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--;                }            }        }    }

}