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>
14 /* Define this for better optimization if you never override errfn
15 * to something tat returns */
16 #ifdef CCAN_TAL_NEVER_RETURN_NULL
17 #define TAL_RETURN_PTR RETURNS_NONNULL
19 #define TAL_RETURN_PTR
20 #endif /* CCAN_TAL_NEVER_RETURN_NULL */
23 * tal_t - convenient alias for void to mark tal pointers.
25 * Since any pointer can be a tal-allocated pointer, it's often
26 * useful to use this typedef to mark them explicitly.
31 * tal - basic allocator function
32 * @ctx: NULL, or tal allocated object to be parent.
33 * @type: the type to allocate.
35 * Allocates a specific type, with a given parent context. The name
36 * of the object is a string of the type, but if CCAN_TAL_DEBUG is
37 * defined it also contains the file and line which allocated it.
39 * tal_count() of the return will be 1.
42 * int *p = tal(NULL, int);
45 #define tal(ctx, type) \
46 tal_label(ctx, type, TAL_LABEL(type, ""))
49 * talz - zeroing allocator function
50 * @ctx: NULL, or tal allocated object to be parent.
51 * @type: the type to allocate.
53 * Equivalent to tal() followed by memset() to zero.
56 * p = talz(NULL, int);
59 #define talz(ctx, type) \
60 talz_label(ctx, type, TAL_LABEL(type, ""))
63 * tal_free - free a tal-allocated pointer.
64 * @p: NULL, or tal allocated object to free.
66 * This calls the destructors for p (if any), then does the same for all its
67 * children (recursively) before finally freeing the memory. It returns
68 * NULL, for convenience.
70 * Note: errno is preserved by this call, and also saved and restored
71 * for any destructors or notifiers.
76 void *tal_free(const tal_t *p);
79 * tal_arr - allocate an array of objects.
80 * @ctx: NULL, or tal allocated object to be parent.
81 * @type: the type to allocate.
82 * @count: the number to allocate.
84 * tal_count() of the returned pointer will be @count.
87 * p = tal_arr(NULL, int, 2);
91 #define tal_arr(ctx, type, count) \
92 tal_arr_label(ctx, type, count, TAL_LABEL(type, "[]"))
95 * tal_arrz - allocate an array of zeroed objects.
96 * @ctx: NULL, or tal allocated object to be parent.
97 * @type: the type to allocate.
98 * @count: the number to allocate.
100 * Equivalent to tal_arr() followed by memset() to zero.
103 * p = tal_arrz(NULL, int, 2);
104 * assert(p[0] == 0 && p[1] == 0);
106 #define tal_arrz(ctx, type, count) \
107 tal_arrz_label(ctx, type, count, TAL_LABEL(type, "[]"))
110 * tal_resize - enlarge or reduce a tal object.
111 * @p: A pointer to the tal allocated array to resize.
112 * @count: the number to allocate.
114 * This returns true on success (and may move *@p), or false on failure.
115 * On success, tal_count() of *@p will be @count.
117 * Note: if *p is take(), it will still be take() upon return, even if it
121 * tal_resize(&p, 100);
123 #define tal_resize(p, count) \
124 tal_resize_((void **)(p), sizeof**(p), (count), false)
127 * tal_resizez - enlarge or reduce a tal object; zero out extra.
128 * @p: A pointer to the tal allocated array to resize.
129 * @count: the number to allocate.
131 * This returns true on success (and may move *@p), or false on failure.
134 * tal_resizez(&p, 200);
136 #define tal_resizez(p, count) \
137 tal_resize_((void **)(p), sizeof**(p), (count), true)
140 * tal_steal - change the parent of a tal-allocated pointer.
141 * @ctx: The new parent.
142 * @ptr: The tal allocated object to move, or NULL.
