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.
73 * p = tal_arr(NULL, int, 2);
77 #define tal_arr(ctx, type, count) \
78 ((type *)tal_alloc_((ctx), tal_sizeof_(sizeof(type), (count)), false, \
79 TAL_LABEL(type, "[]")))
82 * tal_arrz - allocate an array of zeroed objects.
83 * @ctx: NULL, or tal allocated object to be parent.
84 * @type: the type to allocate.
85 * @count: the number to allocate.
88 * p = tal_arrz(NULL, int, 2);
89 * assert(p[0] == 0 && p[1] == 0);
91 #define tal_arrz(ctx, type, count) \
92 ((type *)tal_alloc_((ctx), tal_sizeof_(sizeof(type), (count)), true, \
93 TAL_LABEL(type, "[]")))
96 * tal_resize - enlarge or reduce a tal_arr[z].
97 * @p: A pointer to the tal allocated array to resize.
98 * @count: the number to allocate.
100 * This returns true on success (and may move *@p), or false on failure.
103 * tal_resize(&p, 100);
105 #define tal_resize(p, count) \
106 tal_resize_((void **)(p), tal_sizeof_(sizeof**(p), (count)))
109 * tal_steal - change the parent of a tal-allocated pointer.
110 * @ctx: The new parent.
111 * @ptr: The tal allocated object to move.
113 * This may need to perform an allocation, in which case it may fail; thus
114 * it can return NULL, otherwise returns @ptr.
116 #if HAVE_STATEMENT_EXPR
117 /* Weird macro avoids gcc's 'warning: value computed is not used'. */
118 #define tal_steal(ctx, ptr) \
119 ({ (tal_typeof(ptr) tal_steal_((ctx),(ptr))); })
121 #define tal_steal(ctx, ptr) \
122 (tal_typeof(ptr) tal_steal_((ctx),(ptr)))
126 * tal_add_destructor - add a callback function when this context is destroyed.
127 * @ptr: The tal allocated object.
128 * @function: the function to call before it's freed.
130 * Note that this can only fail if your allocfn fails and your errorfn returns.
132 #define tal_add_destructor(ptr, function) \
133 tal_add_destructor_((ptr), typesafe_cb(void, void *, (function), (ptr)))
136 * tal_del_destructor - remove a destructor callback function.
137 * @ptr: The tal allocated object.
138 * @function: the function to call before it's freed.
140 * If @function has not been successfully added as a destructor, this returns
143 #define tal_del_destructor(ptr, function) \
144 tal_del_destructor_((ptr), typesafe_cb(void, void *, (function), (ptr)))
146 enum tal_notify_type {
148 TAL_NOTIFY_STEAL = 2,
150 TAL_NOTIFY_RESIZE = 8,
151 TAL_NOTIFY_RENAME = 16,
152 TAL_NOTIFY_ADD_CHILD = 32,
153 TAL_NOTIFY_DEL_CHILD = 64,
154 TAL_NOTIFY_ADD_NOTIFIER = 128,
155 TAL_NOTIFY_DEL_NOTIFIER = 256
159 * tal_add_notifier - add a callback function when this context changes.
160 * @ptr: The tal allocated object.
161 * @types: Bitwise OR of the types the callback is interested in.
162 * @callback: the function to call.
164 * Note that this can only fail if your allocfn fails and your errorfn
165 * returns. Also note that notifiers are not reliable in the case
166 * where an allocation fails, as they may be called before any
167 * allocation is actually done.
169 * TAL_NOTIFY_FREE is called when @ptr is freed, either directly or
170 * because an ancestor is freed: @info is the argument to tal_free().
171 * It is exactly equivalent to a destructor, with more information.
173 * TAL_NOTIFY_STEAL is called when @ptr's parent changes: @info is the
176 * TAL_NOTIFY_MOVE is called when @ptr is realloced (via tal_resize)
177 * and moved. In this case, @ptr arg here is the new memory, and
178 * @info is the old pointer.
180 * TAL_NOTIFY_RESIZE is called when @ptr is realloced via tal_resize:
181 * @info is the new size, in bytes. If the pointer has moved,
182 * TAL_NOTIFY_MOVE callbacks are called first.
