标签:[] start 问题 override 同步 string 数值 oid sys
饥饿与公平:
1.高优先级吞噬所有低优先级的CPU时间片
2.线程被永久堵塞在一个等待进入同步块的状态
3.等待的线程永远不被唤醒
关于优先级,编程的时候注意:
不要假定高优先级的线程一定先于低优先级的线程,不要有逻辑依赖线程优先级,否则可能有意外错误。因为,不同的平台,对于同一个优先级的数值,可能代表的含义不一样。
但是,大多数我们看到的还是,优先级高的,抢到CPU的概念执行更高。
package com.roocon.thread.t4; public class Target implements Runnable{ @Override public void run() { while(true){ System.out.println(Thread.currentThread().getName()+"is running"); } } }
package com.roocon.thread.t4; public class Demo { public static void main(String[] args) { Thread t0 = new Thread(new Target()); Thread t1 = new Thread(new Target()); t0.setPriority(Thread.MAX_PRIORITY); t1.setPriority(Thread.MIN_PRIORITY); t0.start(); t1.start(); } }
运行结果:
Thread-1is running Thread-1is running Thread-1is running Thread-1is running Thread-1is running Thread-1is running Thread-1is running Thread-1is running Thread-1is running Thread-1is running
...//大多数都是Thread-1is running,偶尔是Thread-0is running
Thread-1is running
标签:[] start 问题 override 同步 string 数值 oid sys
原文地址:http://www.cnblogs.com/sunnyDream/p/8001415.html