144 * This may need to perform an allocation, in which case it may fail; thus
145 * it can return NULL, otherwise returns @ptr. If @ptr is NULL, this function does
148 #if HAVE_STATEMENT_EXPR
149 /* Weird macro avoids gcc's 'warning: value computed is not used'. */
150 #define tal_steal(ctx, ptr) \
151 ({ (tal_typeof(ptr) tal_steal_((ctx),(ptr))); })
153 #define tal_steal(ctx, ptr) \
154 (tal_typeof(ptr) tal_steal_((ctx),(ptr)))
158 * tal_add_destructor - add a callback function when this context is destroyed.
159 * @ptr: The tal allocated object.
160 * @function: the function to call before it's freed.
162 * This is a more convenient form of tal_add_notifier(@ptr,
163 * TAL_NOTIFY_FREE, ...), in that the function prototype takes only @ptr.
165 * Note that this can only fail if your allocfn fails and your errorfn returns.
167 #define tal_add_destructor(ptr, function) \
168 tal_add_destructor_((ptr), typesafe_cb(void, void *, (function), (ptr)))
171 * tal_del_destructor - remove a destructor callback function.
172 * @ptr: The tal allocated object.
173 * @function: the function to call before it's freed.
175 * If @function has not been successfully added as a destructor, this returns
176 * false. Note that if we're inside the destructor call itself, this will
179 #define tal_del_destructor(ptr, function) \
180 tal_del_destructor_((ptr), typesafe_cb(void, void *, (function), (ptr)))
183 * tal_add_destructor2 - add a 2-arg callback function when context is destroyed.
184 * @ptr: The tal allocated object.
185 * @function: the function to call before it's freed.
186 * @arg: the extra argument to the function.
188 * Sometimes an extra argument is required for a destructor; this
189 * saves the extra argument internally to avoid the caller having to
190 * do an extra allocation.
192 * Note that this can only fail if your allocfn fails and your errorfn returns.
194 #define tal_add_destructor2(ptr, function, arg) \
195 tal_add_destructor2_((ptr), \
196 typesafe_cb_cast(void (*)(tal_t *, void *), \
197 void (*)(__typeof__(ptr), \
203 * tal_del_destructor - remove a destructor callback function.
204 * @ptr: The tal allocated object.
205 * @function: the function to call before it's freed.
207 * If @function has not been successfully added as a destructor, this returns
208 * false. Note that if we're inside the destructor call itself, this will
211 #define tal_del_destructor(ptr, function) \
212 tal_del_destructor_((ptr), typesafe_cb(void, void *, (function), (ptr)))
215 * tal_del_destructor2 - remove 2-arg callback function.
216 * @ptr: The tal allocated object.
217 * @function: the function to call before it's freed.
218 * @arg: the extra argument to the function.
220 * If @function has not been successfully added as a destructor with
221 * @arg, this returns false.
223 #define tal_del_destructor2(ptr, function, arg) \
224 tal_del_destructor2_((ptr), \
225 typesafe_cb_cast(void (*)(tal_t *, void *), \
226 void (*)(__typeof__(ptr), \
230 enum tal_notify_type {
232 TAL_NOTIFY_STEAL = 2,
234 TAL_NOTIFY_RESIZE = 8,
235 TAL_NOTIFY_RENAME = 16,
236 TAL_NOTIFY_ADD_CHILD = 32,
237 TAL_NOTIFY_DEL_CHILD = 64,
238 TAL_NOTIFY_ADD_NOTIFIER = 128,
239 TAL_NOTIFY_DEL_NOTIFIER = 256
243 * tal_add_notifier - add a callback function when this context changes.
244 * @ptr: The tal allocated object, or NULL.
245 * @types: Bitwise OR of the types the callback is interested in.
246 * @callback: the function to call.
248 * Note that this can only fail if your allocfn fails and your errorfn
249 * returns. Also note that notifiers are not reliable in the case
250 * where an allocation fails, as they may be called before any
251 * allocation is actually done.
253 * TAL_NOTIFY_FREE is called when @ptr is freed, either directly or
254 * because an ancestor is freed: @info is the argument to tal_free().
255 * It is exactly equivalent to a destructor, with more information.
256 * errno is set to the value it was at the call of tal_free().
