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.
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 object; 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.
123 * tal_resizez(&p, 200);
125 #define tal_resizez(p, count) \
126 tal_resize_((void **)(p), sizeof**(p), (count), true)
129 * tal_steal - change the parent of a tal-allocated pointer.
130 * @ctx: The new parent.
131 * @ptr: The tal allocated object to move.
133 * This may need to perform an allocation, in which case it may fail; thus
134 * it can return NULL, otherwise returns @ptr.
136 #if HAVE_STATEMENT_EXPR
137 /* Weird macro avoids gcc's 'warning: value computed is not used'. */
138 #define tal_steal(ctx, ptr) \
139 ({ (tal_typeof(ptr) tal_steal_((ctx),(ptr))); })
141 #define tal_steal(ctx, ptr) \
142 (tal_typeof(ptr) tal_steal_((ctx),(ptr)))
146 * tal_add_destructor - add a callback function when this context is destroyed.
147 * @ptr: The tal allocated object.
148 * @function: the function to call before it's freed.
150 * This is a more convenient form of tal_add_notifier(@ptr,
151 * TAL_NOTIFY_FREE, ...), in that the function prototype takes only @ptr.
153 * Note that this can only fail if your allocfn fails and your errorfn returns.
155 #define tal_add_destructor(ptr, function) \
156 tal_add_destructor_((ptr), typesafe_cb(void, void *, (function), (ptr)))
159 * tal_del_destructor - remove a destructor callback function.
160 * @ptr: The tal allocated object.
161 * @function: the function to call before it's freed.
163 * If @function has not been successfully added as a destructor, this returns
166 #define tal_del_destructor(ptr, function) \
167 tal_del_destructor_((ptr), typesafe_cb(void, void *, (function), (ptr)))
170 * tal_add_destructor2 - add a 2-arg callback function when context is destroyed.
171 * @ptr: The tal allocated object.
172 * @function: the function to call before it's freed.
173 * @arg: the extra argument to the function.
175 * Sometimes an extra argument is required for a destructor; this
176 * saves the extra argument internally to avoid the caller having to
177 * do an extra allocation.
179 * Note that this can only fail if your allocfn fails and your errorfn returns.
181 #define tal_add_destructor2(ptr, function, arg) \
182 tal_add_destructor2_((ptr), \
183 typesafe_cb_cast(void (*)(tal_t *, void *), \
184 void (*)(__typeof__(ptr), \
190 * tal_del_destructor - remove a destructor callback function.
191 * @ptr: The tal allocated object.
192 * @function: the function to call before it's freed.
194 * If @function has not been successfully added as a destructor, this returns
197 #define tal_del_destructor(ptr, function) \
198 tal_del_destructor_((ptr), typesafe_cb(void, void *, (function), (ptr)))
201 * tal_del_destructor2 - remove 2-arg callback function.
202 * @ptr: The tal allocated object.
203 * @function: the function to call before it's freed.
204 * @arg: the extra argument to the function.
206 * If @function has not been successfully added as a destructor with
207 * @arg, this returns false.
209 #define tal_del_destructor2(ptr, function, arg) \
210 tal_del_destructor2_((ptr), \
211 typesafe_cb_cast(void (*)(tal_t *, void *), \
212 void (*)(__typeof__(ptr), \
216 enum tal_notify_type {
218 TAL_NOTIFY_STEAL = 2,
220 TAL_NOTIFY_RESIZE = 8,
221 TAL_NOTIFY_RENAME = 16,
222 TAL_NOTIFY_ADD_CHILD = 32,
223 TAL_NOTIFY_DEL_CHILD = 64,
224 TAL_NOTIFY_ADD_NOTIFIER = 128,
225 TAL_NOTIFY_DEL_NOTIFIER = 256
229 * tal_add_notifier - add a callback function when this context changes.
230 * @ptr: The tal allocated object.
231 * @types: Bitwise OR of the types the callback is interested in.
232 * @callback: the function to call.
234 * Note that this can only fail if your allocfn fails and your errorfn
235 * returns. Also note that notifiers are not reliable in the case
236 * where an allocation fails, as they may be called before any
237 * allocation is actually done.
239 * TAL_NOTIFY_FREE is called when @ptr is freed, either directly or
240 * because an ancestor is freed: @info is the argument to tal_free().
241 * It is exactly equivalent to a destructor, with more information.
242 * errno is set to the value it was at the call of tal_free().
244 * TAL_NOTIFY_STEAL is called when @ptr's parent changes: @info is the
247 * TAL_NOTIFY_MOVE is called when @ptr is realloced (via tal_resize)
248 * and moved. In this case, @ptr arg here is the new memory, and
249 * @info is the old pointer.
251 * TAL_NOTIFY_RESIZE is called when @ptr is realloced via tal_resize:
252 * @info is the new size, in bytes. If the pointer has moved,
253 * TAL_NOTIFY_MOVE callbacks are called first.
