Linux2.6.32内核笔记（5）在应用程序中移植使用内核链表【转】

转自：http://blog.csdn.net/Deep_l_zh/article/details/48392935

版权声明：本文为博主原创文章，未经博主允许不得转载。

    摘要：将内核链表移植到应用程序中，实现创建，添加节点，遍历，删除的操作。

    首先复习一下内核链表中经常使用的几个函数，在/include/Linux/list.h中。

    创建链表：

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    <span style="font-size:18px;">INIT_LIST_HEAD（）
    staticinline void INIT_LIST_HEAD(struct list_head *list)
    {
        list->next = list;
        list->prev = list;
    }</span>  

    插入节点：

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    <span style="font-size:18px;">list_add（）在链表头插入
    list_add_tail()在链表尾插入
    staticinline void list_add(struct list_head *new, struct list_head *head)
    {
        __list_add(new, head, head->next);
    }
    staticinline void list_add_tail(struct list_head *new, struct list_head *head)
    {
        __list_add(new, head->prev, head);
    }</span>  

    删除节点：

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    <span style="font-size:18px;">list_del()
    staticinline void list_del(struct list_head *entry)
    {
        __list_del(entry->prev, entry->next);
        entry->next = LIST_POISON1;
        entry->prev = LIST_POISON2;
    }</span>  

    遍历链表：

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    <span style="font-size:18px;">list_for_each()
    #definelist_for_each(pos, head) \
    for(pos = (head)->next; prefetch(pos->next), pos != (head); \
          pos = pos->next)</span>  

    取出节点：

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    <span style="font-size:18px;">list_entry()
    #definelist_entry(ptr, type, member) \
    container_of(ptr,type, member)</span>  

    移植过程中用到的其他函数：

    .malloc

    函数原型：extern void *malloc(unsigned int num_bytes);

   功能：分配字节长度为num_bytes内存，如果成功则返回指向内存起始地址的指针，否则返回null。

    说明：这里声明为void *表示未确定类型的指针，这样使用的时候就可以强制转换为其他我们需要的任何类型的指针。

    .memset

    函数原型：void *memset(void *s,int ch,seze_t n);

    功能：将s指向的某一块内存中的前n个字节的内容全部填充为ch。一般用来对新申请的内存做初始化工作，ch一般都是填充0。我们在使用较大的结构体和数组的时候，都会使用其对分配到的内存清零。

    .sprintf

    函数原型：int sprintf(char *buffer,const char *format，[arugument]…);

    功能：把格式化的数据写入某个字符串中，返回值是字符串的长度。

    移植步骤：

    .创建list.h

    因为我们要写成一个app，里面用到很多内核链表的函数，都在list.h里面声明的，一开始这里我就偷懒把内核里面的list.h拷贝一份，放到我当前的工作目录下，命名为list.h，后来编译的时候提示找不到list.h里面加进去的那三个头文件，于是我又把position.h,这三个头文件注释掉了，但是提示LIST_POSITION1和LIST_POSITION2没有定义还有别的错误，于是利用grep查找，到源码目录下，把这部分拷贝到我们的list.h前面部分里面来就可以了。完整的list.c附在最后。

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    <span style="font-size:18px;">#ifndef _LINUX_LIST_H
    #define _LINUX_LIST_H  

    #include <linux/stddef.h>  

    #ifndef ARCH_HAS_PREFETCH
    #define ARCH_HAS_PREFETCH
    static inline void prefetch(const voidvoid *x){;}
    #endif  

    #define LIST_POISON1 ((void *) 0x0)
    #define LIST_POISON2 ((void *) 0x0)  

    #define container_of(ptr ,type,member)({              \
       const typeof( ((type *))->member ) *__mptr = (ptr);     \
       (type *)( (charchar *)__mptr - offsetof(type,member) );})</span>  

    .创建listapp.c添加头文件

    这里我命名为listapp.c，因为我们要用到很多头文件，这里都添加进去，我添加的如下;

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    <span style="font-size:18px;">#include"list.h"//内核链表操作函数
    #include<malloc.h>//使用malloc分配内存
    #include<stdio.h>//sprintf和printf
    #include<string.h>//memset</span><span style="font-size:14px; font-family: Arial, Helvetica, sans-serif; background-color: rgb(255, 255, 255);">                </span>  

     .创建球员信息结构体

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    <span style="font-size:18px;">    structmember
    {
        charname[];
        intnum;
        intscore;
        intassists;
        structlist_head list;
    };</span>  

