374752a26b
Xenstore watch call-backs are already abstracted away from XenBus using
the XenWatch data structure but the associated NotifierList manipulation
and file handle registration is still open coded in various xen_bus_...()
functions.
This patch creates a new XenWatchList data structure to allow these
interactions to be abstracted away from XenBus as well. This is in
preparation for a subsequent patch which will introduce separate watch lists
for XenBus and XenDevice objects.
NOTE: This patch also introduces a new notifier_list_empty() helper function
for the purposes of adding an assertion that a XenWatchList is not
freed whilst its associated NotifierList is still occupied.
Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Reviewed-by: Anthony Perard <anthony.perard@citrix.com>
Message-Id: <20190913082159.31338-2-paul.durrant@citrix.com>
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
75 lines
1.9 KiB
C
75 lines
1.9 KiB
C
/*
|
|
* Notifier lists
|
|
*
|
|
* Copyright IBM, Corp. 2010
|
|
*
|
|
* Authors:
|
|
* Anthony Liguori <aliguori@us.ibm.com>
|
|
*
|
|
* This work is licensed under the terms of the GNU GPL, version 2. See
|
|
* the COPYING file in the top-level directory.
|
|
*
|
|
*/
|
|
|
|
#ifndef QEMU_NOTIFY_H
|
|
#define QEMU_NOTIFY_H
|
|
|
|
#include "qemu/queue.h"
|
|
|
|
typedef struct Notifier Notifier;
|
|
|
|
struct Notifier
|
|
{
|
|
void (*notify)(Notifier *notifier, void *data);
|
|
QLIST_ENTRY(Notifier) node;
|
|
};
|
|
|
|
typedef struct NotifierList
|
|
{
|
|
QLIST_HEAD(, Notifier) notifiers;
|
|
} NotifierList;
|
|
|
|
#define NOTIFIER_LIST_INITIALIZER(head) \
|
|
{ QLIST_HEAD_INITIALIZER((head).notifiers) }
|
|
|
|
void notifier_list_init(NotifierList *list);
|
|
|
|
void notifier_list_add(NotifierList *list, Notifier *notifier);
|
|
|
|
void notifier_remove(Notifier *notifier);
|
|
|
|
void notifier_list_notify(NotifierList *list, void *data);
|
|
|
|
bool notifier_list_empty(NotifierList *list);
|
|
|
|
/* Same as Notifier but allows .notify() to return errors */
|
|
typedef struct NotifierWithReturn NotifierWithReturn;
|
|
|
|
struct NotifierWithReturn {
|
|
/**
|
|
* Return 0 on success (next notifier will be invoked), otherwise
|
|
* notifier_with_return_list_notify() will stop and return the value.
|
|
*/
|
|
int (*notify)(NotifierWithReturn *notifier, void *data);
|
|
QLIST_ENTRY(NotifierWithReturn) node;
|
|
};
|
|
|
|
typedef struct NotifierWithReturnList {
|
|
QLIST_HEAD(, NotifierWithReturn) notifiers;
|
|
} NotifierWithReturnList;
|
|
|
|
#define NOTIFIER_WITH_RETURN_LIST_INITIALIZER(head) \
|
|
{ QLIST_HEAD_INITIALIZER((head).notifiers) }
|
|
|
|
void notifier_with_return_list_init(NotifierWithReturnList *list);
|
|
|
|
void notifier_with_return_list_add(NotifierWithReturnList *list,
|
|
NotifierWithReturn *notifier);
|
|
|
|
void notifier_with_return_remove(NotifierWithReturn *notifier);
|
|
|
|
int notifier_with_return_list_notify(NotifierWithReturnList *list,
|
|
void *data);
|
|
|
|
#endif
|