diff options
Diffstat (limited to 'lab02/list.h')
| -rw-r--r-- | lab02/list.h | 212 |
1 files changed, 212 insertions, 0 deletions
diff --git a/lab02/list.h b/lab02/list.h new file mode 100644 index 0000000..f04df43 --- /dev/null +++ b/lab02/list.h @@ -0,0 +1,212 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef LIST_H +#define LIST_H + +#include <stddef.h> +#include <stdbool.h> +#include <assert.h> + +#include "container_of.h" + +struct list_head { + struct list_head *next; + struct list_head *prev; +}; + +#define LIST_POISON1 ((void *) 0x100) +#define LIST_POISON2 ((void *) 0x122) + +#define LIST_HEAD_INIT(name) { &(name), &(name) } + +#define LIST_HEAD(name) \ + struct list_head name = LIST_HEAD_INIT(name) + +static inline void INIT_LIST_HEAD(struct list_head *list) +{ + list->next = list; + list->prev = list; +} + +static inline void __list_add(struct list_head *node, + struct list_head *prev, + struct list_head *next) +{ + next->prev = node; + node->next = next; + node->prev = prev; + prev->next = node; +} + +static inline void list_add(struct list_head *node, + struct list_head *head) +{ + __list_add(node, head, head->next); +} + +static inline void list_add_tail(struct list_head *node, + struct list_head *head) +{ + __list_add(node, head->prev, head); +} + +static inline void __list_del(struct list_head *prev, + struct list_head *next) +{ + next->prev = prev; + prev->next = next; +} + +static inline void __list_del_entry(struct list_head *entry) +{ + __list_del(entry->prev, entry->next); +} + +static inline void list_del(struct list_head *entry) +{ + __list_del_entry(entry); + entry->next = LIST_POISON1; + entry->prev = LIST_POISON2; +} + + +static inline void list_replace(struct list_head *old, + struct list_head *new) +{ + new->next = old->next; + new->next->prev = new; + new->prev = old->prev; + new->prev->next = new; +} + +static inline void list_replace_init(struct list_head *old, + struct list_head *new) +{ + list_replace(old, new); + INIT_LIST_HEAD(old); +} + +static inline void list_move(struct list_head *list, struct list_head *head) +{ + __list_del_entry(list); + list_add(list, head); +} + +static inline void list_move_tail(struct list_head *list, + struct list_head *head) +{ + __list_del_entry(list); + list_add_tail(list, head); +} + +static inline int list_is_first(const struct list_head *list, const struct list_head *head) +{ + return list->prev == head; +} + +static inline int list_is_last(const struct list_head *list, const struct list_head *head) +{ + return list->next == head; +} + +static inline int list_is_head(const struct list_head *list, const struct list_head *head) +{ + return list == head; +} + +static inline int list_empty(const struct list_head *head) +{ + return head->next == head; +} + +/** + * list_entry - get the struct for this entry + * @ptr: the &struct list_head pointer. + * @type: the type of the struct this is embedded in. + * @member: the name of the list_head within the struct. + */ +#define list_entry(ptr, type, member) \ + container_of(ptr, type, member) + +/** + * list_first_entry - get the first element from a list + * @ptr: the list head to take the element from. + * @type: the type of the struct this is embedded in. + * @member: the name of the list_head within the struct. + * + * Note, that list is expected to be not empty. + */ +#define list_first_entry(ptr, type, member) \ + list_entry((ptr)->next, type, member) + +/** + * list_last_entry - get the last element from a list + * @ptr: the list head to take the element from. + * @type: the type of the struct this is embedded in. + * @member: the name of the list_head within the struct. + * + * Note, that list is expected to be not empty. + */ +#define list_last_entry(ptr, type, member) \ + list_entry((ptr)->prev, type, member) + +/** + * list_next_entry - get the next element in list + * @pos: the type * to cursor + * @member: the name of the list_head within the struct. + */ +#define list_next_entry(pos, member) \ + list_entry((pos)->member.next, typeof(*(pos)), member) + +/** + * list_prev_entry - get the prev element in list + * @pos: the type * to cursor + * @member: the name of the list_head within the struct. + */ +#define list_prev_entry(pos, member) \ + list_entry((pos)->member.prev, typeof(*(pos)), member) + +/** + * list_entry_is_head - test if the entry points to the head of the list + * @pos: the type * to cursor + * @head: the head for your list. + * @member: the name of the list_head within the struct. + */ +#define list_entry_is_head(pos, head, member) \ + (&pos->member == (head)) + +/** + * list_for_each_entry - iterate over list of given type + * @pos: the type * to use as a loop cursor. + * @head: the head for your list. + * @member: the name of the list_head within the struct. + */ +#define list_for_each_entry(pos, head, member) \ + for (pos = list_first_entry(head, typeof(*pos), member); \ + !list_entry_is_head(pos, head, member); \ + pos = list_next_entry(pos, member)) + +/** + * list_for_each_entry_reverse - iterate backwards over list of given type. + * @pos: the type * to use as a loop cursor. + * @head: the head for your list. + * @member: the name of the list_head within the struct. + */ +#define list_for_each_entry_reverse(pos, head, member) \ + for (pos = list_last_entry(head, typeof(*pos), member); \ + !list_entry_is_head(pos, head, member); \ + pos = list_prev_entry(pos, member)) + +/** + * list_for_each_entry_safe - iterate over list of given type. Safe against removal of list entry + * @pos: the type * to use as a loop cursor. + * @n: another type * to use as temporary storage + * @head: the head for your list. + * @member: the name of the list_head within the struct. + */ +#define list_for_each_entry_safe(pos, n, head, member) \ + for (pos = list_first_entry(head, typeof(*pos), member), \ + n = list_next_entry(pos, member); \ + !list_entry_is_head(pos, head, member); \ + pos = n, n = list_next_entry(n, member)) + +#endif /* LIST_H */ |