线程的状态

JAVA的6中线程状态:

1. NEW ： 线程刚刚创建，还没有启动
2. RUNNABLE ： 可运行状态，由线程调度器可以安排执行。
   • 包括READY和RUNNING两种细分状态
3. WAITING： 等待被唤醒
4. TIMED WAITING： 隔一段时间后自动唤醒
5. BLOCKED： 被阻塞，正在等待锁
6. TERMINATED： 线程结束

线程状态图

** 线程状态测试代码 **

o.wait() t.join() LockSupport.park() Lock.lock() 这四个方法都是返回waiting状态。
synchronized(o) 返回BLOCKED 状态，看上图所画。

package sc.app.stc.qdm2;

import java.util.concurrent.TimeUnit;
import java.util.concurrent.locks.LockSupport;

/** * @ClassName ThreadStatus * @Description 线程状态 * @Date 2022/8/4 10:35 **/
public class ThreadStatus {
    
    public static void main(String[] args) throws Exception {
    
        MyThread myThread = new MyThread();
        System.out.println("刚创建的线程状态为"+myThread.getState());
        myThread.start();
        System.out.println("启动后的线程状态为"+myThread.getState());
        myThread.sleep(1000);
        System.out.println("隔断时间后自动唤醒的线程状态为"+myThread.getState());
        MyThread2 myThread2 = new MyThread2();
        myThread2.start();
        TimeUnit.SECONDS.sleep(1);
        System.out.println("线程锁住后状态为: " + myThread2.getState());
       	//放开线程
        LockSupport.unpark(myThread2);
        TimeUnit.SECONDS.sleep(2);
        System.out.println("线程解锁后状态为: " + myThread2.getState());
        final Object o = new Object();
        Thread myThread3 = new Thread(()->{
    
            synchronized (o) {
    
                System.out.println("t3 得到了锁 o");
            }
        });

        new Thread(()-> {
    
            synchronized (o) {
    
                try {
    
                    TimeUnit.SECONDS.sleep(5);
                } catch (InterruptedException e) {
    
                    e.printStackTrace();
                }
            }
        }).start();

        TimeUnit.SECONDS.sleep(1);
        myThread3.start();
        TimeUnit.SECONDS.sleep(1);
        System.out.println("线程同步锁状态为: " + myThread3.getState());
    }



    static class MyThread2 extends Thread {
    
        @Override
        public void run() {
    
            try {
    
                //阻塞线程
                LockSupport.park();
                System.out.println("t2 go on!");
                TimeUnit.SECONDS.sleep(1);
            }catch (Exception e){
    
                e.printStackTrace();
            }
        }
    }


    static class MyThread extends Thread {
    
        @Override
        public void run() {
    
            for (int i = 0; i < 10; i++) {
    
                try {
    
                    Thread.sleep(1000);
                } catch (InterruptedException e) {
    
                    e.printStackTrace();
                }
            }
            System.out.println();
        }
    }
}