]> git.ozlabs.org Git - ccan/blobdiff - ccan/tal/tal.c
tal: handle take() pointers more carefully.
[ccan] / ccan / tal / tal.c
index 7018d9fc98b3d80f33fcdaab0f4ad0ea2609fbf7..dff0dcfba2058b0815f79423c0798af9b806fb67 100644 (file)
@@ -24,7 +24,6 @@ enum prop_type {
        CHILDREN = 0x00c1d500,
        NAME = 0x00111100,
        NOTIFIER = 0x00071f00,
-       LENGTH = 0x00515300
 };
 
 struct tal_hdr {
@@ -32,6 +31,7 @@ struct tal_hdr {
        struct prop_hdr *prop;
        /* XOR with TAL_PTR_OBFUSTICATOR */
        intptr_t parent_child;
+       size_t bytelen;
 };
 
 struct prop_hdr {
@@ -50,11 +50,6 @@ struct name {
        char name[];
 };
 
-struct length {
-       struct prop_hdr hdr; /* LENGTH */
-       size_t len;
-};
-
 struct notifier {
        struct prop_hdr hdr; /* NOTIFIER */
        enum tal_notify_type types;
@@ -77,7 +72,7 @@ static struct {
        struct tal_hdr hdr;
        struct children c;
 } null_parent = { { { &null_parent.hdr.list, &null_parent.hdr.list },
-                   &null_parent.c.hdr, TAL_PTR_OBFUSTICATOR },
+                   &null_parent.c.hdr, TAL_PTR_OBFUSTICATOR, 0 },
                  { { CHILDREN, NULL },
                    &null_parent.hdr,
                    { { &null_parent.c.children.n,
@@ -196,14 +191,14 @@ static void *from_tal_hdr(const struct tal_hdr *hdr)
        return (void *)(hdr + 1);
 }
 
-#ifdef TAL_DEBUG
-static void *from_tal_hdr_or_null(struct tal_hdr *hdr)
+static void *from_tal_hdr_or_null(const struct tal_hdr *hdr)
 {
        if (hdr == &null_parent.hdr)
                return NULL;
        return from_tal_hdr(hdr);
 }
 
+#ifdef TAL_DEBUG
 static struct tal_hdr *debug_tal(struct tal_hdr *tal)
 {
        tal_check(from_tal_hdr_or_null(tal), "TAL_DEBUG ");
@@ -239,7 +234,7 @@ static void notify(const struct tal_hdr *ctx,
                                else
                                        n->u.destroy(from_tal_hdr(ctx));
                        } else
-                               n->u.notifyfn(from_tal_hdr(ctx), type,
+                               n->u.notifyfn(from_tal_hdr_or_null(ctx), type,
                                              (void *)info);
                }
        }
@@ -390,6 +385,8 @@ static void del_tree(struct tal_hdr *t, const tal_t *orig, int saved_errno)
 {
        struct prop_hdr **prop, *p, *next;
 
+       assert(!taken(from_tal_hdr(t)));
+
         /* Already being destroyed?  Don't loop. */
         if (unlikely(get_destroying_bit(t->parent_child)))
                 return;
@@ -414,50 +411,23 @@ static void del_tree(struct tal_hdr *t, const tal_t *orig, int saved_errno)
         /* Finally free our properties. */
         for (p = t->prop; p && !is_literal(p); p = next) {
                 next = p->next;
-               /* LENGTH is appended, so don't free separately! */
-               if (p->type != LENGTH)
-                       freefn(p);
+               freefn(p);
         }
         freefn(t);
 }
 
-static size_t extra_for_length(size_t size)
-{
-       size_t extra;
-       const size_t align = ALIGNOF(struct length);
-
-       /* Round up size, and add tailer. */
-       extra = ((size + align-1) & ~(align-1)) - size;
-       extra += sizeof(struct length);
-       return extra;
-}
-
-void *tal_alloc_(const tal_t *ctx, size_t size,
-                bool clear, bool add_length, const char *label)
+void *tal_alloc_(const tal_t *ctx, size_t size, bool clear, const char *label)
 {
-       size_t req_size = size;
         struct tal_hdr *child, *parent = debug_tal(to_tal_hdr_or_null(ctx));
 
-#ifdef CCAN_TAL_DEBUG
-       /* Always record length if debugging. */
-       add_length = true;
-#endif
-       if (add_length)
-               size += extra_for_length(size);
-
         child = allocate(sizeof(struct tal_hdr) + size);
        if (!child)
                return NULL;
        if (clear)
-               memset(from_tal_hdr(child), 0, req_size);
+               memset(from_tal_hdr(child), 0, size);
         child->prop = (void *)label;
+       child->bytelen = size;
 