258 * TAL_NOTIFY_STEAL is called when @ptr's parent changes: @info is the
261 * TAL_NOTIFY_MOVE is called when @ptr is realloced (via tal_resize)
262 * and moved. In this case, @ptr arg here is the new memory, and
263 * @info is the old pointer.
265 * TAL_NOTIFY_RESIZE is called when @ptr is realloced via tal_resize:
266 * @info is the new size, in bytes. If the pointer has moved,
267 * TAL_NOTIFY_MOVE callbacks are called first.
269 * TAL_NOTIFY_ADD_CHILD/TAL_NOTIFY_DEL_CHILD are called when @ptr is
270 * the context for a tal() allocating call, or a direct child is
271 * tal_free()d: @info is the child. Note that TAL_NOTIFY_DEL_CHILD is
272 * not called when this context is tal_free()d: TAL_NOTIFY_FREE is
273 * considered sufficient for that case.
275 * TAL_NOTIFY_ADD_NOTIFIER/TAL_NOTIFIER_DEL_NOTIFIER are called when a
276 * notifier is added or removed (not for this notifier): @info is the
277 * callback. This is also called for tal_add_destructor and
278 * tal_del_destructor.
280 #define tal_add_notifier(ptr, types, callback) \
281 tal_add_notifier_((ptr), (types), \
282 typesafe_cb_postargs(void, tal_t *, (callback), \
284 enum tal_notify_type, void *))
287 * tal_del_notifier - remove a notifier callback function.
288 * @ptr: The tal allocated object.
289 * @callback: the function to call.
291 #define tal_del_notifier(ptr, callback) \
292 tal_del_notifier_((ptr), \
293 typesafe_cb_postargs(void, void *, (callback), \
295 enum tal_notify_type, void *), \
299 * tal_set_name - attach a name to a tal pointer.
300 * @ptr: The tal allocated object.
301 * @name: The name to use.
303 * The name is copied, unless we're certain it's a string literal.
305 #define tal_set_name(ptr, name) \
306 tal_set_name_((ptr), (name), TAL_IS_LITERAL(name))
309 * tal_name - get the name for a tal pointer.
310 * @ptr: The tal allocated object.
312 * Returns NULL if no name has been set.
314 const char *tal_name(const tal_t *ptr);
317 * tal_count - get the count of objects in a tal object.
318 * @ptr: The tal allocated object (or NULL)
320 * Returns 0 if @ptr is NULL. Note that if the allocation was done as a
321 * different type to @ptr, the result may not match the @count argument
322 * (or implied 1) of that allocation!
324 #define tal_count(p) (tal_bytelen(p) / sizeof(*p))
327 * tal_bytelen - get the count of bytes in a tal object.
328 * @ptr: The tal allocated object (or NULL)
330 * Returns 0 if @ptr is NULL.
332 size_t tal_bytelen(const tal_t *ptr);
335 * tal_first - get the first immediate tal object child.
336 * @root: The tal allocated object to start with, or NULL.
338 * Returns NULL if there are no children.
340 tal_t *tal_first(const tal_t *root);
343 * tal_next - get the next immediate tal object child.
344 * @prev: The return value from tal_first or tal_next.
346 * Returns NULL if there are no more immediate children. This should be safe to
347 * call on an altering tree unless @prev is no longer valid.
349 tal_t *tal_next(const tal_t *prev);
352 * tal_parent - get the parent of a tal object.
353 * @ctx: The tal allocated object.
355 * Returns the parent, which may be NULL. Returns NULL if @ctx is NULL.
357 tal_t *tal_parent(const tal_t *ctx);
360 * tal_dup - duplicate an object.
361 * @ctx: The tal allocated object to be parent of the result (may be NULL).
362 * @type: the type (should match type of @p!)
363 * @p: the object to copy (or reparented if take()). Must not be NULL.
365 #define tal_dup(ctx, type, p) \
366 tal_dup_label(ctx, type, p, TAL_LABEL(type, ""), false)
369 * tal_dup_or_null - duplicate an object, or just pass NULL.
