[libvirt] [PATCH 2/6] domain_event: Add common domain event queue/flush helpers

[Cole Robinson]

The same code for queueing, flushing, and deregistering events exists
in multiple drivers, which will soon use these common functions.

v2:
    Adjust libvirt_private.syms
    isDispatching bool fixes
    NONNULL tagging

Signed-off-by: Cole Robinson <crobinso at redhat.com>
---
 src/conf/domain_event.c  |   74 +++++++++++++++++++++++++++++++++++++++++++++-
 src/conf/domain_event.h  |   21 +++++++++++++
 src/libvirt_private.syms |    4 ++
 3 files changed, 98 insertions(+), 1 deletions(-)

diff --git a/src/conf/domain_event.c b/src/conf/domain_event.c
index c80b891..90153df 100644
--- a/src/conf/domain_event.c
+++ b/src/conf/domain_event.c
@@ -582,7 +582,8 @@ virDomainEventStateNew(virEventTimeoutCallback timeout_cb,
                                            timeout_cb,
                                            timeout_opaque,
                                            timeout_free)) < 0) {
-        goto error;
+        DEBUG0("virEventAddTimeout failed: No addTimeoutImpl defined. "
+               "continuing without events.");
     }
 
     return state;
@@ -1051,3 +1052,74 @@ void virDomainEventQueueDispatch(virDomainEventQueuePtr queue,
     VIR_FREE(queue->events);
     queue->count = 0;
 }
+
+void
+virDomainEventStateQueue(virDomainEventStatePtr state,
+                         virDomainEventPtr event)
+{
+    if (state->timer < 0) {
+        virDomainEventFree(event);
+        return;
+    }
+
+    if (virDomainEventQueuePush(state->queue, event) < 0) {
+        DEBUG0("Error adding event to queue");
+        virDomainEventFree(event);
+    }
+
+    if (state->queue->count == 1)
+        virEventUpdateTimeout(state->timer, 0);
+}
+
+void
+virDomainEventStateFlush(virDomainEventStatePtr state,
+                         virDomainEventDispatchFunc dispatchFunc,
+                         void *opaque)
+{
+    virDomainEventQueue tempQueue;
+
+    state->isDispatching = true;
+
+    /* Copy the queue, so we're reentrant safe when dispatchFunc drops the
+     * driver lock */
+    tempQueue.count = state->queue->count;
+    tempQueue.events = state->queue->events;
+    state->queue->count = 0;
+    state->queue->events = NULL;
+
+    virEventUpdateTimeout(state->timer, -1);
+    virDomainEventQueueDispatch(&tempQueue,
+                                state->callbacks,
+                                dispatchFunc,
+                                opaque);
+
+    /* Purge any deleted callbacks */
+    virDomainEventCallbackListPurgeMarked(state->callbacks);
+
+    state->isDispatching = false;
+}
+
+int
+virDomainEventStateDeregister(virConnectPtr conn,
+                              virDomainEventStatePtr state,
+                              virConnectDomainEventCallback callback)
+{
+    if (state->isDispatching)
+        return virDomainEventCallbackListMarkDelete(conn,
+                                                    state->callbacks, callback);
+    else
+        return virDomainEventCallbackListRemove(conn, state->callbacks, callback);
+}
+
+int
+virDomainEventStateDeregisterAny(virConnectPtr conn,
+                                 virDomainEventStatePtr state,
+                                 int callbackID)
+{
+    if (state->isDispatching)
+        return virDomainEventCallbackListMarkDeleteID(conn,
+                                                      state->callbacks, callbackID);
+    else
+        return virDomainEventCallbackListRemoveID(conn,
+                                                  state->callbacks, callbackID);
+}
diff --git a/src/conf/domain_event.h b/src/conf/domain_event.h
index a465536..ad7e825 100644
--- a/src/conf/domain_event.h
+++ b/src/conf/domain_event.h
@@ -204,4 +204,25 @@ void virDomainEventQueueDispatch(virDomainEventQueuePtr queue,
                                  virDomainEventDispatchFunc dispatch,
                                  void *opaque);
 
+
+void
+virDomainEventStateQueue(virDomainEventStatePtr state,
+                         virDomainEventPtr event)
+    ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2);
+void
+virDomainEventStateFlush(virDomainEventStatePtr state,
+                         virDomainEventDispatchFunc dispatchFunc,
+                         void *opaque)
+    ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2);
+int
+virDomainEventStateDeregister(virConnectPtr conn,
+                              virDomainEventStatePtr state,
+                              virConnectDomainEventCallback callback)
+    ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2) ATTRIBUTE_NONNULL(3);
+int
+virDomainEventStateDeregisterAny(virConnectPtr conn,
+                                 virDomainEventStatePtr state,
+                                 int callbackID)
+    ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2);
+
 #endif
diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
index 5bfbb92..699d602 100644
--- a/src/libvirt_private.syms
+++ b/src/libvirt_private.syms
@@ -349,8 +349,12 @@ virDomainEventRTCChangeNewFromDom;
 virDomainEventRTCChangeNewFromObj;
 virDomainEventRebootNewFromDom;
 virDomainEventRebootNewFromObj;
+virDomainEventStateDeregister;
+virDomainEventStateDeregisterAny;
+virDomainEventStateFlush;
 virDomainEventStateFree;
 virDomainEventStateNew;
+virDomainEventStateQueue;
 virDomainEventWatchdogNewFromDom;
 virDomainEventWatchdogNewFromObj;
 
-- 
1.7.3.3