    .main函数

    主要思想是创建链表，分配内存，插入节点，遍历输出，删除节点。

    编译成功后运行出现如下信息;

    可以看到我们的链表操作是成功了，输出信息也与期望值一样，但是最后free的时候出现了core dump，这个问题查了下有几种解释，这里大概是数组操作越界，或者我们修改了mem区的指针信息，导致free释放内存的时候，释放到别的地方去了，这里不做深究了，留待之后结局。

    最后附上list.h和listapp.c的代码，结束，如有不正确的地方还请指出，大家共同进步。

list.h如下
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    <span style="font-size:14px;">#ifndef _LINUX_LIST_H
    #define _LINUX_LIST_H  

    #include <linux/stddef.h>  

    #ifndef ARCH_HAS_PREFETCH
    #define ARCH_HAS_PREFETCH
    static inline void prefetch(const voidvoid *x) {;}
    #endif  

    #define LIST_POISON1 ((void *) 0x0)
    #define LIST_POISON2 ((void *) 0x0)  

    #define container_of(ptr ,type,member) ({              \
        const typeof( ((type *))->member ) *__mptr = (ptr);     \
        (type *)( (charchar *)__mptr - offsetof(type,member) );})  

    /*
     * Simple doubly linked list implementation.
     *
     * Some of the internal functions ("__xxx") are useful when
     * manipulating whole lists rather than single entries, as
     * sometimes we already know the next/prev entries and we can
     * generate better code by using them directly rather than
     * using the generic single-entry routines.
     */  

    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)  

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

    /*
     * Insert a new entry between two known consecutive entries.
     *
     * This is only for internal list manipulation where we know
     * the prev/next entries already!
     */
    #ifndef CONFIG_DEBUG_LIST
    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;
    }
    #else
    extern void __list_add(struct list_head *new,
                      struct list_head *prev,
                      struct list_head *next);
    #endif  

    /**
     * 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);
    }  

    /*
     * Delete a list entry by making the prev/next entries
     * point to each other.
     *
     * This is only for internal list manipulation where we know
     * the prev/next entries already!
     */
    static inline void __list_del(struct list_head * prev, struct list_head * next)
    {
        next->prev = prev;
        prev->next = next;
    }  

    /**
     * list_del - deletes entry from list.
     * @entry: the element to delete from the list.
     * Note: list_empty() on entry does not return true after this, the entry is
     * in an undefined state.
     */
    #ifndef CONFIG_DEBUG_LIST
    static inline void list_del(struct list_head *entry)
    {
        __list_del(entry->prev, entry->next);
        entry->next = LIST_POISON1;
        entry->prev = LIST_POISON2;
    }
    #else
    extern void list_del(struct list_head *entry);
    #endif  

    /**
     * list_replace - replace old entry by new one
     * @old : the element to be replaced
     * @new : the new element to insert
     *
     * If @old was empty, it will be overwritten.
     */
    static inline void list_replace(struct list_head *old,
                    struct list_head *new)
    {
        new->next = old->next;
        new->next->prev = new;
        new->prev = old->prev;
        new->prev->next = new;
    }  

    static inline void list_replace_init(struct list_head *old,
                        struct list_head *new)
    {
        list_replace(old, new);
        INIT_LIST_HEAD(old);
    }  

    /**
     * list_del_init - deletes entry from list and reinitialize it.
     * @entry: the element to delete from the list.
     */
    static inline void list_del_init(struct list_head *entry)
    {
        __list_del(entry->prev, entry->next);
        INIT_LIST_HEAD(entry);
    }  

    /**
     * list_move - delete from one list and add as another's head
     * @list: the entry to move
     * @head: the head that will precede our entry
     */
    static inline void list_move(struct list_head *list, struct list_head *head)
    {
        __list_del(list->prev, list->next);
        list_add(list, head);
    }  

    /**
     * list_move_tail - delete from one list and add as another's tail
     * @list: the entry to move
     * @head: the head that will follow our entry
     */
    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);
    }  

    /**
     * list_is_last - tests whether @list is the last entry in list @head
     * @list: the entry to test
     * @head: the head of the list
     */
    static inline int list_is_last(const struct list_head *list,
                    const struct list_head *head)
    {
        return list->next == head;
    }  

    /**
     * list_empty - tests whether a list is empty
     * @head: the list to test.
     */
    static inline int list_empty(const struct list_head *head)
    {
        return head->next == head;
    }  

