Topology recompute task now runs every half a second.

src/main/java/net/floodlightcontroller/topology/TopologyManager.java

@@ -120,6 +120,8 @@ public class TopologyManager implements
      */
     protected boolean dtLinksUpdated;
 
+    protected final int TOPOLOGY_COMPUTE_INTERVAL_MS = 500;
+
     /**
      * Thread for recomputing topology.  The thread is always running, 
      * however the function applyUpdates() has a blocking call.
@@ -133,10 +135,15 @@ public class TopologyManager implements
         @Override 
         public void run() {
             try {
-                updateTopology();
+                if (ldUpdates.peek() != null)
+                    updateTopology();
             }
             catch (Exception e) {
                 log.error("Error in topology instance task thread", e);
+            } finally {
+                if (floodlightProvider.getRole() != Role.SLAVE)
+                    newInstanceTask.reschedule(TOPOLOGY_COMPUTE_INTERVAL_MS,
+                                           TimeUnit.MILLISECONDS);
             }
         }
     }
@@ -158,20 +165,10 @@ public class TopologyManager implements
 
     @Override
     public void linkDiscoveryUpdate(LDUpdate update) {
-        boolean scheduleFlag = false;
-        // if there's no udpates in the queue, then
-        // we need to schedule an update.
-        if (ldUpdates.peek() == null)
-            scheduleFlag = true;
-
         if (log.isTraceEnabled()) {
             log.trace("Queuing update: {}", update);
         }
         ldUpdates.add(update);
-
-        if (scheduleFlag) {
-            newInstanceTask.reschedule(1, TimeUnit.MICROSECONDS);
-        }
     }
     
     // ****************
@@ -582,12 +579,14 @@ public class TopologyManager implements
                 if (oldRole == Role.SLAVE) {
                     log.debug("Re-computing topology due " +
                             "to HA change from SLAVE->MASTER");
-                    newInstanceTask.reschedule(1, TimeUnit.MILLISECONDS);
+                    newInstanceTask.reschedule(TOPOLOGY_COMPUTE_INTERVAL_MS,
+                                               TimeUnit.MILLISECONDS);
                 }
                 break;
             case SLAVE:
                 log.debug("Clearing topology due to " +
                         "HA change to SLAVE");
+                ldUpdates.clear();
                 clearCurrentTopology();
                 break;
             default:
@@ -666,6 +665,11 @@ public class TopologyManager implements
     public void startUp(FloodlightModuleContext context) {
         ScheduledExecutorService ses = threadPool.getScheduledExecutor();
         newInstanceTask = new SingletonTask(ses, new UpdateTopologyWorker());
+
+        if (floodlightProvider.getRole() != Role.SLAVE)
+            newInstanceTask.reschedule(TOPOLOGY_COMPUTE_INTERVAL_MS,
+                                   TimeUnit.MILLISECONDS);
+
         linkDiscovery.addListener(this);
         floodlightProvider.addOFMessageListener(OFType.PACKET_IN, this);
         floodlightProvider.addHAListener(this);