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>
14 * tal_t - convenient alias for void to mark tal pointers.
16 * Since any pointer can be a tal-allocated pointer, it's often
17 * useful to use this typedef to mark them explicitly.
22 * tal - basic allocator function
23 * @ctx: NULL, or tal allocated object to be parent.
24 * @type: the type to allocate.
26 * Allocates a specific type, with a given parent context. The name
27 * of the object is a string of the type, but if CCAN_TAL_DEBUG is
28 * defined it also contains the file and line which allocated it.
31 * int *p = tal(NULL, int);
34 #define tal(ctx, type) \
35 ((type *)tal_alloc_((ctx), sizeof(type), false, false, TAL_LABEL(type, "")))
38 * talz - zeroing allocator function
39 * @ctx: NULL, or tal allocated object to be parent.
40 * @type: the type to allocate.
42 * Equivalent to tal() followed by memset() to zero.
45 * p = talz(NULL, int);
48 #define talz(ctx, type) \
49 ((type *)tal_alloc_((ctx), sizeof(type), true, false, TAL_LABEL(type, "")))
52 * tal_free - free a tal-allocated pointer.
53 * @p: NULL, or tal allocated object to free.
55 * This calls the destructors for p (if any), then does the same for all its
56 * children (recursively) before finally freeing the memory. It returns
57 * NULL, for convenience.
59 * Note: errno is preserved by this call, and also saved and restored
60 * for any destructors or notifiers.
65 void *tal_free(const tal_t *p);
68 * tal_arr - allocate an array of objects.
69 * @ctx: NULL, or tal allocated object to be parent.
70 * @type: the type to allocate.
71 * @count: the number to allocate.
73 * Note that an object allocated with tal_arr() has a length property;
77 * p = tal_arr(NULL, int, 2);
81 #define tal_arr(ctx, type, count) \
82 ((type *)tal_alloc_arr_((ctx), sizeof(type), (count), false, \
83 true, 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 ((type *)tal_alloc_arr_((ctx), sizeof(type), (count), true, \
100 true, TAL_LABEL(type, "[]")))
103 * tal_resize - enlarge or reduce a tal_arr[z].
104 * @p: A pointer to the tal allocated array to resize.
105 * @count: the number to allocate.
107 * This returns true on success (and may move *@p), or false on failure.
108 * If @p has a length property, it is updated on success.
111 * tal_resize(&p, 100);
113 #define tal_resize(p, count) \
114 tal_resize_((void **)(p), sizeof**(p), (count), false)
117 * tal_resizez - enlarge or reduce a tal_arr[z]; zero out extra.
118 * @p: A pointer to the tal allocated array to resize.
119 * @count: the number to allocate.
121 * This returns true on success (and may move *@p), or false on failure.
122 * If @p has a length property, it is updated on success.
123 * On expand, new elements are memset to 0 bytes.
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)))
172 enum tal_notify_type {
174 TAL_NOTIFY_STEAL = 2,
176 TAL_NOTIFY_RESIZE = 8,
177 TAL_NOTIFY_RENAME = 16,
178 TAL_NOTIFY_ADD_CHILD = 32,
179 TAL_NOTIFY_DEL_CHILD = 64,
180 TAL_NOTIFY_ADD_NOTIFIER = 128,
181 TAL_NOTIFY_DEL_NOTIFIER = 256
185 * tal_add_notifier - add a callback function when this context changes.
186 * @ptr: The tal allocated object.
187 * @types: Bitwise OR of the types the callback is interested in.
188 * @callback: the function to call.
190 * Note that this can only fail if your allocfn fails and your errorfn
191 * returns. Also note that notifiers are not reliable in the case
192 * where an allocation fails, as they may be called before any
193 * allocation is actually done.
195 * TAL_NOTIFY_FREE is called when @ptr is freed, either directly or
196 * because an ancestor is freed: @info is the argument to tal_free().
197 * It is exactly equivalent to a destructor, with more information.
198 * errno is set to the value it was at the call of tal_free().
200 * TAL_NOTIFY_STEAL is called when @ptr's parent changes: @info is the
203 * TAL_NOTIFY_MOVE is called when @ptr is realloced (via tal_resize)
204 * and moved. In this case, @ptr arg here is the new memory, and
205 * @info is the old pointer.
207 * TAL_NOTIFY_RESIZE is called when @ptr is realloced via tal_resize:
208 * @info is the new size, in bytes. If the pointer has moved,
209 * TAL_NOTIFY_MOVE callbacks are called first.
