diff options
Diffstat (limited to 'xorg-server/include/list.h')
| -rw-r--r-- | xorg-server/include/list.h | 160 |
1 files changed, 160 insertions, 0 deletions
diff --git a/xorg-server/include/list.h b/xorg-server/include/list.h index 5933b973d..7825dce52 100644 --- a/xorg-server/include/list.h +++ b/xorg-server/include/list.h @@ -278,4 +278,164 @@ list_is_empty(struct list *head) &pos->member != (head); \ pos = tmp, tmp = __container_of(pos->member.next, tmp, member)) + + +/* NULL-Terminated List Interface + * + * The interface below does _not_ use the struct list as described above. + * It is mainly for legacy structures that cannot easily be switched to + * struct list. + * + * This interface is for structs like + * struct foo { + * [...] + * struct foo *next; + * [...] + * }; + * + * The position and field name of "next" are arbitrary. + */ + +/** + * Init the element as null-terminated list. + * + * Example: + * struct foo *list = malloc(); + * nt_list_init(list, next); + * + * @param list The list element that will be the start of the list + * @param member Member name of the field pointing to next struct + */ +#define nt_list_init(_list, _member) \ + (_list)->_member = NULL + +/** + * Returns the next element in the list or NULL on termination. + * + * Example: + * struct foo *element = list; + * while ((element = nt_list_next(element, next)) { } + * + * This macro is not safe for node deletion. Use list_for_each_entry_safe + * instead. + * + * @param list The list or current element. + * @param member Member name of the field pointing to next struct. + */ +#define nt_list_next(_list, _member) \ + (_list)->_member + +/** + * Iterate through each element in the list. + * + * Example: + * struct foo *iterator; + * nt_list_for_each_entry(iterator, list, next) { + * [modify iterator] + * } + * + * @param entry Assigned to the current list element + * @param list The list to iterate through. + * @param member Member name of the field pointing to next struct. + */ +#define nt_list_for_each_entry(_entry, _list, _member) \ + for (_entry = _list; _entry; _entry = (_entry)->_member) + +/** + * Iterate through each element in the list, keeping a backup pointer to the + * element. This macro allows for the deletion of a list element while + * looping through the list. + * + * See nt_list_for_each_entry for more details. + * + * @param entry Assigned to the current list element + * @param tmp The pointer to the next element + * @param list The list to iterate through. + * @param member Member name of the field pointing to next struct. + */ +#define nt_list_for_each_entry_safe(_entry, _tmp, _list, _member) \ + for (_entry = _list, _tmp = (_entry) ? (_entry)->_member : NULL;\ + _entry; \ + _entry = _tmp, _tmp = (_tmp) ? (_tmp)->_member: NULL) + + +/** + * Append the element to the end of the list. This macro may be used to + * merge two lists. + * + * Example: + * struct foo *elem = malloc(...); + * nt_list_init(elem, next) + * nt_list_append(elem, list, struct foo, next); + * + * Resulting list order: + * list_item_0 -> list_item_1 -> ... -> elem_item_0 -> elem_item_1 ... + * + * @param entry An entry (or list) to append to the list + * @param list The list to append to. This list must be a valid list, not + * NULL. + * @param type The list type + * @param member Member name of the field pointing to next struct + */ +#define nt_list_append(_entry, _list, _type, _member) \ + do { \ + _type *__iterator = _list; \ + while (__iterator->_member) { __iterator = __iterator->_member;}\ + __iterator->_member = _entry; \ + } while (0) + +/** + * Insert the element at the next position in the list. This macro may be + * used to insert a list into a list. + * + * struct foo *elem = malloc(...); + * nt_list_init(elem, next) + * nt_list_insert(elem, list, struct foo, next); + * + * Resulting list order: + * list_item_0 -> elem_item_0 -> elem_item_1 ... -> list_item_1 -> ... + * + * @param entry An entry (or list) to append to the list + * @param list The list to insert to. This list must be a valid list, not + * NULL. + * @param type The list type + * @param member Member name of the field pointing to next struct + */ +#define nt_list_insert(_entry, _list, _type, _member) \ + do { \ + nt_list_append((_list)->_member, _entry, _type, _member); \ + (_list)->_member = _entry; \ + } while (0) + +/** + * Delete the entry from the list by iterating through the list and + * removing any reference from the list to the entry. + * + * Example: + * struct foo *elem = <assign to right element> + * nt_list_del(elem, list, struct foo, next); + * + * @param entry The entry to delete from the list. entry is always + * re-initialized as a null-terminated list. + * @param list The list containing the entry, set to the new list without + * the removed entry. + * @param type The list type + * @param member Member name of the field pointing to the next entry + */ +#define nt_list_del(_entry, _list, _type, _member) \ + do { \ + _type *__e = _entry; \ + if (__e == NULL) break; \ + if ((_list) == __e) { \ + _list = __e->_member; \ + } else { \ + _type *__prev = _list; \ + while (__prev->_member && __prev->_member != __e) \ + __prev = nt_list_next(__prev, _member); \ + if (__prev->_member) \ + __prev->_member = __e->_member; \ + } \ + nt_list_init(__e, _member); \ + } while(0) + #endif |