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 tal_label(ctx, type, 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 talz_label(ctx, type, 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 tal_arr_label(ctx, type, count, TAL_LABEL(type, "[]"))
86 * tal_arrz - allocate an array of zeroed objects.
87 * @ctx: NULL, or tal allocated object to be parent.
88 * @type: the type to allocate.
89 * @count: the number to allocate.
91 * Note that an object allocated with tal_arrz() has a length property;
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_arr[z].
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 * If @p has a length property, it is updated on success.
110 * tal_resize(&p, 100);
112 #define tal_resize(p, count) \
113 tal_resize_((void **)(p), sizeof**(p), (count), false)
116 * tal_resizez - enlarge or reduce a tal_arr[z]; zero out extra.
117 * @p: A pointer to the tal allocated array to resize.
118 * @count: the number to allocate.
120 * This returns true on success (and may move *@p), or false on failure.
121 * If @p has a length property, it is updated on success.
122 * On expand, new elements are memset to 0 bytes.
125 * tal_resizez(&p, 200);
127 #define tal_resizez(p, count) \
128 tal_resize_((void **)(p), sizeof**(p), (count), true)
131 * tal_steal - change the parent of a tal-allocated pointer.
132 * @ctx: The new parent.
133 * @ptr: The tal allocated object to move.
135 * This may need to perform an allocation, in which case it may fail; thus
136 * it can return NULL, otherwise returns @ptr.
138 #if HAVE_STATEMENT_EXPR
139 /* Weird macro avoids gcc's 'warning: value computed is not used'. */
140 #define tal_steal(ctx, ptr) \
141 ({ (tal_typeof(ptr) tal_steal_((ctx),(ptr))); })
143 #define tal_steal(ctx, ptr) \
144 (tal_typeof(ptr) tal_steal_((ctx),(ptr)))
148 * tal_add_destructor - add a callback function when this context is destroyed.
149 * @ptr: The tal allocated object.
150 * @function: the function to call before it's freed.
152 * This is a more convenient form of tal_add_notifier(@ptr,
153 * TAL_NOTIFY_FREE, ...), in that the function prototype takes only @ptr.
155 * Note that this can only fail if your allocfn fails and your errorfn returns.
157 #define tal_add_destructor(ptr, function) \
158 tal_add_destructor_((ptr), typesafe_cb(void, void *, (function), (ptr)))
161 * tal_del_destructor - remove a destructor callback function.
162 * @ptr: The tal allocated object.
163 * @function: the function to call before it's freed.
165 * If @function has not been successfully added as a destructor, this returns
168 #define tal_del_destructor(ptr, function) \
169 tal_del_destructor_((ptr), typesafe_cb(void, void *, (function), (ptr)))
172 * tal_add_destructor2 - add a 2-arg callback function when context is destroyed.
173 * @ptr: The tal allocated object.
174 * @function: the function to call before it's freed.
175 * @arg: the extra argument to the function.
177 * Sometimes an extra argument is required for a destructor; this
178 * saves the extra argument internally to avoid the caller having to
179 * do an extra allocation.
181 * Note that this can only fail if your allocfn fails and your errorfn returns.
183 #define tal_add_destructor2(ptr, function, arg) \
184 tal_add_destructor2_((ptr), \
185 typesafe_cb_cast(void (*)(tal_t *, void *), \
186 void (*)(__typeof__(ptr), \
192 * tal_del_destructor - remove a destructor callback function.
193 * @ptr: The tal allocated object.
194 * @function: the function to call before it's freed.
196 * If @function has not been successfully added as a destructor, this returns
199 #define tal_del_destructor(ptr, function) \
200 tal_del_destructor_((ptr), typesafe_cb(void, void *, (function), (ptr)))
203 * tal_del_destructor2 - remove 2-arg callback function.
204 * @ptr: The tal allocated object.
205 * @function: the function to call before it's freed.
206 * @arg: the extra argument to the function.
208 * If @function has not been successfully added as a destructor with
209 * @arg, this returns false.
