应用层调用内核中的链表操作.

今天上班没有事做,自己折腾了一下应用层使用内核链表的用法.因为内核中的list.h文件中包含了汇编和依赖了其他文件,直接包含内核的list.h文件编译出大量的错误,要使用下面的list.h.

网上有大量的链表中函数的讲解,所以我直接上程序.

list.h 代码:

#ifndef _LINUX_LIST_H
#define _LINUX_LIST_H
#include <stdio.h>
#include <stdlib.h>
#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) ); } )

static inline void prefetch(const void *x) {;}
static inline void prefetchw(const void *x) {;}

#define LIST_POISON1  ((void *) 0x00100100)
#define LIST_POISON2  ((void *) 0x00200200)

struct list_head {
struct list_head *next, *prev;
};

#define LIST_HEAD_INIT(name) { &(name), &(name) }

#define LIST_HEAD(name) \
struct list_head name = LIST_HEAD_INIT(name)

#define INIT_LIST_HEAD(ptr) do { \
(ptr)->next = (ptr); (ptr)->prev = (ptr); \
} while (0)

/*
* Insert a new entry between two known consecutive entries.
*
* This is only for internal list manipulation where we know
* the prev/next entries already!
*/
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;
}

/**
* list_add - add a new entry
* @new: new entry to be added
* @head: list head to add it after
*
* Insert a new entry after the specified head.
* This is good for implementing stacks.
*/
static inline void list_add(struct list_head *new, struct list_head *head)
{
__list_add(new, head, head->next);
}

/**
* list_add_tail - add a new entry
* @new: new entry to be added
* @head: list head to add it before
*
* Insert a new entry before the specified head.
* This is useful for implementing queues.
*/
static inline void list_add_tail(struct list_head *new, struct list_head *head)
{
__list_add(new, 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(struct list_head *entry)
{
__list_del(entry->prev, entry->next);
entry->next = LIST_POISON1;
entry->prev = LIST_POISON2;
}

static inline void list_del_init(struct list_head *entry)
{
__list_del(entry->prev, entry->next);
INIT_LIST_HEAD(entry);
}

static inline void list_move(struct list_head *list, struct list_head *head)
{
__list_del(list->prev, list->next);
list_add(list, head);
}

static inline void list_move_tail(struct list_head *list,
struct list_head *head)
{
__list_del(list->prev, list->next);
list_add_tail(list, head);
}

static inline int list_empty(const struct list_head *head)
{
return head->next == head;
}

static inline int list_empty_careful(const struct list_head *head)
{
struct list_head *next = head->next;
return (next == head) && (next == head->prev);
}

static inline void __list_splice(struct list_head *list,
struct list_head *head)
{
struct list_head *first = list->next;
struct list_head *last = list->prev;
struct list_head *at = head->next;

first->prev = head;
head->next = first;

last->next = at;
at->prev = last;
}

/**
* list_splice - join two lists
* @list: the new list to add.
* @head: the place to add it in the first list.
*/
static inline void list_splice(struct list_head *list, struct list_head *head)
{
if (!list_empty(list))
__list_splice(list, head);
}

/**
* list_splice_init - join two lists and reinitialise the emptied list.
* @list: the new list to add.
* @head: the place to add it in the first list.
*
* The list at @list is reinitialised
*/
static inline void list_splice_init(struct list_head *list,
struct list_head *head)
{
if (!list_empty(list)) {
__list_splice(list, head);
INIT_LIST_HEAD(list);
}
}

#define list_entry(ptr, type, member) container_of(ptr, type, member)

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

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

#define list_for_each_prev(pos, head) \
for (pos = (head)->prev; prefetch(pos->prev), pos != (head); \
pos = pos->prev)

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

#define list_for_each_entry(pos, head, member)                                \
for (pos = list_entry((head)->next, typeof(*pos), member);        \
prefetch(pos->member.next), &pos->member != (head);         \
pos = list_entry(pos->member.next, typeof(*pos), member))

#define list_for_each_entry_reverse(pos, head, member)                        \
for (pos = list_entry((head)->prev, typeof(*pos), member);        \
prefetch(pos->member.prev), &pos->member != (head);         \
pos = list_entry(pos->member.prev, typeof(*pos), member))

#define list_prepare_entry(pos, head, member) \
((pos) ? : list_entry(head, typeof(*pos), member))

#define list_for_each_entry_continue(pos, head, member)                 \
for (pos = list_entry(pos->member.next, typeof(*pos), member);        \
prefetch(pos->member.next), &pos->member != (head);        \
pos = list_entry(pos->member.next, typeof(*pos), member))

