1 /* Licensed under BSD-MIT - see LICENSE file for details */
2 #include <ccan/tal/tal.h>
3 #include <ccan/compiler/compiler.h>
4 #include <ccan/list/list.h>
5 #include <ccan/alignof/alignof.h>
16 #define NOTIFY_IS_DESTRUCTOR 512
17 #define NOTIFY_EXTRA_ARG 1024
19 /* This makes our parent_child ptr stand out for to_tal_hdr checks */
20 #define TAL_PTR_OBFUSTICATOR ((intptr_t)0x1984200820142016ULL)
22 /* 32-bit type field, first byte 0 in either endianness. */
24 CHILDREN = 0x00c1d500,
26 NOTIFIER = 0x00071f00,
30 struct list_node list;
31 struct prop_hdr *prop;
32 /* XOR with TAL_PTR_OBFUSTICATOR */
33 intptr_t parent_child;
39 struct prop_hdr *next;
43 struct prop_hdr hdr; /* CHILDREN */
44 struct tal_hdr *parent;
45 struct list_head children; /* Head of siblings. */
49 struct prop_hdr hdr; /* NAME */
54 struct prop_hdr hdr; /* NOTIFIER */
55 enum tal_notify_type types;
57 void (*notifyfn)(tal_t *, enum tal_notify_type, void *);
58 void (*destroy)(tal_t *); /* If NOTIFY_IS_DESTRUCTOR set */
59 void (*destroy2)(tal_t *, void *); /* If NOTIFY_EXTRA_ARG */
64 struct notifier_extra_arg {
69 #define EXTRA_ARG(n) (((struct notifier_extra_arg *)(n))->arg)
74 } null_parent = { { { &null_parent.hdr.list, &null_parent.hdr.list },
75 &null_parent.c.hdr, TAL_PTR_OBFUSTICATOR, 0 },
78 { { &null_parent.c.children.n,
79 &null_parent.c.children.n } }
84 static void *(*allocfn)(size_t size) = malloc;
85 static void *(*resizefn)(void *, size_t size) = realloc;
86 static void (*freefn)(void *) = free;
87 static void (*errorfn)(const char *msg) = (void *)abort;
88 /* Count on non-destrutor notifiers; often stays zero. */
89 static size_t notifiers = 0;
91 static inline void COLD call_error(const char *msg)
96 static bool get_destroying_bit(intptr_t parent_child)
98 return parent_child & 1;
101 static void set_destroying_bit(intptr_t *parent_child)
106 static struct children *ignore_destroying_bit(intptr_t parent_child)
108 return (void *)((parent_child ^ TAL_PTR_OBFUSTICATOR) & ~(intptr_t)1);
111 /* This means valgrind can see leaks. */
112 void tal_cleanup(void)
116 while ((i = list_top(&null_parent.c.children, struct tal_hdr, list))) {
118 memset(i, 0, sizeof(*i));
121 /* Cleanup any taken pointers. */
125 /* We carefully start all real properties with a zero byte. */
126 static bool is_literal(const struct prop_hdr *prop)
128 return ((char *)prop)[0] != 0;
132 static const void *bounds_start, *bounds_end;
134 static void update_bounds(const void *new, size_t size)
136 if (unlikely(!bounds_start)) {
138 bounds_end = (char *)new + size;
139 } else if (new < bounds_start)
141 else if ((char *)new + size > (char *)bounds_end)
142 bounds_end = (char *)new + size;
145 static bool in_bounds(const void *p)
148 || (p >= (void *)&null_parent && p <= (void *)(&null_parent + 1))
149 || (p >= bounds_start && p <= bounds_end);
152 static void update_bounds(const void *new, size_t size)
156 static bool in_bounds(const void *p)
162 static void check_bounds(const void *p)
165 call_error("Not a valid header");
168 static struct tal_hdr *to_tal_hdr(const void *ctx)
172 t = (struct tal_hdr *)((char *)ctx - sizeof(struct tal_hdr));
174 check_bounds(ignore_destroying_bit(t->parent_child));
175 check_bounds(t->list.next);
176 check_bounds(t->list.prev);
177 if (t->prop && !is_literal(t->prop))
178 check_bounds(t->prop);
182 static struct tal_hdr *to_tal_hdr_or_null(const void *ctx)
185 return &null_parent.hdr;
