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.
136 * This may need to perform an allocation, in which case it may fail; thus
137 * it can return NULL, otherwise returns @ptr.
139 #if HAVE_STATEMENT_EXPR
140 /* Weird macro avoids gcc's 'warning: value computed is not used'. */
141 #define tal_steal(ctx, ptr) \
142 ({ (tal_typeof(ptr) tal_steal_((ctx),(ptr))); })
144 #define tal_steal(ctx, ptr) \
145 (tal_typeof(ptr) tal_steal_((ctx),(ptr)))
149 * tal_add_destructor - add a callback function when this context is destroyed.
150 * @ptr: The tal allocated object.
151 * @function: the function to call before it's freed.
153 * This is a more convenient form of tal_add_notifier(@ptr,
154 * TAL_NOTIFY_FREE, ...), in that the function prototype takes only @ptr.
156 * Note that this can only fail if your allocfn fails and your errorfn returns.
158 #define tal_add_destructor(ptr, function) \
159 tal_add_destructor_((ptr), typesafe_cb(void, void *, (function), (ptr)))
162 * tal_del_destructor - remove a destructor callback function.
163 * @ptr: The tal allocated object.
164 * @function: the function to call before it's freed.
166 * If @function has not been successfully added as a destructor, this returns
169 #define tal_del_destructor(ptr, function) \
170 tal_del_destructor_((ptr), typesafe_cb(void, void *, (function), (ptr)))
173 * tal_add_destructor2 - add a 2-arg callback function when context is destroyed.
174 * @ptr: The tal allocated object.
175 * @function: the function to call before it's freed.
176 * @arg: the extra argument to the function.
178 * Sometimes an extra argument is required for a destructor; this
179 * saves the extra argument internally to avoid the caller having to
180 * do an extra allocation.
182 * Note that this can only fail if your allocfn fails and your errorfn returns.
184 #define tal_add_destructor2(ptr, function, arg) \
185 tal_add_destructor2_((ptr), \
186 typesafe_cb_cast(void (*)(tal_t *, void *), \
187 void (*)(__typeof__(ptr), \
193 * tal_del_destructor - remove a destructor callback function.
194 * @ptr: The tal allocated object.
195 * @function: the function to call before it's freed.
197 * If @function has not been successfully added as a destructor, this returns
200 #define tal_del_destructor(ptr, function) \
201 tal_del_destructor_((ptr), typesafe_cb(void, void *, (function), (ptr)))
204 * tal_del_destructor2 - remove 2-arg callback function.
205 * @ptr: The tal allocated object.
206 * @function: the function to call before it's freed.
207 * @arg: the extra argument to the function.
209 * If @function has not been successfully added as a destructor with
210 * @arg, this returns false.
212 #define tal_del_destructor2(ptr, function, arg) \
213 tal_del_destructor2_((ptr), \
214 typesafe_cb_cast(void (*)(tal_t *, void *), \
215 void (*)(__typeof__(ptr), \
219 enum tal_notify_type {
221 TAL_NOTIFY_STEAL = 2,
223 TAL_NOTIFY_RESIZE = 8,
224 TAL_NOTIFY_RENAME = 16,
225 TAL_NOTIFY_ADD_CHILD = 32,
226 TAL_NOTIFY_DEL_CHILD = 64,
227 TAL_NOTIFY_ADD_NOTIFIER = 128,
228 TAL_NOTIFY_DEL_NOTIFIER = 256
232 * tal_add_notifier - add a callback function when this context changes.
233 * @ptr: The tal allocated object, or NULL.
234 * @types: Bitwise OR of the types the callback is interested in.
235 * @callback: the function to call.
237 * Note that this can only fail if your allocfn fails and your errorfn
238 * returns. Also note that notifiers are not reliable in the case
239 * where an allocation fails, as they may be called before any
240 * allocation is actually done.
242 * TAL_NOTIFY_FREE is called when @ptr is freed, either directly or
243 * because an ancestor is freed: @info is the argument to tal_free().
244 * It is exactly equivalent to a destructor, with more information.
245 * errno is set to the value it was at the call of tal_free().
247 * TAL_NOTIFY_STEAL is called when @ptr's parent changes: @info is the
250 * TAL_NOTIFY_MOVE is called when @ptr is realloced (via tal_resize)
251 * and moved. In this case, @ptr arg here is the new memory, and
252 * @info is the old pointer.
254 * TAL_NOTIFY_RESIZE is called when @ptr is realloced via tal_resize:
255 * @info is the new size, in bytes. If the pointer has moved,
256 * TAL_NOTIFY_MOVE callbacks are called first.
258 * TAL_NOTIFY_ADD_CHILD/TAL_NOTIFY_DEL_CHILD are called when @ptr is
259 * the context for a tal() allocating call, or a direct child is
260 * tal_free()d: @info is the child. Note that TAL_NOTIFY_DEL_CHILD is
261 * not called when this context is tal_free()d: TAL_NOTIFY_FREE is
262 * considered sufficient for that case.
