第一次理解通用链表

 1 #ifndef _LIST_H
  2 #define _LIST_H
  3 #include"stdio.h"
  4 #define _INLINE_ static inline
  5
  6 struct list_head {
  7                 struct list_head *next, *prev;
  8 };
  9
 10 #define LIST_HEAD_INIT(name) {&(name), &(name)}
 11
 12 #define LIST_HEAD(name)
 13                 struct list_head name = LIST_HEAD_INIT(name)
 14
 15 #define INIT_LIST_HEAD(ptr) do {
 16                 (ptr)->next = (ptr); (ptr)->prev = (ptr);
 17 } while (0)
 18
 19 _INLINE_ void __list_add(struct list_head *add,
 20                                 struct list_head *prev,
 21                                                 struct list_head *next)
 22 {
 23                 next->prev = add;
 24                         add->next = next;
 25                                 add->prev = prev;
 26                                         prev->next = add;
 27 }
 28
 29 _INLINE_ void list_add(struct list_head *add, struct list_head *head) {
 30                 __list_add(add, head, head->next);
 31 }
 32
 33 _INLINE_ void list_add_tail(struct list_head *add, struct list_head *head)
 34 {
 35                 __list_add(add, head->prev, head);
 36 }
 37
 38 _INLINE_ void __list_del(struct list_head *prev, struct list_head *next)
 39 {
 40                 next->prev = prev;
 41                         prev->next = next;
 42 }
 43
 44 _INLINE_ void list_del(struct list_head *entry)
 45 {
 46                 __list_del(entry->prev, entry->next);
 47 }
 48
 49 _INLINE_ void list_del_init(struct list_head *entry)
 50 {
 51                 __list_del(entry->prev, entry->next);
 52                         INIT_LIST_HEAD(entry);
 53 }
 54
 55 _INLINE_ int list_empty(struct list_head *head)
 56 {
 57                 return head->next == head;
 58 }
 59 
  76 #define list_entry(ptr, type, member)
 77                 ((type *)((char *)(ptr) - (unsigned long)(&((type *)0)->member)))
 78
 79 #define list_for_each(pos, head)
 80                 for (pos = (head)->next; pos != (head); pos = pos->next)
 81
 82 #define list_for_each_safe(pos, pnext, head)
 83                 for (pos = (head)->next, pnext = pos->next; pos != (head);
 84                                                         pos = pnext, pnext = pos->next)
 85
 86 #undef _INLINE_
 87 #endif
 88
~          1 #include"list.h"
  2 typedef struct m
  3 {
  4         int a;
  5         int b;
  6         struct list_head list;
  7 }Q;
  8 int main(int argc,char *argv[])
  9 {
 10         int i;
 11         Q *p=NULL;
 12         struct list_head *ptr=NULL;
 13         LIST_HEAD(t);
 14         for(i=0;i<10;i++)
 15         {
 16                 p=(Q*)malloc(sizeof(Q));
 17                 p->a=i;
 18                 p->b=i+2;
 19                 list_add(&(p->list),&t);
 20         }
 21         list_for_each(ptr,&t)
 22         {
 23                 p=list_entry(ptr,Q,list);
 24                 printf("%d %d ",p->a,p->b);
 25
 26         }
 27         return 0;
 28 }