Linux内核双向循环链表分析

来源：互联网发布：浩辰cad建筑软件编辑：程序博客网时间：2024/05/21 14:51

#include <stdio.h>struct list_head{struct list_head *next;struct list_head *prev;};struct score{int num;int math;struct list_head list;};#define list_for_each(pos, head) \for (pos = (head)->next; pos != (head); pos = pos->next)#define offsetof(TYPE, MEMBER)((size_t) &((TYPE*)0)->MEMBER)#define container_of(ptr, type, member) ({\const typeof( ((type *)0)->member ) *__mptr = (ptr);\(type *)( (char *)__mptr - offsetof(type,member) );})#define list_entry(ptr, type, member)\container_of(ptr, type, member)static void INIT_LIST_HEAD(struct list_head *list){list->prev = list;list->next = list;}static 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;}static void list_add_tail(struct list_head *new, struct list_head *head){__list_add(new, head->prev, head);}static void list_add(struct list_head *new, struct list_head *head){__list_add(new, head, head->next);}static void __list_del(struct list_head *prev, struct list_head *next){next->prev = prev;prev->next = next;}static void list_del(struct list_head *entry){__list_del(entry->prev, entry->next);} int main(){struct score stu1;struct score stu2;struct score stu3;struct score stu4;struct score stu5;struct score stu6;struct score *temp;struct list_head *pos;struct list_head score_head;INIT_LIST_HEAD(&score_head);stu1.num = 1;stu2.num = 2;stu3.num = 3;stu4.num = 4;stu5.num = 5;stu6.num = 6;stu1.math = 60;stu2.math = 70;stu3.math = 80;stu4.math = 90;stu5.math = 20;stu6.math = 30;//在表尾部插入 list_add_tail(&(stu1.list), &score_head);list_add_tail(&(stu2.list), &score_head);list_add_tail(&(stu3.list), &score_head);list_add_tail(&(stu4.list), &score_head);list_for_each(pos, &score_head){temp = list_entry(pos, struct score, list);printf("num = %d, math = %d\n", temp->num, temp->math);}printf("\n");//在表头插入 list_add(&(stu5.list), &score_head);list_add(&(stu6.list), &score_head);list_for_each(pos, &score_head){temp = list_entry(pos, struct score, list);printf("num = %d, math = %d\n", temp->num, temp->math);}printf("\n");//删除list_del(&(stu5.list)); list_for_each(pos, &score_head){temp = list_entry(pos, struct score, list);printf("num = %d, math = %d\n", temp->num, temp->math);}printf("\n");return 0;}

运行效果：

内核双链表效果图：

大体的效果图就是如此，增加一个节点，删除一个节点都是基于这个模型展开的。

读者可以手动画画增加和删除的操作。

其实关于内核中链表的操作还有很多的函数，目前就分析这几个。其余留给自己尝试。

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