-       if (add_length) {
-               struct length *lprop;
-               lprop = (struct length *)((char *)(child+1) + size) - 1;
-               init_property(&lprop->hdr, child, LENGTH);
-               lprop->len = req_size;
-       }
         if (!add_child(parent, child)) {
                freefn(child);
                return NULL;
@@ -470,7 +440,7 @@ void *tal_alloc_(const tal_t *ctx, size_t size,
 
 static bool adjust_size(size_t *size, size_t count)
 {
-       const size_t extra = sizeof(struct tal_hdr) + sizeof(struct length)*2;
+       const size_t extra = sizeof(struct tal_hdr);
 
        /* Multiplication wrap */
         if (count && unlikely(*size * count / *size != count))
@@ -478,7 +448,7 @@ static bool adjust_size(size_t *size, size_t count)
 
         *size *= count;
 
-        /* Make sure we don't wrap adding header/tailer. */
+        /* Make sure we don't wrap adding header. */
         if (*size + extra < extra)
                goto overflow;
        return true;
@@ -488,12 +458,12 @@ overflow:
 }
 
 void *tal_alloc_arr_(const tal_t *ctx, size_t size, size_t count, bool clear,
-                    bool add_length, const char *label)
+                    const char *label)
 {
        if (!adjust_size(&size, count))
                return NULL;
 
-       return tal_alloc_(ctx, size, clear, add_length, label);
+       return tal_alloc_(ctx, size, clear, label);
 }
 
 void *tal_free(const tal_t *ctx)
@@ -527,7 +497,7 @@ void *tal_steal_(const tal_t *new_parent, const tal_t *ctx)
                old_parent = ignore_destroying_bit(t->parent_child)->parent;
 
                 if (unlikely(!add_child(newpar, t))) {
-                       /* We can always add to old parent, becuase it has a
+                       /* We can always add to old parent, because it has a
                         * children property already. */
                        if (!add_child(old_parent, t))
                                abort();
@@ -560,7 +530,7 @@ bool tal_add_destructor2_(const tal_t *ctx, void (*destroy)(void *me, void *arg)
 bool tal_add_notifier_(const tal_t *ctx, enum tal_notify_type types,
                       void (*callback)(tal_t *, enum tal_notify_type, void *))
 {
-       tal_t *t = debug_tal(to_tal_hdr(ctx));
+       struct tal_hdr *t = debug_tal(to_tal_hdr_or_null(ctx));
        struct notifier *n;
 
        assert(types);
@@ -588,7 +558,7 @@ bool tal_del_notifier_(const tal_t *ctx,
                       void (*callback)(tal_t *, enum tal_notify_type, void *),
                       bool match_extra_arg, void *extra_arg)
 {
-       struct tal_hdr *t = debug_tal(to_tal_hdr(ctx));
+       struct tal_hdr *t = debug_tal(to_tal_hdr_or_null(ctx));
        enum tal_notify_type types;
 
         types = del_notifier_property(t, callback, match_extra_arg, extra_arg);
@@ -658,15 +628,10 @@ const char *tal_name(const tal_t *t)
 
 size_t tal_bytelen(const tal_t *ptr)
 {
-       struct length *l;
-
-       if (!ptr)
-               return 0;
+       /* NULL -> null_parent which has bytelen 0 */
+       struct tal_hdr *t = debug_tal(to_tal_hdr_or_null(ptr));
 
-       l = find_property(debug_tal(to_tal_hdr(ptr)), LENGTH);
-       if (!l)
-               return 0;
-       return l->len;
+       return t->bytelen;
 }
 
 /* Start one past first child: make stopping natural in circ. list. */
@@ -720,58 +685,37 @@ bool tal_resize_(tal_t **ctxp, size_t size, size_t count, bool clear)
 {
         struct tal_hdr *old_t, *t;
         struct children *child;
-       struct prop_hdr **lenp;
-       struct length len;
-       size_t extra = 0;
 
         old_t = debug_tal(to_tal_hdr(*ctxp));
 
        if (!adjust_size(&size, count))
                return false;
 
-       lenp = find_property_ptr(old_t, LENGTH);
-       if (lenp) {
-               /* Copy here, in case we're shrinking! */
-               len = *(struct length *)*lenp;
-               extra = extra_for_length(size);
-       } else /* If we don't have an old length, we can't clear! */
-               assert(!clear);
-
-        t = resizefn(old_t, sizeof(struct tal_hdr) + size + extra);
+        t = resizefn(old_t, sizeof(struct tal_hdr) + size);
        if (!t) {
                call_error("Reallocation failure");
                return false;
        }
 
