All Threads in Blocked State ( Program Hangs )

[thehellmaker]

Hi All,

I have a basic data structure FileQueue which contains a linked list and a hash map. I am inserting data into to it as a single thread .. but multiple threads access popFile and processed methods which are synchronized. I have an issue with this .. and at sometime all threads go into blocked state and the program hangs . I am not able to figure out why could some1 help me out.

import java.util.Collections;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.HashMap;
import java.util.Vector;
import java.util.Map.Entry;


public class FileQueue {
        private LinkedList<Integer> nextFile;
        private HashMap<Integer,LinkedList<String>> terminalQueue;
        int fileCount;

        FileQueue(){
                fileCount = 0;
                nextFile = new LinkedList<Integer>();
                terminalQueue = new HashMap<Integer,LinkedList<String>>();
        }

        FileQueue(Vector<String> files){
                this();
                Collections.sort(files);
                Iterator<String> it = files.iterator();
                while(it.hasNext())
                        this.pushFile(it.next());
        }

        public boolean hasFiles(){
                return (fileCount>0)?true:false;
        }

               
        public void pushFile(String filePath){
                int lastSlashIndex = filePath.lastIndexOf("/");
                String fileName = filePath.substring(lastSlashIndex+1);
                int terminalId = Integer.parseInt(fileName.substring(19,fileName.lastIndexOf("_")).trim());
                LinkedList file = terminalQueue.get(terminalId);
                if(file==null) {
                        synchronized(this){
                                nextFile.addLast(terminalId);
                                LinkedList<String> newList = new LinkedList<String>();
                                newList.addLast(filePath);
                                terminalQueue.put(terminalId,newList );
                                fileCount++;
                        }
                }
                else {
                        synchronized(this){
                                terminalQueue.get(terminalId).addLast(filePath);
                                fileCount++;
                        }
                }
        }

        public synchronized void processed(int terminalId)throws InterruptedException{
                if(terminalQueue.containsKey(terminalId))
                        nextFile.addLast(terminalId);
                notify();

        }


          public synchronized String popFile() throws InterruptedException{
                        if(nextFile.size()==0) wait();
                        int terminalId = nextFile.poll().intValue();
                        LinkedList<String> queueFileNames = terminalQueue.get(terminalId);
                        fileCount--;
                        String retValue = queueFileNames.poll();
                        if(queueFileNames.size()==0)
                                terminalQueue.remove(terminalId);
                        return retValue;

        }

In the main program the code is being called this way

public void run(){
     while(fileQueue.hasFiles()){
                  String retname = fileQueue.popFile();
                  // Process file with name stored in retname 
    }
}

Thanks in advance

[Hibernate]

More code?