*/
typedef void tal_t;
-/**
- * TAL_TAKE - fake tal_t to indicate function will own arguments.
- *
- * Various functions take a context on which to allocate: if you use
- * TAL_TAKE there instead, it means that the argument(s) are actually
- * tal objects. The returned value will share the same parent; it may
- * even be the same pointer as the arguments. The arguments themselves
- * will be reused, freed, or made a child of the return value: they are
- * no longer valid for external use.
- */
-#define TAL_TAKE ((tal_t *)-2L)
-
/**
* tal - basic allocator function
* @ctx: NULL, or tal allocated object to be parent.
* Allocates a specific type, with a given parent context. The name
* of the object is a string of the type, but if CCAN_TAL_DEBUG is
* defined it also contains the file and line which allocated it.
+ *
+ * Example:
+ * int *p = tal(NULL, int);
+ * *p = 1;
*/
#define tal(ctx, type) \
((type *)tal_alloc_((ctx), sizeof(type), false, TAL_LABEL(type, "")))
* @type: the type to allocate.
*
* Equivalent to tal() followed by memset() to zero.
+ *
+ * Example:
+ * p = talz(NULL, int);
+ * assert(*p == 0);
*/
#define talz(ctx, type) \
((type *)tal_alloc_((ctx), sizeof(type), true, TAL_LABEL(type, "")))
* @p: NULL, or tal allocated object to free.
*
* This calls the destructors for p (if any), then does the same for all its
- * children (recursively) before finally freeing the memory.
+ * children (recursively) before finally freeing the memory. It returns
+ * NULL, for convenience.
*
* Note: errno is preserved by this call.
+ *
+ * Example:
+ * p = tal_free(p);
*/
-void tal_free(const tal_t *p);
+void *tal_free(const tal_t *p);
/**
* tal_arr - allocate an array of objects.
* @ctx: NULL, or tal allocated object to be parent.
* @type: the type to allocate.
* @count: the number to allocate.
+ *
+ * Example:
+ * p = tal_arr(NULL, int, 2);
+ * p[0] = 0;
+ * p[1] = 1;
*/
#define tal_arr(ctx, type, count) \
((type *)tal_alloc_((ctx), tal_sizeof_(sizeof(type), (count)), false, \
* @ctx: NULL, or tal allocated object to be parent.
* @type: the type to allocate.
* @count: the number to allocate.
+ *
+ * Example:
+ * p = tal_arrz(NULL, int, 2);
+ * assert(p[0] == 0 && p[1] == 0);
*/
#define tal_arrz(ctx, type, count) \
((type *)tal_alloc_((ctx), tal_sizeof_(sizeof(type), (count)), true, \
TAL_LABEL(type, "[]")))
/**
- * tal_resize - enlarge or reduce a tal_arr(z).
- * @p: The tal allocated array to resize.
+ * tal_resize - enlarge or reduce a tal_arr[z].
+ * @p: A pointer to the tal allocated array to resize.
* @count: the number to allocate.
*
- * This returns the new pointer, or NULL (and destroys the old one)
- * on failure.
+ * This returns true on success (and may move *@p), or false on failure.
+ *
+ * Example:
+ * tal_resize(&p, 100);
*/
#define tal_resize(p, count) \
- ((tal_typeof(p) tal_realloc_((p), tal_sizeof_(sizeof(*p), (count)))))
+ tal_resize_((void **)(p), tal_sizeof_(sizeof**(p), (count)))
/**
* tal_steal - change the parent of a tal-allocated pointer.
*
* This may need to perform an allocation, in which case it may fail; thus
* it can return NULL, otherwise returns @ptr.
- *
- * Weird macro avoids gcc's 'warning: value computed is not used'.
*/
#if HAVE_STATEMENT_EXPR
+/* Weird macro avoids gcc's 'warning: value computed is not used'. */
#define tal_steal(ctx, ptr) \
({ (tal_typeof(ptr) tal_steal_((ctx),(ptr))); })
#else
* tal_add_destructor - add a callback function when this context is destroyed.
* @ptr: The tal allocated object.
* @function: the function to call before it's freed.
