Documentation Added with Some updates on Code.

modules/cloudsim/src/main/java/org/cloudbus/cloudsim/network/datacenter/AggregateSwitch.java

@@ -9,44 +9,74 @@ import org.cloudbus.cloudsim.core.CloudSimTags;
 import org.cloudbus.cloudsim.core.SimEvent;
 import org.cloudbus.cloudsim.core.predicates.PredicateType;
 
-public class AggregateSwitch extends Switch{
-
+/**
+ * This class allows to simulate aggregate switch for Datacenter network.
+ * It interacts with other switches in order to exchange
+ * packets. Please refer to following publication for more details:
+ * 
+ * Saurabh Kumar Garg and Rajkumar Buyya, NetworkCloudSim: Modelling Parallel 
+ * Applications in Cloud Simulations, Proceedings of the 4th IEEE/ACM International 
+ * Conference on Utility and Cloud Computing (UCC 2011, IEEE CS Press, USA), 
+ * Melbourne, Australia, December 5-7, 2011. 
+ *
+ * @author		Saurabh Kumar Garg
+ * @since		CloudSim Toolkit 3.0
+ * 
+ */
+
+
+public class AggregateSwitch extends Switch {
+
+	
+	/**
+	 * Constructor for Aggregate  Switch
+	 * We have to specify switches that are connected to its downlink and uplink ports,
+	 * and corresponding bandwidths
+	 *
+	 * @param name Name of the switch 
+	 * @param level At which level switch is with respect to hosts.
+	 * @param dc  Pointer to Datacenter
+	 */
 	public AggregateSwitch(String name, int level, NetworkDatacenter dc) {
 		super(name, level, dc);
 		// TODO Auto-generated constructor stub
 
-		downlinkswitchpktlist=new HashMap<Integer,List<HostPacket>>();
-		uplinkswitchpktlist=new HashMap<Integer,List<HostPacket>>();
-		  uplinkbandwidth=Constants.BandWidthAggRoot;
-			downlinkbandwidth=Constants.BandWidthEdgeAgg;
-			latency=Constants.SwitchingDelayAgg;
-			numport=Constants.AggSwitchPort;
-			uplinkswitches=new ArrayList<Switch>();
-			downlinkswitches=new ArrayList<Switch>();
+		downlinkswitchpktlist = new HashMap<Integer, List<NetworkPacket>>();
+		uplinkswitchpktlist = new HashMap<Integer, List<NetworkPacket>>();
+		uplinkbandwidth = NetworkConstants.BandWidthAggRoot;
+		downlinkbandwidth = NetworkConstants.BandWidthEdgeAgg;
+		latency = NetworkConstants.SwitchingDelayAgg;
+		numport = NetworkConstants.AggSwitchPort;
+		uplinkswitches = new ArrayList<Switch>();
+		downlinkswitches = new ArrayList<Switch>();
 	}
 	
-	
-	private void processpacket_down(SimEvent ev) {
-		// TODO Auto-generated method stub
-		//packet coming from up level router.
-		//has to send downward
-		//check which switch to forward to 
-		//add packet in the switch list
-		//add packet in the host list
-		//int src=ev.getSource();
-		HostPacket hspkt=(HostPacket) ev.getData();
-	    int recvVMid=hspkt.pkt.reciever;
-		CloudSim.cancelAll(getId(), new PredicateType(CloudSimTags.Network_Event_send));
-		schedule(getId(),this.latency, CloudSimTags.Network_Event_send);
-	    
-	    if(this.level==Constants.Agg_LEVEL)
-	    {
-	    	//packet is coming from root so need to be sent to edgelevel swich
-	    	//find the id for edgelevel switch
-	    	int switchid=dc.VmToSwitchid.get(recvVMid);
-	    	List<HostPacket> pktlist=this.downlinkswitchpktlist.get(switchid);
-	    	if(pktlist==null){
-	    		pktlist=new ArrayList<HostPacket>();
+	/**
+	 * Send Packet to switch connected through a downlink port
+	 *
+	 * @param ev Event/packet to process
+	 */
+	
+	@Override
+	protected void processpacket_down(SimEvent ev) {
+		// packet coming from up level router.
+		// has to send downward
+		// check which switch to forward to
+		// add packet in the switch list
+		// add packet in the host list
+		NetworkPacket hspkt = (NetworkPacket) ev.getData();
+		int recvVMid = hspkt.pkt.reciever;
+		CloudSim.cancelAll(getId(), new PredicateType(
+				CloudSimTags.Network_Event_send));
+		schedule(getId(), this.latency, CloudSimTags.Network_Event_send);
+
+		if (this.level == NetworkConstants.Agg_LEVEL) {
+			// packet is coming from root so need to be sent to edgelevel swich
+			// find the id for edgelevel switch
+			int switchid = dc.VmToSwitchid.get(recvVMid);
+			List<NetworkPacket> pktlist = this.downlinkswitchpktlist.get(switchid);
+			if (pktlist == null) {
+				pktlist = new ArrayList<NetworkPacket>();
 				this.downlinkswitchpktlist.put(switchid, pktlist);
 			}
 			pktlist.add(hspkt);
@@ -54,46 +84,51 @@ public class AggregateSwitch extends Switch{
 		}
 
 	}
-
-
-	private void processpacket_up(SimEvent ev) {
-		// TODO Auto-generated method stub
-		//packet coming from down level router.
-		//has to send up
-		//check which switch to forward to 
-		//add packet in the switch list
+	/**
+	 * Send Packet to switch connected through a uplink port
+	 *
+	 * @param ev Event/packet to process
+	 */
+	@Override
+	protected void processpacket_up(SimEvent ev) {
+	
+		// packet coming from down level router.
+		// has to send up
+		// check which switch to forward to
+		// add packet in the switch list
 		//
-		//int src=ev.getSource();
-		HostPacket hspkt=(HostPacket) ev.getData();
-	    int recvVMid=hspkt.pkt.reciever;
-	    CloudSim.cancelAll(getId(), new PredicateType(CloudSimTags.Network_Event_send));
-		schedule(getId(),this.switching_delay, CloudSimTags.Network_Event_send);
-	    
-	    if(this.level==Constants.Agg_LEVEL)
-	    {
-	    	//packet is coming from edge level router so need to be sent to either root or another edge level swich
-	    	//find the id for edgelevel switch
-	    	int switchid=dc.VmToSwitchid.get(recvVMid);
-	    	boolean flagtoswtich=false;
-	    	for(Switch sw:this.downlinkswitches)
-	    	{
-        	   if(switchid==sw.getId()) flagtoswtich=true; 
+		// int src=ev.getSource();
+		NetworkPacket hspkt = (NetworkPacket) ev.getData();
+		int recvVMid = hspkt.pkt.reciever;
+		CloudSim.cancelAll(getId(), new PredicateType(
+				CloudSimTags.Network_Event_send));
+		schedule(getId(), this.switching_delay, CloudSimTags.Network_Event_send);
+
+		if (this.level == NetworkConstants.Agg_LEVEL) {
+			// packet is coming from edge level router so need to be sent to
+			// either root or another edge level swich
+			// find the id for edgelevel switch
+			int switchid = dc.VmToSwitchid.get(recvVMid);
+			boolean flagtoswtich = false;
+			for (Switch sw : this.downlinkswitches) {
+				if (switchid == sw.getId())
+					flagtoswtich = true;
 			}
-	    	if(flagtoswtich)
-	    	{
-		    	List<HostPacket> pktlist=this.downlinkswitchpktlist.get(switchid);
-		    	if(pktlist==null){
-		    		pktlist=new ArrayList<HostPacket>();
+			if (flagtoswtich) {
+				List<NetworkPacket> pktlist = this.downlinkswitchpktlist
+						.get(switchid);
+				if (pktlist == null) {
+					pktlist = new ArrayList<NetworkPacket>();
 					this.downlinkswitchpktlist.put(switchid, pktlist);
 				}
 				pktlist.add(hspkt);
-	    	}
-	    	else//send to up
+			} else// send to up
 			{
-	    		Switch sw=this.uplinkswitches.get(0);
-		    	List<HostPacket> pktlist=this.uplinkswitchpktlist.get(sw.getId());
-		    	if(pktlist==null){
-		    		pktlist=new ArrayList<HostPacket>();
+				Switch sw = this.uplinkswitches.get(0);
+				List<NetworkPacket> pktlist = this.uplinkswitchpktlist.get(sw
+						.getId());
+				if (pktlist == null) {
+					pktlist = new ArrayList<NetworkPacket>();
 					this.uplinkswitchpktlist.put(sw.getId(), pktlist);
 				}
 				pktlist.add(hspkt);
@@ -101,7 +136,4 @@ public class AggregateSwitch extends Switch{
 		}
 	}
 
