RT-Thread ------ 链表的操作（不同于常规链表操作）

RT-Thread中的链表指针定义为rt_list_t或者rt_slist_t，而不是节点类型作为指针，这就可以使链表的操作（例如：插入、删除）不用和节点类型绑定，使得一套插入删除函数可以被各种节点类型使用，甚至可以将不同类型的节点插入链表。

 

 

使用举例：

//定义单向链表结构体类型
struct rt_slist_node
{
    struct rt_slist_node *next;
};
typedef struct rt_slist_node rt_slist_t;              

//定义一个全局的链表变量
static rt_slist_t at_device_list = {0};

//链表初始化
rt_inline void rt_slist_init(rt_slist_t *l)
{
    l->next = RT_NULL;
}

//定义节点类型
struct at_device
{
    char name[RT_NAME_MAX];                      /* AT device name */
    rt_bool_t is_init;                           /* AT device initialization completed */
    struct at_device_class *class;               /* AT device class object */
    struct at_client *client;                    /* AT Client object for AT device */
    struct netdev *netdev;                       /* Network interface device for AT device */

    rt_slist_t list;                             /* AT device list */

    void *user_data;                             /* User-specific data */
};

//链表尾添加节点
void list_append(struct at_device *device)
{
    rt_slist_init(&(device->list));

    rt_slist_append(&at_device_list, &(device->list));
}

rt_inline void rt_slist_append(rt_slist_t *l, rt_slist_t *n)
{
    rt_slist_t *node;

    node = l;
    while (node->next) node = node->next;

    /* append the node to the tail */
    node->next = n;
    n->next = RT_NULL;
}

//遍历链表
void list_foreach()
{
    rt_slist_t *node = RT_NULL;
    struct at_device *device = RT_NULL;

    rt_slist_for_each(node, &at_device_list)
    {
        device = rt_slist_entry(node, struct at_device, list);
    }
}
#define rt_slist_for_each(pos, head) \
    for (pos = (head)->next; pos != RT_NULL; pos = pos->next)

#define rt_slist_entry(node, type, member) \
    rt_container_of(node, type, member)

#define rt_container_of(ptr, type, member) \
    ((type *)((char *)(ptr) - (unsigned long)(&((type *)0)->member)))

//移除指定节点
rt_inline rt_slist_t *rt_slist_remove(rt_slist_t *l, rt_slist_t *n)
{
    /* remove slist head */
    struct rt_slist_node *node = l;
    while (node->next && node->next != n) node = node->next;

    /* remove node */
    if (node->next != (rt_slist_t *)0) node->next = node->next->next;

    return l;
}