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))
116 * tal_steal - change the parent of a tal-allocated pointer.
117 * @ctx: The new parent.
118 * @ptr: The tal allocated object to move.
120 * This may need to perform an allocation, in which case it may fail; thus
121 * it can return NULL, otherwise returns @ptr.
123 #if HAVE_STATEMENT_EXPR
124 /* Weird macro avoids gcc's 'warning: value computed is not used'. */
125 #define tal_steal(ctx, ptr) \
126 ({ (tal_typeof(ptr) tal_steal_((ctx),(ptr))); })
128 #define tal_steal(ctx, ptr) \
129 (tal_typeof(ptr) tal_steal_((ctx),(ptr)))
133 * tal_add_destructor - add a callback function when this context is destroyed.
134 * @ptr: The tal allocated object.
135 * @function: the function to call before it's freed.
137 * This is a more convenient form of tal_add_notifier(@ptr,
138 * TAL_NOTIFY_FREE, ...), in that the function prototype takes only @ptr.
140 * Note that this can only fail if your allocfn fails and your errorfn returns.
142 #define tal_add_destructor(ptr, function) \
143 tal_add_destructor_((ptr), typesafe_cb(void, void *, (function), (ptr)))
146 * tal_del_destructor - remove a destructor callback function.
147 * @ptr: The tal allocated object.
148 * @function: the function to call before it's freed.
150 * If @function has not been successfully added as a destructor, this returns
153 #define tal_del_destructor(ptr, function) \
154 tal_del_destructor_((ptr), typesafe_cb(void, void *, (function), (ptr)))
156 enum tal_notify_type {
158 TAL_NOTIFY_STEAL = 2,
160 TAL_NOTIFY_RESIZE = 8,
161 TAL_NOTIFY_RENAME = 16,
162 TAL_NOTIFY_ADD_CHILD = 32,
163 TAL_NOTIFY_DEL_CHILD = 64,
164 TAL_NOTIFY_ADD_NOTIFIER = 128,
165 TAL_NOTIFY_DEL_NOTIFIER = 256
169 * tal_add_notifier - add a callback function when this context changes.
170 * @ptr: The tal allocated object.
171 * @types: Bitwise OR of the types the callback is interested in.
172 * @callback: the function to call.
174 * Note that this can only fail if your allocfn fails and your errorfn
175 * returns. Also note that notifiers are not reliable in the case
176 * where an allocation fails, as they may be called before any
177 * allocation is actually done.
179 * TAL_NOTIFY_FREE is called when @ptr is freed, either directly or
180 * because an ancestor is freed: @info is the argument to tal_free().
181 * It is exactly equivalent to a destructor, with more information.
183 * TAL_NOTIFY_STEAL is called when @ptr's parent changes: @info is the
186 * TAL_NOTIFY_MOVE is called when @ptr is realloced (via tal_resize)
187 * and moved. In this case, @ptr arg here is the new memory, and
188 * @info is the old pointer.
190 * TAL_NOTIFY_RESIZE is called when @ptr is realloced via tal_resize:
191 * @info is the new size, in bytes. If the pointer has moved,
192 * TAL_NOTIFY_MOVE callbacks are called first.
194 * TAL_NOTIFY_ADD_CHILD/TAL_NOTIFY_DEL_CHILD are called when @ptr is
195 * the context for a tal() allocating call, or a direct child is
196 * tal_free()d: @info is the child. Note that TAL_NOTIFY_DEL_CHILD is
197 * not called when this context is tal_free()d: TAL_NOTIFY_FREE is
198 * considered sufficient for that case.
200 * TAL_NOTIFY_ADD_NOTIFIER/TAL_NOTIFIER_DEL_NOTIFIER are called when a
201 * notifier is added or removed (not for this notifier): @info is the
202 * callback. This is also called for tal_add_destructor and
203 * tal_del_destructor.
205 #define tal_add_notifier(ptr, types, callback) \
206 tal_add_notifier_((ptr), (types), \
207 typesafe_cb_postargs(void, tal_t *, (callback), \
209 enum tal_notify_type, void *))
212 * tal_del_notifier - remove a notifier callback function.
213 * @ptr: The tal allocated object.
214 * @callback: the function to call.
216 #define tal_del_notifier(ptr, callback) \
217 tal_del_notifier_((ptr), \
218 typesafe_cb_postargs(void, void *, (callback), \
220 enum tal_notify_type, void *))
223 * tal_set_name - attach a name to a tal pointer.
224 * @ptr: The tal allocated object.
225 * @name: The name to use.
227 * The name is copied, unless we're certain it's a string literal.
229 #define tal_set_name(ptr, name) \
230 tal_set_name_((ptr), (name), TAL_IS_LITERAL(name))
233 * tal_name - get the name for a tal pointer.
234 * @ptr: The tal allocated object.
236 * Returns NULL if no name has been set.
238 const char *tal_name(const tal_t *ptr);
241 * tal_count - get the count of objects in a tal_arr.
242 * @ptr: The tal allocated object array.
244 * Returns 0 if @ptr has no length property, but we aware that that is
247 size_t tal_count(const tal_t *ptr);
250 * tal_first - get the first tal object child.
251 * @root: The tal allocated object to start with, or NULL.
253 * Returns NULL if there are no children.
255 tal_t *tal_first(const tal_t *root);
258 * tal_next - get the next tal object child.
259 * @root: The tal allocated object to start with, or NULL.
260 * @prev: The return value from tal_first or tal_next.
262 * Returns NULL if there are no more children. This should be safe to
263 * call on an altering tree unless @prev is no longer a descendent of
266 tal_t *tal_next(const tal_t *root, const tal_t *prev);
269 * tal_parent - get the parent of a tal object.