-
-		
-
 }

modules/cloudsim/src/main/java/org/cloudbus/cloudsim/network/datacenter/AppCloudlet.java

@@ -7,20 +7,38 @@ import org.cloudbus.cloudsim.UtilizationModel;
 import org.cloudbus.cloudsim.UtilizationModelFull;
 import org.cloudbus.cloudsim.core.CloudSim;
 
+/**
+ * AppCloudlet class represents an application which user submit for execution within datacenter. 
+ * It consist of several networkClouds.
+ * 
+ * Please refer to following publication for more details:
+ * 
+ * Saurabh Kumar Garg and Rajkumar Buyya, NetworkCloudSim: Modelling Parallel
+ * Applications in Cloud Simulations, Proceedings of the 4th IEEE/ACM
+ * International Conference on Utility and Cloud Computing (UCC 2011, IEEE CS
+ * Press, USA), Melbourne, Australia, December 5-7, 2011.
+ *
+ * 
+ * @author Saurabh Kumar Garg
+ * @since CloudSim Toolkit 1.0
+ */
+
 public class AppCloudlet {
 	public static final int APP_MC = 1;
 	public static final int APP_Workflow = 3;
-	public AppCloudlet(int type, int appID, 
-			double deadline, int numbervm, int userId) {
+
+	public AppCloudlet(int type, int appID, double deadline, int numbervm,
+			int userId) {
 		super();
 		this.type = type;
 		this.appID = appID;
 		this.deadline = deadline;
 		this.numbervm = numbervm;
 		this.userId = userId;
-		clist=new ArrayList<NetworkCloudlet>();
+		clist = new ArrayList<NetworkCloudlet>();
 	}
-	public int type; //fft,fem
+
+	public int type; 
 	public int appID;
 	public ArrayList<NetworkCloudlet> clist;
 	public double deadline;
@@ -29,37 +47,32 @@ public class AppCloudlet {
 	public int userId;
 	public double exeTime;
 	public int requestclass;
-	
-    public void createCloudletList(List<Integer> vmIdList)
-    {
-    	for(int i=0;i<numbervm;i++){
+    /**
+     * An example of creating APPcloudlet
+     * @param vmIdList VMs where Cloudlet will be executed
+     */
+	public void createCloudletList(List<Integer> vmIdList) {
+		for (int i = 0; i < numbervm; i++) {
 			long length = 4;
 			long fileSize = 300;
 			long outputSize = 300;
 			long memory = 256;
 			int pesNumber = 4;
 			UtilizationModel utilizationModel = new UtilizationModelFull();
-    		//HPCCloudlet cl=new HPCCloudlet();
-    		NetworkCloudlet cl = new NetworkCloudlet(Constants.currentCloudletId, length, pesNumber, fileSize, outputSize, memory, utilizationModel, utilizationModel, utilizationModel);
+			// HPCCloudlet cl=new HPCCloudlet();
+			NetworkCloudlet cl = new NetworkCloudlet(
+					NetworkConstants.currentCloudletId, length, pesNumber, fileSize,
+					outputSize, memory, utilizationModel, utilizationModel,
+					utilizationModel);
 			// setting the owner of these Cloudlets
-    		Constants.currentCloudletId++;
+			NetworkConstants.currentCloudletId++;
 			cl.setUserId(userId);
-			cl.submittime=CloudSim.clock();
-//    		TaskStage ts=new TaskStage(Constants.EXECUTION, 0, length, 0,memory, (i+1)%numbervm);
-//    		TaskStage ts1=new TaskStage(Constants.WAIT_SEND, 100, 0, 0, memory, (i+1)%numbervm);
-//    		TaskStage ts2=new TaskStage(Constants.WAIT_RECV, 100, 0, 0, memory, (i+1)%numbervm);
-//    		TaskStage ts3=new TaskStage(Constants.EXECUTION, 0, length, 0, memory, (i+1)%numbervm);
-//			cl.stages.add(ts);
-//    		cl.stages.add(ts1);
-//    		cl.stages.add(ts2);
-//    		cl.stages.add(ts3);
-//    		cl.submittime=CloudSim.clock();
-    		cl.currStagenum=-1;
+			cl.submittime = CloudSim.clock();
+			cl.currStagenum = -1;
 			clist.add(cl);
 
-    		
 		}
-    	//based on type
+		// based on type
 
 	}
 }

modules/cloudsim/src/main/java/org/cloudbus/cloudsim/network/datacenter/MonteCarloApp.java → modules/cloudsim/src/main/java/org/cloudbus/cloudsim/network/datacenter/BagofTaskApp.java

 package org.cloudbus.cloudsim.network.datacenter;
 
+/**
+ * BagofTaskApp is an example of AppCloudlet having three noncommunicating tasks. 
+ * 
+ * 
+ * Please refer to following publication for more details:
+ * 
+ * Saurabh Kumar Garg and Rajkumar Buyya, NetworkCloudSim: Modelling Parallel
+ * Applications in Cloud Simulations, Proceedings of the 4th IEEE/ACM
+ * International Conference on Utility and Cloud Computing (UCC 2011, IEEE CS
+ * Press, USA), Melbourne, Australia, December 5-7, 2011.
+ *
+ * 
+ * @author Saurabh Kumar Garg
+ * @since CloudSim Toolkit 1.0
+ */
+
 import java.util.List;
 
 import org.cloudbus.cloudsim.UtilizationModel;
 import org.cloudbus.cloudsim.UtilizationModelFull;
 import org.cloudbus.cloudsim.core.CloudSim;
 
-public class MonteCarloApp extends AppCloudlet {
+public class BagofTaskApp extends AppCloudlet {
 