186 return to_tal_hdr(ctx);
189 static void *from_tal_hdr(const struct tal_hdr *hdr)
191 return (void *)(hdr + 1);
194 static void *from_tal_hdr_or_null(const struct tal_hdr *hdr)
196 if (hdr == &null_parent.hdr)
198 return from_tal_hdr(hdr);
202 static struct tal_hdr *debug_tal(struct tal_hdr *tal)
204 tal_check(from_tal_hdr_or_null(tal), "TAL_DEBUG ");
208 static struct tal_hdr *debug_tal(struct tal_hdr *tal)
214 static void notify(const struct tal_hdr *ctx,
215 enum tal_notify_type type, const void *info,
218 const struct prop_hdr *p;
220 for (p = ctx->prop; p; p = p->next) {
225 if (p->type != NOTIFIER)
227 n = (struct notifier *)p;
228 if (n->types & type) {
230 if (n->types & NOTIFY_IS_DESTRUCTOR) {
231 /* Blatt this notifier in case it tries to
232 * tal_del_destructor() from inside */
233 union notifier_cb cb = n->u;
234 /* It's a union, so this NULLs destroy2 too! */
236 if (n->types & NOTIFY_EXTRA_ARG)
237 cb.destroy2(from_tal_hdr(ctx),
240 cb.destroy(from_tal_hdr(ctx));
242 n->u.notifyfn(from_tal_hdr_or_null(ctx), type,
248 static void *allocate(size_t size)
250 void *ret = allocfn(size);
252 call_error("allocation failed");
254 update_bounds(ret, size);
258 static struct prop_hdr **find_property_ptr(const struct tal_hdr *t,
263 for (p = (struct prop_hdr **)&t->prop; *p; p = &(*p)->next) {
264 if (is_literal(*p)) {
269 if ((*p)->type == type)
275 static void *find_property(const struct tal_hdr *parent, enum prop_type type)
277 struct prop_hdr **p = find_property_ptr(parent, type);
284 static void init_property(struct prop_hdr *hdr,
285 struct tal_hdr *parent,
289 hdr->next = parent->prop;
293 static struct notifier *add_notifier_property(struct tal_hdr *t,
294 enum tal_notify_type types,
296 enum tal_notify_type,
300 struct notifier *prop;
302 if (types & NOTIFY_EXTRA_ARG)
303 prop = allocate(sizeof(struct notifier_extra_arg));
305 prop = allocate(sizeof(struct notifier));
308 init_property(&prop->hdr, t, NOTIFIER);
310 prop->u.notifyfn = fn;
311 if (types & NOTIFY_EXTRA_ARG)
312 EXTRA_ARG(prop) = extra_arg;
317 static enum tal_notify_type del_notifier_property(struct tal_hdr *t,
319 enum tal_notify_type,
321 bool match_extra_arg,
326 for (p = (struct prop_hdr **)&t->prop; *p; p = &(*p)->next) {
328 enum tal_notify_type types;
332 if ((*p)->type != NOTIFIER)
334 n = (struct notifier *)*p;
335 if (n->u.notifyfn != fn)
339 if ((types & NOTIFY_EXTRA_ARG)
341 && extra_arg != EXTRA_ARG(n))
346 return types & ~(NOTIFY_IS_DESTRUCTOR|NOTIFY_EXTRA_ARG);
351 static struct name *add_name_property(struct tal_hdr *t, const char *name)
355 prop = allocate(sizeof(*prop) + strlen(name) + 1);
357 init_property(&prop->hdr, t, NAME);
358 strcpy(prop->name, name);
363 static struct children *add_child_property(struct tal_hdr *parent,
364 struct tal_hdr *child UNNEEDED)
366 struct children *prop = allocate(sizeof(*prop));
368 init_property(&prop->hdr, parent, CHILDREN);
369 prop->parent = parent;
370 list_head_init(&prop->children);
375 static bool add_child(struct tal_hdr *parent, struct tal_hdr *child)
377 struct children *children = find_property(parent, CHILDREN);
380 children = add_child_property(parent, child);
384 list_add(&children->children, &child->list);
385 child->parent_child = (intptr_t)children ^ TAL_PTR_OBFUSTICATOR;
389 static void del_tree(struct tal_hdr *t, const tal_t *orig, int saved_errno)
391 struct prop_hdr **prop, *p, *next;
393 assert(!taken(from_tal_hdr(t)));
