src/notifier.c

   1 /*
   2  * transsip - the telephony toolkit
   3  * By Daniel Borkmann <daniel@transsip.org>
   4  * Copyright 2011, 2012 Daniel Borkmann <dborkma@tik.ee.ethz.ch>
   5  * Subject to the GPL, version 2.
   6  */
   7
   8 #include <stdint.h>
   9 #include <errno.h>
  10
  11 #include "notifier.h"
  12 #include "built_in.h"
  13
  14 int register_event_hook(struct event_block **head,
  15                         struct event_block *block)
  16 {
  17         if (!block || !head)
  18                 return -EINVAL;
  19         if (!block->hook)
  20                 return -EINVAL;
  21
  22         while ((*head) != NULL) {
  23                 if (block->prio > (*head)->prio)
  24                         break;
  25
  26                 head = &((*head)->next);
  27         }
  28
  29         block->next = (*head);
  30         (*head) = block;
  31
  32         return 0;
  33 }
  34
  35 int register_event_hook_once(struct event_block **head,
  36                              struct event_block *block)
  37 {
  38         if (!block || !head)
  39                 return -EINVAL;
  40         if (!block->hook)
  41                 return -EINVAL;
  42
  43         while ((*head) != NULL) {
  44                 if (unlikely(block == (*head)))
  45                         return -EEXIST;
  46
  47                 if (block->prio > (*head)->prio)
  48                         break;
  49
  50                 head = &((*head)->next);
  51         }
  52
  53         block->next = (*head);
  54         (*head) = block;
  55
  56         return 0;
  57 }
  58
  59 int unregister_event_hook(struct event_block **head,
  60                           struct event_block *block)
  61 {
  62         if (!block || !head)
  63                 return -EINVAL;
  64
  65         while ((*head) != NULL) {
  66                 if (unlikely(block == (*head))) {
  67                         (*head) = block->next;
  68                         break;
  69                 }
  70
  71                 head = &((*head)->next);
  72         }
  73
  74         return 0;
  75 }
  76
  77 int call_event_hooks(struct event_block **head, unsigned long event,
  78                      const void *arg, int *called)
  79 {
  80         int ret = BLOCK_SUCC_DONE;
  81         struct event_block *block = *head, *next_block;
  82
  83         if (!head || !arg)
  84                 return -EINVAL;
  85         if (called)
  86                 (*called) = 0;
  87
  88         while (block) {
  89                 next_block = block->next;
  90
  91                 ret = block->hook(block, event, arg);
  92                 if (ret & BLOCK_STOP_CHAIN)
  93                         break;
  94
  95                 if(called)
  96                         (*called)++;
  97
  98                 block = next_block;
  99         }
 100
 101         return ret;
 102 }