count() of *@p will be @count.
109 * Note: if *p is take(), it will still be take() upon return, even if it
113 * tal_resize(&p, 100);
115 #define tal_resize(p, count) \
116 tal_resize_((void **)(p), sizeof**(p), (count), false)
119 * tal_resizez - enlarge or reduce a tal object; zero out extra.
120 * @p: A pointer to the tal allocated array to resize.
121 * @count: the number to allocate.
123 * This returns true on success (and may move *@p), or false on failure.
126 * tal_resizez(&p, 200);
128 #define tal_resizez(p, count) \
129 tal_resize_((void **)(p), sizeof**(p), (count), true)
132 * tal_steal - change the parent of a tal-allocated pointer.
133 * @ctx: The new parent.
134 * @ptr: The tal allocated object to move, or NULL.
136 * This may need to perform an allocation, in which case it may fail; thus
137 * it can return NULL, otherwise returns @ptr. If @ptr is NULL, this function does
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
168 * false. Note that if we're inside the destructor call itself, this will
171 #define tal_del_destructor(ptr, function) \
172 tal_del_destructor_((ptr), typesafe_cb(void, void *, (function), (ptr)))
175 * tal_add_destructor2 - add a 2-arg callback function when context is destroyed.
176 * @ptr: The tal allocated object.
177 * @function: the function to call before it's freed.
178 * @arg: the extra argument to the function.
180 * Sometimes an extra argument is required for a destructor; this
181 * saves the extra argument internally to avoid the caller having to
182 * do an extra allocation.
184 * Note that this can only fail if your allocfn fails and your errorfn returns.
186 #define tal_add_destructor2(ptr, function, arg) \
187 tal_add_destructor2_((ptr), \
188 typesafe_cb_cast(void (*)(tal_t *, void *), \
189 void (*)(__typeof__(ptr), \
195 * tal_del_destructor - remove a destructor callback function.
196 * @ptr: The tal allocated object.
197 * @function: the function to call before it's freed.
199 * If @function has not been successfully added as a destructor, this returns
200 * false. Note that if we're inside the destructor call itself, this will
203 #define tal_del_destructor(ptr, function) \
204 tal_del_destructor_((ptr), typesafe_cb(void, void *, (function), (ptr)))
207 * tal_del_destructor2 - remove 2-arg callback function.
208 * @ptr: The tal allocated object.
209 * @function: the function to call before it's freed.
210 * @arg: the extra argument to the function.
212 * If @function has not been successfully added as a destructor with
213 * @arg, this returns false.
215 #define tal_del_destructor2(ptr, function, arg) \
216 tal_del_destructor2_((ptr), \
217 typesafe_cb_cast(void (*)(tal_t *, void *), \
218 void (*)(__typeof__(ptr), \
222 enum tal_notify_type {
224 TAL_NOTIFY_STEAL = 2,
226 TAL_NOTIFY_RESIZE = 8,
227 TAL_NOTIFY_RENAME = 16,
228 TAL_NOTIFY_ADD_CHILD = 32,
229 TAL_NOTIFY_DEL_CHILD = 64,
230 TAL_NOTIFY_ADD_NOTIFIER = 128,
231 TAL_NOTIFY_DEL_NOTIFIER = 256
235 * tal_add_notifier - add a callback function when this context changes.
236 * @ptr: The tal allocated object, or NULL.
237 * @types: Bitwise OR of the types the callback is interested in.
238 * @callback: the function to call.
240 * Note that this can only fail if your allocfn fails and your errorfn
241 * returns. Also note that notifiers are not reliable in the case
242 * where an allocation fails, as they may be called before any
243 * allocation is actually done.
245 * TAL_NOTIFY_FREE is called when @ptr is freed, either directly or
246 * because an ancestor is freed: @info is the argument to tal_free().
247 * It is exactly equivalent to a destructor, with more information.
248 * errno is set to the value it was at the call of tal_free().