-	public MonteCarloApp(int type, int appID, double deadline, 	int numbervm, int userId) {
+	public BagofTaskApp(int type, int appID, double deadline, 	int numbervm, int userId) {
 		super(type, appID, deadline, numbervm,userId);
 		
 		this.numbervm=this.getnumvm();
@@ -19,34 +35,39 @@ public class MonteCarloApp extends AppCloudlet {
     public void createCloudletList(List<Integer> vmIdList){
 		//basically, each task runs the simulation and then data is consolidated in one task
 		int executionTime = getExecTime();
-		long memory = accuracyToMemory();
-		long fileSize = Constants.FILE_SIZE;
-		long outputSize = Constants.OUTPUT_SIZE;
-		int pesNumber = Constants.PES_NUMBER;
+		long memory = 1000;
+		long fileSize = NetworkConstants.FILE_SIZE;
+		long outputSize = NetworkConstants.OUTPUT_SIZE;
+		int pesNumber = NetworkConstants.PES_NUMBER;
 		int stgId=0;
-		int t=Constants.currentCloudletId;
+		int t=NetworkConstants.currentCloudletId;
 	  	for(int i=0;i<numbervm;i++){
     		UtilizationModel utilizationModel = new UtilizationModelFull();
-    		NetworkCloudlet cl = new NetworkCloudlet(Constants.currentCloudletId, executionTime/numbervm, pesNumber, fileSize, outputSize, memory, utilizationModel, utilizationModel, utilizationModel);
-    		Constants.currentCloudletId++;
+    		NetworkCloudlet cl = new NetworkCloudlet(NetworkConstants.currentCloudletId, executionTime/numbervm, pesNumber, fileSize, outputSize, memory, utilizationModel, utilizationModel, utilizationModel);
+    		NetworkConstants.currentCloudletId++;
     		cl.setUserId(userId);
 			cl.submittime=CloudSim.clock();
     		cl.currStagenum=-1;
 			cl.setVmId(vmIdList.get(i));
 			//compute and send data to node 0
-    		cl.stages.add(new TaskStage(Constants.EXECUTION, Constants.COMMUNICATION_LENGTH, executionTime/numbervm, stgId++, memory, vmIdList.get(0),cl.getCloudletId()));
+    		cl.stages.add(new TaskStage(NetworkConstants.EXECUTION, NetworkConstants.COMMUNICATION_LENGTH, executionTime/numbervm, stgId++, memory, vmIdList.get(0),cl.getCloudletId()));
     		
     		//0 has an extra stage of waiting for results; others send
     		if (i==0){
     			for(int j=1;j<numbervm;j++)
-    				cl.stages.add(new TaskStage(Constants.WAIT_RECV, Constants.COMMUNICATION_LENGTH, 0, stgId++, memory, vmIdList.get(j),cl.getCloudletId()+j));
+    				cl.stages.add(new TaskStage(NetworkConstants.WAIT_RECV, NetworkConstants.COMMUNICATION_LENGTH, 0, stgId++, memory, vmIdList.get(j),cl.getCloudletId()+j));
     		} else {
-    			cl.stages.add(new TaskStage(Constants.WAIT_SEND, Constants.COMMUNICATION_LENGTH, 0, stgId++, memory, vmIdList.get(0),t));
+    			cl.stages.add(new TaskStage(NetworkConstants.WAIT_SEND, NetworkConstants.COMMUNICATION_LENGTH, 0, stgId++, memory, vmIdList.get(0),t));
     		}
     		
     		clist.add(cl);    			
     	}	
 	}
+	
+	/**
+	 * One can generate number of VMs for each application based on deadline
+	 * @return
+	 */
 	public int getnumvm(){
 		double exetime=getExecTime()/2;//for two vms
 		if(this.deadline>exetime)
@@ -57,14 +78,10 @@ public class MonteCarloApp extends AppCloudlet {
 	}
 	
 	private int getExecTime() {
-		//use exec constraints as Binomial
+		//use exec constraints 
 		
 		return 100;
 	}
 
-	private long accuracyToMemory() {
-		//use same memory constraints as Binomial
 	
-		return 240076;
-	}
 }

modules/cloudsim/src/main/java/org/cloudbus/cloudsim/network/datacenter/EdgeSwitch.java

@@ -11,26 +11,53 @@ import org.cloudbus.cloudsim.core.CloudSimTags;
 import org.cloudbus.cloudsim.core.SimEvent;
 import org.cloudbus.cloudsim.core.predicates.PredicateType;
 
+/**
+ * This class allows to simulate Edge switch for Datacenter network.
+ * It interacts with other switches in order to exchange
+ * packets. Please refer to following publication for more details:
+ * 
+ * Saurabh Kumar Garg and Rajkumar Buyya, NetworkCloudSim: Modelling Parallel 
+ * Applications in Cloud Simulations, Proceedings of the 4th IEEE/ACM International 
+ * Conference on Utility and Cloud Computing (UCC 2011, IEEE CS Press, USA), 
+ * Melbourne, Australia, December 5-7, 2011. 
+ *
+ * @author		Saurabh Kumar Garg
+ * @since		CloudSim Toolkit 3.0
+ * 
+ */
+
 public class EdgeSwitch extends Switch{
 
-	public EdgeSwitch(String name, int dcid, NetworkDatacenter dc) {
-		super(name, dcid, dc);
+	/**
+	 * Constructor for Edge  Switch
+	 * We have to specify switches that are connected to its downlink and uplink ports,
+	 * and corresponding bandwidths. In this switch downlink ports are 
+	 * connected to hosts not to a switch.
+	 *
+	 * @param name Name of the switch 
+	 * @param level At which level switch is with respect to hosts.
+	 * @param dc  Pointer to Datacenter
+	 */
+	
+	public EdgeSwitch(String name, int level, NetworkDatacenter dc) {
+		super(name, level, dc);
 		hostlist=new HashMap<Integer,NetworkHost>();
-		uplinkswitchpktlist=new HashMap<Integer,List<HostPacket>>();
-		packetTohost=new HashMap<Integer,List<HostPacket>>();
-        uplinkbandwidth=Constants.BandWidthEdgeAgg;
-		downlinkbandwidth=Constants.BandWidthEdgeHost;
-		this.switching_delay=Constants.SwitchingDelayEdge;
-		numport=Constants.EdgeSwitchPort;
+		uplinkswitchpktlist=new HashMap<Integer,List<NetworkPacket>>();
+		packetTohost=new HashMap<Integer,List<NetworkPacket>>();
+        uplinkbandwidth=NetworkConstants.BandWidthEdgeAgg;
+		downlinkbandwidth=NetworkConstants.BandWidthEdgeHost;
+		this.switching_delay=NetworkConstants.SwitchingDelayEdge;
+		numport=NetworkConstants.EdgeSwitchPort;
 		uplinkswitches=new ArrayList<Switch>();
 		// TODO Auto-generated constructor stub
 	}
-	private void registerHost(SimEvent ev) {
-		// TODO Auto-generated method stub
-		NetworkHost hs=(NetworkHost)ev.getData();
-		hostlist.put(hs.getId(),(NetworkHost)ev.getData());
-	}
-	private void processpacket_up(SimEvent ev) {
+	/**
+	 * Send Packet to switch connected through a uplink port
+	 *
+	 * @param ev Event/packet to process
+	 */
+	@Override
+	protected void processpacket_up(SimEvent ev) {
 		// TODO Auto-generated method stub
 		//packet coming from down level router/host.
 		//has to send up
@@ -38,7 +65,7 @@ public class EdgeSwitch extends Switch{
 		//add packet in the switch list
 		//
 		//int src=ev.getSource();
-		HostPacket hspkt=(HostPacket) ev.getData();
+		NetworkPacket hspkt=(NetworkPacket) ev.getData();
 	    int recvVMid=hspkt.pkt.reciever;
 	    CloudSim.cancelAll(getId(), new PredicateType(CloudSimTags.Network_Event_send));
 		schedule(getId(),this.switching_delay, CloudSimTags.Network_Event_send);
@@ -54,9 +81,9 @@ public class EdgeSwitch extends Switch{
     	if(hs!=null)
     	{
     		//packet to be sent to host connected to the switch
-    		List<HostPacket> pktlist=this.packetTohost.get(hostid);
+    		List<NetworkPacket> pktlist=this.packetTohost.get(hostid);
 	    	if(pktlist==null){
-	    		pktlist=new ArrayList<HostPacket>();
+	    		pktlist=new ArrayList<NetworkPacket>();
 	    		this.packetTohost.put(hostid, pktlist);
 	    	}
 	    	pktlist.add(hspkt);
@@ -69,9 +96,9 @@ public class EdgeSwitch extends Switch{
     	//if there are more than one Aggregate level switch one need to modify following code
              	