+ *
+ * Note that this can only fail if your allocfn fails and your errorfn returns.
*/
#define tal_add_destructor(ptr, function) \
tal_add_destructor_((ptr), typesafe_cb(void, void *, (function), (ptr)))
+/**
+ * tal_del_destructor - remove a destructor callback function.
+ * @ptr: The tal allocated object.
+ * @function: the function to call before it's freed.
+ *
+ * If @function has not been successfully added as a destructor, this returns
+ * false.
+ */
+#define tal_del_destructor(ptr, function) \
+ tal_del_destructor_((ptr), typesafe_cb(void, void *, (function), (ptr)))
+
+enum tal_notify_type {
+ TAL_NOTIFY_FREE = 1,
+ TAL_NOTIFY_STEAL = 2,
+ TAL_NOTIFY_MOVE = 4,
+ TAL_NOTIFY_RESIZE = 8,
+ TAL_NOTIFY_RENAME = 16,
+ TAL_NOTIFY_ADD_CHILD = 32,
+ TAL_NOTIFY_DEL_CHILD = 64,
+ TAL_NOTIFY_ADD_NOTIFIER = 128,
+ TAL_NOTIFY_DEL_NOTIFIER = 256
+};
+
+/**
+ * tal_add_notifier - add a callback function when this context changes.
+ * @ptr: The tal allocated object.
+ * @types: Bitwise OR of the types the callback is interested in.
+ * @callback: the function to call.
+ *
+ * Note that this can only fail if your allocfn fails and your errorfn
+ * returns. Also note that notifiers are not reliable in the case
+ * where an allocation fails, as they may be called before any
+ * allocation is actually done.
+ *
+ * TAL_NOTIFY_FREE is called when @ptr is freed, either directly or
+ * because an ancestor is freed: @info is the argument to tal_free().
+ * It is exactly equivalent to a destructor, with more information.
+ *
+ * TAL_NOTIFY_STEAL is called when @ptr's parent changes: @info is the
+ * new parent.
+ *
+ * TAL_NOTIFY_MOVE is called when @ptr is realloced (via tal_resize)
+ * and moved. In this case, @ptr arg here is the new memory, and
+ * @info is the old pointer.
+ *
+ * TAL_NOTIFY_RESIZE is called when @ptr is realloced via tal_resize:
+ * @info is the new size, in bytes. If the pointer has moved,
+ * TAL_NOTIFY_MOVE callbacks are called first.
+ *
+ * TAL_NOTIFY_ADD_CHILD/TAL_NOTIFY_DEL_CHILD are called when @ptr is
+ * the context for a tal() allocating call, or a direct child is
+ * tal_free()d: @info is the child. Note that TAL_NOTIFY_DEL_CHILD is
+ * not called when this context is tal_free()d: TAL_NOTIFY_FREE is
+ * considered sufficient for that case.
+ *
+ * TAL_NOTIFY_ADD_NOTIFIER/TAL_NOTIFIER_DEL_NOTIFIER are called when
+ * a notifier is added or removed (not for this notifier): @info is the
+ * callback.
+ */
+#define tal_add_notifier(ptr, types, callback) \
+ tal_add_notifier_((ptr), (types), \
+ typesafe_cb_postargs(void, tal_t *, (callback), \
+ (ptr), \
+ enum tal_notify_type, void *))
+
+/**
+ * tal_del_notifier - remove a notifier callback function.
+ * @ptr: The tal allocated object.
+ * @callback: the function to call.
+ */
+#define tal_del_notifier(ptr, callback) \
+ tal_del_notifier_((ptr), \
+ typesafe_cb_postargs(void, void *, (callback), \
+ (ptr), \
+ enum tal_notify_type, void *))
+
/**
* tal_set_name - attach a name to a tal pointer.
* @ptr: The tal allocated object.
tal_t *tal_parent(const tal_t *ctx);
/**
- * tal_memdup - duplicate memory.
- * @ctx: NULL, or tal allocated object to be parent (or TAL_TAKE).
- * @p: the memory to copy
- * @n: the number of bytes.
- *
+ * tal_dup - duplicate an array.
+ * @ctx: The tal allocated object to be parent of the result (may be NULL).