250 * TAL_NOTIFY_STEAL is called when @ptr's parent changes: @info is the
253 * TAL_NOTIFY_MOVE is called when @ptr is realloced (via tal_resize)
254 * and moved. In this case, @ptr arg here is the new memory, and
255 * @info is the old pointer.
257 * TAL_NOTIFY_RESIZE is called when @ptr is realloced via tal_resize:
258 * @info is the new size, in bytes. If the pointer has moved,
259 * TAL_NOTIFY_MOVE callbacks are called first.
261 * TAL_NOTIFY_ADD_CHILD/TAL_NOTIFY_DEL_CHILD are called when @ptr is
262 * the context for a tal() allocating call, or a direct child is
263 * tal_free()d: @info is the child. Note that TAL_NOTIFY_DEL_CHILD is
264 * not called when this context is tal_free()d: TAL_NOTIFY_FREE is
265 * considered sufficient for that case.
267 * TAL_NOTIFY_ADD_NOTIFIER/TAL_NOTIFIER_DEL_NOTIFIER are called when a
268 * notifier is added or removed (not for this notifier): @info is the
269 * callback. This is also called for tal_add_destructor and
270 * tal_del_destructor.
272 #define tal_add_notifier(ptr, types, callback) \
273 tal_add_notifier_((ptr), (types), \
274 typesafe_cb_postargs(void, tal_t *, (callback), \
276 enum tal_notify_type, void *))
279 * tal_del_notifier - remove a notifier callback function.
280 * @ptr: The tal allocated object.
281 * @callback: the function to call.
283 #define tal_del_notifier(ptr, callback) \
284 tal_del_notifier_((ptr), \
285 typesafe_cb_postargs(void, void *, (callback), \
287 enum tal_notify_type, void *), \
291 * tal_set_name - attach a name to a tal pointer.
292 * @ptr: The tal allocated object.
293 * @name: The name to use.
295 * The name is copied, unless we're certain it's a string literal.
297 #define tal_set_name(ptr, name) \
298 tal_set_name_((ptr), (name), TAL_IS_LITERAL(name))
301 * tal_name - get the name for a tal pointer.
302 * @ptr: The tal allocated object.
304 * Returns NULL if no name has been set.
306 const char *tal_name(const tal_t *ptr);
309 * tal_count - get the count of objects in a tal object.
310 * @ptr: The tal allocated object (or NULL)
312 * Returns 0 if @ptr is NULL. Note that if the allocation was done as a
313 * different type to @ptr, the result may not match the @count argument
314 * (or implied 1) of that allocation!
316 #define tal_count(p) (tal_bytelen(p) / sizeof(*p))
319 * tal_bytelen - get the count of bytes in a tal object.
320 * @ptr: The tal allocated object (or NULL)
322 * Returns 0 if @ptr is NULL.
324 size_t tal_bytelen(const tal_t *ptr);
327 * tal_first - get the first immediate tal object child.
328 * @root: The tal allocated object to start with, or NULL.
330 * Returns NULL if there are no children.
332 tal_t *tal_first(const tal_t *root);
335 * tal_next - get the next immediate tal object child.
336 * @prev: The return value from tal_first or tal_next.
338 * Returns NULL if there are no more immediate children. This should be safe to
339 * call on an altering tree unless @prev is no longer valid.
341 tal_t *tal_next(const tal_t *prev);
344 * tal_parent - get the parent of a tal object.
345 * @ctx: The tal allocated object.
347 * Returns the parent, which may be NULL. Returns NULL if @ctx is NULL.
349 tal_t *tal_parent(const tal_t *ctx);
352 * tal_dup - duplicate an object.
353 * @ctx: The tal allocated object to be parent of the result (may be NULL).
354 * @type: the type (should match type of @p!)
355 * @p: the object to copy (or reparented if take()). Must not be NULL.
357 #define tal_dup(ctx, type, p) \
358 tal_dup_label(ctx, type, p, TAL_LABEL(type, ""), false)
361 * tal_dup_or_null - duplicate an object, or just pass NULL.
