Java Thread Priority 线程优先级

秒速五厘米 2024-03-27 16:16 62阅读 0赞

### Thread Priority 线程优先级 ###

*  Java 提供了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，线程调度按照优先级觉得应该调度哪个线程先执行
 *  线程的优先级用数字表示，范围 1~10
    
     *  Thread.MIN\_PRIORITY = 1;
     *  Thread.MAX\_PRIORITY = 10;
     *  Thread.NORM\_PRIORITY = 5;
 *  获取优先级
    
     *  getPriority()
 *  改变优先级
    
     *  setPriority(int xxx)  
        **注意**：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，这都要看cpu的调度

package com.state;
    
    /*
        测试线程优先级
     */
    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 (3);
            t5.start ();
    
            t6.setPriority (2);
            t6.start ();
    
        }
    
    }
    class MyPriority implements Runnable{
        
        @Override
        public void run () {
        
            System.out.println (Thread.currentThread ().getName ()+"-->"+Thread.currentThread ().getPriority ());
        }
    }