src/notifier.h

   1 #ifndef NOTIFIER_H
   2 #define NOTIFIER_H
   3
   4 #include <stdint.h>
   5 #include <stdio.h>
   6
   7 #include "locking.h"
   8
   9 #define BLOCK_SUCC_DONE   0
  10 #define BLOCK_STOP_CHAIN  1
  11
  12 enum event_prio {
  13         PRIO_VERYLOW,
  14         PRIO_LOW,
  15         PRIO_MEDIUM,
  16         PRIO_HIGH,
  17         PRIO_EXTRA,
  18 };
  19
  20 struct event_block {
  21         enum event_prio prio;
  22         int (*hook)(const struct event_block *self, unsigned long event,
  23                     const void *arg);
  24         struct event_block *next;
  25 };
  26
  27 struct event_head {
  28         struct event_block *head;
  29         struct mutexlock lock;
  30 };
  31
  32 static inline void init_event_head(struct event_head *head)
  33 {
  34         head->head = NULL;
  35         mutexlock_init(&head->lock);
  36 }
  37
  38 extern int register_event_hook(struct event_block **head,
  39                                struct event_block *block);
  40 extern int register_event_hook_once(struct event_block **head,
  41                                     struct event_block *block);
  42 extern int unregister_event_hook(struct event_block **head,
  43                                  struct event_block *block);
  44 extern int call_event_hooks(struct event_block **head, unsigned long event,
  45                             const void *arg, int *called);
  46
  47 #endif /* NOTIFIER_H */