mainthread.java

操作系统课程实习之进程调度模拟实现--采用时间片轮转算法(JAVA版)

/**
 * MainThread类
 * 主线程，调度模拟进程的运行
 * @author linpeitian
 */

import javax.swing.*;

public class MainThread extends Thread{

	/**
	 * 接受传参 MainUI中的控件
	 */
	public int num = 0;           //进程数目
	public int block = 0;         //时间片大小
	public SubThread subThread[] = new SubThread[20];  //进程组
	public JTextArea area = null;   //运行状态显示域
	public JLabel timeSys = null;   //时间显示域
	public JLabel status = null;    //状态显示域
	public JButton reset = null;    //重置按钮    
	
	public boolean running = true; //主控线程运行控制
	
	/**
	 * 构造函数
	 * 将MainUI传
	 * @param mainUI
	 */
	public MainThread(MainUI mainUI){
		this.num = mainUI.number;         //模拟进程的个数赋值
		this.block = mainUI.timeblock;    //时间片大小赋值
		this.subThread = mainUI.subThread;//具体的线程数组赋值
		this.area = mainUI.area;          //运行显示域赋值
		this.timeSys = mainUI.timeSys;    //时间显示域赋值
		this.status = mainUI.status;      //状态显示域赋值
		this.reset = mainUI.reset;        //重置按钮赋值
	}
	
	/**
	 * 主线程的run方法
	 * 线程体
	 */
	public void run(){
		int mainTime = 0;   //记录系统运行总时间
		int curTmp = 0;   
		int runTime = 0;    //记录进程需耗费时间长度
		int curThread = 0;  //记录当前运行的下个进程
		//主程序，调度其他进程，一直运行，知道所有进程均完成为止
		while(running){
			if(check()){
				//检测是否进程都运行完之一没运行完情况
				//启动未启动的进程
				for(int i = 0; i < num; i++){
				    if(subThread[i].getStart() <= mainTime && subThread[i].getStatus().equals(SubThread.NOTREADY)){
					    subThread[i].start();
					    subThread[i].setStatus(SubThread.READY);
					    subThread[i].suspend();
					    curTmp ++;
				    }
				    if(subThread[i].getStart() > mainTime)
					    break;
			    }
				show();
				int kk = 0;        //标记是否有进程在占cpu，还是cpu空闲
				int circle = 0;    //防止死循环
				int t = curThread; //记录下个将运行的进程
				for( ; t < curTmp; t++){
					if(circle == curTmp){
						break;
					}
					circle ++;
					if(subThread[t].getStatus().equals(SubThread.STOP)){
						if(t == curTmp-1)
							t = -1;
						continue;
					}else{
						kk = 1;
						runTime = subThread[t].getTime() - subThread[t].getRun();
						if(runTime > block) 
							runTime = block;
						subThread[t].setStatus(SubThread.RUNNING);
						subThread[t].resume();
						curThread = t+1;
						if(curThread == curTmp){
							if(curTmp == num ||subThread[curTmp].getStart() > runTime + mainTime)
								curThread = 0;
						}
						break;
					}
				}
				//CPU处于空闲状态
				if(kk == 0){
					for(int i = 0; i < num; i++){
						if(subThread[i].getStart() > mainTime){
							runTime = subThread[i].getStart() - mainTime;
							break;
						}
					}
					status.setText("CPU处于空闲状态");
				}
				show();
				//进程的具体操作
				try{
					for(int i = 0; i < runTime; i++){
						for(int tt = curTmp; tt < num; tt++){
						    if(subThread[tt].getStart() <= mainTime + i && subThread[tt].getStatus().equals(SubThread.NOTREADY)){
							    subThread[tt].start();
							    subThread[tt].setStatus(SubThread.READY);
							    subThread[tt].suspend();
							    curTmp ++;
						    }
						    if(subThread[tt].getStart() > mainTime)
							    break;
					    }
						sleep(1000);
						if(kk == 1){
							subThread[t].setRun(subThread[t].getRun() + 1);
						}
						timeSys.setText("第" + new Integer(mainTime+i+1).toString() + "秒");
						show();
					}
				}catch(InterruptedException e){
					e.printStackTrace();
				}
				//进程时间片用完后的操作
				mainTime = mainTime + runTime;
				if( kk == 1){
					if((subThread[t].getTime() - subThread[t].getRun()) == 0){
					    subThread[t].setStatus(SubThread.STOP);
					    subThread[t].stop();
				    }else{
					    subThread[t].setStatus(SubThread.READY);
					    subThread[t].suspend();
				    }
				}
				show();
			}else {
				//检测是否进程都运行完之一运行完情况
				running = false;
			}
		}
		status.setText("进程运行完成,若要继续，按重置按钮");
		reset.setEnabled(true);
	}
	
	/**
	 * 显示进程的具体信息
	 */
	public void show(){
		area.setText("");
		area.setText("进程名字\t进程状态\t到达时间\tCPU时间\t已运行时间\n");
		for(int i = 0 ; i < num; i++)
		area.append(subThread[i].getProcess() + "\t" 
				+ subThread[i].getStatus() + "\t"
				+ subThread[i].getStart() + "\t"
				+ subThread[i].getTime() + "\t"
				+ subThread[i].getRun() + "\n");
	}

	/**
	 * 用于检测是否所有进程都运行完了
	 * @return
	 */
	public boolean check(){
		for(int i = 0; i < num; i++){
			if(!subThread[i].getStatus().equals(SubThread.STOP))
				return true;
		}
		return false;
	}

}