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, 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, 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.
64 void *tal_free(const tal_t *p);
67 * tal_arr - allocate an array of objects.
68 * @ctx: NULL, or tal allocated object to be parent.
69 * @type: the type to allocate.
70 * @count: the number to allocate.
72 * Note that an object allocated with tal_arr() has a length property;
76 * p = tal_arr(NULL, int, 2);
80 #define tal_arr(ctx, type, count) \
81 ((type *)tal_alloc_arr_((ctx), sizeof(type), (count), false, \
82 true, TAL_LABEL(type, "[]")))
85 * tal_arrz - allocate an array of zeroed objects.
86 * @ctx: NULL, or tal allocated object to be parent.
87 * @type: the type to allocate.
88 * @count: the number to allocate.
90 * Note that an object allocated with tal_arrz() has a length property;
94 * p = tal_arrz(NULL, int, 2);
95 * assert(p[0] == 0 && p[1] == 0);
97 #define tal_arrz(ctx, type, count) \
98 ((type *)tal_alloc_arr_((ctx), sizeof(type), (count), true, \
99 true, 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)))
171 enum tal_notify_type {
173 TAL_NOTIFY_STEAL = 2,
175 TAL_NOTIFY_RESIZE = 8,
176 TAL_NOTIFY_RENAME = 16,
177 TAL_NOTIFY_ADD_CHILD = 32,
178 TAL_NOTIFY_DEL_CHILD = 64,
179 TAL_NOTIFY_ADD_NOTIFIER = 128,
180 TAL_NOTIFY_DEL_NOTIFIER = 256
184 * tal_add_notifier - add a callback function when this context changes.
185 * @ptr: The tal allocated object.
186 * @types: Bitwise OR of the types the callback is interested in.
187 * @callback: the function to call.
189 * Note that this can only fail if your allocfn fails and your errorfn
190 * returns. Also note that notifiers are not reliable in the case
191 * where an allocation fails, as they may be called before any
192 * allocation is actually done.
194 * TAL_NOTIFY_FREE is called when @ptr is freed, either directly or
195 * because an ancestor is freed: @info is the argument to tal_free().
196 * It is exactly equivalent to a destructor, with more information.
198 * TAL_NOTIFY_STEAL is called when @ptr's parent changes: @info is the
201 * TAL_NOTIFY_MOVE is called when @ptr is realloced (via tal_resize)
202 * and moved. In this case, @ptr arg here is the new memory, and
203 * @info is the old pointer.
205 * TAL_NOTIFY_RESIZE is called when @ptr is realloced via tal_resize:
206 * @info is the new size, in bytes. If the pointer has moved,
207 * TAL_NOTIFY_MOVE callbacks are called first.
209 * TAL_NOTIFY_ADD_CHILD/TAL_NOTIFY_DEL_CHILD are called when @ptr is
210 * the context for a tal() allocating call, or a direct child is
211 * tal_free()d: @info is the child. Note that TAL_NOTIFY_DEL_CHILD is
212 * not called when this context is tal_free()d: TAL_NOTIFY_FREE is
213 * considered sufficient for that case.
215 * TAL_NOTIFY_ADD_NOTIFIER/TAL_NOTIFIER_DEL_NOTIFIER are called when a
216 * notifier is added or removed (not for this notifier): @info is the
217 * callback. This is also called for tal_add_destructor and
218 * tal_del_destructor.
220 #define tal_add_notifier(ptr, types, callback) \
221 tal_add_notifier_((ptr), (types), \
222 typesafe_cb_postargs(void, tal_t *, (callback), \
224 enum tal_notify_type, void *))
227 * tal_del_notifier - remove a notifier callback function.
228 * @ptr: The tal allocated object.
229 * @callback: the function to call.
231 #define tal_del_notifier(ptr, callback) \
232 tal_del_notifier_((ptr), \
233 typesafe_cb_postargs(void, void *, (callback), \
235 enum tal_notify_type, void *))
238 * tal_set_name - attach a name to a tal pointer.
239 * @ptr: The tal allocated object.
240 * @name: The name to use.
242 * The name is copied, unless we're certain it's a string literal.
244 #define tal_set_name(ptr, name) \
245 tal_set_name_((ptr), (name), TAL_IS_LITERAL(name))
248 * tal_name - get the name for a tal pointer.
249 * @ptr: The tal allocated object.
251 * Returns NULL if no name has been set.
253 const char *tal_name(const tal_t *ptr);
256 * tal_count - get the count of objects in a tal_arr.
257 * @ptr: The tal allocated object array.
259 * Returns 0 if @ptr has no length property, but we aware that that is
262 size_t tal_count(const tal_t *ptr);
265 * tal_first - get the first tal object child.
266 * @root: The tal allocated object to start with, or NULL.
268 * Returns NULL if there are no children.
270 tal_t *tal_first(const tal_t *root);
273 * tal_next - get the next tal object child.
274 * @root: The tal allocated object to start with, or NULL.
275 * @prev: The return value from tal_first or tal_next.
277 * Returns NULL if there are no more children. This should be safe to
278 * call on an altering tree unless @prev is no longer a descendent of
281 tal_t *tal_next(const tal_t *root, const tal_t *prev);
284 * tal_parent - get the parent of a tal object.
285 * @ctx: The tal allocated object.
287 * Returns the parent, which may be NULL. Returns NULL if @ctx is NULL.
289 tal_t *tal_parent(const tal_t *ctx);
292 * tal_dup - duplicate an object.
293 * @ctx: The tal allocated object to be parent of the result (may be NULL).
294 * @type: the type (should match type of @p!)
295 * @p: the object to copy (or reparented if take())
297 #define tal_dup(ctx, type, p) \
298 ((type *)tal_dup_((ctx), tal_typechk_(p, type *), \
299 sizeof(type), 1, 0, \
300 false, TAL_LABEL(type, "")))
303 * tal_dup_arr - duplicate an array.