395 /* Already being destroyed? Don't loop. */
396 if (unlikely(get_destroying_bit(t->parent_child)))
399 set_destroying_bit(&t->parent_child);
401 /* Call free notifiers. */
402 notify(t, TAL_NOTIFY_FREE, (tal_t *)orig, saved_errno);
404 /* Now free children and groups. */
405 prop = find_property_ptr(t, CHILDREN);
408 struct children *c = (struct children *)*prop;
410 while ((i = list_top(&c->children, struct tal_hdr, list))) {
412 del_tree(i, orig, saved_errno);
416 /* Finally free our properties. */
417 for (p = t->prop; p && !is_literal(p); p = next) {
424 void *tal_alloc_(const tal_t *ctx, size_t size, bool clear, const char *label)
426 struct tal_hdr *child, *parent = debug_tal(to_tal_hdr_or_null(ctx));
428 child = allocate(sizeof(struct tal_hdr) + size);
432 memset(from_tal_hdr(child), 0, size);
433 child->prop = (void *)label;
434 child->bytelen = size;
436 if (!add_child(parent, child)) {
442 notify(parent, TAL_NOTIFY_ADD_CHILD, from_tal_hdr(child), 0);
443 return from_tal_hdr(debug_tal(child));
446 static bool adjust_size(size_t *size, size_t count)
448 const size_t extra = sizeof(struct tal_hdr);
450 /* Multiplication wrap */
451 if (count && unlikely(*size * count / *size != count))
456 /* Make sure we don't wrap adding header. */
457 if (*size + extra < extra)
461 call_error("allocation size overflow");
465 void *tal_alloc_arr_(const tal_t *ctx, size_t size, size_t count, bool clear,
468 if (!adjust_size(&size, count))
471 return tal_alloc_(ctx, size, clear, label);
474 void *tal_free(const tal_t *ctx)
478 int saved_errno = errno;
479 t = debug_tal(to_tal_hdr(ctx));
480 if (unlikely(get_destroying_bit(t->parent_child)))
483 notify(ignore_destroying_bit(t->parent_child)->parent,
484 TAL_NOTIFY_DEL_CHILD, ctx, saved_errno);
486 del_tree(t, ctx, saved_errno);
492 void *tal_steal_(const tal_t *new_parent, const tal_t *ctx)
495 struct tal_hdr *newpar, *t, *old_parent;
497 newpar = debug_tal(to_tal_hdr_or_null(new_parent));
498 t = debug_tal(to_tal_hdr(ctx));
500 /* Unlink it from old parent. */
502 old_parent = ignore_destroying_bit(t->parent_child)->parent;
504 if (unlikely(!add_child(newpar, t))) {
505 /* We can always add to old parent, because it has a
506 * children property already. */
507 if (!add_child(old_parent, t))
513 notify(t, TAL_NOTIFY_STEAL, new_parent, 0);
518 bool tal_add_destructor_(const tal_t *ctx, void (*destroy)(void *me))
520 tal_t *t = debug_tal(to_tal_hdr(ctx));
521 return add_notifier_property(t, TAL_NOTIFY_FREE|NOTIFY_IS_DESTRUCTOR,
522 (void *)destroy, NULL);
525 bool tal_add_destructor2_(const tal_t *ctx, void (*destroy)(void *me, void *arg),
528 tal_t *t = debug_tal(to_tal_hdr(ctx));
529 return add_notifier_property(t, TAL_NOTIFY_FREE|NOTIFY_IS_DESTRUCTOR
531 (void *)destroy, arg);
534 /* We could support notifiers with an extra arg, but we didn't add to API */
535 bool tal_add_notifier_(const tal_t *ctx, enum tal_notify_type types,
536 void (*callback)(tal_t *, enum tal_notify_type, void *))
538 struct tal_hdr *t = debug_tal(to_tal_hdr_or_null(ctx));
542 assert((types & ~(TAL_NOTIFY_FREE | TAL_NOTIFY_STEAL | TAL_NOTIFY_MOVE
543 | TAL_NOTIFY_RESIZE | TAL_NOTIFY_RENAME
544 | TAL_NOTIFY_ADD_CHILD | TAL_NOTIFY_DEL_CHILD
545 | TAL_NOTIFY_ADD_NOTIFIER
546 | TAL_NOTIFY_DEL_NOTIFIER)) == 0);
548 /* Don't call notifier about itself: set types after! */
549 n = add_notifier_property(t, 0, callback, NULL);
554 notify(t, TAL_NOTIFY_ADD_NOTIFIER, callback, 0);
