Linux内核list链表学习（一）--- list_for_each_entry_safe

【说明】学习Linux内核list链表，利用list.h中函数实现某些功能，直接上整理；

一、list_for_each_entry_safe — 遍历整个链表，安全地组织删除表中元素

（1）定义及说明

/* @ pos:	 用作循环光标的类型*
 * @ n:		 另一种类型*用作临时存储
 * @ head:	 链表list的头节点
 * @ member: struct中list_struct的名称 */
 
#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))
		    

（2）代码应用示例

// struct结构请根据需求填写，此处只是随意举例
struct offset {
	struct list_head list;
	int off_set; 
	off_t pos; 
};


struct task_stat {
	struct list_head list;
	pthread_t thid; 
	int sockfd; 
	int timeout; 
	int port;
	struct list_head offsets; /* list of struct offset */
};

void free_stat(struct task_stat* stat)
{
	struct offset *off, *off_tmp;
	if (!stat){
		return;
	}
	
	list_for_each_entry_safe(off, off_tmp, &stat->offsets, list) {
		list_del(&off->list);
		free(off);
	}
	free(stat);
}