package?jmm;

/**
?*?Created?by?WangLong?on?2017-05-28.
?*/
public?class?SynchronizedDemo?{
????//共享變量
????private?boolean?ready=false;
????private?int?result=0;
????private?int?number=1;

????/**
?????*?寫操作
?????*/
????public?synchronized?void?write(){
????????ready=true;
????????number=2;
????}

????/**
?????*?讀操作
?????*/
????public?synchronized?void?read(){
????????if(ready){
????????????result=number*3;
????????}
????????System.out.println("result的值為："+result);
????}

????/**
?????*?內部線程類
?????*/
????private?class?ReadWriteThread?extends?Thread{
????????private?boolean?flag;
????????public?ReadWriteThread(boolean?flag){
????????????this.flag=flag;
????????}

????????public?void?run(){
????????????if(flag){
????????????????write();????//構造方法中傳入true，執(zhí)行寫操作
????????????}else{
????????????????read();?????//構造方法中傳入false，執(zhí)行讀操作
????????????}
????????}
????}

????public?static?void?main(String[]?args)?{
????????SynchronizedDemo?demo=new?SynchronizedDemo();
????????demo.new?ReadWriteThread(true).start();?????//啟動線程執(zhí)行寫操作
????????/*try?{
????????????Thread.sleep(1000);
????????}?catch?(InterruptedException?e)?{
????????????e.printStackTrace();
????????}*/
????????demo.new?ReadWriteThread(false).start();?????//啟動線程執(zhí)行讀操作
????}
}

/**

????代碼如上：僅僅加入synchronized關鍵字之后，執(zhí)行結果還是不確定?。?br />

*/