264 * TAL_NOTIFY_ADD_NOTIFIER/TAL_NOTIFIER_DEL_NOTIFIER are called when a
265 * notifier is added or removed (not for this notifier): @info is the
266 * callback. This is also called for tal_add_destructor and
267 * tal_del_destructor.
269 #define tal_add_notifier(ptr, types, callback) \
270 tal_add_notifier_((ptr), (types), \
271 typesafe_cb_postargs(void, tal_t *, (callback), \
273 enum tal_notify_type, void *))
276 * tal_del_notifier - remove a notifier callback function.
277 * @ptr: The tal allocated object.
278 * @callback: the function to call.
280 #define tal_del_notifier(ptr, callback) \
281 tal_del_notifier_((ptr), \
282 typesafe_cb_postargs(void, void *, (callback), \
284 enum tal_notify_type, void *), \
288 * tal_set_name - attach a name to a tal pointer.
289 * @ptr: The tal allocated object.
290 * @name: The name to use.
292 * The name is copied, unless we're certain it's a string literal.
294 #define tal_set_name(ptr, name) \
295 tal_set_name_((ptr), (name), TAL_IS_LITERAL(name))
298 * tal_name - get the name for a tal pointer.
299 * @ptr: The tal allocated object.
301 * Returns NULL if no name has been set.
303 const char *tal_name(const tal_t *ptr);
306 * tal_count - get the count of objects in a tal object.
307 * @ptr: The tal allocated object (or NULL)
309 * Returns 0 if @ptr is NULL. Note that if the allocation was done as a
310 * different type to @ptr, the result may not match the @count argument
311 * (or implied 1) of that allocation!
313 #define tal_count(p) (tal_bytelen(p) / sizeof(*p))
316 * tal_bytelen - get the count of bytes in a tal object.
317 * @ptr: The tal allocated object (or NULL)
319 * Returns 0 if @ptr is NULL.
321 size_t tal_bytelen(const tal_t *ptr);
324 * tal_first - get the first immediate tal object child.
325 * @root: The tal allocated object to start with, or NULL.
327 * Returns NULL if there are no children.
329 tal_t *tal_first(const tal_t *root);
332 * tal_next - get the next immediate tal object child.
333 * @prev: The return value from tal_first or tal_next.
335 * Returns NULL if there are no more immediate children. This should be safe to
336 * call on an altering tree unless @prev is no longer valid.
338 tal_t *tal_next(const tal_t *prev);
341 * tal_parent - get the parent of a tal object.
342 * @ctx: The tal allocated object.
344 * Returns the parent, which may be NULL. Returns NULL if @ctx is NULL.
346 tal_t *tal_parent(const tal_t *ctx);
349 * tal_dup - duplicate an object.
350 * @ctx: The tal allocated object to be parent of the result (may be NULL).
351 * @type: the type (should match type of @p!)
352 * @p: the object to copy (or reparented if take())
354 #define tal_dup(ctx, type, p) \
355 tal_dup_label(ctx, type, p, TAL_LABEL(type, ""))
358 * tal_dup_arr - duplicate an array.
359 * @ctx: The tal allocated object to be parent of the result (may be NULL).
360 * @type: the type (should match type of @p!)
361 * @p: the array to copy (or resized & reparented if take())
362 * @n: the number of sizeof(type) entries to copy.
363 * @extra: the number of extra sizeof(type) entries to allocate.
365 #define tal_dup_arr(ctx, type, p, n, extra) \
366 tal_dup_arr_label(ctx, type, p, n, extra, TAL_LABEL(type, "[]"))
370 /* Lower-level interfaces, where you want to supply your own label string. */
371 #define tal_label(ctx, type, label) \
372 ((type *)tal_alloc_((ctx), sizeof(type), false, label))
373 #define talz_label(ctx, type, label) \
374 ((type *)tal_alloc_((ctx), sizeof(type), true, label))
375 #define tal_arr_label(ctx, type, count, label) \
376 ((type *)tal_alloc_arr_((ctx), sizeof(type), (count), false, label))
377 #define tal_arrz_label(ctx, type, count, label) \
378 ((type *)tal_alloc_arr_((ctx), sizeof(type), (count), true, label))
379 #define tal_dup_label(ctx, type, p, label) \
380 ((type *)tal_dup_((ctx), tal_typechk_(p, type *), \
381 sizeof(type), 1, 0, \
383 #define tal_dup_arr_label(ctx, type, p, n, extra, label) \
384 ((type *)tal_dup_((ctx), tal_typechk_(p, type *), \
385 sizeof(type), (n), (extra), \
389 * tal_set_backend - set the allocation or error functions to use
390 * @alloc_fn: allocator or NULL (default is malloc)
391 * @resize_fn: re-allocator or NULL (default is realloc)
392 * @free_fn: free function or NULL (default is free)
393 * @error_fn: called on errors or NULL (default is abort)
395 * The defaults are set up so tal functions never return NULL, but you
396 * can override erorr_fn to change that. error_fn can return, and is
397 * called if alloc_fn or resize_fn fail.