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 object to copy (or reparented if take())
366 * if @p is NULL, just return NULL, otherwise to tal_dup().
368 #define tal_dup_or_null(ctx, type, p) \
369 tal_dup_label(ctx, type, p, TAL_LABEL(type, ""), true)
372 * tal_dup_arr - duplicate an array.
373 * @ctx: The tal allocated object to be parent of the result (may be NULL).
374 * @type: the type (should match type of @p!)
375 * @p: the array to copy (or resized & reparented if take())
376 * @n: the number of sizeof(type) entries to copy.
377 * @extra: the number of extra sizeof(type) entries to allocate.
379 #define tal_dup_arr(ctx, type, p, n, extra) \
380 tal_dup_arr_label(ctx, type, p, n, extra, TAL_LABEL(type, "[]"))
384 * tal_dup_arr - duplicate a tal array.
385 * @ctx: The tal allocated object to be parent of the result (may be NULL).
386 * @type: the type (should match type of @p!)
387 * @p: the tal array to copy (or resized & reparented if take())
389 * The comon case of duplicating an entire tal array.
391 #define tal_dup_talarr(ctx, type, p) \
392 ((type *)tal_dup_talarr_((ctx), tal_typechk_(p, type *), \
393 TAL_LABEL(type, "[]")))
394 /* Lower-level interfaces, where you want to supply your own label string. */
395 #define tal_label(ctx, type, label) \
396 ((type *)tal_alloc_((ctx), sizeof(type), false, label))
397 #define talz_label(ctx, type, label) \
398 ((type *)tal_alloc_((ctx), sizeof(type), true, label))
399 #define tal_arr_label(ctx, type, count, label) \
400 ((type *)tal_alloc_arr_((ctx), sizeof(type), (count), false, label))
401 #define tal_arrz_label(ctx, type, count, label) \
402 ((type *)tal_alloc_arr_((ctx), sizeof(type), (count), true, label))
403 #define tal_dup_label(ctx, type, p, label, nullok) \
404 ((type *)tal_dup_((ctx), tal_typechk_(p, type *), \
405 sizeof(type), 1, 0, nullok, \
407 #define tal_dup_arr_label(ctx, type, p, n, extra, label) \
408 ((type *)tal_dup_((ctx), tal_typechk_(p, type *), \
409 sizeof(type), (n), (extra), false, \
413 * tal_set_backend - set the allocation or error functions to use
414 * @alloc_fn: allocator or NULL (default is malloc)
415 * @resize_fn: re-allocator or NULL (default is realloc)
416 * @free_fn: free function or NULL (default is free)
417 * @error_fn: called on errors or NULL (default is abort)
419 * The defaults are set up so tal functions never return NULL, but you
420 * can override erorr_fn to change that. error_fn can return, and is
421 * called if alloc_fn or resize_fn fail.
423 * If any parameter is NULL, that function is unchanged.
425 void tal_set_backend(void *(*alloc_fn)(size_t size),
426 void *(*resize_fn)(void *, size_t size),
427 void (*free_fn)(void *),
428 void (*error_fn)(const char *msg));
431 * tal_expand - expand a tal array with contents.
432 * @a1p: a pointer to the tal array to expand.
433 * @a2: the second array (can be take()).
434 * @num2: the number of elements in the second array.
436 * Note that *@a1 and @a2 should be the same type. tal_count(@a1) will
437 * be increased by @num2.
440 * int *arr1 = tal_arrz(NULL, int, 2);
441 * int arr2[2] = { 1, 3 };
443 * tal_expand(&arr1, arr2, 2);
444 * assert(tal_count(arr1) == 4);
445 * assert(arr1[2] == 1);
446 * assert(arr1[3] == 3);
448 #define tal_expand(a1p, a2, num2) \
449 tal_expand_((void **)(a1p), (a2), sizeof**(a1p), \
450 (num2) + 0*sizeof(*(a1p) == (a2)))
453 * tal_cleanup - remove pointers from NULL node
455 * Internally, tal keeps a list of nodes allocated from @ctx NULL; this
456 * prevents valgrind from noticing memory leaks. This re-initializes
457 * that list to empty.