184 * TAL_NOTIFY_ADD_CHILD/TAL_NOTIFY_DEL_CHILD are called when @ptr is
185 * the context for a tal() allocating call, or a direct child is
186 * tal_free()d: @info is the child. Note that TAL_NOTIFY_DEL_CHILD is
187 * not called when this context is tal_free()d: TAL_NOTIFY_FREE is
188 * considered sufficient for that case.
190 * TAL_NOTIFY_ADD_NOTIFIER/TAL_NOTIFIER_DEL_NOTIFIER are called when
191 * a notifier is added or removed (not for this notifier): @info is the
194 #define tal_add_notifier(ptr, types, callback) \
195 tal_add_notifier_((ptr), (types), \
196 typesafe_cb_postargs(void, tal_t *, (callback), \
198 enum tal_notify_type, void *))
201 * tal_del_notifier - remove a notifier callback function.
202 * @ptr: The tal allocated object.
203 * @callback: the function to call.
205 #define tal_del_notifier(ptr, callback) \
206 tal_del_notifier_((ptr), \
207 typesafe_cb_postargs(void, void *, (callback), \
209 enum tal_notify_type, void *))
212 * tal_set_name - attach a name to a tal pointer.
213 * @ptr: The tal allocated object.
214 * @name: The name to use.
216 * The name is copied, unless we're certain it's a string literal.
218 #define tal_set_name(ptr, name) \
219 tal_set_name_((ptr), (name), TAL_IS_LITERAL(name))
222 * tal_name - get the name for a tal pointer.
223 * @ptr: The tal allocated object.
225 * Returns NULL if no name has been set.
227 const char *tal_name(const tal_t *ptr);
230 * tal_first - get the first tal object child.
231 * @root: The tal allocated object to start with, or NULL.
233 * Returns NULL if there are no children.
235 tal_t *tal_first(const tal_t *root);
238 * tal_next - get the next tal object child.
239 * @root: The tal allocated object to start with, or NULL.
240 * @prev: The return value from tal_first or tal_next.
242 * Returns NULL if there are no more children. This should be safe to
243 * call on an altering tree unless @prev is no longer a descendent of
246 tal_t *tal_next(const tal_t *root, const tal_t *prev);
249 * tal_parent - get the parent of a tal object.
250 * @ctx: The tal allocated object.
252 * Returns the parent, which may be NULL. Returns NULL if @ctx is NULL.
254 tal_t *tal_parent(const tal_t *ctx);
257 * tal_dup - duplicate an array.
258 * @ctx: The tal allocated object to be parent of the result (may be NULL).
259 * @type: the type (should match type of @p!)
260 * @p: the array to copy (or resized & reparented if take())
261 * @n: the number of sizeof(type) entries to copy.
262 * @extra: the number of extra sizeof(type) entries to allocate.
264 #define tal_dup(ctx, type, p, n, extra) \
265 ((type *)tal_dup_((ctx), tal_typechk_(p, type *), \
266 tal_sizeof_(sizeof(type), (n)), \
267 tal_sizeof_(sizeof(type), (extra)), \
268 TAL_LABEL(type, "[]")))
271 * tal_strdup - duplicate a string
272 * @ctx: NULL, or tal allocated object to be parent.
273 * @p: the string to copy (can be take()).
275 char *tal_strdup(const tal_t *ctx, const char *p);
278 * tal_strndup - duplicate a limited amount of a string.
279 * @ctx: NULL, or tal allocated object to be parent.
280 * @p: the string to copy (can be take()).
281 * @n: the maximum length to copy.
283 * Always gives a nul-terminated string, with strlen() <= @n.
285 char *tal_strndup(const tal_t *ctx, const char *p, size_t n);
288 * tal_asprintf - allocate a formatted string
289 * @ctx: NULL, or tal allocated object to be parent.
290 * @fmt: the printf-style format (can be take()).
292 char *tal_asprintf(const tal_t *ctx, const char *fmt, ...) PRINTF_FMT(2,3);
295 * tal_vasprintf - allocate a formatted string (va_list version)
296 * @ctx: NULL, or tal allocated object to be parent.