     	Switch sw=this.uplinkswitches.get(0);
-    	List<HostPacket> pktlist=this.uplinkswitchpktlist.get(sw.getId());
+    	List<NetworkPacket> pktlist=this.uplinkswitchpktlist.get(sw.getId());
     	if(pktlist==null){
-    		pktlist=new ArrayList<HostPacket>();
+    		pktlist=new ArrayList<NetworkPacket>();
     		this.uplinkswitchpktlist.put(sw.getId(), pktlist);
     	}
     	pktlist.add(hspkt);
@@ -79,24 +106,31 @@ public class EdgeSwitch extends Switch{
 	  	    
 	   
 	}
-	private void processpacketforward(SimEvent ev) {
+	/**
+	 * Send Packet to hosts connected to the switch
+	 *
+	 * @param ev Event/packet to process
+	 */
+	
+	@Override
+	protected void processpacketforward(SimEvent ev) {
 		// TODO Auto-generated method stub
 		//search for the host and packets..send to them
 		
 		
 		if(this.uplinkswitchpktlist!=null)
 		{
-			for(Entry<Integer, List<HostPacket>> es:uplinkswitchpktlist.entrySet())
+			for(Entry<Integer, List<NetworkPacket>> es:uplinkswitchpktlist.entrySet())
 			{
 				int tosend=es.getKey();
-				List<HostPacket> hspktlist=es.getValue();
+				List<NetworkPacket> hspktlist=es.getValue();
 				if(!hspktlist.isEmpty()){
 					//sharing bandwidth between packets
 					double avband=this.uplinkbandwidth/hspktlist.size();
-					Iterator<HostPacket> it=hspktlist.iterator();
+					Iterator<NetworkPacket> it=hspktlist.iterator();
 					while(it.hasNext())
 					{
-						HostPacket hspkt=it.next();
+						NetworkPacket hspkt=it.next();
 						double delay=1000*hspkt.pkt.data/avband;
 						
 						this.send(tosend,delay,CloudSimTags.Network_Event_UP, hspkt);
@@ -107,16 +141,16 @@ public class EdgeSwitch extends Switch{
 		}
 		if(this.packetTohost!=null)
 		{
-			for(Entry<Integer, List<HostPacket>> es:packetTohost.entrySet())
+			for(Entry<Integer, List<NetworkPacket>> es:packetTohost.entrySet())
 			{
 				int tosend=es.getKey();
 				NetworkHost hs=this.hostlist.get(tosend);
-				List<HostPacket> hspktlist=es.getValue();
+				List<NetworkPacket> hspktlist=es.getValue();
 				if(!hspktlist.isEmpty()){
 					double avband=this.downlinkbandwidth/hspktlist.size();
-					Iterator<HostPacket> it=hspktlist.iterator();
+					Iterator<NetworkPacket> it=hspktlist.iterator();
 					while(it.hasNext()){
-						HostPacket hspkt=it.next();
+						NetworkPacket hspkt=it.next();
 						//hspkt.recieverhostid=tosend;
 						//hs.packetrecieved.add(hspkt);
 						this.send(this.getId(),hspkt.pkt.data/avband,CloudSimTags.Network_Event_Host, hspkt);

modules/cloudsim/src/main/java/org/cloudbus/cloudsim/network/datacenter/HostPacket.java

 package org.cloudbus.cloudsim.network.datacenter;
 
-public class HostPacket {
-	public HostPacket(int id, NetPacket pkt2, int vmid, int cloudletid) {
-		// TODO Auto-generated constructor stub
-		this.pkt=pkt2;
-		this.sendervmid=vmid;
-		this.cloudletid=cloudletid;
-		this.senderhostid=id;
-		this.stime=pkt.sendtime;
-		this.recievervmid=pkt2.reciever;
+/**
+ * HostPacket represents the packet that travels through the virtual network with a Host. 
+ * It contains information about cloudlets  which are communicating
+ * 
+ * Please refer to following publication for more details:
+ * 
+ * Saurabh Kumar Garg and Rajkumar Buyya, NetworkCloudSim: Modelling Parallel
+ * Applications in Cloud Simulations, Proceedings of the 4th IEEE/ACM
+ * International Conference on Utility and Cloud Computing (UCC 2011, IEEE CS
+ * Press, USA), Melbourne, Australia, December 5-7, 2011.
+ *
+ * 
+ * @author Saurabh Kumar Garg
+ * @since CloudSim Toolkit 1.0
+ */
 
+public class HostPacket {
+	public HostPacket(int sender, int reciever, double data, double sendtime,
+			double recievetime, int vsnd, int vrvd) {
+		super();
+		this.sender = sender;
+		this.reciever = reciever;
+		this.data = data;
+		this.sendtime = sendtime;
+		this.recievetime = recievetime;
+		this.virtualrecvid = vrvd;
+		this.virtualsendid = vsnd;
 	}
-	NetPacket pkt;
-    int senderhostid;
-    int recieverhostid;
-    int sendervmid;
-    int recievervmid;
-    int cloudletid;
-    double stime;//time when sent
-    double rtime;//time when received
+
+	int sender;
+	int virtualrecvid;
+	int virtualsendid;
+	int reciever;
+	double data;
+	double sendtime;
+	double recievetime;
 }

modules/cloudsim/src/main/java/org/cloudbus/cloudsim/network/datacenter/NetPacket.java

-package org.cloudbus.cloudsim.network.datacenter;
-
-public class NetPacket {
-     public NetPacket(int sender, int reciever, double data, double sendtime,
-			double recievetime,int vsnd,int vrvd) {
-		super();
-		this.sender = sender;
-		this.reciever = reciever;
-		this.data = data;
-		this.sendtime = sendtime;
-		this.recievetime = recievetime;
-		this.virtualrecvid=vrvd;
-		this.virtualsendid=vsnd;
-	}
-	int sender;
-	int virtualrecvid;
-	int virtualsendid;
-     int reciever;
-     double data;
-     double sendtime;
-     double recievetime;
-}

modules/cloudsim/src/main/java/org/cloudbus/cloudsim/network/datacenter/NetworkCloudlet.java

 package org.cloudbus.cloudsim.network.datacenter;
 
