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 * This is a more convenient form of tal_add_notifier(@ptr,
131 * TAL_NOTIFY_FREE, ...), in that the function prototype takes only @ptr.
133 * Note that this can only fail if your allocfn fails and your errorfn returns.
135 #define tal_add_destructor(ptr, function) \
136 tal_add_destructor_((ptr), typesafe_cb(void, void *, (function), (ptr)))
139 * tal_del_destructor - remove a destructor callback function.
140 * @ptr: The tal allocated object.
141 * @function: the function to call before it's freed.
143 * If @function has not been successfully added as a destructor, this returns
146 #define tal_del_destructor(ptr, function) \
147 tal_del_destructor_((ptr), typesafe_cb(void, void *, (function), (ptr)))
149 enum tal_notify_type {
151 TAL_NOTIFY_STEAL = 2,
153 TAL_NOTIFY_RESIZE = 8,
154 TAL_NOTIFY_RENAME = 16,
155 TAL_NOTIFY_ADD_CHILD = 32,
156 TAL_NOTIFY_DEL_CHILD = 64,
157 TAL_NOTIFY_ADD_NOTIFIER = 128,
158 TAL_NOTIFY_DEL_NOTIFIER = 256
162 * tal_add_notifier - add a callback function when this context changes.
163 * @ptr: The tal allocated object.
164 * @types: Bitwise OR of the types the callback is interested in.
165 * @callback: the function to call.
167 * Note that this can only fail if your allocfn fails and your errorfn
168 * returns. Also note that notifiers are not reliable in the case
169 * where an allocation fails, as they may be called before any
170 * allocation is actually done.
172 * TAL_NOTIFY_FREE is called when @ptr is freed, either directly or
173 * because an ancestor is freed: @info is the argument to tal_free().
174 * It is exactly equivalent to a destructor, with more information.
176 * TAL_NOTIFY_STEAL is called when @ptr's parent changes: @info is the
179 * TAL_NOTIFY_MOVE is called when @ptr is realloced (via tal_resize)
180 * and moved. In this case, @ptr arg here is the new memory, and
181 * @info is the old pointer.
183 * TAL_NOTIFY_RESIZE is called when @ptr is realloced via tal_resize:
184 * @info is the new size, in bytes. If the pointer has moved,
185 * TAL_NOTIFY_MOVE callbacks are called first.
187 * TAL_NOTIFY_ADD_CHILD/TAL_NOTIFY_DEL_CHILD are called when @ptr is
188 * the context for a tal() allocating call, or a direct child is
189 * tal_free()d: @info is the child. Note that TAL_NOTIFY_DEL_CHILD is
190 * not called when this context is tal_free()d: TAL_NOTIFY_FREE is
191 * considered sufficient for that case.
193 * TAL_NOTIFY_ADD_NOTIFIER/TAL_NOTIFIER_DEL_NOTIFIER are called when a
194 * notifier is added or removed (not for this notifier): @info is the
195 * callback. This is also called for tal_add_destructor and
196 * tal_del_destructor.
198 #define tal_add_notifier(ptr, types, callback) \
199 tal_add_notifier_((ptr), (types), \
200 typesafe_cb_postargs(void, tal_t *, (callback), \
202 enum tal_notify_type, void *))
205 * tal_del_notifier - remove a notifier callback function.
206 * @ptr: The tal allocated object.
207 * @callback: the function to call.
209 #define tal_del_notifier(ptr, callback) \
210 tal_del_notifier_((ptr), \
211 typesafe_cb_postargs(void, void *, (callback), \
213 enum tal_notify_type, void *))
216 * tal_set_name - attach a name to a tal pointer.
217 * @ptr: The tal allocated object.
218 * @name: The name to use.
220 * The name is copied, unless we're certain it's a string literal.
222 #define tal_set_name(ptr, name) \
223 tal_set_name_((ptr), (name), TAL_IS_LITERAL(name))
226 * tal_name - get the name for a tal pointer.
227 * @ptr: The tal allocated object.
229 * Returns NULL if no name has been set.
231 const char *tal_name(const tal_t *ptr);
234 * tal_first - get the first tal object child.
235 * @root: The tal allocated object to start with, or NULL.
237 * Returns NULL if there are no children.
239 tal_t *tal_first(const tal_t *root);
242 * tal_next - get the next tal object child.
243 * @root: The tal allocated object to start with, or NULL.
244 * @prev: The return value from tal_first or tal_next.
246 * Returns NULL if there are no more children. This should be safe to
247 * call on an altering tree unless @prev is no longer a descendent of
250 tal_t *tal_next(const tal_t *root, const tal_t *prev);
253 * tal_parent - get the parent of a tal object.
254 * @ctx: The tal allocated object.
256 * Returns the parent, which may be NULL. Returns NULL if @ctx is NULL.
258 tal_t *tal_parent(const tal_t *ctx);
261 * tal_dup - duplicate an array.
262 * @ctx: The tal allocated object to be parent of the result (may be NULL).
263 * @type: the type (should match type of @p!)
264 * @p: the array to copy (or resized & reparented if take())
265 * @n: the number of sizeof(type) entries to copy.
266 * @extra: the number of extra sizeof(type) entries to allocate.