    /**
     * list_empty_careful - tests whether a list is empty and not being modified
     * @head: the list to test
     *
     * Description:
     * tests whether a list is empty _and_ checks that no other CPU might be
     * in the process of modifying either member (next or prev)
     *
     * NOTE: using list_empty_careful() without synchronization
     * can only be safe if the only activity that can happen
     * to the list entry is list_del_init(). Eg. it cannot be used
     * if another CPU could re-list_add() it.
     */
    static inline int list_empty_careful(const struct list_head *head)
    {
        struct list_head *next = head->next;
        return (next == head) && (next == head->prev);
    }  

    /**
     * list_is_singular - tests whether a list has just one entry.
     * @head: the list to test.
     */
    static inline int list_is_singular(const struct list_head *head)
    {
        return !list_empty(head) && (head->next == head->prev);
    }  

    static inline void __list_cut_position(struct list_head *list,
            struct list_head *head, struct list_head *entry)
    {
        struct list_head *new_first = entry->next;
        list->next = head->next;
        list->next->prev = list;
        list->prev = entry;
        entry->next = list;
        head->next = new_first;
        new_first->prev = head;
    }  

    /**
     * list_cut_position - cut a list into two
     * @list: a new list to add all removed entries
     * @head: a list with entries
     * @entry: an entry within head, could be the head itself
     *  and if so we won't cut the list
     *
     * This helper moves the initial part of @head, up to and
     * including @entry, from @head to @list. You should
     * pass on @entry an element you know is on @head. @list
     * should be an empty list or a list you do not care about
     * losing its data.
     *
     */
    static inline void list_cut_position(struct list_head *list,
            struct list_head *head, struct list_head *entry)
    {
        if (list_empty(head))
            return;
        if (list_is_singular(head) &&
            (head->next != entry && head != entry))
            return;
        if (entry == head)
            INIT_LIST_HEAD(list);
        else
            __list_cut_position(list, head, entry);
    }  

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

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

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

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

    /**
     * list_splice_tail - join two lists, each list being a queue
     * @list: the new list to add.
     * @head: the place to add it in the first list.
     */
    static inline void list_splice_tail(struct list_head *list,
                    struct list_head *head)
    {
        if (!list_empty(list))
            __list_splice(list, head->prev, 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, head->next);
            INIT_LIST_HEAD(list);
        }
    }  

    /**
     * list_splice_tail_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.
     *
     * Each of the lists is a queue.
     * The list at @list is reinitialised
     */
    static inline void list_splice_tail_init(struct list_head *list,
                         struct list_head *head)
    {
        if (!list_empty(list)) {
            __list_splice(list, head->prev, head);
            INIT_LIST_HEAD(list);
        }
    }  

    /**
     * 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)  

    /**
     * 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_struct 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_for_each    -   iterate over a list
     * @pos:    the &struct list_head to use as a loop cursor.
     * @head:   the head for your list.
     */
    #define list_for_each(pos, head) \
        for (pos = (head)->next; prefetch(pos->next), pos != (head); \
                pos = pos->next)  

    /**
     * __list_for_each  -   iterate over a list
     * @pos:    the &struct list_head to use as a loop cursor.
     * @head:   the head for your list.
     *
     * This variant differs from list_for_each() in that it's the
     * simplest possible list iteration code, no prefetching is done.
     * Use this for code that knows the list to be very short (empty
     * or 1 entry) most of the time.
     */
    #define __list_for_each(pos, head) \
        for (pos = (head)->next; pos != (head); pos = pos->next)  

    /**
     * list_for_each_prev   -   iterate over a list backwards
     * @pos:    the &struct list_head to use as a loop cursor.
     * @head:   the head for your list.
     */
    #define list_for_each_prev(pos, head) \
        for (pos = (head)->prev; prefetch(pos->prev), pos != (head); \
                pos = pos->prev)  

    /**
     * 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:   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_for_each_prev_safe - iterate over a list backwards 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:   the head for your list.
     */
    #define list_for_each_prev_safe(pos, n, head) \
        for (pos = (head)->prev, n = pos->prev; \
             prefetch(pos->prev), pos != (head); \
             pos = n, n = pos->prev)  

    /**
     * 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_struct within the struct.
     */
    #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))  

    /**
     * list_for_each_entry_reverse - iterate backwards 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_struct within the struct.
     */
    #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))  

    /**
     * list_prepare_entry - prepare a pos entry for use in list_for_each_entry_continue()
     * @pos:    the type * to use as a start point
     * @head:   the head of the list
     * @member: the name of the list_struct within the struct.
     *
     * Prepares a pos entry for use as a start point in list_for_each_entry_continue().
     */
    #define list_prepare_entry(pos, head, member) \
        ((pos) ? : list_entry(head, typeof(*pos), member))  

