Java多线程14-线程优先级

14、线程的优先级

• java提供一个线程调度器来监控程序中启动后进入就绪状态的所有线程，线程调度器按照优先级决定应该调度哪个线程
• 线程的优先级用数字表示，范围从1~10
  • Thread.MIN_PRIORITY =1
  • Thread.MAX_PRIORITY =10
  • Thread.NORM_PRIORITY =5
• 使用以下方式改变或获取优先级
  • getPriority() setPriority(int x)

优先级的设置建议在start()调度前

优先级低只是意味着获取调度的概率低，并不是优先级低就不会被调用了，这都是看cup的调度

public class tESTpRIORITY{
    public static void main(String[] args) {
        System.out.println(Thread.currentThread().getName()+"-->"+Thread.currentThread().getPriority());
        myPriority myPriority=new myPriority();
        Thread t1=new Thread(myPriority);
        Thread t2=new Thread(myPriority);
        Thread t3=new Thread(myPriority);
        Thread t4=new Thread(myPriority);

        //设置优先级，再启动
        t1.start();
        t2.setPriority(1);
        t2.start();
        t3.setPriority(4);
        t3.start();
        t4.setPriority(Thread.MAX_PRIORITY);//MAX_PRIORITY=10
        t4.start();

    }
}

class myPriority implements Runnable{
    @Override
    public void run() {
        System.out.println(Thread.currentThread().getName()+"-->"+Thread.currentThread().getPriority());

    }
}

结果

main-->5
Thread-3-->10
Thread-0-->5
Thread-2-->4
Thread-1-->1