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 19 typedef struct Notifier Notifier; 20 21 struct Notifier 22 { 23 void (*notify)(Notifier *notifier, void *data); 24 QLIST_ENTRY(Notifier) node; 25 }; 26 27 typedef struct NotifierList 28 { 29 QLIST_HEAD(, Notifier) notifiers; 30 } NotifierList; 31 32 #define NOTIFIER_LIST_INITIALIZER(head) \ 33 { QLIST_HEAD_INITIALIZER((head).notifiers) } 34 35 void notifier_list_init(NotifierList *list); 36 37 void notifier_list_add(NotifierList *list, Notifier *notifier); 38 39 void notifier_remove(Notifier *notifier); 40 41 void notifier_list_notify(NotifierList *list, void *data); 42 43 bool notifier_list_empty(NotifierList *list); 44 45 /* Same as Notifier but allows .notify() to return errors */ 46 typedef struct NotifierWithReturn NotifierWithReturn; 47 48 struct 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 57 typedef 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 64 void notifier_with_return_list_init(NotifierWithReturnList *list); 65 66 void notifier_with_return_list_add(NotifierWithReturnList *list, 67 NotifierWithReturn *notifier); 68 69 void notifier_with_return_remove(NotifierWithReturn *notifier); 70 71 int notifier_with_return_list_notify(NotifierWithReturnList *list, 72 void *data); 73 74 #endif 75