openwrt中用到双向无头链表,实际应用时应在外部定义实体链表头,后续可直接应用链表函数(宏定义已将链表头排除在外):
static struct list_head timeouts = LIST_HEAD_INIT(timeouts);
static struct list_head processes = LIST_HEAD_INIT(processes);与linux相同,定义如下:
#ifndef _LINUX_LIST_H_#define _LINUX_LIST_H_#include#include #define prefetch(x)#ifndef container_of#define container_of(ptr, type, member) \ ({ \ const typeof(((type *)NULL)->member) *__mptr = (ptr); \ (type *)((char *)__mptr - offsetof(type, member)); \ })#endifstruct list_head { struct list_head *next; struct list_head *prev;};
初始化
#define LIST_HEAD_INIT(name) {&(name), &(name)}#undef LIST_HEAD#define LIST_HEAD(name) struct list_head name = LIST_HEAD_INIT(name)static inline voidINIT_LIST_HEAD(struct list_head *list){ list->next = list->prev = list;}
list属性
static inline boollist_empty(const struct list_head *head){ return (head->next == head);}static inline boollist_is_first(const struct list_head *list, const struct list_head *head){ return (list->prev == head);}static inline boollist_is_last(const struct list_head *list, const struct list_head *head){ return (list->next == head);}
list常用操作--增add
static inline void_list_add(struct list_head *_new, struct list_head *prev, struct list_head *next){ prev->next = _new; _new->prev = prev; _new->next = next; next->prev = _new;}static inline voidlist_add(struct list_head *_new, struct list_head *head){ _list_add(_new, head, head->next);}static inline voidlist_add_tail(struct list_head *_new, struct list_head, *head){ _list_add(_new, head->prev, head);}
list常用操作--删del
static inline void_list_del(struct list_head *entry){ entry->next->prev = entry->prev; entry->prev->next = entry->next;}static inline voidlist_del(struct list_head *entry){ _list_del(entry); entry->next = entry->prev = NULL;}static inline voidlist_del_init(struct list_head *entry){ _list_del(entry); INIT_LIST_HEAD(entry);}
list常用操作--改move
static inline voidlist_move(struct list_head *list, struct list_head * head){ _list_del(list); list_add(list, head);}static inline voidlist_move_tail(struct list_head *list, struct list_head *head){ _list_del(list); list_add_tail(list, head);}
list常用操作--查
#define list_entry(ptr, type, field) container_of(ptr, type, field)#define list_first_entry(ptr, type, field) list_entry((ptr)->next, type, field)#define list_last_entry(ptr, type, field) list_entry((ptr)->prev, type, field)#define list_for_each(p, head) \ for(p=(head)->next; p!=(head); p=p->next)#define list_for_each_safe(p, n, head) \ for(p = (head)->next, n=p->next; p!= (head); p=n, n=p->next)#define list_for_each_entry(p, h, field) \ for(p = list_first_entry(h, typeof(*p), field); \ &p->field != (h); \ p = list_entry(p->field.next, typeof(*p), field))#define list_for_each_entry_safe(p, n, h, field) \ for(p = list_first_entry(h, typeof(*p), field), \ n = list_entry(p->field.next, typeof(*p), field); \ &p->field != (h); \ p = n, n = list_entry(n->field.next, typeof(*p), field))#define list_for_each_entry_reverse(p, h, field) \ for(p = list_last_entry(h, typeof(*p), field); \ &p->field != (h); \ p = list_entry(p->field.prev, typeof(*p), field))#define list_for_each_prev(p, h) \ for(p = (h)->prev; p != (h); p = p->prev)#define list_for_each_prev_safe(p, n, h) \ for(p = (h)->prev, n = p->prev; p != (h); \ p = n, n = p->prev)
list常用操作--拼接splice
static inline void_list_splice(const struct list_head *list, struct list_head *prev, struct list_head *next){ struct list_head *first, last; if(list_empty(list)) return ; first = list->next; last = list->prev; first->prev = prev; prev->next = first; last->next = next; next->prev = last;}static inline voidlist_splice(const struct list_head *list, struct list_head *head){ _list_splice(list, head, head->next);}static inline voidlist_splice_tail(struct list_head *list, struct list_head *head){ _list_splice(list, head->prev, head);}static inline voidlist_splice_init(struct list_head *list, struct list_head *head){ _list_splice(list, head, head->next); INIT_LIST_HEAD(list);}static inline voidlist_splice_tail_init(struct list_head *list, struct list_head *head){ _list_splice(list, head->prev, head); INIT_LIST_HEAD(list);}#endif