adds listeners

CHANGELOG.md

@@ -1,5 +1,10 @@
 # Changelog
 
+## Version 5.3 Changelog (April 4th 2024)
+
+*   Improved code quality (Listener Design Pattern)
+*   Switched back to Java 8 for broader compatibility
+
 ## Version 5.2 Changelog (June 11th 2023)
 
 *   Improved performance

PureEdgeSim/com/mechalikh/pureedgesim/datacentersmanager/AbstractNode.java

@@ -18,12 +18,13 @@
 
 import com.mechalikh.pureedgesim.scenariomanager.SimulationParameters;
 import com.mechalikh.pureedgesim.simulationengine.Event;
+import com.mechalikh.pureedgesim.simulationengine.OnSimulationStartListener;
 import com.mechalikh.pureedgesim.simulationengine.SimEntity;
 import com.mechalikh.pureedgesim.simulationmanager.SimulationManager;
 /**
  * This abstract class represents a computing node in the simulation.
  */
-public abstract class AbstractNode extends SimEntity implements ComputingNode {
+public abstract class AbstractNode extends SimEntity implements ComputingNode, OnSimulationStartListener {
 
     /**
      * The update status event ID.
@@ -82,7 +83,8 @@ protected AbstractNode(SimulationManager simulationManager) {
      * Defines the logic to be performed by the computing node when the simulation
      * starts.
      */
-    public void startInternal() {
+    @Override
+    public void onSimulationStart() {
         scheduleNow(this, UPDATE_STATUS);
     }
 

PureEdgeSim/com/mechalikh/pureedgesim/datacentersmanager/ComputingNodesGenerator.java

@@ -22,8 +22,6 @@
 
 import java.util.ArrayList;
 import java.util.List;
-import java.util.Random;
-
 import org.w3c.dom.Element;
 
 import com.mechalikh.pureedgesim.locationmanager.MobilityModel;

PureEdgeSim/com/mechalikh/pureedgesim/datacentersmanager/DefaultComputingNode.java

@@ -316,9 +316,6 @@ public void setApplicationPlacementLocation(ComputingNode node) {
 
 	}
 
-	@Override
-	protected void onSimulationEnd() {
-		// Do something when the simulation finishes.
-	}
+
 
 }

PureEdgeSim/com/mechalikh/pureedgesim/datacentersmanager/DefaultComputingNodesGenerator.java

@@ -173,14 +173,14 @@ protected void generateDataCenters(String file, TYPES type) {
 					cloudOnlyList.add(computingNode);
 					mistAndCloudListSensorsExcluded.add(computingNode);
 					if (SimulationParameters.enableOrchestrators
-							&& SimulationParameters.deployOrchestrators == "CLOUD") {
+							&& "CLOUD".equals(SimulationParameters.deployOrchestrators)) {
 						orchestratorsList.add(computingNode);
 					}
 				} else {
 					edgeOnlyList.add(computingNode);
 					mistAndEdgeListSensorsExcluded.add(computingNode);
 					if (SimulationParameters.enableOrchestrators
-							&& SimulationParameters.deployOrchestrators == "EDGE") {
+							&& "EDGE".equals(SimulationParameters.deployOrchestrators)) {
 						orchestratorsList.add(computingNode);
 					}
 				}

PureEdgeSim/com/mechalikh/pureedgesim/datacentersmanager/LocationAwareNode.java

@@ -35,8 +35,8 @@ protected LocationAwareNode(SimulationManager simulationManager) {
 	}
 
 	@Override
-	public void startInternal() {
-		super.startInternal();
+	public void onSimulationStart() {
+		super.onSimulationStart();
 		mobilityModel.generatePath();
 	}
 

PureEdgeSim/com/mechalikh/pureedgesim/datacentersmanager/Router.java

@@ -8,11 +8,6 @@ public Router(SimulationManager simulationManager) {
 		super(simulationManager, 0, 0, 0, 0);
 	}
 
-	@Override
-	public void startInternal() {
-		// Do nothing
-	}
-
 	@Override
 	public void setApplicationPlacementLocation(ComputingNode node) {
 		// Do nothing

PureEdgeSim/com/mechalikh/pureedgesim/network/DefaultNetworkModel.java

@@ -257,21 +257,5 @@ protected void offloadingRequestRecievedByOrchestrator(TransferProgress transfer
 		scheduleNow(simulationManager, DefaultSimulationManager.SEND_TASK_FROM_ORCH_TO_DESTINATION, transfer.getTask());
 	}
 