#define list_for_each_entry_safe(pos, n, head, member)                        \
for (pos = list_entry((head)->next, typeof(*pos), member),        \
n = list_entry(pos->member.next, typeof(*pos), member);        \
&pos->member != (head);                                         \
pos = n, n = list_entry(n->member.next, typeof(*n), member))

//HASH LIST
struct hlist_head {
struct hlist_node *first;
};

struct hlist_node {
struct hlist_node *next, **pprev;
};

#define HLIST_HEAD_INIT { .first = NULL }
#define HLIST_HEAD(name) struct hlist_head name = {  .first = NULL }
#define INIT_HLIST_HEAD(ptr) ((ptr)->first = NULL)
#define INIT_HLIST_NODE(ptr) ((ptr)->next = NULL, (ptr)->pprev = NULL)

static inline int hlist_unhashed(const struct hlist_node *h)
{
return !h->pprev;
}

static inline int hlist_empty(const struct hlist_head *h)
{
return !h->first;
}

static inline void __hlist_del(struct hlist_node *n)
{
struct hlist_node *next = n->next;
struct hlist_node **pprev = n->pprev;
*pprev = next;
if (next)
next->pprev = pprev;
}

static inline void hlist_del(struct hlist_node *n)
{
__hlist_del(n);
n->next = LIST_POISON1;
n->pprev = LIST_POISON2;
}

static inline void hlist_del_init(struct hlist_node *n)
{
if (n->pprev)  {
__hlist_del(n);
INIT_HLIST_NODE(n);
}
}

static inline void hlist_add_head(struct hlist_node *n, struct hlist_head *h)
{
struct hlist_node *first = h->first;
n->next = first;
if (first)
first->pprev = &n->next;
h->first = n;
n->pprev = &h->first;
}

/* next must be != NULL */
static inline void hlist_add_before(struct hlist_node *n,
struct hlist_node *next)
{
n->pprev = next->pprev;
n->next = next;
next->pprev = &n->next;
*(n->pprev) = n;
}

static inline void hlist_add_after(struct hlist_node *n,
struct hlist_node *next)
{
next->next = n->next;
n->next = next;
next->pprev = &n->next;

if(next->next)
next->next->pprev  = &next->next;
}

#define hlist_entry(ptr, type, member) container_of(ptr,type,member)

#define hlist_for_each(pos, head) \
for (pos = (head)->first; pos && ({ prefetch(pos->next); 1; }); \
pos = pos->next)

#define hlist_for_each_safe(pos, n, head) \
for (pos = (head)->first; pos && ({ n = pos->next; 1; }); \
pos = n)

#define hlist_for_each_entry(tpos, pos, head, member)                         \
for (pos = (head)->first;                                         \
pos && ({ prefetch(pos->next); 1;}) &&                         \
({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \
pos = pos->next)

#define hlist_for_each_entry_continue(tpos, pos, member)                 \
for (pos = (pos)->next;                                                 \
pos && ({ prefetch(pos->next); 1;}) &&                         \
({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \
pos = pos->next)

#define hlist_for_each_entry_from(tpos, pos, member)                         \
for (; pos && ({ prefetch(pos->next); 1;}) &&                         \
({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \
pos = pos->next)

#define hlist_for_each_entry_safe(tpos, pos, n, head, member)                  \
for (pos = (head)->first;                                         \
pos && ({ n = pos->next; 1; }) &&                                  \
({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \
pos = n)

#endif

以上的list.h中的代码是网上找到,感谢那位大神帮忙将内核中的list.h整理出来.我复制下来编译代码会出现没有NULL定义,所以我加了头文件进去了,当然也可以自己定义一个NULL.你可以将list.h拷贝到你的任意工程中使用.以下是我使用链表的代码.

stuinfo.h文件中的代码:

#ifndef __LIST_STU__
#define __LIST_STU__

#include "list.h"
struct stuinfo{
char name[30];
int age;
char addr[50];
struct list_head list;
};
struct stuinfo *init_stuinfo(void);
int insertstuinfo(char name[30],int age,char addr[50],struct list_head *head);
void iterator_stuinfolist(struct list_head *head);
struct stuinfo *find_stuinfo_by_name(char *name,struct list_head *head);
void del_stuinfo(char *name,struct list_head *head);