399 * If any parameter is NULL, that function is unchanged.
401 void tal_set_backend(void *(*alloc_fn)(size_t size),
402 void *(*resize_fn)(void *, size_t size),
403 void (*free_fn)(void *),
404 void (*error_fn)(const char *msg));
407 * tal_expand - expand a tal array with contents.
408 * @a1p: a pointer to the tal array to expand.
409 * @a2: the second array (can be take()).
410 * @num2: the number of elements in the second array.
412 * Note that *@a1 and @a2 should be the same type. tal_count(@a1) will
413 * be increased by @num2.
416 * int *arr1 = tal_arrz(NULL, int, 2);
417 * int arr2[2] = { 1, 3 };
419 * tal_expand(&arr1, arr2, 2);
420 * assert(tal_count(arr1) == 4);
421 * assert(arr1[2] == 1);
422 * assert(arr1[3] == 3);
424 #define tal_expand(a1p, a2, num2) \
425 tal_expand_((void **)(a1p), (a2), sizeof**(a1p), \
426 (num2) + 0*sizeof(*(a1p) == (a2)))
429 * tal_cleanup - remove pointers from NULL node
431 * Internally, tal keeps a list of nodes allocated from @ctx NULL; this
432 * prevents valgrind from noticing memory leaks. This re-initializes
433 * that list to empty.
435 * It also calls take_cleanup() for you.
437 void tal_cleanup(void);
441 * tal_check - sanity check a tal context and its children.
442 * @ctx: a tal context, or NULL.
443 * @errorstr: a string to prepend calls to error_fn, or NULL.
445 * This sanity-checks a tal tree (unless NDEBUG is defined, in which case
446 * it simply returns true). If errorstr is not null, error_fn is called
447 * when a problem is found, otherwise it is not.
452 bool tal_check(const tal_t *ctx, const char *errorstr);
454 #ifdef CCAN_TAL_DEBUG
456 * tal_dump - dump entire tal tree.
458 * This is a helper for debugging tal itself, which dumps all the tal internal
464 /* Internal support functions */
466 #ifdef CCAN_TAL_NO_LABELS
467 #define TAL_LABEL(type, arr) NULL
469 #ifdef CCAN_TAL_DEBUG
470 #define TAL_LABEL(type, arr) \
471 __FILE__ ":" stringify(__LINE__) ":" stringify(type) arr
473 #define TAL_LABEL(type, arr) stringify(type) arr
474 #endif /* CCAN_TAL_DEBUG */
478 #if HAVE_BUILTIN_CONSTANT_P
479 #define TAL_IS_LITERAL(str) __builtin_constant_p(str)
481 #define TAL_IS_LITERAL(str) (sizeof(&*(str)) != sizeof(char *))
484 bool tal_set_name_(tal_t *ctx, const char *name, bool literal);
487 #define tal_typeof(ptr) (__typeof__(ptr))
488 #if HAVE_STATEMENT_EXPR
489 /* Careful: ptr can be const foo *, ptype is foo *. Also, ptr could
490 * be an array, eg "hello". */
491 #define tal_typechk_(ptr, ptype) ({ __typeof__((ptr)+0) _p = (ptype)(ptr); _p; })
493 #define tal_typechk_(ptr, ptype) (ptr)
495 #else /* !HAVE_TYPEOF */
496 #define tal_typeof(ptr)
497 #define tal_typechk_(ptr, ptype) (ptr)
500 void *tal_alloc_(const tal_t *ctx, size_t bytes, bool clear, const char *label);
501 void *tal_alloc_arr_(const tal_t *ctx, size_t bytes, size_t count, bool clear,
504 void *tal_dup_(const tal_t *ctx, const void *p TAKES, size_t size,
505 size_t n, size_t extra, const char *label);
507 tal_t *tal_steal_(const tal_t *new_parent, const tal_t *t);
509 bool tal_resize_(tal_t **ctxp, size_t size, size_t count, bool clear);
510 bool tal_expand_(tal_t **ctxp, const void *src TAKES, size_t size, size_t count);
512 bool tal_add_destructor_(const tal_t *ctx, void (*destroy)(void *me));
513 bool tal_add_destructor2_(const tal_t *ctx, void (*destroy)(void *me, void *arg),
515 bool tal_del_destructor_(const tal_t *ctx, void (*destroy)(void *me));
516 bool tal_del_destructor2_(const tal_t *ctx, void (*destroy)(void *me, void *arg),
519 bool tal_add_notifier_(const tal_t *ctx, enum tal_notify_type types,
520 void (*notify)(tal_t *ctx, enum tal_notify_type,
522 bool tal_del_notifier_(const tal_t *ctx,
523 void (*notify)(tal_t *ctx, enum tal_notify_type,
525 bool match_extra_arg, void *arg);
526 #endif /* CCAN_TAL_H */