-	/**
-	 * Defines the logic to be performed by the default network model when the
-	 * simulation starts.
-	 */
-	@Override
-	public void startInternal() {
-		// Do nothing.
-	}
-
-	/**
-	 * Defines the logic to be performed by the default network model when the
-	 * simulation ends.
-	 */
-	@Override
-	public void onSimulationEnd() {
-		// Do something when the simulation finishes.
-	}
+
 }

PureEdgeSim/com/mechalikh/pureedgesim/network/NetworkLink.java

@@ -80,15 +80,6 @@ public NetworkLink setBandwidth(double bandwidth) {
 		return this;
 	}
 
-	/**
-	 * Defines the logic to be performed by the network link when the simulation
-	 * starts.
-	 */
-	@Override
-	public void startInternal() {
-		// Do nothing for now.
-	}
-
 	public ComputingNode getSrc() {
 		return src;
 	}
@@ -230,12 +221,4 @@ public double getTotalTransferredData() {
 		return totalTrasferredData;
 	}
 
-	/**
-	 * Defines the logic to be performed by the network link when the simulation
-	 * ends.
-	 */
-	@Override
-	public void onSimulationEnd() {
-		// Do something when the simulation finishes.
-	}
 }

PureEdgeSim/com/mechalikh/pureedgesim/scenariomanager/EdgeDevicesParser.java

@@ -1,5 +1,6 @@
 package com.mechalikh.pureedgesim.scenariomanager;
 
+import java.util.Arrays;
 import java.util.List;
 
 import org.w3c.dom.Document;
@@ -34,9 +35,9 @@ protected boolean typeSpecificChecking(Document xmlDoc) {
 	}
 
 	protected void checkEdgeDevice(Element deviceElement) {
-		for (String element : List.of("connectivity", "mobility", "battery", "percentage", "speed", "minPauseDuration",
+		for (String element : Arrays.asList(new String[]{"connectivity", "mobility", "battery", "percentage", "speed", "minPauseDuration",
 				"maxPauseDuration", "minMobilityDuration", "maxMobilityDuration", "batteryCapacity", "generateTasks",
-				"isOrchestrator", "idleConsumption", "maxConsumption", "cores", "mips", "ram", "storage"))
+				"isOrchestrator", "idleConsumption", "maxConsumption", "cores", "mips", "ram", "storage"}))
 			isElementPresent(deviceElement, element);
 
 		for (String element : List.of("speed", "minPauseDuration", "minMobilityDuration", "batteryCapacity",

PureEdgeSim/com/mechalikh/pureedgesim/scenariomanager/SimulationParameters.java

@@ -86,7 +86,7 @@ public class SimulationParameters {
 	/**
 	 * Simualtion time in seconds.
 	 * 
-	 * @see com.mechalikh.pureedgesim.simulationmanager.DefaultSimulationManager#startInternal()
+	 * @see com.mechalikh.pureedgesim.simulationmanager.DefaultSimulationManager#onSimulationStart()
 	 */
 	public static double simulationDuration;
 
@@ -459,7 +459,7 @@ public enum TYPES {
 	/**
 	 * The network model update interval.
 	 * 
-	 * @see com.mechalikh.pureedgesim.network.NetworkLink#startInternal()
+	 * @see com.mechalikh.pureedgesim.network.NetworkLink#onSimulationStart()
 	 */
 	public static double networkUpdateInterval;
 

PureEdgeSim/com/mechalikh/pureedgesim/simulationengine/OnSimulationEndListener.java

@@ -0,0 +1,11 @@
+package com.mechalikh.pureedgesim.simulationengine;
+
+/**
+ * An interface to listen for events when the simulation ends.
+ */
+public interface OnSimulationEndListener {
+    /**
+     * Called when the simulation ends.
+     */
+    void onSimulationEnd();
+}

PureEdgeSim/com/mechalikh/pureedgesim/simulationengine/OnSimulationStartListener.java

@@ -0,0 +1,11 @@
+package com.mechalikh.pureedgesim.simulationengine;
+
+/**
+ * An interface to listen for events when the simulation starts.
+ */
+public interface OnSimulationStartListener {
+    /**
+     * Called when the simulation starts.
+     */ 
+	void onSimulationStart();
+}