-
 import java.util.ArrayList;
 import java.util.Map;
 
 import org.cloudbus.cloudsim.Cloudlet;
 import org.cloudbus.cloudsim.UtilizationModel;
-
-
-public class NetworkCloudlet extends Cloudlet implements Comparable{
+/**
+ * NetworkCloudlet class extends Cloudlet to support simulation of complex applications. 
+ * Each such network Cloudlet represents a task of the application. Each task consists of several
+ * stages. 
+ * 
+ * Please refer to following publication for more details:
+ * 
+ * Saurabh Kumar Garg and Rajkumar Buyya, NetworkCloudSim: Modelling Parallel
+ * Applications in Cloud Simulations, Proceedings of the 4th IEEE/ACM
+ * International Conference on Utility and Cloud Computing (UCC 2011, IEEE CS
+ * Press, USA), Melbourne, Australia, December 5-7, 2011.
+ *
+ * 
+ * @author Saurabh Kumar Garg
+ * @since CloudSim Toolkit 1.0
+ */
+public class NetworkCloudlet extends Cloudlet implements Comparable {
 
 	long memory;
 
-	public NetworkCloudlet(int cloudletId, long cloudletLength,
-			int pesNumber, long cloudletFileSize, long cloudletOutputSize, long memory,
+	public NetworkCloudlet(int cloudletId, long cloudletLength, int pesNumber,
+			long cloudletFileSize, long cloudletOutputSize, long memory,
 			UtilizationModel utilizationModelCpu,
 			UtilizationModel utilizationModelRam,
 			UtilizationModel utilizationModelBw) {
@@ -21,41 +34,36 @@ public class NetworkCloudlet extends Cloudlet implements Comparable{
 				cloudletOutputSize, utilizationModelCpu, utilizationModelRam,
 				utilizationModelBw);
 		// TODO Auto-generated constructor stub
-		currStagenum=-1;
-		this.memory=memory;
-		stages=new ArrayList<TaskStage>();
+		currStagenum = -1;
+		this.memory = memory;
+		stages = new ArrayList<TaskStage>();
 	}
-	public double submittime;
-	public double finishtime;
-	public double exetime;
-    public double numStage;
-	public int currStagenum;
+
+	public double submittime; //time when cloudlet will be submitted
+	public double finishtime; //time when cloudlet finish execution
+	public double exetime; //execution time for cloudlet
+	public double numStage;//number of stages in cloudlet
+	public int currStagenum; //current stage of cloudlet execution
 	public double timetostartStage;
-	public double timespentInStage;
-	public Map<Double, NetPacket> timeCommunicate;
+	public double timespentInStage; //how much time spent in particular stage
+	public Map<Double, HostPacket> timeCommunicate;
 
-	public ArrayList<TaskStage> stages;
+	public ArrayList<TaskStage> stages; //all stages which cloudlet execution consists of. 
 
 	public double starttime;
 
-
-
 	@Override
 	public int compareTo(Object arg0) {
 		// TODO Auto-generated method stub
-		NetworkCloudlet s1=(NetworkCloudlet)arg0;
-		int alpha=0;
-		
+		NetworkCloudlet s1 = (NetworkCloudlet) arg0;
+		int alpha = 0;
 
 		return 0;
 	}
 
-
-
 	public double getSubmittime() {
 		// TODO Auto-generated method stub
 		return submittime;
 	};
 
-    
 }

modules/cloudsim/src/main/java/org/cloudbus/cloudsim/network/datacenter/Constants.java → modules/cloudsim/src/main/java/org/cloudbus/cloudsim/network/datacenter/NetworkConstants.java

@@ -4,25 +4,29 @@ import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 
-public class Constants {
+public class NetworkConstants {
 
-public static final int FFT = 0;
 
-public static int roundrobinRack=0;
 public static int maxhostVM=2;
 public static int HOST_PEs=8;
 
 public static double maxMemperVM=1024*1024;//kb
 
-public static final int BIN_NODE_TIME=10;
+
 
 public static int currentCloudletId=0;
 public static int currentAppId=0;
 
+
+//stage type
 public static final int EXECUTION=0;
 public static final int WAIT_SEND=1;
 public static final int WAIT_RECV=2;
 public static final int FINISH=-2;
+
+
+
+//number of switches at each level
 public static final int ROOT_LEVEL=0;
 public static final int Agg_LEVEL=1;
 public static final int EDGE_LEVEL=2;
@@ -30,17 +34,8 @@ public static final int EDGE_LEVEL=2;
 public static final int PES_NUMBER=4;
 public static final int FILE_SIZE=300;
 public static final int OUTPUT_SIZE=300;
-public static  int REQUESTS_PER_SECOND=200;
-public static final int COMMUNICATION_LENGTH=1;
-
-public static  int Requestspersecond = 2;
-public static  int REQUEST_CLASSES=10; 
-public static  double LOW_ACCURACY_RATE=0.2;
-public static  double MEDIUM_ACCURACY_RATE=.3;
-public static  double HIGH_ACCURACY_RATE=0.9;
-
-public static boolean schedulerOverlap=true;
 
+public static final int COMMUNICATION_LENGTH=1;
 
 public static  boolean BASE = true;
 
@@ -62,7 +57,7 @@ public static double RootSwitchPort=1;//number of Agg
 public static double seed=199;
 
 public static boolean logflag=false;
-public static Map<Integer,Map<Integer,Boolean>> Cache=new HashMap<Integer,Map<Integer,Boolean>>();
+
 
 public static int iteration=10;
 public static int nexttime=1000;

modules/cloudsim/src/main/java/org/cloudbus/cloudsim/network/datacenter/NetworkPacket.java

+package org.cloudbus.cloudsim.network.datacenter;
+
+/**
+ * NewtorkPacket represents the packet which travel from one server to another. 
+ * Each packet contains ids of the sender VM and receiver VM, 
+ * time at which it is send and received, type and virtual ids of tasks, which are communicating.
+ * 
+ * Please refer to following publication for more details:
+ * 
+ * Saurabh Kumar Garg and Rajkumar Buyya, NetworkCloudSim: Modelling Parallel
+ * Applications in Cloud Simulations, Proceedings of the 4th IEEE/ACM
+ * International Conference on Utility and Cloud Computing (UCC 2011, IEEE CS
+ * Press, USA), Melbourne, Australia, December 5-7, 2011.
+ *
+ * 
+ * @author Saurabh Kumar Garg
+ * @since CloudSim Toolkit 1.0
+ */
+
+public class NetworkPacket {
+	public NetworkPacket(int id, HostPacket pkt2, int vmid, int cloudletid) {
+		// TODO Auto-generated constructor stub
+		this.pkt = pkt2;
+		this.sendervmid = vmid;
+		this.cloudletid = cloudletid;
+		this.senderhostid = id;
+		this.stime = pkt.sendtime;
+		this.recievervmid = pkt2.reciever;
+
+	}
+
+	HostPacket pkt;
+	int senderhostid;
+	int recieverhostid;
+	int sendervmid;
+	int recievervmid;
+	int cloudletid;
+	double stime;// time when sent
+	double rtime;// time when received
+}

modules/cloudsim/src/main/java/org/cloudbus/cloudsim/network/datacenter/NetworkVm.java

