线程优先级

线程优先级

 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来执行

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 xxx)

 优先级的设定建议在start（）调度前

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

package thread.state;

public class TestPriority {
    public static void main(String[] args) {
        //主线程默认优先级
        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);
        Thread t5 = new Thread(myPriority);
        Thread t6 = new Thread(myPriority);

        //先设置优先级，再启动
        t1.start();

        t2.setPriority(1);//设置优先级为1
        t2.start();

        t3.setPriority(Thread.MAX_PRIORITY);//MAX_PRIORITY=10
        t3.start();

        t4.setPriority(6);
        t4.start();

        t5.setPriority(8);
        t5.start();

        t6.setPriority(3);
        t6.start();
    }
}
class MyPriority implements Runnable{
    @Override
    public void run() {
        System.out.println(Thread.currentThread().getName()+"--->"+Thread.currentThread().getPriority());
        //线程的名字与优先级
    }
}