| 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 | /* Return int to allow for different failure modes and recovery actions */ |
| 49 | typedef int (*NotifierWithReturnFunc)(NotifierWithReturn *notifier, void *data, |
| 50 | Error **errp); |
| 51 | |
| 52 | struct NotifierWithReturn { |
| 53 | /** |
| 54 | * Return 0 on success (next notifier will be invoked), otherwise |
| 55 | * notifier_with_return_list_notify() will stop and return the value. |
| 56 | */ |
| 57 | NotifierWithReturnFunc notify; |
| 58 | QLIST_ENTRY(NotifierWithReturn) node; |
| 59 | }; |
| 60 | |
| 61 | typedef struct NotifierWithReturnList { |
| 62 | QLIST_HEAD(, NotifierWithReturn) notifiers; |
| 63 | } NotifierWithReturnList; |
| 64 | |
| 65 | #define NOTIFIER_WITH_RETURN_LIST_INITIALIZER(head) \ |
| 66 | { QLIST_HEAD_INITIALIZER((head).notifiers) } |
| 67 | |
| 68 | void notifier_with_return_list_init(NotifierWithReturnList *list); |
| 69 | |
| 70 | void notifier_with_return_list_add(NotifierWithReturnList *list, |
| 71 | NotifierWithReturn *notifier); |
| 72 | |
| 73 | void notifier_with_return_remove(NotifierWithReturn *notifier); |
| 74 | |
| 75 | int notifier_with_return_list_notify(NotifierWithReturnList *list, |
| 76 | void *data, Error **errp); |
| 77 | |
| 78 | bool notifier_with_return_list_empty(NotifierWithReturnList *list); |
| 79 | |
| 80 | #endif |