+ * @type: the type (should match type of @p!)
+ * @p: the array to copy (or resized & reparented if take())
+ * @n: the number of sizeof(type) entries to copy.
+ * @extra: the number of extra sizeof(type) entries to allocate.
*/
-void *tal_memdup(const tal_t *ctx, const void *p, size_t n);
+#define tal_dup(ctx, type, p, n, extra) \
+ ((type *)tal_dup_((ctx), tal_typechk_(p, type *), \
+ tal_sizeof_(sizeof(type), (n)), \
+ tal_sizeof_(sizeof(type), (extra)), \
+ TAL_LABEL(type, "[]")))
/**
* tal_strdup - duplicate a string
- * @ctx: NULL, or tal allocated object to be parent (or TAL_TAKE).
- * @p: the string to copy
+ * @ctx: NULL, or tal allocated object to be parent.
+ * @p: the string to copy (can be take()).
*/
char *tal_strdup(const tal_t *ctx, const char *p);
/**
* tal_strndup - duplicate a limited amount of a string.
- * @ctx: NULL, or tal allocated object to be parent (or TAL_TAKE).
- * @p: the string to copy
+ * @ctx: NULL, or tal allocated object to be parent.
+ * @p: the string to copy (can be take()).
* @n: the maximum length to copy.
*
* Always gives a nul-terminated string, with strlen() <= @n.
/**
* tal_asprintf - allocate a formatted string
- * @ctx: NULL, or tal allocated object to be parent (or TAL_TAKE).
- * @fmt: the printf-style format.
- *
- * If @ctx is TAL_TAKE, @fmt is freed and its parent will be the parent
- * of the return value.
+ * @ctx: NULL, or tal allocated object to be parent.
+ * @fmt: the printf-style format (can be take()).
*/
char *tal_asprintf(const tal_t *ctx, const char *fmt, ...) PRINTF_FMT(2,3);
/**
* tal_vasprintf - allocate a formatted string (va_list version)
- * @ctx: NULL, or tal allocated object to be parent (or TAL_TAKE).
- * @fmt: the printf-style format.
+ * @ctx: NULL, or tal allocated object to be parent.
+ * @fmt: the printf-style format (can be take()).
* @va: the va_list containing the format args.
- *
- * If @ctx is TAL_TAKE, @fmt is freed and its parent will be the parent
- * of the return value.
*/
char *tal_vasprintf(const tal_t *ctx, const char *fmt, va_list ap)
PRINTF_FMT(2,0);
#if HAVE_TYPEOF
#define tal_typeof(ptr) (__typeof__(ptr))
+#if HAVE_STATEMENT_EXPR
+/* Careful: ptr can be const foo *, ptype is foo *. Also, ptr could
+ * be an array, eg "hello". */
+#define tal_typechk_(ptr, ptype) ({ __typeof__((ptr)+0) _p = (ptype)(ptr); _p; })
#else
+#define tal_typechk_(ptr, ptype) (ptr)
+#endif
+#else /* !HAVE_TYPEOF */
#define tal_typeof(ptr)
+#define tal_typechk_(ptr, ptype) (ptr)
#endif
void *tal_alloc_(const tal_t *ctx, size_t bytes, bool clear, const char *label);
+void *tal_dup_(const tal_t *ctx, const void *p, size_t n, size_t extra,
+ const char *label);
+
tal_t *tal_steal_(const tal_t *new_parent, const tal_t *t);
-void *tal_realloc_(tal_t *ctx, size_t size);
+bool tal_resize_(tal_t **ctxp, size_t size);
bool tal_add_destructor_(tal_t *ctx, void (*destroy)(void *me));
-
+bool tal_del_destructor_(tal_t *ctx, void (*destroy)(void *me));
+
+bool tal_add_notifier_(tal_t *ctx, enum tal_notify_type types,
+ void (*notify)(tal_t *ctx, enum tal_notify_type,
+ void *info));
+bool tal_del_notifier_(tal_t *ctx,
+ void (*notify)(tal_t *ctx, enum tal_notify_type,
+ void *info));
#endif /* CCAN_TAL_H */
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