211 #define tal_del_destructor2(ptr, function, arg) \
212 tal_del_destructor2_((ptr), \
213 typesafe_cb_cast(void (*)(tal_t *, void *), \
214 void (*)(__typeof__(ptr), \
218 enum tal_notify_type {
220 TAL_NOTIFY_STEAL = 2,
222 TAL_NOTIFY_RESIZE = 8,
223 TAL_NOTIFY_RENAME = 16,
224 TAL_NOTIFY_ADD_CHILD = 32,
225 TAL_NOTIFY_DEL_CHILD = 64,
226 TAL_NOTIFY_ADD_NOTIFIER = 128,
227 TAL_NOTIFY_DEL_NOTIFIER = 256
231 * tal_add_notifier - add a callback function when this context changes.
232 * @ptr: The tal allocated object.
233 * @types: Bitwise OR of the types the callback is interested in.
234 * @callback: the function to call.
236 * Note that this can only fail if your allocfn fails and your errorfn
237 * returns. Also note that notifiers are not reliable in the case
238 * where an allocation fails, as they may be called before any
239 * allocation is actually done.
241 * TAL_NOTIFY_FREE is called when @ptr is freed, either directly or
242 * because an ancestor is freed: @info is the argument to tal_free().
243 * It is exactly equivalent to a destructor, with more information.
244 * errno is set to the value it was at the call of tal_free().
246 * TAL_NOTIFY_STEAL is called when @ptr's parent changes: @info is the
249 * TAL_NOTIFY_MOVE is called when @ptr is realloced (via tal_resize)
250 * and moved. In this case, @ptr arg here is the new memory, and
251 * @info is the old pointer.
253 * TAL_NOTIFY_RESIZE is called when @ptr is realloced via tal_resize:
254 * @info is the new size, in bytes. If the pointer has moved,
255 * TAL_NOTIFY_MOVE callbacks are called first.
257 * TAL_NOTIFY_ADD_CHILD/TAL_NOTIFY_DEL_CHILD are called when @ptr is
258 * the context for a tal() allocating call, or a direct child is
259 * tal_free()d: @info is the child. Note that TAL_NOTIFY_DEL_CHILD is
260 * not called when this context is tal_free()d: TAL_NOTIFY_FREE is
261 * considered sufficient for that case.
263 * TAL_NOTIFY_ADD_NOTIFIER/TAL_NOTIFIER_DEL_NOTIFIER are called when a
264 * notifier is added or removed (not for this notifier): @info is the
265 * callback. This is also called for tal_add_destructor and
266 * tal_del_destructor.
268 #define tal_add_notifier(ptr, types, callback) \
269 tal_add_notifier_((ptr), (types), \
270 typesafe_cb_postargs(void, tal_t *, (callback), \
272 enum tal_notify_type, void *))
275 * tal_del_notifier - remove a notifier callback function.
276 * @ptr: The tal allocated object.
277 * @callback: the function to call.
279 #define tal_del_notifier(ptr, callback) \
280 tal_del_notifier_((ptr), \
281 typesafe_cb_postargs(void, void *, (callback), \
283 enum tal_notify_type, void *), \
287 * tal_set_name - attach a name to a tal pointer.
288 * @ptr: The tal allocated object.
289 * @name: The name to use.
291 * The name is copied, unless we're certain it's a string literal.
293 #define tal_set_name(ptr, name) \
294 tal_set_name_((ptr), (name), TAL_IS_LITERAL(name))
297 * tal_name - get the name for a tal pointer.
298 * @ptr: The tal allocated object.
300 * Returns NULL if no name has been set.
302 const char *tal_name(const tal_t *ptr);
305 * tal_count - get the count of objects in a tal_arr.
306 * @ptr: The tal allocated object array (or NULL)
308 * Returns 0 if @ptr has no length property or is NULL, but be aware
309 * that that is also a valid size!
311 #define tal_count(p) (tal_bytelen(p) / sizeof(*p))
314 * tal_bytelen - get the count of bytes in a tal_arr.
