simulation.java

CPU分时模型的java模拟 50个工作站

package com.persia.simulation;

import java.util.LinkedList;
import java.util.Random;

public class Simulation {

	private Random ran=new Random();
	private LinkedList<Task> queue=new LinkedList<Task>();
	private int taskSize=0;
	private int TerminalSize=0;
	private double[] events=new double[1000];
	private final double INFINITE=Math.pow(10.0,10);
	private int targetTaskSize=0;
	private Task task=new Task();
	private boolean statusBusy=false;
	private double cycleTime=0.1;
	private double currentTime=0.0;
	private int numberOfTaskInSystem=0;
	private int finishNumer=0;
	private double stayingTime=0.0;
	private double theta1=25;
	private double theta2=0.8;
	
	
	public int getTerminalSize() {
		return TerminalSize;
	}

	public void setTerminalSize(int terminalSize) {
		TerminalSize = terminalSize;
	}

	public Simulation(int terminalSize,int targetTaskSize){
		this.TerminalSize=terminalSize;
		this.targetTaskSize=targetTaskSize;
	}
	
	public Simulation(){
		
	}

	public void initSimulation(){
		for(int i=1;i<TerminalSize+1;i++){
			events[i]=this.GenerateExpRandom(theta1);
		}
		events[TerminalSize+1]=this.INFINITE;
			
	}
	
	public int minEvents(){
		double min=this.INFINITE;
		int location=-1;
		for(int i=1;i<=TerminalSize+1;i++){
			if(events[i]<min){
				min=events[i];
				location=i;
			}
		}
		
		return location;
	}
	
	public void arrive(int terminalNo){
		this.currentTime=events[terminalNo];
		this.numberOfTaskInSystem++;
		Task tmp=new Task();
		tmp.setArriveTime(events[terminalNo]);
		tmp.setServiceTime(this.GenerateExpRandom(theta2));
		tmp.setTerminalNo(terminalNo);
		queue.add(tmp);
		System.out.println("at "+this.currentTime+"----terminal["+tmp.getTerminalNo()+"] arrived...");
		events[terminalNo]=this.INFINITE;
		
		if(statusBusy==false){
			this.statusBusy=true;
			this.task=this.queue.getFirst();
			this.occupyCPU();
		}
		
		
	}
	
	public void occupyCPU(){
		//this.task=queue.getFirst();
		if(task.getServiceTime()<=this.cycleTime){
			events[TerminalSize+1]=task.getServiceTime()+this.currentTime;
			task.setServiceTime(0.0);
		}else{
			events[TerminalSize+1]=this.cycleTime+this.currentTime;
			task.setServiceTime(task.getServiceTime()-this.cycleTime);
		}
	}
	public void depart(){
		this.currentTime=events[TerminalSize+1];
		if(task.getServiceTime()==0){
			// 可以离开系统,计算停留时间
			this.stayingTime+=this.currentTime-task.getArriveTime();
			this.finishNumer++;
			//安排此终端下次到达时间
			events[task.getTerminalNo()]=this.currentTime+this.GenerateExpRandom(theta1);
			this.numberOfTaskInSystem--;
			queue.removeFirst();
			System.out.println("at "+this.currentTime+"----terminal["+task.getTerminalNo()+"] depart cpu...");
		//	System.out.println("这个终端下次到达的时间："+events[task.getTerminalNo()]);
		//	System.out.println("这个终端前一个终端到达的时间："+events[task.getTerminalNo()-1]);
			//System.out.println("这个终端后一个终端到达的时间："+events[task.getTerminalNo()+1]);
			if(this.numberOfTaskInSystem==0){
				this.statusBusy=false;
				events[TerminalSize+1]=this.INFINITE;
				
			}else{
				
				this.task=queue.getFirst();
				this.occupyCPU();
			}
		}else{
			if(this.numberOfTaskInSystem==1){
				this.occupyCPU();
			}else{
				Task tmp=queue.getFirst();
				queue.removeFirst();
				queue.addLast(tmp);
				this.task=queue.getFirst();
				this.occupyCPU();
			}
		}
	}
	
	public double startSimulation(){
		this.initSimulation();
		while(this.taskSize<=targetTaskSize){
			int next=this.minEvents();
			if(next>0 && next<TerminalSize+1){
				arrive(next);
				this.taskSize++;
			}
				
			else
				depart();
			
			
		}
		
		return this.stayingTime/this.finishNumer;
		
	}
	

	
	public double GenerateExpRandom(double theta){
		double random=ran.nextDouble();
		return (-1/theta)*Math.log(1-random);
	}
	

}