270 * @ctx: The tal allocated object.
272 * Returns the parent, which may be NULL. Returns NULL if @ctx is NULL.
274 tal_t *tal_parent(const tal_t *ctx);
277 * tal_dup - duplicate an array.
278 * @ctx: The tal allocated object to be parent of the result (may be NULL).
279 * @type: the type (should match type of @p!)
280 * @p: the array to copy (or resized & reparented if take())
281 * @n: the number of sizeof(type) entries to copy.
282 * @extra: the number of extra sizeof(type) entries to allocate.
284 #define tal_dup(ctx, type, p, n, extra) \
285 ((type *)tal_dup_((ctx), tal_typechk_(p, type *), \
286 sizeof(type), (n), (extra), \
287 true, TAL_LABEL(type, "[]")))
291 * tal_set_backend - set the allocation or error functions to use
292 * @alloc_fn: allocator or NULL (default is malloc)
293 * @resize_fn: re-allocator or NULL (default is realloc)
294 * @free_fn: free function or NULL (default is free)
295 * @error_fn: called on errors or NULL (default is abort)
297 * The defaults are set up so tal functions never return NULL, but you
298 * can override erorr_fn to change that. error_fn can return, and is
299 * called if alloc_fn or resize_fn fail.
301 * If any parameter is NULL, that function is unchanged.
303 void tal_set_backend(void *(*alloc_fn)(size_t size),
304 void *(*resize_fn)(void *, size_t size),
305 void (*free_fn)(void *),
306 void (*error_fn)(const char *msg));
309 * tal_expand - expand a tal array with contents.
310 * @a1p: a pointer to the tal array to expand.
311 * @a2: the second array (can be take()).
312 * @num2: the number of elements in the second array.
314 * Note that *@a1 and @a2 should be the same type. tal_count(@a1) will
315 * be increased by @num2.
318 * int *arr1 = tal_arrz(NULL, int, 2);
319 * int arr2[2] = { 1, 3 };
321 * tal_expand(&arr1, arr2, 2);
322 * assert(tal_count(arr1) == 4);
323 * assert(arr1[2] == 1);
324 * assert(arr1[3] == 3);
326 #define tal_expand(a1p, a2, num2) \
327 tal_expand_((void **)(a1p), (a2), sizeof**(a1p), \
328 (num2) + 0*sizeof(*(a1p) == (a2)))
332 * tal_check - set the allocation or error functions to use
333 * @ctx: a tal context, or NULL.
334 * @errorstr: a string to prepend calls to error_fn, or NULL.
336 * This sanity-checks a tal tree (unless NDEBUG is defined, in which case
337 * it simply returns true). If errorstr is not null, error_fn is called
338 * when a problem is found, otherwise it is not.
340 bool tal_check(const tal_t *ctx, const char *errorstr);
342 #ifdef CCAN_TAL_DEBUG
344 * tal_dump - dump entire tal tree.
346 * This is a helper for debugging tal itself, which dumps all the tal internal
352 /* Internal support functions */
354 #ifdef CCAN_TAL_NO_LABELS
355 #define TAL_LABEL(type, arr) NULL
357 #ifdef CCAN_TAL_DEBUG
358 #define TAL_LABEL(type, arr) \
359 __FILE__ ":" stringify(__LINE__) ":" stringify(type) arr
361 #define TAL_LABEL(type, arr) stringify(type) arr
362 #endif /* CCAN_TAL_DEBUG */
366 #if HAVE_BUILTIN_CONSTANT_P
367 #define TAL_IS_LITERAL(str) __builtin_constant_p(str)
369 #define TAL_IS_LITERAL(str) (sizeof(&*(str)) != sizeof(char *))
372 bool tal_set_name_(tal_t *ctx, const char *name, bool literal);
375 #define tal_typeof(ptr) (__typeof__(ptr))
376 #if HAVE_STATEMENT_EXPR
377 /* Careful: ptr can be const foo *, ptype is foo *. Also, ptr could
378 * be an array, eg "hello". */
379 #define tal_typechk_(ptr, ptype) ({ __typeof__((ptr)+0) _p = (ptype)(ptr); _p; })
381 #define tal_typechk_(ptr, ptype) (ptr)
383 #else /* !HAVE_TYPEOF */
384 #define tal_typeof(ptr)
385 #define tal_typechk_(ptr, ptype) (ptr)
388 void *tal_alloc_(const tal_t *ctx, size_t bytes, bool clear, const char *label);
389 void *tal_alloc_arr_(const tal_t *ctx, size_t bytes, size_t count, bool clear,
390 bool add_count, const char *label);
392 void *tal_dup_(const tal_t *ctx, const void *p, size_t size,
393 size_t n, size_t extra, bool add_count,
396 tal_t *tal_steal_(const tal_t *new_parent, const tal_t *t);
398 bool tal_resize_(tal_t **ctxp, size_t size, size_t count);
399 bool tal_expand_(tal_t **ctxp, const void *src, size_t size, size_t count);
401 bool tal_add_destructor_(const tal_t *ctx, void (*destroy)(void *me));
402 bool tal_del_destructor_(const tal_t *ctx, void (*destroy)(void *me));
404 bool tal_add_notifier_(const tal_t *ctx, enum tal_notify_type types,
405 void (*notify)(tal_t *ctx, enum tal_notify_type,
407 bool tal_del_notifier_(const tal_t *ctx,
408 void (*notify)(tal_t *ctx, enum tal_notify_type,
410 #endif /* CCAN_TAL_H */