315 * @ptr: The tal allocated object array (or NULL)
317 * Returns 0 if @ptr has no length property or NULL, but be aware that that is
320 size_t tal_bytelen(const tal_t *ptr);
323 * tal_first - get the first immediate tal object child.
324 * @root: The tal allocated object to start with, or NULL.
326 * Returns NULL if there are no children.
328 tal_t *tal_first(const tal_t *root);
331 * tal_next - get the next immediate tal object child.
332 * @prev: The return value from tal_first or tal_next.
334 * Returns NULL if there are no more immediate children. This should be safe to
335 * call on an altering tree unless @prev is no longer valid.
337 tal_t *tal_next(const tal_t *prev);
340 * tal_parent - get the parent of a tal object.
341 * @ctx: The tal allocated object.
343 * Returns the parent, which may be NULL. Returns NULL if @ctx is NULL.
345 tal_t *tal_parent(const tal_t *ctx);
348 * tal_dup - duplicate an object.
349 * @ctx: The tal allocated object to be parent of the result (may be NULL).
350 * @type: the type (should match type of @p!)
351 * @p: the object to copy (or reparented if take())
353 #define tal_dup(ctx, type, p) \
354 tal_dup_label(ctx, type, p, TAL_LABEL(type, ""))
357 * tal_dup_arr - duplicate an array.
358 * @ctx: The tal allocated object to be parent of the result (may be NULL).
359 * @type: the type (should match type of @p!)
360 * @p: the array to copy (or resized & reparented if take())
361 * @n: the number of sizeof(type) entries to copy.
362 * @extra: the number of extra sizeof(type) entries to allocate.
364 #define tal_dup_arr(ctx, type, p, n, extra) \
365 tal_dup_arr_label(ctx, type, p, n, extra, TAL_LABEL(type, "[]"))
369 /* Lower-level interfaces, where you want to supply your own label string. */
370 #define tal_label(ctx, type, label) \
371 ((type *)tal_alloc_((ctx), sizeof(type), false, false, label))
372 #define talz_label(ctx, type, label) \
373 ((type *)tal_alloc_((ctx), sizeof(type), true, false, label))
374 #define tal_arr_label(ctx, type, count, label) \
375 ((type *)tal_alloc_arr_((ctx), sizeof(type), (count), false, true, label))
376 #define tal_arrz_label(ctx, type, count, label) \
377 ((type *)tal_alloc_arr_((ctx), sizeof(type), (count), true, true, label))
378 #define tal_dup_label(ctx, type, p, label) \
379 ((type *)tal_dup_((ctx), tal_typechk_(p, type *), \
380 sizeof(type), 1, 0, \
382 #define tal_dup_arr_label(ctx, type, p, n, extra, label) \
383 ((type *)tal_dup_((ctx), tal_typechk_(p, type *), \
384 sizeof(type), (n), (extra), \
388 * tal_set_backend - set the allocation or error functions to use
389 * @alloc_fn: allocator or NULL (default is malloc)
390 * @resize_fn: re-allocator or NULL (default is realloc)
391 * @free_fn: free function or NULL (default is free)
392 * @error_fn: called on errors or NULL (default is abort)
394 * The defaults are set up so tal functions never return NULL, but you
395 * can override erorr_fn to change that. error_fn can return, and is
396 * called if alloc_fn or resize_fn fail.
398 * If any parameter is NULL, that function is unchanged.
400 void tal_set_backend(void *(*alloc_fn)(size_t size),
401 void *(*resize_fn)(void *, size_t size),
402 void (*free_fn)(void *),
403 void (*error_fn)(const char *msg));
406 * tal_expand - expand a tal array with contents.
407 * @a1p: a pointer to the tal array to expand.
408 * @a2: the second array (can be take()).
409 * @num2: the number of elements in the second array.
411 * Note that *@a1 and @a2 should be the same type. tal_count(@a1) will
412 * be increased by @num2.