@@ -6,29 +6,49 @@ import java.util.List;
 import org.cloudbus.cloudsim.CloudletScheduler;
 import org.cloudbus.cloudsim.Vm;
 
+/**
+ * NetworkVm class extends Vm to support simulation of networked datacenters. 
+ * It executes actions related to management of packets (send and receive).
+ * 
+ * Please refer to following publication for more details:
+ * 
+ * Saurabh Kumar Garg and Rajkumar Buyya, NetworkCloudSim: Modelling Parallel
+ * Applications in Cloud Simulations, Proceedings of the 4th IEEE/ACM
+ * International Conference on Utility and Cloud Computing (UCC 2011, IEEE CS
+ * Press, USA), Melbourne, Australia, December 5-7, 2011.
+ *
+ * 
+ * @author Saurabh Kumar Garg
+ * @since CloudSim Toolkit 1.0
+ */
 
-public class NetworkVm extends Vm implements Comparable{
+public class NetworkVm extends Vm implements Comparable {
 
 	public NetworkVm(int id, int userId, double mips, int pesNumber, int ram,
 			long bw, long size, String vmm, CloudletScheduler cloudletScheduler) {
-		super(id, userId, mips, pesNumber, ram, bw, size, vmm, cloudletScheduler);
+		super(id, userId, mips, pesNumber, ram, bw, size, vmm,
+				cloudletScheduler);
 		// TODO Auto-generated constructor stub
-		cloudletlist=new ArrayList<NetworkCloudlet>();
+		cloudletlist = new ArrayList<NetworkCloudlet>();
 	}
+
 	public ArrayList<NetworkCloudlet> cloudletlist;
 	int type;
-	public ArrayList<NetPacket> recvPktlist;
+	public ArrayList<HostPacket> recvPktlist;
 	public double memory;
-	public boolean flagfree;//if true it is free
+	public boolean flagfree;// if true it is free
 	public double finishtime;
-	public boolean isFree()
-	{
+
+	public boolean isFree() {
 		return flagfree;
 	}
+
 	public int compareTo(Object arg0) {
-		NetworkVm hs=(NetworkVm)arg0;
-		if(hs.finishtime>this.finishtime) return -1;
-		if(hs.finishtime<this.finishtime) return 1;
+		NetworkVm hs = (NetworkVm) arg0;
+		if (hs.finishtime > this.finishtime)
+			return -1;
+		if (hs.finishtime < this.finishtime)
+			return 1;
 		return 0;
 	}
 }

modules/cloudsim/src/main/java/org/cloudbus/cloudsim/network/datacenter/VmHPCAllocationPolicySimple.java → modules/cloudsim/src/main/java/org/cloudbus/cloudsim/network/datacenter/NetworkVmAllocationPolicy.java

@@ -21,15 +21,16 @@ import org.cloudbus.cloudsim.core.CloudSim;
 import org.cloudbus.cloudsim.power.PowerHost;
 
 /**
- * VmAllocationPolicySimple is an VmAllocationPolicy that
+ * NetworkVmAllocationPolicy is an VmAllocationPolicy that
  * chooses, as the host for a VM, the host with
  * less PEs in use.
  *
  * @author		Rodrigo N. Calheiros
  * @author		Anton Beloglazov
+ * @author      Saurabh Kumar Garg
  * @since		CloudSim Toolkit 1.0
  */
-public class VmHPCAllocationPolicySimple extends VmAllocationPolicy {
+public class NetworkVmAllocationPolicy extends VmAllocationPolicy {
 
 	/** The vm table. */
 	private Map<String, Host> vmTable;
@@ -48,7 +49,7 @@ public class VmHPCAllocationPolicySimple extends VmAllocationPolicy {
 	 * @pre $none
 	 * @post $none
 	 */
-	public VmHPCAllocationPolicySimple(List<? extends Host> list) {
+	public NetworkVmAllocationPolicy(List<? extends Host> list) {
 		super(list);
 
 		setFreePes(new ArrayList<Integer>());
@@ -74,34 +75,51 @@ public class VmHPCAllocationPolicySimple extends VmAllocationPolicy {
 	@Override
 
 		public boolean allocateHostForVm(Vm vm) {
-			NetworkHost allocatedHost = findHostForVm(vm);
-			if (allocatedHost != null && allocatedHost.vmCreate(vm)) { //if vm has been succesfully created in the host
-				getVmTable().put(vm.getUid(), allocatedHost);
-				if (!Log.isDisabled()) {
-					Log.print(String.format("%.2f: VM #" + vm.getId() + " has been allocated to the host #" + allocatedHost.getId() + "\n", CloudSim.clock()));
+				
+			int requiredPes = vm.getPesNumber();
+			boolean result = false;
+			int tries = 0;
+			List<Integer> freePesTmp = new ArrayList<Integer>();
+			for (Integer freePes : getFreePes()) {
+				freePesTmp.add(freePes);
 			}
-				return true;
+
+			if (!getVmTable().containsKey(vm.getUid())) { //if this vm was not created
+				do {//we still trying until we find a host or until we try all of them
+					int moreFree = Integer.MIN_VALUE;
+					int idx = -1;
+
+					//we want the host with less pes in use
+					for (int i=0; i < freePesTmp.size(); i++) {
+						if (freePesTmp.get(i) > moreFree) {
+							moreFree = freePesTmp.get(i);
+							idx = i;
 						}
-			return false;
 					}
 
+					NetworkHost host =this.<NetworkHost>getHostList().get(idx);
+					result = host.vmCreate(vm);
 
-	public NetworkHost findHostForVm(Vm vm) {
-		double minPower = Double.MAX_VALUE;
-		NetworkHost allocatedHost = null;
-
-		for (NetworkHost host : this.<NetworkHost>getHostList()) {
-			if (host.isSuitableForVm(vm)) {
-				double maxUtilization = getMaxUtilizationAfterAllocation(host, vm);
-				if ((!vm.isRecentlyCreated() && maxUtilization > 1) || (vm.isRecentlyCreated() && maxUtilization > 1.0)) {
-					continue;
-				}
-				allocatedHost = host;
+					if (result) { //if vm were succesfully created in the host
+						//Log.printLine("VmAllocationPolicy: VM #"+vm.getVmId()+ "Chosen host: #"+host.getMachineID()+" idx:"+idx);
+						getVmTable().put(vm.getUid(), host);
+						getUsedPes().put(vm.getUid(), requiredPes);
+						getFreePes().set(idx, getFreePes().get(idx) - requiredPes);
+						result = true;
+						break;
+					} else {
+						freePesTmp.set(idx, Integer.MIN_VALUE);
 					}
+					tries++;
+				} while (!result && tries < getFreePes().size());
+
 			}
 