211 * TAL_NOTIFY_ADD_CHILD/TAL_NOTIFY_DEL_CHILD are called when @ptr is
212 * the context for a tal() allocating call, or a direct child is
213 * tal_free()d: @info is the child. Note that TAL_NOTIFY_DEL_CHILD is
214 * not called when this context is tal_free()d: TAL_NOTIFY_FREE is
215 * considered sufficient for that case.
217 * TAL_NOTIFY_ADD_NOTIFIER/TAL_NOTIFIER_DEL_NOTIFIER are called when a
218 * notifier is added or removed (not for this notifier): @info is the
219 * callback. This is also called for tal_add_destructor and
220 * tal_del_destructor.
222 #define tal_add_notifier(ptr, types, callback) \
223 tal_add_notifier_((ptr), (types), \
224 typesafe_cb_postargs(void, tal_t *, (callback), \
226 enum tal_notify_type, void *))
229 * tal_del_notifier - remove a notifier callback function.
230 * @ptr: The tal allocated object.
231 * @callback: the function to call.
233 #define tal_del_notifier(ptr, callback) \
234 tal_del_notifier_((ptr), \
235 typesafe_cb_postargs(void, void *, (callback), \
237 enum tal_notify_type, void *))
240 * tal_set_name - attach a name to a tal pointer.
241 * @ptr: The tal allocated object.
242 * @name: The name to use.
244 * The name is copied, unless we're certain it's a string literal.
246 #define tal_set_name(ptr, name) \
247 tal_set_name_((ptr), (name), TAL_IS_LITERAL(name))
250 * tal_name - get the name for a tal pointer.
251 * @ptr: The tal allocated object.
253 * Returns NULL if no name has been set.
255 const char *tal_name(const tal_t *ptr);
258 * tal_count - get the count of objects in a tal_arr.
259 * @ptr: The tal allocated object array.
261 * Returns 0 if @ptr has no length property, but be aware that that is
264 #define tal_count(p) (tal_len(p) / sizeof(*p))
267 * tal_len - get the count of bytes in a tal_arr.
268 * @ptr: The tal allocated object array.
270 * Returns 0 if @ptr has no length property, but be aware that that is
273 size_t tal_len(const tal_t *ptr);
276 * tal_first - get the first immediate tal object child.
277 * @root: The tal allocated object to start with, or NULL.
279 * Returns NULL if there are no children.
281 tal_t *tal_first(const tal_t *root);
284 * tal_next - get the next immediate tal object child.
285 * @prev: The return value from tal_first or tal_next.
287 * Returns NULL if there are no more immediate children. This should be safe to
288 * call on an altering tree unless @prev is no longer valid.
290 tal_t *tal_next(const tal_t *prev);
293 * tal_parent - get the parent of a tal object.
294 * @ctx: The tal allocated object.
296 * Returns the parent, which may be NULL. Returns NULL if @ctx is NULL.
298 tal_t *tal_parent(const tal_t *ctx);
301 * tal_dup - duplicate an object.
302 * @ctx: The tal allocated object to be parent of the result (may be NULL).
303 * @type: the type (should match type of @p!)
304 * @p: the object to copy (or reparented if take())
306 #define tal_dup(ctx, type, p) \
307 ((type *)tal_dup_((ctx), tal_typechk_(p, type *), \
308 sizeof(type), 1, 0, \
309 false, TAL_LABEL(type, "")))
312 * tal_dup_arr - duplicate an array.
313 * @ctx: The tal allocated object to be parent of the result (may be NULL).
314 * @type: the type (should match type of @p!)
315 * @p: the array to copy (or resized & reparented if take())
316 * @n: the number of sizeof(type) entries to copy.
317 * @extra: the number of extra sizeof(type) entries to allocate.
319 #define tal_dup_arr(ctx, type, p, n, extra) \
320 ((type *)tal_dup_((ctx), tal_typechk_(p, type *), \
321 sizeof(type), (n), (extra), \
322 true, TAL_LABEL(type, "[]")))
326 * tal_set_backend - set the allocation or error functions to use
327 * @alloc_fn: allocator or NULL (default is malloc)
328 * @resize_fn: re-allocator or NULL (default is realloc)
329 * @free_fn: free function or NULL (default is free)
330 * @error_fn: called on errors or NULL (default is abort)
332 * The defaults are set up so tal functions never return NULL, but you
333 * can override erorr_fn to change that. error_fn can return, and is
334 * called if alloc_fn or resize_fn fail.
336 * If any parameter is NULL, that function is unchanged.