255 * TAL_NOTIFY_ADD_CHILD/TAL_NOTIFY_DEL_CHILD are called when @ptr is
256 * the context for a tal() allocating call, or a direct child is
257 * tal_free()d: @info is the child. Note that TAL_NOTIFY_DEL_CHILD is
258 * not called when this context is tal_free()d: TAL_NOTIFY_FREE is
259 * considered sufficient for that case.
261 * TAL_NOTIFY_ADD_NOTIFIER/TAL_NOTIFIER_DEL_NOTIFIER are called when a
262 * notifier is added or removed (not for this notifier): @info is the
263 * callback. This is also called for tal_add_destructor and
264 * tal_del_destructor.
266 #define tal_add_notifier(ptr, types, callback) \
267 tal_add_notifier_((ptr), (types), \
268 typesafe_cb_postargs(void, tal_t *, (callback), \
270 enum tal_notify_type, void *))
273 * tal_del_notifier - remove a notifier callback function.
274 * @ptr: The tal allocated object.
275 * @callback: the function to call.
277 #define tal_del_notifier(ptr, callback) \
278 tal_del_notifier_((ptr), \
279 typesafe_cb_postargs(void, void *, (callback), \
281 enum tal_notify_type, void *), \
285 * tal_set_name - attach a name to a tal pointer.
286 * @ptr: The tal allocated object.
287 * @name: The name to use.
289 * The name is copied, unless we're certain it's a string literal.
291 #define tal_set_name(ptr, name) \
292 tal_set_name_((ptr), (name), TAL_IS_LITERAL(name))
295 * tal_name - get the name for a tal pointer.
296 * @ptr: The tal allocated object.
298 * Returns NULL if no name has been set.
300 const char *tal_name(const tal_t *ptr);
303 * tal_count - get the count of objects in a tal object.
304 * @ptr: The tal allocated object (or NULL)
306 * Returns 0 if @ptr is NULL. Note that if the allocation was done as a
307 * different type to @ptr, the result may not match the @count argument
308 * (or implied 1) of that allocation!
310 #define tal_count(p) (tal_bytelen(p) / sizeof(*p))
313 * tal_bytelen - get the count of bytes in a tal object.
314 * @ptr: The tal allocated object (or NULL)
316 * Returns 0 if @ptr is NULL.
318 size_t tal_bytelen(const tal_t *ptr);
321 * tal_first - get the first immediate tal object child.
322 * @root: The tal allocated object to start with, or NULL.
324 * Returns NULL if there are no children.
326 tal_t *tal_first(const tal_t *root);
329 * tal_next - get the next immediate tal object child.
330 * @prev: The return value from tal_first or tal_next.
332 * Returns NULL if there are no more immediate children. This should be safe to
333 * call on an altering tree unless @prev is no longer valid.
335 tal_t *tal_next(const tal_t *prev);
338 * tal_parent - get the parent of a tal object.
339 * @ctx: The tal allocated object.
341 * Returns the parent, which may be NULL. Returns NULL if @ctx is NULL.
343 tal_t *tal_parent(const tal_t *ctx);
346 * tal_dup - duplicate an object.
347 * @ctx: The tal allocated object to be parent of the result (may be NULL).
348 * @type: the type (should match type of @p!)
349 * @p: the object to copy (or reparented if take())
351 #define tal_dup(ctx, type, p) \
352 tal_dup_label(ctx, type, p, TAL_LABEL(type, ""))
355 * tal_dup_arr - duplicate an array.
356 * @ctx: The tal allocated object to be parent of the result (may be NULL).
357 * @type: the type (should match type of @p!)
358 * @p: the array to copy (or resized & reparented if take())
359 * @n: the number of sizeof(type) entries to copy.
360 * @extra: the number of extra sizeof(type) entries to allocate.
362 #define tal_dup_arr(ctx, type, p, n, extra) \
363 tal_dup_arr_label(ctx, type, p, n, extra, TAL_LABEL(type, "[]"))
367 /* Lower-level interfaces, where you want to supply your own label string. */
368 #define tal_label(ctx, type, label) \
369 ((type *)tal_alloc_((ctx), sizeof(type), false, label))
370 #define talz_label(ctx, type, label) \
371 ((type *)tal_alloc_((ctx), sizeof(type), true, label))
372 #define tal_arr_label(ctx, type, count, label) \
373 ((type *)tal_alloc_arr_((ctx), sizeof(type), (count), false, label))
374 #define tal_arrz_label(ctx, type, count, label) \
375 ((type *)tal_alloc_arr_((ctx), sizeof(type), (count), true, label))
376 #define tal_dup_label(ctx, type, p, label) \
377 ((type *)tal_dup_((ctx), tal_typechk_(p, type *), \
378 sizeof(type), 1, 0, \
380 #define tal_dup_arr_label(ctx, type, p, n, extra, label) \
381 ((type *)tal_dup_((ctx), tal_typechk_(p, type *), \
382 sizeof(type), (n), (extra), \
386 * tal_set_backend - set the allocation or error functions to use
387 * @alloc_fn: allocator or NULL (default is malloc)
388 * @resize_fn: re-allocator or NULL (default is realloc)
389 * @free_fn: free function or NULL (default is free)
390 * @error_fn: called on errors or NULL (default is abort)
392 * The defaults are set up so tal functions never return NULL, but you
393 * can override erorr_fn to change that. error_fn can return, and is
394 * called if alloc_fn or resize_fn fail.