-		return allocatedHost;
+			return result;
 		}
+         
+
+	
 	protected double getMaxUtilizationAfterAllocation(NetworkHost host, Vm vm) {
 		List<Double> allocatedMipsForVm = null;
 		NetworkHost allocatedHost = (NetworkHost) vm.getHost();
@@ -248,6 +266,12 @@ public class VmHPCAllocationPolicySimple extends VmAllocationPolicy {
 	public boolean allocateHostForVm(Vm vm, Host host) {
 		if (host.vmCreate(vm)) { //if vm has been succesfully created in the host
 			getVmTable().put(vm.getUid(), host);
+			
+			 int requiredPes = vm.getPesNumber();
+		     int idx = getHostList().indexOf(host);
+		     getUsedPes().put(vm.getUid(), requiredPes);
+		     getFreePes().set(idx, getFreePes().get(idx) - requiredPes);
+			
 			Log.formatLine("%.2f: VM #" + vm.getId() + " has been allocated to the host #" + host.getId(), CloudSim.clock());
 			return true;
 		}

modules/cloudsim/src/main/java/org/cloudbus/cloudsim/network/datacenter/RootSwitch.java

@@ -9,60 +9,92 @@ import org.cloudbus.cloudsim.core.CloudSimTags;
 import org.cloudbus.cloudsim.core.SimEvent;
 import org.cloudbus.cloudsim.core.predicates.PredicateType;
 
-public class RootSwitch extends Switch{
+/**
+ * This class allows to simulate Root switch which connects Datacenter to
+ * external network. It interacts with other switches in order to exchange
+ * packets. Please refer to following publication for more details:
+ * 
+ * Saurabh Kumar Garg and Rajkumar Buyya, NetworkCloudSim: Modelling Parallel
+ * Applications in Cloud Simulations, Proceedings of the 4th IEEE/ACM
+ * International Conference on Utility and Cloud Computing (UCC 2011, IEEE CS
+ * Press, USA), Melbourne, Australia, December 5-7, 2011.
+ * 
+ * @author Saurabh Kumar Garg
+ * @since CloudSim Toolkit 3.0
+ * 
+ */
 
+public class RootSwitch extends Switch {
+
+	/**
+	 * Constructor for Root Switch We have to specify switches that are
+	 * connected to its downlink ports, and corresponding bandwidths
+	 * 
+	 * @param name
+	 *            Name of the switch
+	 * @param level
+	 *            At which level switch is with respect to hosts.
+	 * @param dc
+	 *            Pointer to Datacenter
+	 */
 	public RootSwitch(String name, int level, NetworkDatacenter dc) {
 		super(name, level, dc);
-		downlinkswitchpktlist=new HashMap<Integer,List<HostPacket>>();
-		downlinkswitches=new ArrayList<Switch>();
+		downlinkswitchpktlist = new HashMap<Integer, List<NetworkPacket>>();
+		downlinkswitches = new ArrayList<Switch>();
 
-		downlinkbandwidth=Constants.BandWidthAggRoot;
-		latency=Constants.SwitchingDelayRoot;
-		numport=Constants.RootSwitchPort;
+		downlinkbandwidth = NetworkConstants.BandWidthAggRoot;
+		latency = NetworkConstants.SwitchingDelayRoot;
+		numport = NetworkConstants.RootSwitchPort;
 
 		// TODO Auto-generated constructor stub
 	}
 
+	/**
+	 * Send Packet to switch connected through a downlink port
+	 * 
+	 * @param ev
+	 *            Event/packet to process
+	 */
+	@Override
+	protected void processpacket_up(SimEvent ev) {
 
-	private void processpacket_up(SimEvent ev) {
-		// TODO Auto-generated method stub
-		//packet coming from down level router.
-		//has to send up
-		//check which switch to forward to 
-		//add packet in the switch list
+		// packet coming from down level router.
+		// has to send up
+		// check which switch to forward to
+		// add packet in the switch list
 		//
-		//int src=ev.getSource();
-		HostPacket hspkt=(HostPacket) ev.getData();
-	    int recvVMid=hspkt.pkt.reciever;
-	    CloudSim.cancelAll(getId(), new PredicateType(CloudSimTags.Network_Event_send));
-		schedule(getId(),this.switching_delay, CloudSimTags.Network_Event_send);
 		
-	    if(this.level==Constants.ROOT_LEVEL)
-	    {
-	    	//get id of edge router
-	    	int edgeswitchid=dc.VmToSwitchid.get(recvVMid);
-	    	//search which aggregate switch has it
-	    	int aggSwtichid=-1;;
-	    	for(Switch sw:this.downlinkswitches)
-	    	{
-        	    for(Switch edge:sw.downlinkswitches)
-        	    {
-        	    	if(edge.getId()==edgeswitchid){
-        	    		aggSwtichid=sw.getId();
+		NetworkPacket hspkt = (NetworkPacket) ev.getData();
+		int recvVMid = hspkt.pkt.reciever;
+		CloudSim.cancelAll(getId(), new PredicateType(
+				CloudSimTags.Network_Event_send));
+		schedule(getId(), this.switching_delay, CloudSimTags.Network_Event_send);
+
+		if (this.level == NetworkConstants.ROOT_LEVEL) {
+			// get id of edge router
+			int edgeswitchid = dc.VmToSwitchid.get(recvVMid);
+			// search which aggregate switch has it
+			int aggSwtichid = -1;
+			;
+			for (Switch sw : this.downlinkswitches) {
+				for (Switch edge : sw.downlinkswitches) {
+					if (edge.getId() == edgeswitchid) {
+						aggSwtichid = sw.getId();
 						break;
 					}
 				}
 			}
-	    	if(aggSwtichid<0) System.out.println(" No destination for this packet");
-	    	else{
-		    	List<HostPacket> pktlist=this.downlinkswitchpktlist.get(aggSwtichid);
-		    	if(pktlist==null){
-		    		pktlist=new ArrayList<HostPacket>();
+			if (aggSwtichid < 0)
+				System.out.println(" No destination for this packet");
+			else {
+				List<NetworkPacket> pktlist = this.downlinkswitchpktlist
+						.get(aggSwtichid);
+				if (pktlist == null) {
+					pktlist = new ArrayList<NetworkPacket>();
 					this.downlinkswitchpktlist.put(aggSwtichid, pktlist);
 				}
 				pktlist.add(hspkt);
 			}
 		}
 	}
-
 }

modules/cloudsim/src/main/java/org/cloudbus/cloudsim/network/datacenter/TaskStage.java

 package org.cloudbus.cloudsim.network.datacenter;
 
+/**
+ * Taskstage represents various stages a networkCloudlet can have during execution. 
+ * Four stage types which are possible-> EXECUTION=0; WAIT_SEND=1; WAIT_RECV=2; FINISH=-2; 
+ * Check NeworkConstants.java file for that. 
+ * 
+ * Please refer to following publication for more details:
+ * 
+ * Saurabh Kumar Garg and Rajkumar Buyya, NetworkCloudSim: Modelling Parallel
+ * Applications in Cloud Simulations, Proceedings of the 4th IEEE/ACM
+ * International Conference on Utility and Cloud Computing (UCC 2011, IEEE CS
+ * Press, USA), Melbourne, Australia, December 5-7, 2011.
+ *
+ * 
+ * @author Saurabh Kumar Garg
+ * @since CloudSim Toolkit 1.0
+ */
+
 public class TaskStage {
-	public TaskStage(int type, double data, double time, double stageid,long memory,
-			int peer,int vpeer) {
+	public TaskStage(int type, double data, double time, double stageid,
+			long memory, int peer, int vpeer) {
 		super();
 		this.type = type;
 		this.data = data;
@@ -10,14 +27,15 @@ public class TaskStage {
 		this.stageid = stageid;
 		this.memory = memory;
 		this.peer = peer;
-		this.vpeer=vpeer;
+		this.vpeer = vpeer;
 	}
+
 	int vpeer;
-	int type;//execution, recv, send,
-	double data;//data generated or send or recv
-	double time;//execution time for this stage
+	int type;// execution, recv, send,
+	double data;// data generated or send or recv
+	double time;// execution time for this stage
 	double stageid;
 	long memory;
-	int peer;//from whom data needed to be recieved or send
+	int peer;// from whom data needed to be recieved or send
 