PureEdgeSim/com/mechalikh/pureedgesim/simulationengine/PureEdgeSim.java

@@ -41,14 +41,13 @@
  * <p>
  * Once the PureEdgeSim simulation engine has started, it notifies all
  * simulation entities of the start of the simulation in order to schedule their
- * first event. This is guaranteed by the {@link SimEntity#startInternal()
- * startInternal()} method.
+ * first event. This is guaranteed by the {@link OnSimulationStartListener#onSimulationStart()} method.
  * 
  * @see com.mechalikh.pureedgesim.simulationengine.PureEdgeSim#start()
  * @see com.mechalikh.pureedgesim.simulationmanager.SimulationThread#startSimulation()
- * @see SimEntity#startInternal()
+ * @see OnSimulationStartListener.onSimulationStart()
  * @see com.mechalikh.pureedgesim.simulationmanager.DefaultSimulationManager#startSimulation()
- * @see com.mechalikh.pureedgesim.simulationmanager.DefaultSimulationManager#startInternal()
+ * @see com.mechalikh.pureedgesim.simulationmanager.DefaultSimulationManager#onSimulationStart()
  *
  * @author Charafeddine Mechalikh
  * @since PureEdgeSim 5.0
@@ -82,9 +81,9 @@ public PureEdgeSim() {
 	}
 
 	/**
-	 * Starts the simulation. First, it notifies all simulation entities that the
-	 * simulation has started by calling their {@link SimEntity#startInternal()
-	 * startInternal()} method. The entities will then schedule their first events.
+	 * Starts the simulation. First, it notifies all simulation entities that implement the {@link OnSimulationStartListener} interface that the
+	 * simulation has started by calling their {@link OnSimulationStartListener#onSimulationStart()
+	 * onSimulationStart()} method. The entities will then schedule their first events.
 	 * Once, all the entities has scheduled their fist events, a loop will go
 	 * through all those events to process them one by one, and the simulation time
 	 * is updated according to the time of last processed event. With each processed
@@ -96,19 +95,28 @@ public PureEdgeSim() {
 	 * @see com.mechalikh.pureedgesim.simulationmanager.Simulation#launchSimulation()
 	 * @see com.mechalikh.pureedgesim.simulationmanager.SimulationThread#startSimulation()
 	 * @see com.mechalikh.pureedgesim.simulationmanager.DefaultSimulationManager#startSimulation()
-	 * @see SimEntity#startInternal()
+	 * @see OnSimulationStartListener.onSimulationStart()
 	 * @see #terminate()
 	 */
 	public void start() {
-		// Notify all entities that the simulation has started.
-		entitiesList.forEach(SimEntity::startInternal);
+		// Notify all entities that the simulation has started. 
+		entitiesList.forEach(entity -> {
+		    if (entity instanceof OnSimulationStartListener) {
+		        ((OnSimulationStartListener) entity).onSimulationStart();
+		    }
+		});
+
 
 		while (runClockTickAndProcessFutureEvents(Double.MAX_VALUE) && isRunning) {
 			// All the processing happens inside the method called above
 		}
 
 		// Iteration finished, notify all entities and clear their list
-		entitiesList.forEach(SimEntity::onSimulationEnd);
+		entitiesList.forEach(entity -> {
+		    if (entity instanceof OnSimulationEndListener) {
+		        ((OnSimulationEndListener) entity).onSimulationEnd();
+		    }
+		});
 		entitiesList.clear();
 	}
 
@@ -185,7 +193,7 @@ protected void processEvent(final Event event) {
 	 * @param event the new event.
 	 * @see SimEntity#schedule(SimEntity, Double, int)
 	 * @see SimEntity#schedule(SimEntity, Double, int, Object)
-	 * @see SimEntity#startInternal()
+	 * @see OnSimulationStartListener#onSimulationStart()
 	 * @see FutureQueue
 	 * @see #start()
 	 * @see #runClockTickAndProcessFutureEvents(double)
@@ -201,7 +209,7 @@ void insert(Event event) {
 	 * @param event the new event.
 	 * @see SimEntity#schedule(SimEntity, Double, int)
 	 * @see SimEntity#schedule(SimEntity, Double, int, Object)
-	 * @see SimEntity#startInternal()
+	 * @see OnSimulationStartListener#onSimulationStart()
 	 * @see FutureQueue
 	 * @see #start()
 	 * @see #runClockTickAndProcessFutureEvents(double)
@@ -222,7 +230,7 @@ public void insertFirst(Event event) {
 	 * @see com.mechalikh.pureedgesim.simulationmanager.SimulationThread#loadModels(DefaultSimulationManager
 	 *      simulationManager)
 	 * @see #start()
-	 * @see SimEntity#startInternal()
+	 * @see OnSimulationStartListener#onSimulationStart()
 	 */
 	public void addEntity(SimEntity simEntity) {
 		entitiesList.add(simEntity);

