- Performance optimization

modules/cloudsim/src/main/java/org/cloudbus/cloudsim/core/CloudSim.java

@@ -543,7 +543,7 @@ public class CloudSim {
 		SimEvent e = new SimEvent(SimEvent.SEND, clock + delay, src, dest, tag, data);
 		future.addEvent(e);
 	}
-	
+
 	/**
 	 * Used to send an event from one entity to another, with priority in the queue.
 	 *
@@ -620,6 +620,25 @@ public class CloudSim {
 		return ev;
 	}
 
+	/**
+	 * Find first deferred event matching a predicate.
+	 *
+	 * @param src the src
+	 * @param p the p
+	 * @return the sim event
+	 */
+	public static SimEvent findFirstDeferred(int src, Predicate p) {
+		SimEvent ev = null;
+		Iterator<SimEvent> iterator = deferred.iterator();
+		while (iterator.hasNext()) {
+			ev = iterator.next();
+			if (ev.getDestination() == src && p.match(ev)) {
+				break;
+			}
+		}
+		return ev;
+	}
+
 	/**
 	 * Removes an event from the event queue.
 	 *

modules/cloudsim/src/main/java/org/cloudbus/cloudsim/power/PowerDatacenter.java

@@ -87,7 +87,7 @@ public class PowerDatacenter extends Datacenter {
 
 		// if some time passed since last processing
 		if (currentTime > getLastProcessTime()) {
-			double minTime = updateCloudetProcessingWithoutSchedulingFutureEvents();
+			double minTime = updateCloudetProcessingWithoutSchedulingFutureEventsForce();
 
 			if (!isDisableMigrations()) {
 				List<Map<String, Object>> migrationMap = getVmAllocationPolicy().optimizeAllocation(getVmList());
@@ -131,6 +131,18 @@ public class PowerDatacenter extends Datacenter {
 	 * @return the double
 	 */
 	protected double updateCloudetProcessingWithoutSchedulingFutureEvents() {
+		if (CloudSim.clock() > getLastProcessTime()) {
+			return updateCloudetProcessingWithoutSchedulingFutureEventsForce();
+		}
+		return 0;
+	}
+
+	/**
+	 * Update cloudet processing without scheduling future events.
+	 *
+	 * @return the double
+	 */
+	protected double updateCloudetProcessingWithoutSchedulingFutureEventsForce() {
 		double currentTime = CloudSim.clock();
 		double minTime = Double.MAX_VALUE;
 		double timeDiff = currentTime - getLastProcessTime();
@@ -191,7 +203,10 @@ public class PowerDatacenter extends Datacenter {
 	protected void processVmMigrate(SimEvent ev, boolean ack) {
 		updateCloudetProcessingWithoutSchedulingFutureEvents();
 		super.processVmMigrate(ev, ack);
-		updateCloudetProcessingWithoutSchedulingFutureEvents();
+		SimEvent event = CloudSim.findFirstDeferred(getId(), new PredicateType(CloudSimTags.VM_MIGRATE));
+		if (event == null || event.eventTime() > CloudSim.clock()) {
+			updateCloudetProcessingWithoutSchedulingFutureEventsForce();
+		}
     }
 
 	/* (non-Javadoc)