-       /* Copy length to end. */
-       if (lenp) {
-               struct length *new_len;
-
-               /* Clear between old end and new end. */
-               if (clear && size > len.len) {
-                       char *old_end = (char *)(t + 1) + len.len;
-                       memset(old_end, 0, size - len.len);
-               }
-
-               new_len = (struct length *)((char *)(t + 1) + size
-                                           + extra - sizeof(len));
-               len.len = size;
-               *new_len = len;
-
-               /* Be careful replacing next ptr; could be old hdr. */
-               if (lenp == &old_t->prop)
-                       t->prop = &new_len->hdr;
-               else
-                       *lenp = &new_len->hdr;
+       /* Clear between old end and new end. */
+       if (clear && size > t->bytelen) {
+               char *old_end = (char *)(t + 1) + t->bytelen;
+               memset(old_end, 0, size - t->bytelen);
        }
 
-       update_bounds(t, sizeof(struct tal_hdr) + size + extra);
+       /* Update length. */
+       t->bytelen = size;
+       update_bounds(t, sizeof(struct tal_hdr) + size);
 
        /* If it didn't move, we're done! */
         if (t != old_t) {
                /* Fix up linked list pointers. */
                t->list.next->prev = t->list.prev->next = &t->list;
 
+               /* Copy take() property. */
+               if (taken(from_tal_hdr(old_t)))
+                       take(from_tal_hdr(t));
+
                /* Fix up child property's parent pointer. */
                child = find_property(t, CHILDREN);
                if (child) {
@@ -790,12 +734,10 @@ bool tal_resize_(tal_t **ctxp, size_t size, size_t count, bool clear)
 
 bool tal_expand_(tal_t **ctxp, const void *src, size_t size, size_t count)
 {
-       struct length *l;
        size_t old_len;
        bool ret = false;
 
-       l = find_property(debug_tal(to_tal_hdr(*ctxp)), LENGTH);
-       old_len = l->len;
+       old_len = debug_tal(to_tal_hdr(*ctxp))->bytelen;
 
        /* Check for additive overflow */
        if (old_len + count * size < old_len) {
@@ -820,8 +762,7 @@ out:
 }
 
 void *tal_dup_(const tal_t *ctx, const void *p, size_t size,
-              size_t n, size_t extra, bool add_length,
-              const char *label)
+              size_t n, size_t extra, const char *label)
 {
        void *ret;
        size_t nbytes = size;
@@ -850,7 +791,7 @@ void *tal_dup_(const tal_t *ctx, const void *p, size_t size,
                return (void *)p;
        }
 
-       ret = tal_alloc_arr_(ctx, size, n + extra, false, add_length, label);
+       ret = tal_alloc_arr_(ctx, size, n + extra, false, label);
        if (ret)
                memcpy(ret, p, nbytes);
        return ret;
@@ -879,12 +820,11 @@ static void dump_node(unsigned int indent, const struct tal_hdr *t)
 
        for (i = 0; i < indent; i++)
                printf("  ");
-       printf("%p", t);
+       printf("%p len=%zu", t, t->bytelen);
         for (p = t->prop; p; p = p->next) {
                struct children *c;
                struct name *n;
                struct notifier *no;
-               struct length *l;
                 if (is_literal(p)) {
                        printf(" \"%s\"", (const char *)p);
                        break;
@@ -904,10 +844,6 @@ static void dump_node(unsigned int indent, const struct tal_hdr *t)
                        no = (struct notifier *)p;
                        printf(" NOTIFIER(%p):fn=%p", p, no->u.notifyfn);
                        break;
-               case LENGTH:
-                       l = (struct length *)p;
-                       printf(" LENGTH(%p):len=%zu", p, l->len);
-                       break;
                default:
                        printf(" **UNKNOWN(%p):%i**", p, p->type);
                }
@@ -955,7 +891,6 @@ static bool check_node(struct children *parent_child,
        struct prop_hdr *p;
        struct name *name = NULL;
        struct children *children = NULL;
-       struct length *length = NULL;
 
        if (!in_bounds(t))
                return check_err(t, errorstr, "invalid pointer");
@@ -981,12 +916,6 @@ static bool check_node(struct children *parent_child,
                                                 "has two child nodes");
                        children = (struct children *)p;
                        break;
-               case LENGTH:
-                       if (length)
-                               return check_err(t, errorstr,
-                                                "has two lengths");
-                       length = (struct length *)p;
-                       break;
                case NOTIFIER:
                        break;
                case NAME: