RMI

Client

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+in Client: id : 3| type:  0| time: 1333077450548| startTime: 1333077445931
+in Client: id : 6| type:  1| time: 1333077450552| startTime: 1333077445931
+in Client: id : 2| type:  0| time: 1333077450555| startTime: 1333077445931
+in Client: id : 5| type:  1| time: 1333077450558| startTime: 1333077445931
+in Client: id : 4| type:  0| time: 1333077450576| startTime: 1333077445931
+in Client: id : 1| type:  0| time: 1333077450605| startTime: 1333077445931
+in Client: id : 8| type:  1| time: 1333077451778| startTime: 1333077445931
+in Clientjava.rmi.UnmarshalException: Error unmarshaling return header; nested exception is: 
+	java.io.EOFException
+in Client: id : 6| type:  1| time: 1333077948735| startTime: 1333077944072
+in Client: id : 3| type:  0| time: 1333077948747| startTime: 1333077944072
+in Client: id : 5| type:  1| time: 1333077948755| startTime: 1333077944072
+in Client: id : 7| type:  1| time: 1333077948768| startTime: 1333077944072
+in Client: id : 4| type:  0| time: 1333077948769| startTime: 1333077944072
+in Client: id : 1| type:  0| time: 1333077948787| startTime: 1333077944072
+in Client: id : 8| type:  1| time: 1333077950078| startTime: 1333077944072
+in Clientjava.rmi.UnmarshalException: Error unmarshaling return header; nested exception is: 
+	java.io.EOFException

Hello.java

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+import java.rmi.*;
+import java.util.*;
+import java.rmi.server.*;
+import java.rmi.registry.*;
+import java.rmi.registry.LocateRegistry;
+import java.io.*;
+class Pair{
+	public int id;
+	public int priority;
+	Pair(int id, int pr){
+		this.id = id;
+		this.priority = pr;
+	}
+}
+public class Hello extends UnicastRemoteObject implements HelloInterface {
+	public synchronized static void writeToFile(String s){
+		// Stream to write file
+		FileOutputStream fout;
+		try{
+			String fileName = "crew.log";
+			fout = new FileOutputStream (fileName,true);
+			new PrintStream(fout).println(s);
+			fout.flush();
+			fout.close();
+		}
+		catch (IOException e){
+			System.err.println ("Unable to write to file");
+			System.exit(-1);
+		}
+	}
+
+
+	public void shutDown() throws RemoteException {
+		try{
+			//Registry registry = LocateRegistry.getRegistry(Registry.REGISTRY_PORT);
+			//Registry registry = LocateRegistry.getRegistry(2222);
+			//registry.unbind("//thunder.cise.ufl.edu/kabhishe");
+			//registry.unbind(this.serviceName);
+			//UnicastRemoteObject.unexportObject(this, true);
+			System.exit(0);
+		}catch(Exception e){
+			//writeToFile("cant unbind" + e.getMessage());
+		}
+	}
+
+	private static int ServiceSequence, ObjectValue ;
+	private int numberOfAccesses, numberOfReaders, numberOfWriters;
+	private String message;
+	private long startTime;
+	public static Boolean isCriticalSectionEmpty = true;
+	public static ArrayList<Pair> priorityArrReaders = new ArrayList<Pair>();
+	public static ArrayList<Integer> priorityArrWriters = new ArrayList<Integer>();
+	public Hello (long sTime, int numAccesses, int port, int numReaders, int numWriters) throws RemoteException {
+		//	writeToFile("" + sTime);
+		startTime = sTime;
+		numberOfAccesses = numAccesses;
+		ServiceSequence = 1;
+		ObjectValue = -1;
+		numberOfReaders = numReaders;
+		numberOfWriters = numWriters;
+		try{ 
+		//	Registry registry = LocateRegistry.createRegistry(port);
+			//registry.rebind("//thunder.cise.ufl.edu/kabhishe", this);
+		}catch(Exception e){
+			writeToFile("exception while binding " + e);
+		}
+
+	}
+	public String say(int id, int type, int sleepTime, int opTime) throws RemoteException {
+		for(int num = 1; num <= numberOfAccesses ; num++)
+		{
+			synchronized(this){
+			//	writeToFile("My id : " + id + "type: " + type + " " + System.currentTimeMillis() + "starttime: " + startTime);
+			}
+
+			try{
+				Thread.sleep(sleepTime);
+			}
+			catch(Exception e){
+				//writeToFile("in Hello.java: expcetion 1" );
+				System.out.println(e);
+			}
+
+			//writeToFile("checking for cs My id : " + id + "type: " + type);
+
+			Boolean canGetIntoCS = false;
+			//check whether its a reader's request or writer's request: GET its ID in parameter as well
+			//type : 0:reader, 1:writer
+			//if a reader' s request: append it in to priority array
+			synchronized(this){
+				if(type == 0){//reader
+					priorityArrReaders.add(new Pair(id,1));
+				}
+				else //writer
+					priorityArrWriters.add(id);
+			}
+			//writeToFile("checking for cs 2222 My id : " + id + "type: " + type);
+
+			synchronized(this) {
+				while(canGetIntoCS == false){
+					//writeToFile("checking for cs 3333 My id : " + id + "type: " + type);
+					if(type == 0){ //reader
+						//if in 1st 3 in array or no writer in array 
+						if(priorityArrWriters.isEmpty()){
+							canGetIntoCS = true;
+							break;
+						}
+						int pos = -1;
+						for(int i =0;i<priorityArrReaders.size();i++){
+							if(priorityArrReaders.get(i).id == id){
+								pos = i;
+								break;
+							}
+						}
+						if(pos > 2 || pos == -1){
+							try{
+								wait();
+							}
+							catch(Exception e){ } 
+							continue;
+						}
+
+						if(priorityArrReaders.get(0).priority > 3){
+							canGetIntoCS = true;
+							break;
+						}
+						try { 
+							wait();
+						}
+						catch ( Exception e){ } 
+						continue;
+					}
+					else{ //writer
+						if (isCriticalSectionEmpty == false)
+							try{
+								wait();
+								continue;
+							}
+						catch(Exception e){ } 
+
+
+						int pos = priorityArrWriters.indexOf(new Integer(id));
+						if(pos != 0){
+							try{
+								wait();
+								continue;
+							}
+							catch(Exception e){  }
+						}
+
+						if(!priorityArrReaders.isEmpty() && priorityArrReaders.get(0).priority > 3){ 
+							try{
+								wait();
+								continue;
+							}
+							catch(Exception e) { }
+						}
+						else {
+							canGetIntoCS = true;
+							break;
+						}	 
+					}
+				}
+			}
+			//enter into CS and at the end of it notifyAll
+			//if(canGetIntoCS == true)
+			{
+				//writeToFile("entered cs My id : " + id + "type: " + type);
+
+				//whoever goes next into CS:
+				synchronized(this){
+					isCriticalSectionEmpty = false;
+				}
+				String AccessedBy = "invalidValue" ;
+				if(type == 0)
+					AccessedBy = "R" + id;
+				else if(type == 1) {
+					AccessedBy = "W" + id;
+					ObjectValue = id;
+				}
+				else {
+					//writeToFile("in valid vale of nextClientType");
+				}
+				try{
+					long start = System.currentTimeMillis() - startTime;
+					Thread.sleep(opTime);
+					long finish = System.currentTimeMillis() - startTime;
+					synchronized(this){
+						writeToFile(ServiceSequence + "\t" + ObjectValue + "\t" +AccessedBy+ "\t" + start + "-" + finish);
+						++ServiceSequence; 
+					}
+				}
+				catch(Exception e){
+					//writeToFile("in Hello.java: expcetion 1: " + e  );
+					System.out.println(e);
+				}
+
+				//done executing in CS:remove from array 
+				if(type == 0 && !priorityArrReaders.isEmpty()){
+					int removeId = -1;
+					for(int i =0;i<priorityArrReaders.size();i++)
+						if(priorityArrReaders.get(i).id == id){
+							removeId = i;
+							break;
+						}
+					if(removeId != -1){
+						synchronized(this){
+							priorityArrReaders.remove(removeId);
+						}
+					}
+					else
+						System.out.println("ERROR: REMOVE ID  NOT FOUND");
+				}
+				else if(type == 1 && !priorityArrWriters.isEmpty())
+					synchronized(this){
+						priorityArrWriters.remove(0);
+					}
+				synchronized(this){
+					isCriticalSectionEmpty = true;
+					notifyAll();
+					//writeToFile("notified by : " + id + "type: " + type );
+				}
+			}
+		}
+
+		if(numberOfAccesses * (numberOfReaders + numberOfWriters) <= ServiceSequence ){
+			shutDown();
+		}
+		return message;
+	}
+}