 }

modules/cloudsim/src/main/java/org/cloudbus/cloudsim/network/datacenter/WorkflowApp.java

 package org.cloudbus.cloudsim.network.datacenter;
 
+/**
+ * WorkflowApp is an example of AppCloudlet having three communicating tasks. 
+ * Task A and B sends the data (packet) while Task C receives them
+ * 
+ * Please refer to following publication for more details:
+ * 
+ * Saurabh Kumar Garg and Rajkumar Buyya, NetworkCloudSim: Modelling Parallel
+ * Applications in Cloud Simulations, Proceedings of the 4th IEEE/ACM
+ * International Conference on Utility and Cloud Computing (UCC 2011, IEEE CS
+ * Press, USA), Melbourne, Australia, December 5-7, 2011.
+ *
+ * 
+ * @author Saurabh Kumar Garg
+ * @since CloudSim Toolkit 1.0
+ */
+
 import java.util.List;
 
 import org.cloudbus.cloudsim.UtilizationModel;
@@ -16,30 +32,30 @@ public class WorkflowApp extends AppCloudlet{
 		this.numbervm=3;
 	}
 	public void createCloudletList(List<Integer> vmIdList){
-		long fileSize = Constants.FILE_SIZE;
-		long outputSize = Constants.OUTPUT_SIZE;
-		int pesNumber = Constants.PES_NUMBER;
+		long fileSize = NetworkConstants.FILE_SIZE;
+		long outputSize = NetworkConstants.OUTPUT_SIZE;
+		int pesNumber = NetworkConstants.PES_NUMBER;
 		int memory=100;
 		UtilizationModel utilizationModel = new UtilizationModelFull();
 		int i=0;
 		//Task A
-		NetworkCloudlet cl = new NetworkCloudlet(Constants.currentCloudletId, 0, 1, fileSize, outputSize, memory, utilizationModel, utilizationModel, utilizationModel);
+		NetworkCloudlet cl = new NetworkCloudlet(NetworkConstants.currentCloudletId, 0, 1, fileSize, outputSize, memory, utilizationModel, utilizationModel, utilizationModel);
 	    cl.numStage=2;
-	    Constants.currentCloudletId++;
+	    NetworkConstants.currentCloudletId++;
   		cl.setUserId(userId);
   		cl.submittime=CloudSim.clock();
   		cl.currStagenum=-1;
   		cl.setVmId(vmIdList.get(i));
   		
   		//first stage: big computation
-  		cl.stages.add(new TaskStage(Constants.EXECUTION, 0, 1000*0.8, 0, memory, vmIdList.get(0),cl.getCloudletId()));
-  		cl.stages.add(new TaskStage(Constants.WAIT_SEND, 1000, 0, 1, memory, vmIdList.get(2),cl.getCloudletId()+2));
+  		cl.stages.add(new TaskStage(NetworkConstants.EXECUTION, 0, 1000*0.8, 0, memory, vmIdList.get(0),cl.getCloudletId()));
+  		cl.stages.add(new TaskStage(NetworkConstants.WAIT_SEND, 1000, 0, 1, memory, vmIdList.get(2),cl.getCloudletId()+2));
   		clist.add(cl);
   		i++;
   		//Task B
-  		NetworkCloudlet clb = new NetworkCloudlet(Constants.currentCloudletId, 0, 1, fileSize, outputSize, memory, utilizationModel, utilizationModel, utilizationModel);
+  		NetworkCloudlet clb = new NetworkCloudlet(NetworkConstants.currentCloudletId, 0, 1, fileSize, outputSize, memory, utilizationModel, utilizationModel, utilizationModel);
 	    clb.numStage=2;
-	    Constants.currentCloudletId++;
+	    NetworkConstants.currentCloudletId++;
   		clb.setUserId(userId);
   		clb.submittime=CloudSim.clock();
   		clb.currStagenum=-1;
@@ -47,24 +63,24 @@ public class WorkflowApp extends AppCloudlet{
   	
   		//first stage: big computation
   		
-  		clb.stages.add(new TaskStage(Constants.EXECUTION, 0, 1000*0.8, 0, memory, vmIdList.get(1),clb.getCloudletId()));
-  		clb.stages.add(new TaskStage(Constants.WAIT_SEND, 1000, 0, 1, memory, vmIdList.get(2),clb.getCloudletId()+1));
+  		clb.stages.add(new TaskStage(NetworkConstants.EXECUTION, 0, 1000*0.8, 0, memory, vmIdList.get(1),clb.getCloudletId()));
+  		clb.stages.add(new TaskStage(NetworkConstants.WAIT_SEND, 1000, 0, 1, memory, vmIdList.get(2),clb.getCloudletId()+1));
   		clist.add(clb);
   		i++;
   		
   		//Task C
-  		NetworkCloudlet clc = new NetworkCloudlet(Constants.currentCloudletId, 0, 1, fileSize, outputSize, memory, utilizationModel, utilizationModel, utilizationModel);
+  		NetworkCloudlet clc = new NetworkCloudlet(NetworkConstants.currentCloudletId, 0, 1, fileSize, outputSize, memory, utilizationModel, utilizationModel, utilizationModel);
 	    clc.numStage=2;
-	    Constants.currentCloudletId++;
+	    NetworkConstants.currentCloudletId++;
   		clc.setUserId(userId);
   		clc.submittime=CloudSim.clock();
   		clc.currStagenum=-1;
   		clc.setVmId(vmIdList.get(i));
   	
   		//first stage: big computation
-  		clc.stages.add(new TaskStage(Constants.WAIT_RECV, 1000, 0, 0, memory, vmIdList.get(0),cl.getCloudletId()));
-  		clc.stages.add(new TaskStage(Constants.WAIT_RECV, 1000, 0, 1, memory, vmIdList.get(1),cl.getCloudletId()+1));
-  		clc.stages.add(new TaskStage(Constants.EXECUTION, 0, 1000*0.8, 1, memory, vmIdList.get(0),clc.getCloudletId()));
+  		clc.stages.add(new TaskStage(NetworkConstants.WAIT_RECV, 1000, 0, 0, memory, vmIdList.get(0),cl.getCloudletId()));
+  		clc.stages.add(new TaskStage(NetworkConstants.WAIT_RECV, 1000, 0, 1, memory, vmIdList.get(1),cl.getCloudletId()+1));
+  		clc.stages.add(new TaskStage(NetworkConstants.EXECUTION, 0, 1000*0.8, 1, memory, vmIdList.get(0),clc.getCloudletId()));
   		
   		clist.add(clc);