6:45 a.m.
Currently, push & pop from event queue (both server & client side)
rely on lock from higher levels, e.g. on driver lock (qemu),
private_data (remote), ...; This alone is not sufficient as not
every function that interacts with this queue can/does lock,
esp. in client where we have a different approach, "passing
the buck".
Therefore we need a separate lock just to protect event queue.
For more info see:
https://bugzilla.redhat.com/show_bug.cgi?id=743817
---
src/conf/domain_event.c | 65 +++++++++++++++++++++++++++++++++++++++++------
src/conf/domain_event.h | 1 +
2 files changed, 58 insertions(+), 8 deletions(-)
diff --git a/src/conf/domain_event.c b/src/conf/domain_event.c
index 3189346..6cc8168 100644
--- a/src/conf/domain_event.c
+++ b/src/conf/domain_event.c
@@ -547,6 +547,24 @@ virDomainEventQueuePtr virDomainEventQueueNew(void)
return ret;
}
+static void
+virDomainEventStateLock(virDomainEventStatePtr state)
+{
+ if (!state)
+ return;
+
+ virMutexLock(&state->lock);
+}
+
+static void
+virDomainEventStateUnlock(virDomainEventStatePtr state)
+{
+ if (!state)
+ return;
+
+ virMutexUnlock(&state->lock);
+}
+
/**
* virDomainEventStateFree:
* @list: virDomainEventStatePtr to free
@@ -564,6 +582,8 @@ virDomainEventStateFree(virDomainEventStatePtr state)
if (state->timer != -1)
virEventRemoveTimeout(state->timer);
+
+ virMutexDestroy(&state->lock);
VIR_FREE(state);
}
@@ -590,6 +610,13 @@ virDomainEventStateNew(virEventTimeoutCallback timeout_cb,
goto error;
}
+ if (virMutexInit(&state->lock) < 0) {
+ virReportSystemError(errno, "%s",
+ _("unable to initialize state mutex"));
+ VIR_FREE(state);
+ goto error;
+ }
+
if (VIR_ALLOC(state->callbacks) < 0) {
virReportOOMError();
goto error;
@@ -1161,18 +1188,26 @@ void
virDomainEventStateQueue(virDomainEventStatePtr state,
virDomainEventPtr event)
{
+ int count;
+
if (state->timer < 0) {
virDomainEventFree(event);
return;
}
+ virDomainEventStateLock(state);
+
if (virDomainEventQueuePush(state->queue, event) < 0) {
VIR_DEBUG("Error adding event to queue");
virDomainEventFree(event);
}
- if (state->queue->count == 1)
+ count = state->queue->count;
+ virDomainEventStateUnlock(state);
+
+ if (count == 1)
virEventUpdateTimeout(state->timer, 0);
+
}
void
@@ -1182,6 +1217,7 @@ virDomainEventStateFlush(virDomainEventStatePtr state,
{
virDomainEventQueue tempQueue;
+ virDomainEventStateLock(state);
state->isDispatching = true;
/* Copy the queue, so we're reentrant safe when dispatchFunc drops the
@@ -1190,6 +1226,7 @@ virDomainEventStateFlush(virDomainEventStatePtr state,
tempQueue.events = state->queue->events;
state->queue->count = 0;
state->queue->events = NULL;
+ virDomainEventStateUnlock(state);
virEventUpdateTimeout(state->timer, -1);
virDomainEventQueueDispatch(&tempQueue,
@@ -1198,9 +1235,11 @@ virDomainEventStateFlush(virDomainEventStatePtr state,
opaque);
/* Purge any deleted callbacks */
+ virDomainEventStateLock(state);
virDomainEventCallbackListPurgeMarked(state->callbacks);
state->isDispatching = false;
+ virDomainEventStateUnlock(state);
}
int
@@ -1208,11 +1247,16 @@ virDomainEventStateDeregister(virConnectPtr conn,
virDomainEventStatePtr state,
virConnectDomainEventCallback callback)
{
+ int ret;
+
+ virDomainEventStateLock(state);
if (state->isDispatching)
- return virDomainEventCallbackListMarkDelete(conn,
- state->callbacks, callback);
+ ret = virDomainEventCallbackListMarkDelete(conn,
+ state->callbacks, callback);
else
- return virDomainEventCallbackListRemove(conn, state->callbacks, callback);
+ ret = virDomainEventCallbackListRemove(conn, state->callbacks, callback);
+ virDomainEventStateUnlock(state);
+ return ret;
}
int
@@ -1220,10 +1264,15 @@ virDomainEventStateDeregisterAny(virConnectPtr conn,
virDomainEventStatePtr state,
int callbackID)
{
+ int ret;
+
+ virDomainEventStateLock(state);
if (state->isDispatching)
- return virDomainEventCallbackListMarkDeleteID(conn,
- state->callbacks, callbackID);
+ ret = virDomainEventCallbackListMarkDeleteID(conn,
+ state->callbacks, callbackID);
else
- return virDomainEventCallbackListRemoveID(conn,
- state->callbacks, callbackID);
+ ret = virDomainEventCallbackListRemoveID(conn,
+ state->callbacks, callbackID);
+ virDomainEventStateUnlock(state);
+ return ret;
}
diff --git a/src/conf/domain_event.h b/src/conf/domain_event.h
index b06be16..08930ed 100644
--- a/src/conf/domain_event.h
+++ b/src/conf/domain_event.h
@@ -61,6 +61,7 @@ struct _virDomainEventState {
int timer;
/* Flag if we're in process of dispatching */
bool isDispatching;
+ virMutex lock;
};
typedef struct _virDomainEventState virDomainEventState;
typedef virDomainEventState *virDomainEventStatePtr;
--
1.7.3.4