Linux two-way linked list operation implementation tutorial, linux tutorial

Linux two-way linked list operation implementation tutorial, linux tutorial

Linux bidirectional linked list operation implementation tutorial

The code is located in include/linux/list. h. The linked list is initialized:

static inline void INIT_LIST_HEAD(struct list_head *list){    list->next = list;    list->prev = list;}

After initialization, the status chart of the linked list is shown in the following figure: prev pointer on the left and next pointer on the right:

Use the list_add_tail function to insert a node for the first time. Code:

static inline void list_add_tail(struct list_head *new, struct list_head *head){    __list_add(new, head->prev, head);}static inline void __list_add(struct list_head *new,                  struct list_head *prev,                  struct list_head *next){    next->prev = new;    new->next = next;    new->prev = prev;    prev->next = new;}

The linked list after new1 is inserted on the first node:

The following figure shows how to continue calling the list_add_tail function to insert new2 to the second node:

Circular code of a two-way linked list:

#define list_for_each(pos, head) \    for (pos = (head)->next; pos != (head); pos = pos->next)

The order of loop processing is the same as that of list_add_tail. It starts with the next pointer of the header, namely node new1, followed by node new2, until the header of the node.