c语言链表的类型声明,c语言之————内核链表使用实例

kernel_list.h

/*

* kernel_list.h

* 描述：

* 此为内核链表结构(循环链表)

*/

#pragma once

#include

struct list_head

{

struct list_head *prev;

struct list_head *next;

};

#define LIST_HEAD(name) struct list_head name={&(name),&(name)}

/*

* 初始化链表

*/

static inline void INIT_LIST_HEAD(struct list_head *node)

{

node->prev = node;

node->next = node;

}

/*

* 在prev与next节点之间插入节点new_node

*/

static inline void __list_add(struct list_head *new_node,struct list_head *prev,struct list_head *next)

{

prev->next = new_node;

next->prev = new_node;

new_node->prev = prev;

new_node->next = next;

}

/*

* 头插

*/

static inline void list_add(struct list_head *new_node,struct list_head *head)

{

__list_add(new_node,head,head->next);

}

/*

* 尾插

*/

static inline void list_add_tail(struct list_head *new_node,struct list_head *head)

{

__list_add(new_node,head->prev,head);

}

/*

* 删除节点

*/

static inline void list_del(struct list_head *node)

{

node->prev->next = node->next;

node->next->prev = node->prev;

}

/*

* 删除节点并初始化删除的节点

*/

static inline void list_del_init(struct list_head *node)

{

node->prev->next = node->next;

node->next->prev = node->prev;

INIT_LIST_HEAD(node);

}

/*

* 判断链表是否为空

*/

static inline int list_empty(struct list_head *node)

{

return node->next == node;

}

/*

* offsetof见stddef.h中:

* TYPE是某struct的类型 0是一个假想TYPE类型struct,MEMBER是该struct中的一个成员.

* 由于该struct的基地址为0, MEMBER的地址就是该成员相对与struct头地址的偏移量.

*/

#define offsetof(type, member) \

( (size_t)(&((type*)0)->member) )

/*

* typeof,这是gcc的C语言扩展保留字,用于声明变量类型.

* typeof 关键字将用做类型名(typedef名称)并指定类型

* typeof(int *) p1, p2; －> int *p1, *p2;

*typeof(int [10]) a1, a2; --> int a1[10], a2[10];

*typeof(int) * p3, p4; -> int *p3,p4;

*

*/

/**

* container_of - cast a member of a structure out to the containing structure

* container_of在Linux Kernel中的应用非常广泛,它用于获得某结构中某成员的入口地址.container_of见kernel.h中:

* @ptr: the pointer to the member.ptr是成员变量的指针

* @type: the type of the container struct this is embedded in.type是指结构体的类型

* @member: the name of the member within the struct.member是成员变量的名字

*const typeof( ((type *)0->member ) *__mptr = (ptr);

* 意思是声明一个与member同一个类型的指针常量 *__mptr,并初始化为ptr.

*， ， 。

*(type *)( (char *)__mptr - offsetof(type,member) );

* 意思是__mptr的地址减去member在该struct中的偏移量得到的地址, 再转换成type型指针. 该指针就是member的入口地址了.

*/

#define container_of(ptr, type, member) \

({ typeof(((type*)0)->member) *__mptr = ptr; \

(type*)((char*)__mptr - offsetof(type, member)); })

/*

* 从头节点后面的节点开始遍历链表

*/

#define list_for_each(cur, head) \

for (cur = (head)->next; (cur) != (head); \

cur = (cur)->next)

/*

* 遍历链表,并对cur的节点进行操作

*/

#define list_for_each_safe(cur, tmp, head) \

for (cur = (head)->next, tmp = (cur)->next; \

(cur) != (head); cur = tmp, tmp = (tmp)->next)

/*

* 反向遍历

*/

#define list_for_each_reverse(cur, head) \

for (cur = (head)->prev; (cur) != (head); \

cur = (cur)->prev)

/*

* 从cur节点后的节点开始遍历链表

*/

#define list_for_each_continue(cur, head) \

for (cur = (cur)->next; (cur) != (head); \

cur = (cur)->next)

#define list_for_each_from(cur, head) \

for (; (cur) != (head); cur = (cur)->next)

/*

* 从头节点的下一个节点开始遍历，一直末尾

*/

#define list_for_each_entry(ptr, head, member) \

for ( ptr = container_of((head)->next, typeof(*(ptr)), member); \

&(ptr)->member != (head); \

ptr = container_of((ptr)->member.next, typeof(*(ptr)), member) )

/*

* 从头节点的下一个节点开始遍历，一直末尾,可以进行删除操作

*/

#define list_for_each_entry_safe(ptr, tmp, head, member) \

for ( ptr = container_of((head)->next, typeof(*(ptr)), member), \

tmp = container_of((ptr)->member.next, typeof(*(ptr)), member); \

&(ptr)->member != (head); \

ptr = tmp, \

tmp = container_of((tmp)->member.next, typeof(*(ptr)), member) )

test_list.c

/*

* test_list.c

*/

#include "kernel_list.h"

#include

#include

struct data_info {

const char *name;

size_t age;

struct list_head list;

};

int main()

{

//定义头

LIST_HEAD(head);

struct data_info s[] = {

{"john", 25}, {"kate", 23}, {"hunt", 24},

{"tom", 29}, {"top", 19}

};

size_t i = 0;

for (i = 0; i < sizeof(s) / sizeof(struct data_info); ++i) {

INIT_LIST_HEAD(&s[i].list);

list_add_tail(&s[i].list, &head);

}

struct list_head *cur = NULL;

struct data_info *ptr = NULL;

list_for_each(cur, &head) {

ptr = container_of(cur, struct data_info, list);

printf("%s: %ld\n", ptr->name, ptr->age);

}

printf("=========删除=========\n");

struct list_head *tmp = NULL;

list_for_each_safe(cur, tmp, &head) {

ptr = container_of(cur, struct data_info, list);

if (ptr->age == 19) {

list_del_init(cur);

}

}

struct data_info *ptmp = NULL;

list_for_each_entry_safe(ptr, ptmp, &head, list) {

if (!strcmp(ptr->name, "hunt")) {

list_del_init(&ptr->list);

}

}

printf("=============\n");

list_for_each_entry(ptr, &head, list) {

printf("%s: %ld\n", ptr->name, ptr->age);

}

return 0;

}

Makfile

all:test_list

test_list:test_list.o

gcc -o $@ $^

test_list.o:test_list.c

gcc -c test_list.c

clean:

rm *.o test_list

运行结果：

john: 25

kate: 23

hunt: 24

tom: 29

top: 19

=========删除=========

=============

john: 25

kate: 23

tom: 29