mware/observer.c

   1 /**
   2  * \file
   3  * <!--
   4  * Copyright 2006 Develer S.r.l. (http://www.develer.com/)
   5  * This file is part of DevLib - See README.devlib for information.
   6  * -->
   7  *
   8  * \brief Simple notifier for the observer/subject pattern (implementation)
   9  *
  10  * \version $Id$
  11  * \author Bernardo Innocenti <bernie@develer.com>
  12  */
  13
  14 #include "observer.h"
  15 #include <cfg/cpu.h>  // IRQ_DISABLE/IRQ_ENABLE
  16
  17
  18 void observer_SetEvent(Observer *observer, void (*event)(int event_id, void *param))
  19 {
  20         observer->event = event;
  21 }
  22
  23 void observer_InitSubject(Subject *subject)
  24 {
  25         LIST_INIT(&subject->observers);
  26 }
  27
  28 void observer_Subscribe(Subject *subject, Observer *observer)
  29 {
  30         ATOMIC(ADDHEAD(&subject->observers, &observer->link));
  31 }
  32
  33 void observer_Unsubscribe(UNUSED_ARG(Subject *,subject), Observer *observer)
  34 {
  35         ATOMIC(REMOVE(&observer->link));
  36 }
  37
  38 void observer_notify(Subject *subject, int event_id, void *param)
  39 {
  40         Observer *observer;
  41         cpuflags_t irqstate;
  42         IRQ_SAVE_DISABLE(irqstate);
  43
  44         /*
  45          * Run over list with protection against other
  46          * threads, but re-enable irqs in callbacks.
  47          */
  48         FOREACH_NODE(observer, &subject->observers)
  49         {
  50                 IRQ_RESTORE(irqstate);
  51                 observer->event(event_id, param);
  52                 IRQ_SAVE_DISABLE(irqstate);
  53         }
  54
  55         IRQ_RESTORE(irqstate);
  56 }