package com.kk.thread; /* * 本类演示死锁的形成 * 基本数据类型是不能作为同步块的参考,例:int b;synchronized(b) */ public class TicketsSystem { public static void main(String[] args)throws Exception { SellThread sell=new SellThread(); new Thread(sell).start(); Thread.sleep(1);//让thread1执行,此时b=false; sell.b=true; new Thread(sell).start(); } } class SellThread implements Runnable{ int tickets=1000; Object obj=new Object(); boolean b=false; public void run() { if (b) { sell(); }else{ synchronized(obj){ //将obj锁住 while(true){ if (tickets>0) { try { Thread.currentThread().sleep(10); } catch (InterruptedException e) { e.printStackTrace(); } synchronized(this){ //按照本程序的执行顺序,此时this已经被sell方法锁住 System.out.println("obj___"+Thread.currentThread().getName()+"__"+tickets); tickets--; } } } } } } /* * 同步方法会给类的实例加锁(this) * 静态同步方法会给类加锁(Class) */ private synchronized void sell(){ //将类的实例锁住(this) while(true){ if (tickets>0) { try { Thread.currentThread().sleep(10); } catch (InterruptedException e) { e.printStackTrace(); } synchronized(obj){ //等线程苏醒,obj已经被run方法中的synchronized(obj)锁住 System.out.println("this___"+Thread.currentThread().getName()+"__"+tickets); tickets--; } } } } }