338 void tal_set_backend(void *(*alloc_fn)(size_t size),
339 void *(*resize_fn)(void *, size_t size),
340 void (*free_fn)(void *),
341 void (*error_fn)(const char *msg));
344 * tal_expand - expand a tal array with contents.
345 * @a1p: a pointer to the tal array to expand.
346 * @a2: the second array (can be take()).
347 * @num2: the number of elements in the second array.
349 * Note that *@a1 and @a2 should be the same type. tal_count(@a1) will
350 * be increased by @num2.
353 * int *arr1 = tal_arrz(NULL, int, 2);
354 * int arr2[2] = { 1, 3 };
356 * tal_expand(&arr1, arr2, 2);
357 * assert(tal_count(arr1) == 4);
358 * assert(arr1[2] == 1);
359 * assert(arr1[3] == 3);
361 #define tal_expand(a1p, a2, num2) \
362 tal_expand_((void **)(a1p), (a2), sizeof**(a1p), \
363 (num2) + 0*sizeof(*(a1p) == (a2)))
366 * tal_cleanup - remove pointers from NULL node
368 * Internally, tal keeps a list of nodes allocated from @ctx NULL; this
369 * prevents valgrind from noticing memory leaks. This re-initializes
370 * that list to empty.
372 * It also calls take_cleanup() for you.
374 void tal_cleanup(void);
378 * tal_check - sanity check a tal context and its children.
379 * @ctx: a tal context, or NULL.
380 * @errorstr: a string to prepend calls to error_fn, or NULL.
382 * This sanity-checks a tal tree (unless NDEBUG is defined, in which case
383 * it simply returns true). If errorstr is not null, error_fn is called
384 * when a problem is found, otherwise it is not.
389 bool tal_check(const tal_t *ctx, const char *errorstr);
391 #ifdef CCAN_TAL_DEBUG
393 * tal_dump - dump entire tal tree.
395 * This is a helper for debugging tal itself, which dumps all the tal internal
401 /* Internal support functions */
403 #ifdef CCAN_TAL_NO_LABELS
404 #define TAL_LABEL(type, arr) NULL
406 #ifdef CCAN_TAL_DEBUG
407 #define TAL_LABEL(type, arr) \
408 __FILE__ ":" stringify(__LINE__) ":" stringify(type) arr
410 #define TAL_LABEL(type, arr) stringify(type) arr
411 #endif /* CCAN_TAL_DEBUG */
415 #if HAVE_BUILTIN_CONSTANT_P
416 #define TAL_IS_LITERAL(str) __builtin_constant_p(str)
418 #define TAL_IS_LITERAL(str) (sizeof(&*(str)) != sizeof(char *))
421 bool tal_set_name_(tal_t *ctx, const char *name, bool literal);
424 #define tal_typeof(ptr) (__typeof__(ptr))
425 #if HAVE_STATEMENT_EXPR
426 /* Careful: ptr can be const foo *, ptype is foo *. Also, ptr could
427 * be an array, eg "hello". */
428 #define tal_typechk_(ptr, ptype) ({ __typeof__((ptr)+0) _p = (ptype)(ptr); _p; })
430 #define tal_typechk_(ptr, ptype) (ptr)
432 #else /* !HAVE_TYPEOF */
433 #define tal_typeof(ptr)
434 #define tal_typechk_(ptr, ptype) (ptr)
437 void *tal_alloc_(const tal_t *ctx, size_t bytes, bool clear,
438 bool add_length, const char *label);
439 void *tal_alloc_arr_(const tal_t *ctx, size_t bytes, size_t count, bool clear,
440 bool add_length, const char *label);
442 void *tal_dup_(const tal_t *ctx, const void *p, size_t size,
443 size_t n, size_t extra, bool add_length,
446 tal_t *tal_steal_(const tal_t *new_parent, const tal_t *t);
448 bool tal_resize_(tal_t **ctxp, size_t size, size_t count, bool clear);
449 bool tal_expand_(tal_t **ctxp, const void *src, size_t size, size_t count);
451 bool tal_add_destructor_(const tal_t *ctx, void (*destroy)(void *me));
452 bool tal_del_destructor_(const tal_t *ctx, void (*destroy)(void *me));
454 bool tal_add_notifier_(const tal_t *ctx, enum tal_notify_type types,
455 void (*notify)(tal_t *ctx, enum tal_notify_type,
457 bool tal_del_notifier_(const tal_t *ctx,
458 void (*notify)(tal_t *ctx, enum tal_notify_type,
460 #endif /* CCAN_TAL_H */