qemu/util/notify.c
Paul Durrant 374752a26b xen / notify: introduce a new XenWatchList abstraction
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>
2019-09-24 12:18:47 +01:00

77 lines
1.7 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.
*
* Contributions after 2012-01-13 are licensed under the terms of the
* GNU GPL, version 2 or (at your option) any later version.
*/
#include "qemu/osdep.h"
#include "qemu/notify.h"
void notifier_list_init(NotifierList *list)
{
QLIST_INIT(&list->notifiers);
}
void notifier_list_add(NotifierList *list, Notifier *notifier)
{
QLIST_INSERT_HEAD(&list->notifiers, notifier, node);
}
void notifier_remove(Notifier *notifier)
{
QLIST_REMOVE(notifier, node);
}
void notifier_list_notify(NotifierList *list, void *data)
{
Notifier *notifier, *next;
QLIST_FOREACH_SAFE(notifier, &list->notifiers, node, next) {
notifier->notify(notifier, data);
}
}
bool notifier_list_empty(NotifierList *list)
{
return QLIST_EMPTY(&list->notifiers);
}
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;
}