LXR qemu/include/qemu/notify.h

   1/*
   2 * Notifier lists
   3 *
   4 * Copyright IBM, Corp. 2010
   5 *
   6 * Authors:
   7 *  Anthony Liguori   <aliguori@us.ibm.com>
   8 *
   9 * This work is licensed under the terms of the GNU GPL, version 2.  See
  10 * the COPYING file in the top-level directory.
  11 *
  12 */
  13
  14#ifndef QEMU_NOTIFY_H
  15#define QEMU_NOTIFY_H
  16
  17#include "qemu/queue.h"
  18
  19typedef struct Notifier Notifier;
  20
  21struct Notifier
  22{
  23    void (*notify)(Notifier *notifier, void *data);
  24    QLIST_ENTRY(Notifier) node;
  25};
  26
  27typedef struct NotifierList
  28{
  29    QLIST_HEAD(, Notifier) notifiers;
  30} NotifierList;
  31
  32#define NOTIFIER_LIST_INITIALIZER(head) \
  33    { QLIST_HEAD_INITIALIZER((head).notifiers) }
  34
  35void notifier_list_init(NotifierList *list);
  36
  37void notifier_list_add(NotifierList *list, Notifier *notifier);
  38
  39void notifier_remove(Notifier *notifier);
  40
  41void notifier_list_notify(NotifierList *list, void *data);
  42
  43bool notifier_list_empty(NotifierList *list);
  44
  45/* Same as Notifier but allows .notify() to return errors */
  46typedef struct NotifierWithReturn NotifierWithReturn;
  47
  48struct NotifierWithReturn {
  49    /**
  50     * Return 0 on success (next notifier will be invoked), otherwise
  51     * notifier_with_return_list_notify() will stop and return the value.
  52     */
  53    int (*notify)(NotifierWithReturn *notifier, void *data);
  54    QLIST_ENTRY(NotifierWithReturn) node;
  55};
  56
  57typedef struct NotifierWithReturnList {
  58    QLIST_HEAD(, NotifierWithReturn) notifiers;
  59} NotifierWithReturnList;
  60
  61#define NOTIFIER_WITH_RETURN_LIST_INITIALIZER(head) \
  62    { QLIST_HEAD_INITIALIZER((head).notifiers) }
  63
  64void notifier_with_return_list_init(NotifierWithReturnList *list);
  65
  66void notifier_with_return_list_add(NotifierWithReturnList *list,
  67                                   NotifierWithReturn *notifier);
  68
  69void notifier_with_return_remove(NotifierWithReturn *notifier);
  70
  71int notifier_with_return_list_notify(NotifierWithReturnList *list,
  72                                     void *data);
  73
  74#endif
  75