Java实时多任务调度过程中安全监控设计

package safethread;

// 核心调度程序
public class mythread {

public mythread() { }
public static void main(String[] args) {
M m = new M();
}
}

// A 任务线程
class A extends Thread {
public static boolean dead = false;
M m;
A(M m){
m = m;
start();
}
public void run(){
try{
for(int i=-3;i<= 5;i++){
int j=1/i; // 人为设置过程中陷阱
dead = !dead; // 活动状态
System.out.println("i=" + i + ": status=" + dead);
try{
sleep(2000);
}
catch(InterruptedException ie){
System.out.println("A is Interrupted!");
}
}
m.Keepchecking = false; //A 正常结束后关闭监控线程
System.out.println("A is Ending M");
}
catch(Exception e){
System.out.println("A become Exception!");
}
}
}

// 监控线程
class M extends Thread{

public static boolean Keepchecking = true; // 持续监控标志
boolean laststatus; //保存上次监控状态
int maydeadtimes = 0; //监控线程可能死亡的计数器
int maydeadtimeout = 3;//定义判断线程死亡的边界条件
int deadtimes = 0; //监控线程死亡次数的计数器
int deadtimeout = 3; //定义判断线程不正常的边界条件

A a;

M(){start();}

public void run(){
schedule();
while(Keepchecking){
laststatus = a.dead;
try{
sleep(2000);
}
catch(InterruptedException e){
System.out.println("M is Interrupted!");
}
System.out.println("M read A status = " + a.dead);

if(laststatus == a.dead ){
if(++maydeadtimes >= maydeadtimeout){
if(++deadtimes >= deadtimeout){
System.out.println("Alert! A is unstable, M will stop it");
a = null;
break;
}
else{
System.out.println( "A is deaded!")
schedule();
System.out.println("M is restarting A! ___________ ");
}
}
}
else{
maydeadtimes = 0;
}
}
}

private void schedule(){
A a = new A(this);
}
}