Link discovery manager must send LDUpdate when port status change message is...

Link discovery manager must send LDUpdate when port status change message is received if it affects any links that is already known.

src/main/java/net/floodlightcontroller/linkdiscovery/internal/LinkDiscoveryManager.java

@@ -731,7 +731,7 @@ public class LinkDiscoveryManager
                         ILinkDiscovery.LinkType.INVALID_LINK,
                         EvAction.LINK_DELETED, reason);
 
-                // remove link from 
+                // remove link from storage.
                 removeLinkFromStorage(lt);
 
 
@@ -764,12 +764,11 @@ public class LinkDiscoveryManager
 
         SwitchPortTuple tuple =
                         new SwitchPortTuple(sw, ps.getDesc().getPortNumber());
-        boolean link_deleted  = false;
+        boolean linkDeleted  = false;
+        boolean linkInfoChanged = false;
 
         lock.writeLock().lock();
         try {
-            boolean topologyChanged = false;
-
             // if ps is a delete, or a modify where the port is down or
             // configured down
             if ((byte)OFPortReason.OFPPR_DELETE.ordinal() == ps.getReason() ||
@@ -788,26 +787,25 @@ public class LinkDiscoveryManager
                     }
                     eraseList.addAll(this.portLinks.get(tuple));
                     deleteLinks(eraseList, "Port Status Changed");
-                    topologyChanged = true;
-                    link_deleted    = true;
+                    linkDeleted = true;
                 }
             } else if (ps.getReason() ==
                                     (byte)OFPortReason.OFPPR_MODIFY.ordinal()) {
                 // If ps is a port modification and the port state has changed
                 // that affects links in the topology
                 if (this.portLinks.containsKey(tuple)) {
-                    for (LinkTuple link: this.portLinks.get(tuple)) {
-                        LinkInfo linkInfo = links.get(link);
+                    for (LinkTuple lt: this.portLinks.get(tuple)) {
+                        LinkInfo linkInfo = links.get(lt);
                         assert(linkInfo != null);
                         Integer updatedSrcPortState = null;
                         Integer updatedDstPortState = null;
-                        if (link.getSrc().equals(tuple) &&
+                        if (lt.getSrc().equals(tuple) &&
                                 (linkInfo.getSrcPortState() !=
                                                     ps.getDesc().getState())) {
                             updatedSrcPortState = ps.getDesc().getState();
                             linkInfo.setSrcPortState(updatedSrcPortState);
                         }
-                        if (link.getDst().equals(tuple) &&
+                        if (lt.getDst().equals(tuple) &&
                                 (linkInfo.getDstPortState() !=
                                                     ps.getDesc().getState())) {
                             updatedDstPortState = ps.getDesc().getState();
@@ -815,16 +813,21 @@ public class LinkDiscoveryManager
                         }
                         if ((updatedSrcPortState != null) ||
                                                 (updatedDstPortState != null)) {
-                            writeLink(link, linkInfo);
-                            topologyChanged = true;
+                            // The link is already known to link discovery
+                            // manager and the status has changed, therefore
+                            // send an LDUpdate.
+                            updates.add(new LDUpdate(lt, linkInfo.getSrcPortState(), 
+                                                     linkInfo.getDstPortState(), 
+                                                     getLinkType(lt, linkInfo), 
+                                                     UpdateOperation.ADD_OR_UPDATE));
+                            writeLink(lt, linkInfo);
+                            linkInfoChanged = true;
                         }
                     }
                 }
             }
 
-            if (topologyChanged) {
-                //updateClusters();
-            } else {
+            if (!linkDeleted && !linkInfoChanged){
                 if (log.isDebugEnabled()) {
                     log.debug("handlePortStatus: Switch {} port #{} reason {};"+
                             " no links to update/remove",
@@ -837,12 +840,12 @@ public class LinkDiscoveryManager
             lock.writeLock().unlock();
         }
 
-        if (!link_deleted) {
+        if (!linkDeleted) {
             // Send LLDP right away when port state is changed for faster
             // cluster-merge. If it is a link delete then there is not need
             // to send the LLDPs right away and instead we wait for the LLDPs
             // to be sent on the timer as it is normally done
-        	// do it outside the write-lock
+            // do it outside the write-lock
             sendLLDPTask.reschedule(1000, TimeUnit.MILLISECONDS);
         }
         return Command.CONTINUE;