370 * @ctx: The tal allocated object to be parent of the result (may be NULL).
371 * @type: the type (should match type of @p!)
372 * @p: the object to copy (or reparented if take())
374 * if @p is NULL, just return NULL, otherwise to tal_dup().
376 #define tal_dup_or_null(ctx, type, p) \
377 tal_dup_label(ctx, type, p, TAL_LABEL(type, ""), true)
380 * tal_dup_arr - duplicate an array.
381 * @ctx: The tal allocated object to be parent of the result (may be NULL).
382 * @type: the type (should match type of @p!)
383 * @p: the array to copy (or resized & reparented if take())
384 * @n: the number of sizeof(type) entries to copy.
385 * @extra: the number of extra sizeof(type) entries to allocate.
387 #define tal_dup_arr(ctx, type, p, n, extra) \
388 tal_dup_arr_label(ctx, type, p, n, extra, TAL_LABEL(type, "[]"))
392 * tal_dup_arr - duplicate a tal array.
393 * @ctx: The tal allocated object to be parent of the result (may be NULL).
394 * @type: the type (should match type of @p!)
395 * @p: the tal array to copy (or resized & reparented if take())
397 * The comon case of duplicating an entire tal array.
399 #define tal_dup_talarr(ctx, type, p) \
400 ((type *)tal_dup_talarr_((ctx), tal_typechk_(p, type *), \
401 TAL_LABEL(type, "[]")))
402 /* Lower-level interfaces, where you want to supply your own label string. */
403 #define tal_label(ctx, type, label) \
404 ((type *)tal_alloc_((ctx), sizeof(type), false, label))
405 #define talz_label(ctx, type, label) \
406 ((type *)tal_alloc_((ctx), sizeof(type), true, label))
407 #define tal_arr_label(ctx, type, count, label) \
408 ((type *)tal_alloc_arr_((ctx), sizeof(type), (count), false, label))
409 #define tal_arrz_label(ctx, type, count, label) \
410 ((type *)tal_alloc_arr_((ctx), sizeof(type), (count), true, label))
411 #define tal_dup_label(ctx, type, p, label, nullok) \
412 ((type *)tal_dup_((ctx), tal_typechk_(p, type *), \
413 sizeof(type), 1, 0, nullok, \
415 #define tal_dup_arr_label(ctx, type, p, n, extra, label) \
416 ((type *)tal_dup_((ctx), tal_typechk_(p, type *), \
417 sizeof(type), (n), (extra), false, \
421 * tal_set_backend - set the allocation or error functions to use
422 * @alloc_fn: allocator or NULL (default is malloc)
423 * @resize_fn: re-allocator or NULL (default is realloc)
424 * @free_fn: free function or NULL (default is free)
425 * @error_fn: called on errors or NULL (default is abort)
427 * The defaults are set up so tal functions never return NULL, but you
428 * can override error_fn to change that. error_fn can return (only if
429 * you haven't defined CCAN_TAL_NEVER_RETURN_NULL!), and is
430 * called if alloc_fn or resize_fn fail.
432 * If any parameter is NULL, that function is unchanged.
434 void tal_set_backend(void *(*alloc_fn)(size_t size),
435 void *(*resize_fn)(void *, size_t size),
436 void (*free_fn)(void *),
437 void (*error_fn)(const char *msg));
440 * tal_expand - expand a tal array with contents.
441 * @a1p: a pointer to the tal array to expand.
442 * @a2: the second array (can be take()).
443 * @num2: the number of elements in the second array.
445 * Note that *@a1 and @a2 should be the same type. tal_count(@a1) will
446 * be increased by @num2.