304 * @ctx: The tal allocated object to be parent of the result (may be NULL).
305 * @type: the type (should match type of @p!)
306 * @p: the array to copy (or resized & reparented if take())
307 * @n: the number of sizeof(type) entries to copy.
308 * @extra: the number of extra sizeof(type) entries to allocate.
310 #define tal_dup_arr(ctx, type, p, n, extra) \
311 ((type *)tal_dup_((ctx), tal_typechk_(p, type *), \
312 sizeof(type), (n), (extra), \
313 true, TAL_LABEL(type, "[]")))
317 * tal_set_backend - set the allocation or error functions to use
318 * @alloc_fn: allocator or NULL (default is malloc)
319 * @resize_fn: re-allocator or NULL (default is realloc)
320 * @free_fn: free function or NULL (default is free)
321 * @error_fn: called on errors or NULL (default is abort)
323 * The defaults are set up so tal functions never return NULL, but you
324 * can override erorr_fn to change that. error_fn can return, and is
325 * called if alloc_fn or resize_fn fail.
327 * If any parameter is NULL, that function is unchanged.
329 void tal_set_backend(void *(*alloc_fn)(size_t size),
330 void *(*resize_fn)(void *, size_t size),
331 void (*free_fn)(void *),
332 void (*error_fn)(const char *msg));
335 * tal_expand - expand a tal array with contents.
336 * @a1p: a pointer to the tal array to expand.
337 * @a2: the second array (can be take()).
338 * @num2: the number of elements in the second array.
340 * Note that *@a1 and @a2 should be the same type. tal_count(@a1) will
341 * be increased by @num2.
344 * int *arr1 = tal_arrz(NULL, int, 2);
345 * int arr2[2] = { 1, 3 };
347 * tal_expand(&arr1, arr2, 2);
348 * assert(tal_count(arr1) == 4);
349 * assert(arr1[2] == 1);
350 * assert(arr1[3] == 3);
352 #define tal_expand(a1p, a2, num2) \
353 tal_expand_((void **)(a1p), (a2), sizeof**(a1p), \
354 (num2) + 0*sizeof(*(a1p) == (a2)))
357 * tal_cleanup - remove pointers from NULL node
359 * Internally, tal keeps a list of nodes allocated from @ctx NULL; this
360 * prevents valgrind from noticing memory leaks. This re-initializes
361 * that list to empty.
363 * It also calls take_cleanup() for you.
365 void tal_cleanup(void);
369 * tal_check - sanity check a tal context and its children.
370 * @ctx: a tal context, or NULL.
371 * @errorstr: a string to prepend calls to error_fn, or NULL.
373 * This sanity-checks a tal tree (unless NDEBUG is defined, in which case
374 * it simply returns true). If errorstr is not null, error_fn is called
375 * when a problem is found, otherwise it is not.
380 bool tal_check(const tal_t *ctx, const char *errorstr);
382 #ifdef CCAN_TAL_DEBUG
384 * tal_dump - dump entire tal tree.
386 * This is a helper for debugging tal itself, which dumps all the tal internal
392 /* Internal support functions */
394 #ifdef CCAN_TAL_NO_LABELS
395 #define TAL_LABEL(type, arr) NULL
397 #ifdef CCAN_TAL_DEBUG
398 #define TAL_LABEL(type, arr) \
399 __FILE__ ":" stringify(__LINE__) ":" stringify(type) arr
401 #define TAL_LABEL(type, arr) stringify(type) arr
402 #endif /* CCAN_TAL_DEBUG */
406 #if HAVE_BUILTIN_CONSTANT_P
407 #define TAL_IS_LITERAL(str) __builtin_constant_p(str)
409 #define TAL_IS_LITERAL(str) (sizeof(&*(str)) != sizeof(char *))
412 bool tal_set_name_(tal_t *ctx, const char *name, bool literal);
415 #define tal_typeof(ptr) (__typeof__(ptr))
416 #if HAVE_STATEMENT_EXPR
417 /* Careful: ptr can be const foo *, ptype is foo *. Also, ptr could
418 * be an array, eg "hello". */
419 #define tal_typechk_(ptr, ptype) ({ __typeof__((ptr)+0) _p = (ptype)(ptr); _p; })
421 #define tal_typechk_(ptr, ptype) (ptr)
423 #else /* !HAVE_TYPEOF */
424 #define tal_typeof(ptr)
425 #define tal_typechk_(ptr, ptype) (ptr)
428 void *tal_alloc_(const tal_t *ctx, size_t bytes, bool clear, const char *label);
429 void *tal_alloc_arr_(const tal_t *ctx, size_t bytes, size_t count, bool clear,
430 bool add_count, const char *label);
432 void *tal_dup_(const tal_t *ctx, const void *p, size_t size,
433 size_t n, size_t extra, bool add_count,
436 tal_t *tal_steal_(const tal_t *new_parent, const tal_t *t);
438 bool tal_resize_(tal_t **ctxp, size_t size, size_t count, bool clear);
439 bool tal_expand_(tal_t **ctxp, const void *src, size_t size, size_t count);
441 bool tal_add_destructor_(const tal_t *ctx, void (*destroy)(void *me));
442 bool tal_del_destructor_(const tal_t *ctx, void (*destroy)(void *me));
444 bool tal_add_notifier_(const tal_t *ctx, enum tal_notify_type types,
445 void (*notify)(tal_t *ctx, enum tal_notify_type,
447 bool tal_del_notifier_(const tal_t *ctx,
448 void (*notify)(tal_t *ctx, enum tal_notify_type,
450 #endif /* CCAN_TAL_H */