PureEdgeSim/com/mechalikh/pureedgesim/simulationengine/SimEntity.java

@@ -63,10 +63,6 @@ protected Event scheduleNow(SimEntity simEntity, int tag, Object data) {
 		return e;
 	}
 
-	protected abstract void startInternal();
-
-	protected abstract void onSimulationEnd();
-
 	protected abstract void processEvent(Event e);
 
 }

PureEdgeSim/com/mechalikh/pureedgesim/simulationmanager/DefaultSimulationManager.java

@@ -28,6 +28,7 @@
 import com.mechalikh.pureedgesim.scenariomanager.SimulationParameters;
 import com.mechalikh.pureedgesim.scenariomanager.SimulationParameters.TYPES;
 import com.mechalikh.pureedgesim.simulationengine.Event;
+import com.mechalikh.pureedgesim.simulationengine.OnSimulationStartListener;
 import com.mechalikh.pureedgesim.simulationengine.PureEdgeSim;
 import com.mechalikh.pureedgesim.simulationvisualizer.SimulationVisualizer;
 import com.mechalikh.pureedgesim.taskgenerator.Task;
@@ -50,7 +51,7 @@
  * @author Charafeddine Mechalikh
  * @since PureEdgeSim 4.2
  */
-public class DefaultSimulationManager extends SimulationManager {
+public class DefaultSimulationManager extends SimulationManager implements OnSimulationStartListener {
 
 	/**
 	 * Simulation progress parameters.
@@ -111,7 +112,7 @@ public void startSimulation() {
 	 * simulation starts.
 	 */
 	@Override
-	public void startInternal() {
+	public void onSimulationStart() {
 		// Initialize logger variables.
 		simLog.setGeneratedTasks(taskList.size());
 		simLog.setCurrentOrchPolicy(scenario.getStringOrchArchitecture());
@@ -448,13 +449,6 @@ protected boolean sameLocation(ComputingNode Dev1, ComputingNode Dev2) {
 		return (distance < RANGE);
 	}
 
-	/**
-	 * Defines the logic to be performed by the simulation manager when the
-	 * simulation starts.
-	 */
-	@Override
-	public void onSimulationEnd() {
-		// Do something when the simulation finishes.
-	}
+
 
 }

PureEdgeSim/com/mechalikh/pureedgesim/simulationmanager/SimLog.java

@@ -41,8 +41,7 @@
 import com.mechalikh.pureedgesim.energy.EnergyModelNetworkLink;
 import com.mechalikh.pureedgesim.network.NetworkLink;
 import com.mechalikh.pureedgesim.network.TransferProgress;
-import com.mechalikh.pureedgesim.scenariomanager.SimulationParameters;
-import com.mechalikh.pureedgesim.scenariomanager.SimulationParameters.TYPES;
+import com.mechalikh.pureedgesim.scenariomanager.SimulationParameters; 
 import com.mechalikh.pureedgesim.taskgenerator.Task;
 
 public class SimLog {

PureEdgeSim/com/mechalikh/pureedgesim/simulationmanager/SimulationThread.java

@@ -193,10 +193,8 @@ protected void loadModels(SimulationManager simulationManager) throws Exception
 		// Initialize the network model
 		SimLog.println(this.getClass().getSimpleName() + " - Initializing the Network Module...");
 		Constructor<?> networkConstructor = simulation.networkModel.getConstructor(SimulationManager.class);
-		networkConstructor.newInstance(simulationManager);
-
-		long startTime = System.currentTimeMillis();
-
+		networkConstructor.newInstance(simulationManager); 
+
 		// Generate all data centers, servers, an devices
 		SimLog.println(this.getClass().getSimpleName() + " - Initializing the Datacenters Manager Module...");
 		new DataCentersManager(simulationManager, simulation.mobilityModel, simulation.computingNode,

PureEdgeSim/com/mechalikh/pureedgesim/taskorchestrator/DefaultOrchestrator.java

@@ -110,18 +110,7 @@ public void resultsReturned(Task task) {
 		// Do something with the task that has been finished
 
 	}
-
-	@Override
-	public void startInternal() {
-		// Do something when the simulation starts. e.g., schedule some events
-	}
-
-	@Override
-	public void onSimulationEnd() {
-		// Do something when the simulation finishes. e.g., print some results.
-
-	}
-
+
 	@Override
 	public void processEvent(Event e) {
 		// Process the scheduled events, if any.