557 if (types != TAL_NOTIFY_FREE)
562 bool tal_del_notifier_(const tal_t *ctx,
563 void (*callback)(tal_t *, enum tal_notify_type, void *),
564 bool match_extra_arg, void *extra_arg)
566 struct tal_hdr *t = debug_tal(to_tal_hdr_or_null(ctx));
567 enum tal_notify_type types;
569 types = del_notifier_property(t, callback, match_extra_arg, extra_arg);
571 notify(t, TAL_NOTIFY_DEL_NOTIFIER, callback, 0);
572 if (types != TAL_NOTIFY_FREE)
579 bool tal_del_destructor_(const tal_t *ctx, void (*destroy)(void *me))
581 return tal_del_notifier_(ctx, (void *)destroy, false, NULL);
584 bool tal_del_destructor2_(const tal_t *ctx, void (*destroy)(void *me, void *arg),
587 return tal_del_notifier_(ctx, (void *)destroy, true, arg);
590 bool tal_set_name_(tal_t *ctx, const char *name, bool literal)
592 struct tal_hdr *t = debug_tal(to_tal_hdr(ctx));
593 struct prop_hdr **prop = find_property_ptr(t, NAME);
595 /* Get rid of any old name */
597 struct name *name = (struct name *)*prop;
598 if (is_literal(&name->hdr))
601 *prop = name->hdr.next;
606 if (literal && name[0]) {
609 /* Append literal. */
610 for (p = &t->prop; *p && !is_literal(*p); p = &(*p)->next);
611 *p = (struct prop_hdr *)name;
612 } else if (!add_name_property(t, name))
617 notify(t, TAL_NOTIFY_RENAME, name, 0);
621 const char *tal_name(const tal_t *t)
625 n = find_property(debug_tal(to_tal_hdr(t)), NAME);
629 if (is_literal(&n->hdr))
630 return (const char *)n;
634 size_t tal_bytelen(const tal_t *ptr)
636 /* NULL -> null_parent which has bytelen 0 */
637 struct tal_hdr *t = debug_tal(to_tal_hdr_or_null(ptr));
642 /* Start one past first child: make stopping natural in circ. list. */
643 static struct tal_hdr *first_child(struct tal_hdr *parent)
645 struct children *child;
647 child = find_property(parent, CHILDREN);
651 return list_top(&child->children, struct tal_hdr, list);
654 tal_t *tal_first(const tal_t *root)
656 struct tal_hdr *c, *t = debug_tal(to_tal_hdr_or_null(root));
661 return from_tal_hdr(c);
664 tal_t *tal_next(const tal_t *prev)
666 struct tal_hdr *next, *prevhdr = debug_tal(to_tal_hdr(prev));
667 struct list_head *head;
669 head = &ignore_destroying_bit(prevhdr->parent_child)->children;
670 next = list_next(head, prevhdr, list);
673 return from_tal_hdr(next);
676 tal_t *tal_parent(const tal_t *ctx)
683 t = debug_tal(to_tal_hdr(ctx));
684 if (ignore_destroying_bit(t->parent_child)->parent == &null_parent.hdr)
686 return from_tal_hdr(ignore_destroying_bit(t->parent_child)->parent);
689 bool tal_resize_(tal_t **ctxp, size_t size, size_t count, bool clear)
691 struct tal_hdr *old_t, *t;
692 struct children *child;
694 old_t = debug_tal(to_tal_hdr(*ctxp));
696 if (!adjust_size(&size, count))
699 t = resizefn(old_t, sizeof(struct tal_hdr) + size);
701 call_error("Reallocation failure");
705 /* Clear between old end and new end. */
706 if (clear && size > t->bytelen) {
707 char *old_end = (char *)(t + 1) + t->bytelen;
708 memset(old_end, 0, size - t->bytelen);
713 update_bounds(t, sizeof(struct tal_hdr) + size);
715 /* If it didn't move, we're done! */
717 /* Fix up linked list pointers. */
718 t->list.next->prev = t->list.prev->next = &t->list;
720 /* Copy take() property. */
721 if (taken(from_tal_hdr(old_t)))
722 take(from_tal_hdr(t));
724 /* Fix up child property's parent pointer. */
725 child = find_property(t, CHILDREN);
727 assert(child->parent == old_t);
730 *ctxp = from_tal_hdr(debug_tal(t));
732 notify(t, TAL_NOTIFY_MOVE, from_tal_hdr(old_t), 0);
