How does Thread scheduling Work

Question

Hi to all out there. I have been deweloping a program that is supposed to create a Sceduling Thread that would have the higest priorety and manage three more threads. The sceduler creates a CircularList class to call and run each of the other three threads.
Unfortunatly there are two errors that I can't trace down. If there is any one out there familiar with OS progming I would apreciate a few comments on the following code:
import java.lang.*;
public class TestScheduler
     public static void main (String args[])
          Thread.currentThread().setPriority(Thread.MAX_PRIORITY); //Sets Sceduler Priorety
          Scheduler CPUScheduler = new Scheduler();
          CPUScheduler.start();
/*creates The three other threads to be managed*/
          Thread t1 = new TestThread();
          t1.start();
          //CPUScheduler.addThread(t1);
          Thread t2 = new TestThread();
          t2.start();
          Thread t3 = new TestThread();
          t3.start();
class Scheduler extends Thread
     public Scheduler(){
          timeSlice = DEFAULT_TIME_SLICE;
//creates the queues for threads
          queue = new CircularLi();
     public Scheduler(int quantum){
               timeSlice = quantum;
               queue = new CircularList();
     public void addThread(Thread t){
               t.setPriority(2);
//Error 1 here. Can't recognize the .addItem() method?
               queue.addItem(t);
     private void schedulerSleep(){
               try{
                    Thread.sleep(timeSlice);
               }catch(InterruptedException e){};
     public void run(){
          Thread current;
          this.setPriority(6);
          while (true){
//Error 2 is here. It sais it can't find a method .getNext()?
               current = (Thread)queue.getNext();
               if ((current != null) && (current.isAlive())){
                    current.setPriority(4);
                    schedulerSleep();
                    current.setPriority(2);
     private CircularList queue;
     private int DEFAULT_TIME_SLICE = 100;
     private int timeSlice;
class TestThread extends Thread
     public void run()
          Total = 0;
          Total++;
          System.out.println("This ran for: " Total " times.");
     public int Total;
class CircularList extends Scheduler
     public void run ()
          Thread.currentThread().setPriority(5);
          while(true)
               if(Total < 5)
                    new TestThread().start();
                    Total++;
               else
                    Thread.currentThread().setPriority(2);
                    Total = 0;
     private int Total = 0;
Is there another library class I do not know about or do I have to write this methods myself?

Answer 1

Where have you got the CircularList from?
it is not part of the java API ... so who ever wrote it should be able to answer your question.
If it sticks to the conventions of the collection API
the method addItem is probably simply named add
and instead of queque.next() you use an iterator instead like this:
Iterator iter = queque.iterator();
while (iter.hasNext()){
Object o = iter.next();
// do something with o
HTH
Spieler