    /**
     * list_for_each_entry_continue - continue iteration 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_struct within the struct.
     *
     * Continue to iterate over list of given type, continuing after
     * the current position.
     */
    #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))  

    /**
     * list_for_each_entry_continue_reverse - iterate backwards from the given point
     * @pos:    the type * to use as a loop cursor.
     * @head:   the head for your list.
     * @member: the name of the list_struct within the struct.
     *
     * Start to iterate over list of given type backwards, continuing after
     * the current position.
     */
    #define list_for_each_entry_continue_reverse(pos, head, member)     \
        for (pos = list_entry(pos->member.prev, typeof(*pos), member);   \
             prefetch(pos->member.prev), &pos->member != (head);  \
             pos = list_entry(pos->member.prev, typeof(*pos), member))  

    /**
     * list_for_each_entry_from - iterate over list of given type from the current point
     * @pos:    the type * to use as a loop cursor.
     * @head:   the head for your list.
     * @member: the name of the list_struct within the struct.
     *
     * Iterate over list of given type, continuing from current position.
     */
    #define list_for_each_entry_from(pos, head, member)             \
        for (; prefetch(pos->member.next), &pos->member != (head);    \
             pos = list_entry(pos->member.next, typeof(*pos), member))  

    /**
     * list_for_each_entry_safe - iterate over list of given type safe against removal of list entry
     * @pos:    the type * to use as a loop cursor.
     * @n:      another type * to use as temporary storage
     * @head:   the head for your list.
     * @member: the name of the list_struct within the struct.
     */
    #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))  

    /**
     * list_for_each_entry_safe_continue
     * @pos:    the type * to use as a loop cursor.
     * @n:      another type * to use as temporary storage
     * @head:   the head for your list.
     * @member: the name of the list_struct within the struct.
     *
     * Iterate over list of given type, continuing after current point,
     * safe against removal of list entry.
     */
    #define list_for_each_entry_safe_continue(pos, n, head, member)         \
        for (pos = list_entry(pos->member.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))  

    /**
     * list_for_each_entry_safe_from
     * @pos:    the type * to use as a loop cursor.
     * @n:      another type * to use as temporary storage
     * @head:   the head for your list.
     * @member: the name of the list_struct within the struct.
     *
     * Iterate over list of given type from current point, safe against
     * removal of list entry.
     */
    #define list_for_each_entry_safe_from(pos, n, head, member)             \
        for (n = list_entry(pos->member.next, typeof(*pos), member);     \
             &pos->member != (head);                     \
             pos = n, n = list_entry(n->member.next, typeof(*n), member))  

    /**
     * list_for_each_entry_safe_reverse
     * @pos:    the type * to use as a loop cursor.
     * @n:      another type * to use as temporary storage
     * @head:   the head for your list.
     * @member: the name of the list_struct within the struct.
     *
     * Iterate backwards over list of given type, safe against removal
     * of list entry.
     */
    #define list_for_each_entry_safe_reverse(pos, n, head, member)      \
        for (pos = list_entry((head)->prev, typeof(*pos), member),   \
            n = list_entry(pos->member.prev, typeof(*pos), member);  \
             &pos->member != (head);                     \
             pos = n, n = list_entry(n->member.prev, typeof(*n), member))  

    /*
     * Double linked lists with a single pointer list head.
     * Mostly useful for hash tables where the two pointer list head is
     * too wasteful.
     * You lose the ability to access the tail in O(1).
     */  

    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)  

    static inline void INIT_HLIST_NODE(struct hlist_node *h)
    {
        h->next = NULL;
        h->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 (!hlist_unhashed(n)) {
            __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;
    }  

    /*
     * Move a list from one list head to another. Fixup the pprev
     * reference of the first entry if it exists.
     */
    static inline void hlist_move_list(struct hlist_head *old,
                       struct hlist_head *new)
    {
        new->first = old->first;
        if (new->first)
            new->first->pprev = &new->first;
        old->first = NULL;
    }  

    #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); ; }); \
             pos = pos->next)  

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

    /**
     * hlist_for_each_entry - iterate over list of given type
     * @tpos:   the type * to use as a loop cursor.
     * @pos:    the &struct hlist_node to use as a loop cursor.
     * @head:   the head for your list.
     * @member: the name of the hlist_node within the struct.
     */
    #define hlist_for_each_entry(tpos, pos, head, member)            \
        for (pos = (head)->first;                     \
             pos && ({ prefetch(pos->next); ;}) &&           \
            ({ tpos = hlist_entry(pos, typeof(*tpos), member); ;}); \
             pos = pos->next)  

