线程优先级_priority
- 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;
- 使用以下方法改变或获取优先级
- getPriority().setPriority(int xxx);
- 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,看CPU调度
- 性能倒置:优先级低的线程较优先级高的先执行
- 优先级的设定建议在start()调度前
测试代码:
**package multithreading;
// 测试线程的优先级
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);
// 先设置线程优先级,再启动
t1.start();
t2.setPriority(1);
t2.start();
t3.setPriority(4);
t3.start();
t4.setPriority(Thread.MAX_PRIORITY);
t4.start();
t5.setPriority(7);
t5.start();
t6.setPriority(8);
t6.start();
}
}
class MyPriority implements Runnable{
@Override
public void run() {
System.out.println(Thread.currentThread().getName()+"-->"+Thread.currentThread().getPriority());
}
}
**
运行结果: