/*
下面的程序会出现下面的情况，当Thread-0， Thread-1， Thread-2都被wait的时候，可能会同时苏醒
Thread-0 put
Thread-1 put
Thread-2 put
Thread-3 get//在此处，Thread-3拿到锁之后，将所有的等待的线程唤醒，才有了下面的输出
Thread-2 put
Thread-1 put
Thread-0 put
*/
虽然多个线程会同时苏醒，但是只有一个能获得cpu的执行权！
总之，同步中执行的只能是一个，但是存活的不一定就是一个！
class DuckD{
public void put(){
synchronized(DuckD.class){
System.out.println(Thread.currentThread().getName()+" put");
try{
DuckD.class.wait();//Thread-0， Thread-1， Thread-2可能会同时在这里苏醒！
}catch(InterruptedException e){
}
//........
}
}
public void get(){
synchronized(DuckD.class){
DuckD.class.notifyAll();
System.out.println(Thread.currentThread().getName()+" get");
try{
DuckD.class.wait();
}catch(InterruptedException e){
}
}
}
}
class ProduceD implements Runnable{
DuckD dk;
ProduceD(DuckD dk){
this.dk=dk;
}
public void run(){
while(true)
dk.put();
}
}
class ConsumeD implements Runnable{
DuckD dk;
ConsumeD(DuckD dk){
this.dk=dk;
}
public void run(){
while(true)
dk.get();
}
}
class Test{
public static void main(String[] args){
DuckD dk=new DuckD();
Thread t1=new Thread(new ProduceD(dk));
Thread t2=new Thread(new ProduceD(dk));
Thread t3=new Thread(new ProduceD(dk));
Thread t4=new Thread(new ConsumeD(dk));
t1.start();
t2.start();
t3.start();
t4.start();
}
}