735 notify(t, TAL_NOTIFY_RESIZE, (void *)size, 0);
740 bool tal_expand_(tal_t **ctxp, const void *src, size_t size, size_t count)
745 old_len = debug_tal(to_tal_hdr(*ctxp))->bytelen;
747 /* Check for additive overflow */
748 if (old_len + count * size < old_len) {
749 call_error("dup size overflow");
753 /* Don't point src inside thing we're expanding! */
755 || (char *)src >= (char *)(*ctxp) + old_len);
757 if (!tal_resize_(ctxp, size, old_len/size + count, false))
760 memcpy((char *)*ctxp + old_len, src, count * size);
769 void *tal_dup_(const tal_t *ctx, const void *p, size_t size,
770 size_t n, size_t extra, const char *label)
773 size_t nbytes = size;
775 if (!adjust_size(&nbytes, n)) {
781 /* Beware addition overflow! */
783 call_error("dup size overflow");
792 if (unlikely(!tal_resize_((void **)&p, size, n + extra, false)))
794 if (unlikely(!tal_steal(ctx, p)))
799 ret = tal_alloc_arr_(ctx, size, n + extra, false, label);
801 memcpy(ret, p, nbytes);
805 void tal_set_backend(void *(*alloc_fn)(size_t size),
806 void *(*resize_fn)(void *, size_t size),
807 void (*free_fn)(void *),
808 void (*error_fn)(const char *msg))
813 resizefn = resize_fn;
820 #ifdef CCAN_TAL_DEBUG
821 static void dump_node(unsigned int indent, const struct tal_hdr *t)
824 const struct prop_hdr *p;
826 for (i = 0; i < indent; i++)
828 printf("%p len=%zu", t, t->bytelen);
829 for (p = t->prop; p; p = p->next) {
834 printf(" \"%s\"", (const char *)p);
839 c = (struct children *)p;
840 printf(" CHILDREN(%p):parent=%p,children={%p,%p}\n",
842 c->children.n.prev, c->children.n.next);
845 n = (struct name *)p;
846 printf(" NAME(%p):%s", p, n->name);
849 no = (struct notifier *)p;
850 printf(" NOTIFIER(%p):fn=%p", p, no->u.notifyfn);
853 printf(" **UNKNOWN(%p):%i**", p, p->type);
859 static void tal_dump_(unsigned int level, const struct tal_hdr *t)
861 struct children *children;
865 children = find_property(t, CHILDREN);
869 list_for_each(&children->children, i, list)
870 tal_dump_(level + 1, i);
876 tal_dump_(0, &null_parent.hdr);
878 #endif /* CCAN_TAL_DEBUG */
881 static bool check_err(struct tal_hdr *t, const char *errorstr,
885 /* Try not to malloc: it may be corrupted. */
886 char msg[strlen(errorstr) + 20 + strlen(errmsg) + 1];
887 sprintf(msg, "%s:%p %s", errorstr, from_tal_hdr(t), errmsg);
893 static bool check_node(struct children *parent_child,
894 struct tal_hdr *t, const char *errorstr)
897 struct name *name = NULL;
898 struct children *children = NULL;
901 return check_err(t, errorstr, "invalid pointer");
903 if (ignore_destroying_bit(t->parent_child) != parent_child)
904 return check_err(t, errorstr, "incorrect parent");
906 for (p = t->prop; p; p = p->next) {
909 return check_err(t, errorstr,
910 "has extra literal");
914 return check_err(t, errorstr,
915 "has bad property pointer");
920 return check_err(t, errorstr,
921 "has two child nodes");
922 children = (struct children *)p;
928 return check_err(t, errorstr,
930 name = (struct name *)p;
933 return check_err(t, errorstr, "has unknown property");
939 if (!list_check(&children->children, errorstr))
941 list_for_each(&children->children, i, list) {
942 if (!check_node(children, i, errorstr))
949 bool tal_check(const tal_t *ctx, const char *errorstr)
951 struct tal_hdr *t = to_tal_hdr_or_null(ctx);
953 return check_node(ignore_destroying_bit(t->parent_child), t, errorstr);
956 bool tal_check(const tal_t *ctx, const char *errorstr)