linux c数据结构-内核链表

注意：来自Linux内核链表头文件！

头文件代码list.h（代码就不分析了，网上很多。）

#ifndef _LIST_H
#define _LIST_H
#include <string.h>
/*
 *  * This is a simple doubly linked list implementation that matches the
 *   * way the Linux kernel doubly linked list implementation works.
 *    */
 
struct list_head {
	struct list_head *next; /* next in chain */
	struct list_head *prev; /* previous in chain */
};

/* Initialise a list head to an empty list */
static inline void INIT_LIST_HEAD(struct list_head *list)
{
        list->next = list;
	list->prev = list;
}

#define prefetch(x) __builtin_prefetch(x)
/*
 *  * 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_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);
}
 
/**
 *  *  * 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);
}


/* Take an element out of its current list, with or without
 *  * reinitialising the links.of the entry*/
static inline void list_del(struct list_head *entry)
{
	struct list_head *list_next = entry->next;
	struct list_head *list_prev = entry->prev;
			 
	list_next->prev = list_prev;
	list_prev->next = list_next;
					 
}
 
/**
 *  * list_entry - get the struct for this entry
 *  * @ptr:the &struct list_head pointer.
 *  * @type:the type of the struct this is embedded in.
 *  * @member:the name of the list_struct within the struct.
 *  */
#define list_entry(ptr, type, member) \
	    container_of(ptr, type, member)


/**
 *  * container_of - cast a member of a structure out to the containing structure
 *   * @ptr:    the pointer to the member.
 *    * @type:   the type of the container struct this is embedded in.
 *     * @member: the name of the member within the struct.
 *      *
 *       */
#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_for_each(pos, head) \
	for (pos = (head)->next; prefetch(pos->next), pos != (head); \
	pos = pos->next)
/**
 *  * list_for_each_safe - iterate over a list safe against removal of list entry
 *  * @pos:the &struct list_head to use as a loop cursor.
 *  * @n:another &struct list_head to use as temporary storage
 *  * @head:</span>the head for your list.
 *  */
#define list_for_each_safe(pos, n, head) \
	  for (pos = (head)->next, n = pos->next; pos != (head); \
			pos = n, n = pos->next)



/**
 * list_first_entry - get the first element from a list
 * @ptr:        the list head to take the element from.
 * @type:       the type of the struct this is embedded in.
 * @member:     the name of the list_head within the struct.
 *
 * Note, that list is expected to be not empty.
 */
#define list_first_entry(ptr, type, member) \
        list_entry((ptr)->next, type, member)


/**
 * list_next_entry - get the next element in list
 * @pos:        the type * to cursor
 * @member:     the name of the list_head within the struct.
 */
#define list_next_entry(pos, member) \
        list_entry((pos)->member.next, typeof(*(pos)), member)

		
/**
 * list_for_each_entry  -       iterate over list of given type
 * @pos:        the type * to use as a loop cursor.
 * @head:       the head for your list.
 * @member:     the name of the list_head within the struct.
 */
#define list_for_each_entry(pos, head, member)                          \
        for (pos = list_first_entry(head, typeof(*pos), member);        \
             &pos->member != (head);                                    \
             pos = list_next_entry(pos, member))

实例main.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include "list.h"

typedef struct device
{
	int ID;
	char deviceId[32];
	char meteId[32];
	int value;
	struct list_head list;
}Device;

 
Device* init_list()
{
	Device *head=(Device *)malloc(sizeof(Device));
	if(head==NULL)
	{
		perror("malloc head");
		exit(1);
	}
	INIT_LIST_HEAD(&(head->list));
	return head;

}

Device *new_node(int ID,char *deviceId,char *meteId,int value)
{
	Device* new=(Device *)malloc(sizeof(Device));
	if(new==NULL)
	{
		perror("new node");
		exit(1);
	}
	new->ID=ID;
	strcpy(new->deviceId,deviceId);
	strcpy(new->meteId,meteId);
	new->value=value;
	return new;
}

int delete_node(Device *head,char *deviceId)
{
	Device *p=NULL;
	list_for_each_entry(p,&(head->list),list)
	{
		if(!strcmp(p->deviceId,deviceId))
		{
			list_del(&(p->list));
		}
	}
	return 0;
}


Device *find_node(Device *head,char *deviceId)
{
	Device *p=NULL;
	list_for_each_entry(p,&(head->list),list)
	{
		if(!strcmp(p->deviceId,deviceId))
		{
			return p;
		}
	}
	return NULL;

}

int show_list(Device *head)
{
	Device *p=NULL;
	list_for_each_entry(p,&(head->list),list)
	{
		printf("ID:%d,deviceId:%s,meteId:%s,value:%d\n",p->ID,p->deviceId,p->meteId,p->value);
	}
	return 0;
}
int main(int agc,char *argv[])
{
	Device *mylist=init_list();
	Device *new=new_node(1,"00123456","1123456",0);
	list_add_tail(&(new->list),&(mylist->list));
	show_list(mylist);
	return 0;
}

记录一个错误！！！！！

error: expected declaration specifiers or '...' before '(' token
   const typeof(((type *) NULL)->member) *__mptr = (ptr); \
note: in expansion of macro 'container_of'
 #define list_entry(ptr, type, field) container_of(ptr, type, field)
error: '__mptr' undeclared (first use in this function)
   (type *) ((char *) __mptr - offsetof(type, member)); \
                      ^
note: each undeclared identifier is reported only once for each function it appears in
   (type *) ((char *) __mptr - offsetof(type, member)); \

这个错误找了很久，后来发现原项目指定了-std=c99编译，用c99编译会出现这种鸟问题，原因不知。。。。

为了方便以后项目使用到链表，特此记录一个实例。