From 5dae8e5fb803f53fadc116cefe353953b938cbe1 Mon Sep 17 00:00:00 2001 From: Stefan Hajnoczi Date: Mon, 24 Jun 2013 17:13:09 +0200 Subject: notify: add NotiferWithReturn so notifier list can abort notifier_list_notify() has no return value. This is fine when we just want to invoke side-effects. Sometimes it's useful for notifiers to produce a return value. This allows notifiers to "veto" an operation and will be used by the block layer before-write notifier. Reviewed-by: Eric Blake Reviewed-by: Kevin Wolf Signed-off-by: Stefan Hajnoczi Signed-off-by: Kevin Wolf --- util/notify.c | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) (limited to 'util') diff --git a/util/notify.c b/util/notify.c index 7b7692acb2..f215dfc214 100644 --- a/util/notify.c +++ b/util/notify.c @@ -39,3 +39,33 @@ void notifier_list_notify(NotifierList *list, void *data) notifier->notify(notifier, data); } } + +void notifier_with_return_list_init(NotifierWithReturnList *list) +{ + QLIST_INIT(&list->notifiers); +} + +void notifier_with_return_list_add(NotifierWithReturnList *list, + NotifierWithReturn *notifier) +{ + QLIST_INSERT_HEAD(&list->notifiers, notifier, node); +} + +void notifier_with_return_remove(NotifierWithReturn *notifier) +{ + QLIST_REMOVE(notifier, node); +} + +int notifier_with_return_list_notify(NotifierWithReturnList *list, void *data) +{ + NotifierWithReturn *notifier, *next; + int ret = 0; + + QLIST_FOREACH_SAFE(notifier, &list->notifiers, node, next) { + ret = notifier->notify(notifier, data); + if (ret != 0) { + break; + } + } + return ret; +} -- cgit v1.2.1