415 * int *arr1 = tal_arrz(NULL, int, 2);
416 * int arr2[2] = { 1, 3 };
418 * tal_expand(&arr1, arr2, 2);
419 * assert(tal_count(arr1) == 4);
420 * assert(arr1[2] == 1);
421 * assert(arr1[3] == 3);
423 #define tal_expand(a1p, a2, num2) \
424 tal_expand_((void **)(a1p), (a2), sizeof**(a1p), \
425 (num2) + 0*sizeof(*(a1p) == (a2)))
428 * tal_cleanup - remove pointers from NULL node
430 * Internally, tal keeps a list of nodes allocated from @ctx NULL; this
431 * prevents valgrind from noticing memory leaks. This re-initializes
432 * that list to empty.
434 * It also calls take_cleanup() for you.
436 void tal_cleanup(void);
440 * tal_check - sanity check a tal context and its children.
441 * @ctx: a tal context, or NULL.
442 * @errorstr: a string to prepend calls to error_fn, or NULL.
444 * This sanity-checks a tal tree (unless NDEBUG is defined, in which case
445 * it simply returns true). If errorstr is not null, error_fn is called
446 * when a problem is found, otherwise it is not.
451 bool tal_check(const tal_t *ctx, const char *errorstr);
453 #ifdef CCAN_TAL_DEBUG
455 * tal_dump - dump entire tal tree.
457 * This is a helper for debugging tal itself, which dumps all the tal internal
463 /* Internal support functions */
465 #ifdef CCAN_TAL_NO_LABELS
466 #define TAL_LABEL(type, arr) NULL
468 #ifdef CCAN_TAL_DEBUG
469 #define TAL_LABEL(type, arr) \
470 __FILE__ ":" stringify(__LINE__) ":" stringify(type) arr
472 #define TAL_LABEL(type, arr) stringify(type) arr
473 #endif /* CCAN_TAL_DEBUG */
477 #if HAVE_BUILTIN_CONSTANT_P
478 #define TAL_IS_LITERAL(str) __builtin_constant_p(str)
480 #define TAL_IS_LITERAL(str) (sizeof(&*(str)) != sizeof(char *))
483 bool tal_set_name_(tal_t *ctx, const char *name, bool literal);
486 #define tal_typeof(ptr) (__typeof__(ptr))
487 #if HAVE_STATEMENT_EXPR
488 /* Careful: ptr can be const foo *, ptype is foo *. Also, ptr could
489 * be an array, eg "hello". */
490 #define tal_typechk_(ptr, ptype) ({ __typeof__((ptr)+0) _p = (ptype)(ptr); _p; })
492 #define tal_typechk_(ptr, ptype) (ptr)
494 #else /* !HAVE_TYPEOF */
495 #define tal_typeof(ptr)
496 #define tal_typechk_(ptr, ptype) (ptr)
499 void *tal_alloc_(const tal_t *ctx, size_t bytes, bool clear,
500 bool add_length, const char *label);
501 void *tal_alloc_arr_(const tal_t *ctx, size_t bytes, size_t count, bool clear,
502 bool add_length, const char *label);
504 void *tal_dup_(const tal_t *ctx, const void *p TAKES, size_t size,
505 size_t n, size_t extra, bool add_length,
508 tal_t *tal_steal_(const tal_t *new_parent, const tal_t *t);
510 bool tal_resize_(tal_t **ctxp, size_t size, size_t count, bool clear);
511 bool tal_expand_(tal_t **ctxp, const void *src TAKES, size_t size, size_t count);
513 bool tal_add_destructor_(const tal_t *ctx, void (*destroy)(void *me));
514 bool tal_add_destructor2_(const tal_t *ctx, void (*destroy)(void *me, void *arg),
516 bool tal_del_destructor_(const tal_t *ctx, void (*destroy)(void *me));
517 bool tal_del_destructor2_(const tal_t *ctx, void (*destroy)(void *me, void *arg),
520 bool tal_add_notifier_(const tal_t *ctx, enum tal_notify_type types,
521 void (*notify)(tal_t *ctx, enum tal_notify_type,
523 bool tal_del_notifier_(const tal_t *ctx,
524 void (*notify)(tal_t *ctx, enum tal_notify_type,
526 bool match_extra_arg, void *arg);
527 #endif /* CCAN_TAL_H */