268 #define tal_dup(ctx, type, p, n, extra) \
269 ((type *)tal_dup_((ctx), tal_typechk_(p, type *), \
270 tal_sizeof_(sizeof(type), (n)), \
271 tal_sizeof_(sizeof(type), (extra)), \
272 TAL_LABEL(type, "[]")))
275 * tal_strdup - duplicate a string
276 * @ctx: NULL, or tal allocated object to be parent.
277 * @p: the string to copy (can be take()).
279 char *tal_strdup(const tal_t *ctx, const char *p);
282 * tal_strndup - duplicate a limited amount of a string.
283 * @ctx: NULL, or tal allocated object to be parent.
284 * @p: the string to copy (can be take()).
285 * @n: the maximum length to copy.
287 * Always gives a nul-terminated string, with strlen() <= @n.
289 char *tal_strndup(const tal_t *ctx, const char *p, size_t n);
292 * tal_asprintf - allocate a formatted string
293 * @ctx: NULL, or tal allocated object to be parent.
294 * @fmt: the printf-style format (can be take()).
296 char *tal_asprintf(const tal_t *ctx, const char *fmt, ...) PRINTF_FMT(2,3);
299 * tal_vasprintf - allocate a formatted string (va_list version)
300 * @ctx: NULL, or tal allocated object to be parent.
301 * @fmt: the printf-style format (can be take()).
302 * @va: the va_list containing the format args.
304 char *tal_vasprintf(const tal_t *ctx, const char *fmt, va_list ap)
309 * tal_set_backend - set the allocation or error functions to use
310 * @alloc_fn: allocator or NULL (default is malloc)
311 * @resize_fn: re-allocator or NULL (default is realloc)
312 * @free_fn: free function or NULL (default is free)
313 * @error_fn: called on errors or NULL (default is abort)
315 * The defaults are set up so tal functions never return NULL, but you
316 * can override erorr_fn to change that. error_fn can return, and is
317 * called if alloc_fn or resize_fn fail.
319 * If any parameter is NULL, that function is unchanged.
321 void tal_set_backend(void *(*alloc_fn)(size_t size),
322 void *(*resize_fn)(void *, size_t size),
323 void (*free_fn)(void *),
324 void (*error_fn)(const char *msg));
328 * tal_check - set the allocation or error functions to use
329 * @ctx: a tal context, or NULL.
330 * @errorstr: a string to prepend calls to error_fn, or NULL.
332 * This sanity-checks a tal tree (unless NDEBUG is defined, in which case
333 * it simply returns true). If errorstr is not null, error_fn is called
334 * when a problem is found, otherwise it is not.
336 bool tal_check(const tal_t *ctx, const char *errorstr);
338 #ifdef CCAN_TAL_DEBUG
340 * tal_dump - dump entire tal tree.
342 * This is a helper for debugging tal itself, which dumps all the tal internal
348 /* Internal support functions */
350 #ifdef CCAN_TAL_NO_LABELS
351 #define TAL_LABEL(type, arr) NULL
353 #ifdef CCAN_TAL_DEBUG
354 #define TAL_LABEL(type, arr) \
355 __FILE__ ":" stringify(__LINE__) ":" stringify(type) arr
357 #define TAL_LABEL(type, arr) stringify(type) arr
358 #endif /* CCAN_TAL_DEBUG */
362 #if HAVE_BUILTIN_CONSTANT_P
363 #define TAL_IS_LITERAL(str) __builtin_constant_p(str)
365 #define TAL_IS_LITERAL(str) (sizeof(&*(str)) != sizeof(char *))
368 bool tal_set_name_(tal_t *ctx, const char *name, bool literal);
370 static inline size_t tal_sizeof_(size_t size, size_t count)
372 /* Multiplication wrap */
373 if (count && unlikely(size * count / size != count))
374 return (size_t)-1024;
378 /* Make sure we don't wrap adding header. */
379 if (size > (size_t)-1024)
380 return (size_t)-1024;
386 #define tal_typeof(ptr) (__typeof__(ptr))
387 #if HAVE_STATEMENT_EXPR
388 /* Careful: ptr can be const foo *, ptype is foo *. Also, ptr could
389 * be an array, eg "hello". */
390 #define tal_typechk_(ptr, ptype) ({ __typeof__((ptr)+0) _p = (ptype)(ptr); _p; })
392 #define tal_typechk_(ptr, ptype) (ptr)
394 #else /* !HAVE_TYPEOF */
395 #define tal_typeof(ptr)
396 #define tal_typechk_(ptr, ptype) (ptr)
399 void *tal_alloc_(const tal_t *ctx, size_t bytes, bool clear, const char *label);
401 void *tal_dup_(const tal_t *ctx, const void *p, size_t n, size_t extra,
404 tal_t *tal_steal_(const tal_t *new_parent, const tal_t *t);
406 bool tal_resize_(tal_t **ctxp, size_t size);
408 bool tal_add_destructor_(tal_t *ctx, void (*destroy)(void *me));
409 bool tal_del_destructor_(tal_t *ctx, void (*destroy)(void *me));
411 bool tal_add_notifier_(tal_t *ctx, enum tal_notify_type types,
412 void (*notify)(tal_t *ctx, enum tal_notify_type,
414 bool tal_del_notifier_(tal_t *ctx,
415 void (*notify)(tal_t *ctx, enum tal_notify_type,
417 #endif /* CCAN_TAL_H */