396 * If any parameter is NULL, that function is unchanged.
398 void tal_set_backend(void *(*alloc_fn)(size_t size),
399 void *(*resize_fn)(void *, size_t size),
400 void (*free_fn)(void *),
401 void (*error_fn)(const char *msg));
404 * tal_expand - expand a tal array with contents.
405 * @a1p: a pointer to the tal array to expand.
406 * @a2: the second array (can be take()).
407 * @num2: the number of elements in the second array.
409 * Note that *@a1 and @a2 should be the same type. tal_count(@a1) will
410 * be increased by @num2.
413 * int *arr1 = tal_arrz(NULL, int, 2);
414 * int arr2[2] = { 1, 3 };
416 * tal_expand(&arr1, arr2, 2);
417 * assert(tal_count(arr1) == 4);
418 * assert(arr1[2] == 1);
419 * assert(arr1[3] == 3);
421 #define tal_expand(a1p, a2, num2) \
422 tal_expand_((void **)(a1p), (a2), sizeof**(a1p), \
423 (num2) + 0*sizeof(*(a1p) == (a2)))
426 * tal_cleanup - remove pointers from NULL node
428 * Internally, tal keeps a list of nodes allocated from @ctx NULL; this
429 * prevents valgrind from noticing memory leaks. This re-initializes
430 * that list to empty.
432 * It also calls take_cleanup() for you.
434 void tal_cleanup(void);
438 * tal_check - sanity check a tal context and its children.
439 * @ctx: a tal context, or NULL.
440 * @errorstr: a string to prepend calls to error_fn, or NULL.
442 * This sanity-checks a tal tree (unless NDEBUG is defined, in which case
443 * it simply returns true). If errorstr is not null, error_fn is called
444 * when a problem is found, otherwise it is not.
449 bool tal_check(const tal_t *ctx, const char *errorstr);
451 #ifdef CCAN_TAL_DEBUG
453 * tal_dump - dump entire tal tree.
455 * This is a helper for debugging tal itself, which dumps all the tal internal
461 /* Internal support functions */
463 #ifdef CCAN_TAL_NO_LABELS
464 #define TAL_LABEL(type, arr) NULL
466 #ifdef CCAN_TAL_DEBUG
467 #define TAL_LABEL(type, arr) \
468 __FILE__ ":" stringify(__LINE__) ":" stringify(type) arr
470 #define TAL_LABEL(type, arr) stringify(type) arr
471 #endif /* CCAN_TAL_DEBUG */
475 #if HAVE_BUILTIN_CONSTANT_P
476 #define TAL_IS_LITERAL(str) __builtin_constant_p(str)
478 #define TAL_IS_LITERAL(str) (sizeof(&*(str)) != sizeof(char *))
481 bool tal_set_name_(tal_t *ctx, const char *name, bool literal);
484 #define tal_typeof(ptr) (__typeof__(ptr))
485 #if HAVE_STATEMENT_EXPR
486 /* Careful: ptr can be const foo *, ptype is foo *. Also, ptr could
487 * be an array, eg "hello". */
488 #define tal_typechk_(ptr, ptype) ({ __typeof__((ptr)+0) _p = (ptype)(ptr); _p; })
490 #define tal_typechk_(ptr, ptype) (ptr)
492 #else /* !HAVE_TYPEOF */
493 #define tal_typeof(ptr)
494 #define tal_typechk_(ptr, ptype) (ptr)
497 void *tal_alloc_(const tal_t *ctx, size_t bytes, bool clear, const char *label);
498 void *tal_alloc_arr_(const tal_t *ctx, size_t bytes, size_t count, bool clear,
501 void *tal_dup_(const tal_t *ctx, const void *p TAKES, size_t size,
502 size_t n, size_t extra, const char *label);
504 tal_t *tal_steal_(const tal_t *new_parent, const tal_t *t);
506 bool tal_resize_(tal_t **ctxp, size_t size, size_t count, bool clear);
507 bool tal_expand_(tal_t **ctxp, const void *src TAKES, size_t size, size_t count);
509 bool tal_add_destructor_(const tal_t *ctx, void (*destroy)(void *me));
510 bool tal_add_destructor2_(const tal_t *ctx, void (*destroy)(void *me, void *arg),
512 bool tal_del_destructor_(const tal_t *ctx, void (*destroy)(void *me));
513 bool tal_del_destructor2_(const tal_t *ctx, void (*destroy)(void *me, void *arg),
516 bool tal_add_notifier_(const tal_t *ctx, enum tal_notify_type types,
517 void (*notify)(tal_t *ctx, enum tal_notify_type,
519 bool tal_del_notifier_(const tal_t *ctx,
520 void (*notify)(tal_t *ctx, enum tal_notify_type,
522 bool match_extra_arg, void *arg);
523 #endif /* CCAN_TAL_H */