449 * int *arr1 = tal_arrz(NULL, int, 2);
450 * int arr2[2] = { 1, 3 };
452 * tal_expand(&arr1, arr2, 2);
453 * assert(tal_count(arr1) == 4);
454 * assert(arr1[2] == 1);
455 * assert(arr1[3] == 3);
457 #define tal_expand(a1p, a2, num2) \
458 tal_expand_((void **)(a1p), (a2), sizeof**(a1p), \
459 (num2) + 0*sizeof(*(a1p) == (a2)))
462 * tal_cleanup - remove pointers from NULL node
464 * Internally, tal keeps a list of nodes allocated from @ctx NULL; this
465 * prevents valgrind from noticing memory leaks. This re-initializes
466 * that list to empty.
468 * It also calls take_cleanup() for you.
470 void tal_cleanup(void);
474 * tal_check - sanity check a tal context and its children.
475 * @ctx: a tal context, or NULL.
476 * @errorstr: a string to prepend calls to error_fn, or NULL.
478 * This sanity-checks a tal tree (unless NDEBUG is defined, in which case
479 * it simply returns true). If errorstr is not null, error_fn is called
480 * when a problem is found, otherwise it is not.
485 bool tal_check(const tal_t *ctx, const char *errorstr);
487 #ifdef CCAN_TAL_DEBUG
489 * tal_dump - dump entire tal tree to stderr.
491 * This is a helper for debugging tal itself, which dumps all the tal internal
497 /* Internal support functions */
499 #ifdef CCAN_TAL_NO_LABELS
500 #define TAL_LABEL(type, arr) NULL
502 #ifdef CCAN_TAL_DEBUG
503 #define TAL_LABEL(type, arr) \
504 __FILE__ ":" stringify(__LINE__) ":" stringify(type) arr
506 #define TAL_LABEL(type, arr) stringify(type) arr
507 #endif /* CCAN_TAL_DEBUG */
511 #if HAVE_BUILTIN_CONSTANT_P
512 #define TAL_IS_LITERAL(str) __builtin_constant_p(str)
514 #define TAL_IS_LITERAL(str) (sizeof(&*(str)) != sizeof(char *))
517 bool tal_set_name_(tal_t *ctx, const char *name, bool literal);
520 #define tal_typeof(ptr) (__typeof__(ptr))
521 #if HAVE_STATEMENT_EXPR
522 /* Careful: ptr can be const foo *, ptype is foo *. Also, ptr could
523 * be an array, eg "hello". */
524 #define tal_typechk_(ptr, ptype) ({ __typeof__((ptr)+0) _p = (ptype)(ptr); _p; })
526 #define tal_typechk_(ptr, ptype) (ptr)
528 #else /* !HAVE_TYPEOF */
529 #define tal_typeof(ptr)
530 #define tal_typechk_(ptr, ptype) (ptr)
533 void *tal_alloc_(const tal_t *ctx, size_t bytes, bool clear, const char *label)
535 void *tal_alloc_arr_(const tal_t *ctx, size_t bytes, size_t count, bool clear,
539 void *tal_dup_(const tal_t *ctx, const void *p TAKES, size_t size,
540 size_t n, size_t extra, bool nullok, const char *label);
541 void *tal_dup_talarr_(const tal_t *ctx, const tal_t *src TAKES,
544 tal_t *tal_steal_(const tal_t *new_parent, const tal_t *t);
546 bool tal_resize_(tal_t **ctxp, size_t size, size_t count, bool clear);
547 bool tal_expand_(tal_t **ctxp, const void *src TAKES, size_t size, size_t count);
549 bool tal_add_destructor_(const tal_t *ctx, void (*destroy)(void *me));
550 bool tal_add_destructor2_(const tal_t *ctx, void (*destroy)(void *me, void *arg),
552 bool tal_del_destructor_(const tal_t *ctx, void (*destroy)(void *me));
553 bool tal_del_destructor2_(const tal_t *ctx, void (*destroy)(void *me, void *arg),
556 bool tal_add_notifier_(const tal_t *ctx, enum tal_notify_type types,
557 void (*notify)(tal_t *ctx, enum tal_notify_type,
559 bool tal_del_notifier_(const tal_t *ctx,
560 void (*notify)(tal_t *ctx, enum tal_notify_type,
562 bool match_extra_arg, void *arg);
563 #endif /* CCAN_TAL_H */