linux-kernel/list/list-test.c

   1 /*
   2  * Basic Linux list API usage.
   3  *
   4  * Luiz Fernando N. Capitulino
   5  * <lcapitulino@gmail.com>
   6  */
   7
   8 #include <linux/init.h>
   9 #include <linux/module.h>
  10 #include <linux/kernel.h>
  11 #include <linux/list.h>
  12
  13 struct foobar {
  14         struct list_head list;
  15         int num;
  16 };
  17
  18 static int __init list_test_init(void)
  19 {
  20         int i;
  21         struct foobar head, *p;
  22         struct list_head *pos, *q;
  23         const int max_itens = 10;
  24
  25         /* initialize the head of the list */
  26         INIT_LIST_HEAD(&head.list);
  27
  28         /* populate the list */
  29         for (i = max_itens; i >= 0; i--) {
  30                 p = kzalloc(sizeof(*p), GFP_KERNEL);
  31                 p->num = i;
  32                 list_add(&p->list, &head.list);
  33         }
  34
  35         /* transverse the list */
  36         printk("\n-> Itens in the list:\n");
  37         list_for_each(pos, &head.list) {
  38                 p = list_entry(pos, struct foobar, list);
  39                 printk("\t-> %d\n", p->num);
  40         }
  41
  42         printk("\n\n");
  43
  44         /* delete all list itens */
  45         printk("-> Removing itens:\n");
  46         list_for_each_safe(pos, q, &head.list) {
  47                 p = list_entry(pos, struct foobar, list);
  48                 printk("\t-> %d\n", p->num);
  49                 list_del(pos);
  50                 kfree(p);
  51         }
  52
  53         printk("\n");
  54
  55         return -EINVAL; /* prevent loading the module */
  56 }
  57
  58 module_init(list_test_init);
  59
  60 MODULE_LICENSE("GPL");
  61 MODULE_AUTHOR("Luiz Capitulino <lcapitulino@gmail.com>");