Added the mechanism between the FlowManager and the Hazelcast datagrid
to send/receive Flow-related state.
diff --git a/src/main/java/net/onrc/onos/ofcontroller/flowmanager/IFlowService.java b/src/main/java/net/onrc/onos/ofcontroller/flowmanager/IFlowService.java
index 73f86b6..8c908cf 100644
--- a/src/main/java/net/onrc/onos/ofcontroller/flowmanager/IFlowService.java
+++ b/src/main/java/net/onrc/onos/ofcontroller/flowmanager/IFlowService.java
@@ -114,5 +114,26 @@
      * conditions to install.
      * @return the added shortest-path flow on success, otherwise null.
      */
-    public FlowPath addAndMaintainShortestPathFlow(FlowPath flowPath);
+    FlowPath addAndMaintainShortestPathFlow(FlowPath flowPath);
+
+    /**
+     * Receive a notification that a Flow is added.
+     *
+     * @param flowPath the flow that is added.
+     */
+    void notificationRecvFlowAdded(FlowPath flowPath);
+
+    /**
+     * Receive a notification that a Flow is removed.
+     *
+     * @param flowPath the flow that is removed.
+     */
+    void notificationRecvFlowRemoved(FlowPath flowPath);
+
+    /**
+     * Receive a notification that a Flow is updated.
+     *
+     * @param flowPath the flow that is updated.
+     */
+    void notificationRecvFlowUpdated(FlowPath flowPath);
 }