X-Git-Url: http://git.ozlabs.org/?a=blobdiff_plain;f=ccan%2Flist%2Flist.h;h=90989c5fc04b6bd8436361dcda42f8f5f0ce7853;hb=0201703d51e85e5c3eeeef558176c1ed61369ad8;hp=cdd5eeb7e6e8523a85e348c7f775a65ca1185260;hpb=ec8654d94d3c5c47aa5f82698f7e8048c79765b1;p=ccan diff --git a/ccan/list/list.h b/ccan/list/list.h index cdd5eeb7..90989c5f 100644 --- a/ccan/list/list.h +++ b/ccan/list/list.h @@ -157,6 +157,36 @@ static inline void list_node_init(struct list_node *n) n->next = n->prev = n; } +/** + * list_add_after - add an entry after an existing node in a linked list + * @h: the list_head to add the node to (for debugging) + * @p: the existing list_node to add the node after + * @n: the new list_node to add to the list. + * + * The existing list_node must already be a member of the list. + * The new list_node does not need to be initialized; it will be overwritten. + * + * Example: + * struct child c1, c2, c3; + * LIST_HEAD(h); + * + * list_add_tail(&h, &c1.list); + * list_add_tail(&h, &c3.list); + * list_add_after(&h, &c1.list, &c2.list); + */ +#define list_add_after(h, p, n) list_add_after_(h, p, n, LIST_LOC) +static inline void list_add_after_(struct list_head *h, + struct list_node *p, + struct list_node *n, + const char *abortstr) +{ + n->next = p->next; + n->prev = p; + p->next->prev = n; + p->next = n; + (void)list_debug(h, abortstr); +} + /** * list_add - add an entry at the start of a linked list. * @h: the list_head to add the node to @@ -175,10 +205,34 @@ static inline void list_add_(struct list_head *h, struct list_node *n, const char *abortstr) { - n->next = h->n.next; - n->prev = &h->n; - h->n.next->prev = n; - h->n.next = n; + list_add_after_(h, &h->n, n, abortstr); +} + +/** + * list_add_before - add an entry before an existing node in a linked list + * @h: the list_head to add the node to (for debugging) + * @p: the existing list_node to add the node before + * @n: the new list_node to add to the list. + * + * The existing list_node must already be a member of the list. + * The new list_node does not need to be initialized; it will be overwritten. + * + * Example: + * list_head_init(&h); + * list_add_tail(&h, &c1.list); + * list_add_tail(&h, &c3.list); + * list_add_before(&h, &c3.list, &c2.list); + */ +#define list_add_before(h, p, n) list_add_before_(h, p, n, LIST_LOC) +static inline void list_add_before_(struct list_head *h, + struct list_node *p, + struct list_node *n, + const char *abortstr) +{ + n->next = p; + n->prev = p->prev; + p->prev->next = n; + p->prev = n; (void)list_debug(h, abortstr); } @@ -197,11 +251,7 @@ static inline void list_add_tail_(struct list_head *h, struct list_node *n, const char *abortstr) { - n->next = &h->n; - n->prev = h->n.prev; - h->n.prev->next = n; - h->n.prev = n; - (void)list_debug(h, abortstr); + list_add_before_(h, &h->n, n, abortstr); } /** @@ -318,6 +368,39 @@ static inline void list_del_from(struct list_head *h, struct list_node *n) list_del(n); } +/** + * list_swap - swap out an entry from an (unknown) linked list for a new one. + * @o: the list_node to replace from the list. + * @n: the list_node to insert in place of the old one. + * + * Note that this leaves @o in an undefined state; it can be added to + * another list, but not deleted/swapped again. + * + * See also: + * list_del() + * + * Example: + * struct child x1, x2; + * LIST_HEAD(xh); + * + * list_add(&xh, &x1.list); + * list_swap(&x1.list, &x2.list); + */ +#define list_swap(o, n) list_swap_(o, n, LIST_LOC) +static inline void list_swap_(struct list_node *o, + struct list_node *n, + const char* abortstr) +{ + (void)list_debug_node(o, abortstr); + *n = *o; + n->next->prev = n; + n->prev->next = n; +#ifdef CCAN_LIST_DEBUG + /* Catch use-after-del. */ + o->next = o->prev = NULL; +#endif +} + /** * list_entry - convert a list_node back into the structure containing it. * @n: the list_node @@ -570,6 +653,24 @@ static inline void list_prepend_list_(struct list_head *to, list_head_init(from); } +/* internal macros, do not use directly */ +#define list_for_each_off_dir_(h, i, off, dir) \ + for (i = list_node_to_off_(list_debug(h, LIST_LOC)->n.dir, \ + (off)); \ + list_node_from_off_((void *)i, (off)) != &(h)->n; \ + i = list_node_to_off_(list_node_from_off_((void *)i, (off))->dir, \ + (off))) + +#define list_for_each_safe_off_dir_(h, i, nxt, off, dir) \ + for (i = list_node_to_off_(list_debug(h, LIST_LOC)->n.dir, \ + (off)), \ + nxt = list_node_to_off_(list_node_from_off_(i, (off))->dir, \ + (off)); \ + list_node_from_off_(i, (off)) != &(h)->n; \ + i = nxt, \ + nxt = list_node_to_off_(list_node_from_off_(i, (off))->dir, \ + (off))) + /** * list_for_each_off - iterate through a list of memory regions. * @h: the list_head @@ -600,11 +701,7 @@ static inline void list_prepend_list_(struct list_head *to, * printf("Name: %s\n", child->name); */ #define list_for_each_off(h, i, off) \ - for (i = list_node_to_off_(list_debug(h, LIST_LOC)->n.next, \ - (off)); \ - list_node_from_off_((void *)i, (off)) != &(h)->n; \ - i = list_node_to_off_(list_node_from_off_((void *)i, (off))->next, \ - (off))) + list_for_each_off_dir_((h),(i),(off),next) /** * list_for_each_safe_off - iterate through a list of memory regions, maybe @@ -623,15 +720,7 @@ static inline void list_prepend_list_(struct list_head *to, * printf("Name: %s\n", child->name); */ #define list_for_each_safe_off(h, i, nxt, off) \ - for (i = list_node_to_off_(list_debug(h, LIST_LOC)->n.next, \ - (off)), \ - nxt = list_node_to_off_(list_node_from_off_(i, (off))->next, \ - (off)); \ - list_node_from_off_(i, (off)) != &(h)->n; \ - i = nxt, \ - nxt = list_node_to_off_(list_node_from_off_(i, (off))->next, \ - (off))) - + list_for_each_safe_off_dir_((h),(i),(nxt),(off),next) /* Other -off variants. */ #define list_entry_off(n, type, off) \