    /**
     * hlist_for_each_entry_continue - iterate over a hlist continuing after current point
     * @tpos:   the type * to use as a loop cursor.
     * @pos:    the &struct hlist_node to use as a loop cursor.
     * @member: the name of the hlist_node within the struct.
     */
    #define hlist_for_each_entry_continue(tpos, pos, member)         \
        for (pos = (pos)->next;                       \
             pos && ({ prefetch(pos->next); ;}) &&           \
            ({ tpos = hlist_entry(pos, typeof(*tpos), member); ;}); \
             pos = pos->next)  

    /**
     * hlist_for_each_entry_from - iterate over a hlist continuing from current point
     * @tpos:   the type * to use as a loop cursor.
     * @pos:    the &struct hlist_node to use as a loop cursor.
     * @member: the name of the hlist_node within the struct.
     */
    #define hlist_for_each_entry_from(tpos, pos, member)             \
        for (; pos && ({ prefetch(pos->next); ;}) &&             \
            ({ tpos = hlist_entry(pos, typeof(*tpos), member); ;}); \
             pos = pos->next)  

    /**
     * hlist_for_each_entry_safe - iterate over list of given type safe against removal of list entry
     * @tpos:   the type * to use as a loop cursor.
     * @pos:    the &struct hlist_node to use as a loop cursor.
     * @n:      another &struct hlist_node to use as temporary storage
     * @head:   the head for your list.
     * @member: the name of the hlist_node within the struct.
     */
    #define hlist_for_each_entry_safe(tpos, pos, n, head, member)        \
        for (pos = (head)->first;                     \
             pos && ({ n = pos->next; ; }) &&                \
            ({ tpos = hlist_entry(pos, typeof(*tpos), member); ;}); \
             pos = n)  

    #endif</span>  

listapp.c如下

[objc] view plain copy

    <span style="font-size:14px;">#include"list.h"//内核链表操作函数
    #include<malloc.h>//使用malloc分配内存
    #include<stdio.h>//sprintf和printf
    #include<string.h>//memset  

    struct member
    {
        char name[];
        int num;
        int score;
        struct list_head list;
    };  

    struct list_head *pos;//遍历指针的pos，不断地指向链表中节点的指针域，需要是list_head指针类型
    struct list_head member_list;//名为menber_list的链表
    struct member *tmp;//存放遍历结果，为struct member类型
    struct member *pmember;//member的成员  

    int main(void)
    {
        unsigned int i = ;            //循环变量的声明  

        INIT_LIST_HEAD(&member_list); //创建一个链表头，使其前向和后继指针都指向自己，传入参数必须为指针类型，所以取地址  

        pmember=malloc(sizeof(struct member)*);
        memset(pmember,,sizeof(struct member)*);//为member成员分配内存，这里分配四个成员，并且对分配到的内存清零  

        /*给球员成员命名，编号，进球数*/
        sprintf(pmember[].name,"player %s","xu");
        sprintf(pmember[].name,"player %s","zeng");
        sprintf(pmember[].name,"player %s","le");
        sprintf(pmember[].name,"player %s","suo");  

        pmember[].num=;
        pmember[].num=;
        pmember[].num=;
        pmember[].num=;  

        pmember[].score=;
        pmember[].score=;
        pmember[].score=;
        pmember[].score=;   

        /*插入节点，list_add第一个参数是成员内部list的指针，第二个是刚才创建的链表头，这样就插入进去了*/
        for(i=;i<;i++)
        {
                list_add(&(pmember[i+].list),&member_list);
                printf("###num %d player add sucess!###\n",i+);
            }  

        /*遍历链表，并开始输出球员信息*/
        printf("###start list_for_each player information###\n");
        list_for_each(pos,&member_list)
            {
                tmp=list_entry(pos,struct member,list);//第一个参数为pos，第二个要给进去我们定义的球员信息结构体，最后是结构内部的list名
                printf("play %d name %s score %d\n",tmp->num,tmp->name,tmp->score);
            }  

        /*最后删除节点*/  

        for(i=;i<;i++)
        {
            list_del(&(pmember[i+].list));
            printf("### num %d has deleted###\n",i+);
            }  

        /*释放分配得内存*/
        free(pmember);  

        }
    </span>