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 <eblake@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
		
			
				
	
	
		
			72 lines
		
	
	
		
			1.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			72 lines
		
	
	
		
			1.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/*
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 * Notifier lists
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 *
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 * Copyright IBM, Corp. 2010
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 *
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 * Authors:
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 *  Anthony Liguori   <aliguori@us.ibm.com>
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 *
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 * This work is licensed under the terms of the GNU GPL, version 2.  See
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 * the COPYING file in the top-level directory.
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 *
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 * Contributions after 2012-01-13 are licensed under the terms of the
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 * GNU GPL, version 2 or (at your option) any later version.
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 */
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#include "qemu-common.h"
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#include "qemu/notify.h"
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void notifier_list_init(NotifierList *list)
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{
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    QLIST_INIT(&list->notifiers);
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}
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void notifier_list_add(NotifierList *list, Notifier *notifier)
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{
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    QLIST_INSERT_HEAD(&list->notifiers, notifier, node);
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}
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void notifier_remove(Notifier *notifier)
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{
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    QLIST_REMOVE(notifier, node);
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}
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void notifier_list_notify(NotifierList *list, void *data)
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{
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    Notifier *notifier, *next;
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    QLIST_FOREACH_SAFE(notifier, &list->notifiers, node, next) {
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        notifier->notify(notifier, data);
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    }
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}
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void notifier_with_return_list_init(NotifierWithReturnList *list)
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{
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    QLIST_INIT(&list->notifiers);
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}
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void notifier_with_return_list_add(NotifierWithReturnList *list,
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                                   NotifierWithReturn *notifier)
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{
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    QLIST_INSERT_HEAD(&list->notifiers, notifier, node);
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}
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void notifier_with_return_remove(NotifierWithReturn *notifier)
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{
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    QLIST_REMOVE(notifier, node);
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}
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int notifier_with_return_list_notify(NotifierWithReturnList *list, void *data)
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{
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    NotifierWithReturn *notifier, *next;
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    int ret = 0;
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    QLIST_FOREACH_SAFE(notifier, &list->notifiers, node, next) {
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        ret = notifier->notify(notifier, data);
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        if (ret != 0) {
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            break;
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        }
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    }
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    return ret;
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}
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