#endif

stuinfo.c文件中的代码

#include "stuinfo.h"
#include <string.h>
#include <stdlib.h>

struct stuinfo *init_stuinfo(void)
{
struct stuinfo *tstuinfo;
tstuinfo = (struct stuinfo *)malloc(sizeof(struct stuinfo));
memset(tstuinfo,0,sizeof(struct stuinfo));

INIT_LIST_HEAD(&tstuinfo->list);
return tstuinfo;
}
int insertstuinfo(char name[30],int age,char addr[50],struct list_head *head)//插入链表
{
struct stuinfo *ttmpstuinfo;
ttmpstuinfo = (struct stuinfo *)malloc(sizeof(struct stuinfo));
if(ttmpstuinfo == NULL)
return 1;
strcpy(ttmpstuinfo->name,name);
ttmpstuinfo->age  = age;
strcpy(ttmpstuinfo->addr,addr);
list_add_tail(&ttmpstuinfo->list,head);
return 0;
}
void iterator_stuinfolist(struct list_head *head)//遍历整个链表
{
struct list_head *pos;
struct stuinfo *tmp;
list_for_each(pos,head){
tmp = list_entry(pos,struct stuinfo,list);
printf("tmp->name:%s \t tmp->age:%d \t tmp->addr :%s\n",tmp->name,tmp->age,tmp->addr);
}
}
<pre name="code" class="cpp">struct stuinfo *find_stuinfo_by_name(char *name,struct list_head *head)//通过名字查找stuinfo节点
{
struct list_head *pos;
struct stuinfo *tmp;
list_for_each(pos,head){
tmp = list_entry(pos,struct stuinfo,list);
if(strcmp(tmp->name,name) == 0)
{
return tmp;
}
}
return NULL;
}
void del_stuinfo(char *name,struct list_head *head)//通过名字删除stuinfo节点
{
struct list_head *listtmp;
struct list_head *pos;
struct stuinfo *tmp;

list_for_each(pos,head){
tmp = list_entry(pos,struct stuinfo,list);
if(strcmp(tmp->name,name) == 0)
{
//listtmp = pos->prev;   //如果想让list_for_each继续去掉注释并将return ;语句注释掉
list_del(pos);
//pos = listtmp;
free(tmp);
tmp = NULL;
return ;
}
}
}

main.c文件中的代码:

#include "stuinfo.h"
#include <stdio.h>
#include <unistd.h>

int main(int argc,char* argv[])
{
struct stuinfo *tstuinfo;
struct stuinfo *findstuinfo;
tstuinfo = init_stuinfo();
if (insertstuinfo("xiaoli",18,"beijing",&tstuinfo->list))
{
printf("insert error!\n");
exit(0);
}
if (insertstuinfo("xiaoming",14,"guangzhou",&tstuinfo->list))
{
printf("insert error!\n");
exit(0);
}
if (insertstuinfo("xiaobai",21,"shanghai",&tstuinfo->list))
{
printf("insert error!\n");
exit(0);
}
if (insertstuinfo("xiaohei",25,"hubei",&tstuinfo->list))
{
printf("insert error!\n");
exit(0);
}
iterator_stuinfolist(&tstuinfo->list);
findstuinfo = find_stuinfo_by_name("xiaobai",&tstuinfo->list);
if(findstuinfo == NULL)
printf("not find the name of xiaobai\n");
else
{
printf("findstuinfo->name:%s \t findstuinfo->age:%d \t findstuinfo->addr :%s\n",findstuinfo->name,findstuinfo->age,findstuinfo->addr);

del_stuinfo(findstuinfo->name,&tstuinfo->list);
}
iterator_stuinfolist(&tstuinfo->list);
return 0;
}

最后编译代码: gcc -o main main.c stuinfo.c执行./main可以看到结果如下:tmp->name:xiaoli tmp->age:18 tmp->addr :beijing

tmp->name:xiaoming tmp->age:14 tmp->addr :guangzhou

tmp->name:xiaobai tmp->age:21 tmp->addr :shanghai

tmp->name:xiaohei tmp->age:25 tmp->addr :hubei

findstuinfo->name:xiaobai findstuinfo->age:21 findstuinfo->addr :shanghai

tmp->name:xiaoli tmp->age:18 tmp->addr :beijing

tmp->name:xiaoming tmp->age:14 tmp->addr :guangzhou

tmp->name:xiaohei tmp->age:25 tmp->addr :hubei

以上的操作是应用层使用内核的双链表的插入,查找,删除,遍历的例子.以下这篇文章有讲链表的函数使用还有一个链表使用的驱动程序,http://blog.chinaunix.net/uid-27037833-id-3237153.html