459 * It also calls take_cleanup() for you.
461 void tal_cleanup(void);
465 * tal_check - sanity check a tal context and its children.
466 * @ctx: a tal context, or NULL.
467 * @errorstr: a string to prepend calls to error_fn, or NULL.
469 * This sanity-checks a tal tree (unless NDEBUG is defined, in which case
470 * it simply returns true). If errorstr is not null, error_fn is called
471 * when a problem is found, otherwise it is not.
476 bool tal_check(const tal_t *ctx, const char *errorstr);
478 #ifdef CCAN_TAL_DEBUG
480 * tal_dump - dump entire tal tree to stderr.
482 * This is a helper for debugging tal itself, which dumps all the tal internal
488 /* Internal support functions */
490 #ifdef CCAN_TAL_NO_LABELS
491 #define TAL_LABEL(type, arr) NULL
493 #ifdef CCAN_TAL_DEBUG
494 #define TAL_LABEL(type, arr) \
495 __FILE__ ":" stringify(__LINE__) ":" stringify(type) arr
497 #define TAL_LABEL(type, arr) stringify(type) arr
498 #endif /* CCAN_TAL_DEBUG */
502 #if HAVE_BUILTIN_CONSTANT_P
503 #define TAL_IS_LITERAL(str) __builtin_constant_p(str)
505 #define TAL_IS_LITERAL(str) (sizeof(&*(str)) != sizeof(char *))
508 bool tal_set_name_(tal_t *ctx, const char *name, bool literal);
511 #define tal_typeof(ptr) (__typeof__(ptr))
512 #if HAVE_STATEMENT_EXPR
513 /* Careful: ptr can be const foo *, ptype is foo *. Also, ptr could
514 * be an array, eg "hello". */
515 #define tal_typechk_(ptr, ptype) ({ __typeof__((ptr)+0) _p = (ptype)(ptr); _p; })
517 #define tal_typechk_(ptr, ptype) (ptr)
519 #else /* !HAVE_TYPEOF */
520 #define tal_typeof(ptr)
521 #define tal_typechk_(ptr, ptype) (ptr)
524 void *tal_alloc_(const tal_t *ctx, size_t bytes, bool clear, const char *label);
525 void *tal_alloc_arr_(const tal_t *ctx, size_t bytes, size_t count, bool clear,
528 void *tal_dup_(const tal_t *ctx, const void *p TAKES, size_t size,
529 size_t n, size_t extra, bool nullok, const char *label);
530 void *tal_dup_talarr_(const tal_t *ctx, const tal_t *src TAKES,
533 tal_t *tal_steal_(const tal_t *new_parent, const tal_t *t);
535 bool tal_resize_(tal_t **ctxp, size_t size, size_t count, bool clear);
536 bool tal_expand_(tal_t **ctxp, const void *src TAKES, size_t size, size_t count);
538 bool tal_add_destructor_(const tal_t *ctx, void (*destroy)(void *me));
539 bool tal_add_destructor2_(const tal_t *ctx, void (*destroy)(void *me, void *arg),
541 bool tal_del_destructor_(const tal_t *ctx, void (*destroy)(void *me));
542 bool tal_del_destructor2_(const tal_t *ctx, void (*destroy)(void *me, void *arg),
545 bool tal_add_notifier_(const tal_t *ctx, enum tal_notify_type types,
546 void (*notify)(tal_t *ctx, enum tal_notify_type,
548 bool tal_del_notifier_(const tal_t *ctx,
549 void (*notify)(tal_t *ctx, enum tal_notify_type,
551 bool match_extra_arg, void *arg);
552 #endif /* CCAN_TAL_H */