HelloInterface.java

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+import java.rmi.*;
+
+public interface HelloInterface extends Remote {
+    public String say(int id,int type, int sleepTime ,int opTime) throws RemoteException;
+}

IamServer

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+in server
+Server is connected and ready for operation.1333077954169

README

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+Java Remote Method Invocation project:(read project 3.pdf)
+
+to Compile and Run:
+==================
+javac -souce 1.6 -target 1.6 *.java
+java Start
+
+
+

Server.java

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+import java.rmi.Naming;
+import java.rmi.registry.*;
+import java.rmi.registry.LocateRegistry;
+import java.rmi.server.*;
+import java.io.*;
+
+public class Server 
+{
+        public static void writeToFile(String s){
+                // Stream to write file
+                FileOutputStream fout;
+                try{
+                        String fileName = "IamServer";
+                        fout = new FileOutputStream (fileName,true);
+                        new PrintStream(fout).println(s);
+                        fout.close();
+                }
+                catch (IOException e){
+                        System.err.println ("Unable to write to file");
+                        System.exit(-1);
+                }
+        }
+
+	public static void main (String[] argv) 
+	{
+		try {
+			long startTime = Long.parseLong(argv[0]);
+			int numberOfAccesses = Integer.parseInt(argv[1]);
+			int port = Integer.parseInt(argv[2]);
+			int numReaders = Integer.parseInt(argv[3]);
+			int numWriters = Integer.parseInt(argv[4]);
+			String server = argv[5];
+
+/*
+			Registry registry = LocateRegistry.createRegistry(port);
+			Runtime.getRuntime().exec("rmiregistry 2222");
+			registry.rebind("//thunder.cise.ufl.edu/kabhishe", new Hello (startTime, numberOfAccesses));
+*/
+			writeToFile("in server");
+			Runtime.getRuntime().exec("rmiregistry " + port);
+			//Naming.rebind ("//thunder.cise.ufl.edu:2222/kabhishe", new Hello (startTime, numberOfAccesses, port, numReaders, numWriters));
+			Naming.rebind ("//" + server+ ":" + port + "/kabhishe", new Hello (startTime, numberOfAccesses, port, numReaders, numWriters));
+			//Hello h = new Hello(startTime, numberOfAccesses, port, numReaders, numWriters);
+			writeToFile ("Server is connected and ready for operation." + System.currentTimeMillis());
+
+
+		} 
+		catch (Exception e) {
+			writeToFile("in server: not connnected"+e);
+		}
+	}
+}