297 * @fmt: the printf-style format (can be take()).
298 * @va: the va_list containing the format args.
300 char *tal_vasprintf(const tal_t *ctx, const char *fmt, va_list ap)
305 * tal_set_backend - set the allocation or error functions to use
306 * @alloc_fn: allocator or NULL (default is malloc)
307 * @resize_fn: re-allocator or NULL (default is realloc)
308 * @free_fn: free function or NULL (default is free)
309 * @error_fn: called on errors or NULL (default is abort)
311 * The defaults are set up so tal functions never return NULL, but you
312 * can override erorr_fn to change that. error_fn can return, and is
313 * called if alloc_fn or resize_fn fail.
315 * If any parameter is NULL, that function is unchanged.
317 void tal_set_backend(void *(*alloc_fn)(size_t size),
318 void *(*resize_fn)(void *, size_t size),
319 void (*free_fn)(void *),
320 void (*error_fn)(const char *msg));
324 * tal_check - set the allocation or error functions to use
325 * @ctx: a tal context, or NULL.
326 * @errorstr: a string to prepend calls to error_fn, or NULL.
328 * This sanity-checks a tal tree (unless NDEBUG is defined, in which case
329 * it simply returns true). If errorstr is not null, error_fn is called
330 * when a problem is found, otherwise it is not.
332 bool tal_check(const tal_t *ctx, const char *errorstr);
334 #ifdef CCAN_TAL_DEBUG
336 * tal_dump - dump entire tal tree.
338 * This is a helper for debugging tal itself, which dumps all the tal internal
344 /* Internal support functions */
346 #ifdef CCAN_TAL_NO_LABELS
347 #define TAL_LABEL(type, arr) NULL
349 #ifdef CCAN_TAL_DEBUG
350 #define TAL_LABEL(type, arr) \
351 __FILE__ ":" stringify(__LINE__) ":" stringify(type) arr
353 #define TAL_LABEL(type, arr) stringify(type) arr
354 #endif /* CCAN_TAL_DEBUG */
358 #if HAVE_BUILTIN_CONSTANT_P
359 #define TAL_IS_LITERAL(str) __builtin_constant_p(str)
361 #define TAL_IS_LITERAL(str) (sizeof(&*(str)) != sizeof(char *))
364 bool tal_set_name_(tal_t *ctx, const char *name, bool literal);
366 static inline size_t tal_sizeof_(size_t size, size_t count)
368 /* Multiplication wrap */
369 if (count && unlikely(size * count / size != count))
370 return (size_t)-1024;
374 /* Make sure we don't wrap adding header. */
375 if (size > (size_t)-1024)
376 return (size_t)-1024;
382 #define tal_typeof(ptr) (__typeof__(ptr))
383 #if HAVE_STATEMENT_EXPR
384 /* Careful: ptr can be const foo *, ptype is foo *. Also, ptr could
385 * be an array, eg "hello". */
386 #define tal_typechk_(ptr, ptype) ({ __typeof__((ptr)+0) _p = (ptype)(ptr); _p; })
388 #define tal_typechk_(ptr, ptype) (ptr)
390 #else /* !HAVE_TYPEOF */
391 #define tal_typeof(ptr)
392 #define tal_typechk_(ptr, ptype) (ptr)
395 void *tal_alloc_(const tal_t *ctx, size_t bytes, bool clear, const char *label);
397 void *tal_dup_(const tal_t *ctx, const void *p, size_t n, size_t extra,
400 tal_t *tal_steal_(const tal_t *new_parent, const tal_t *t);
402 bool tal_resize_(tal_t **ctxp, size_t size);
404 bool tal_add_destructor_(tal_t *ctx, void (*destroy)(void *me));
405 bool tal_del_destructor_(tal_t *ctx, void (*destroy)(void *me));
407 bool tal_add_notifier_(tal_t *ctx, enum tal_notify_type types,
408 void (*notify)(tal_t *ctx, enum tal_notify_type,
410 bool tal_del_notifier_(tal_t *ctx,
411 void (*notify)(tal_t *ctx, enum tal_notify_type,
413 #endif /* CCAN_TAL_H */