package com.zhaowd.test.designPattern.singleton;

import java.util.concurrent.CountDownLatch;

import com.zhaowd.test.designPattern.singleton.laze.LazeTwo;

public class Test {
	public static void main(String[] args) {
        int count = 2000;
        
        final CountDownLatch latch = new CountDownLatch(count);
        long time = System.currentTimeMillis();
        for(int i = 0;i < count; i ++){
                
            new Thread(){
                
                @Override
                public void run(){
                    
                    //所有執行緒執行到這裡進行阻塞，count=0時，所有執行緒從該位置同時觸發執行
                    try {
                        latch.await();
                    } catch (InterruptedException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    }
                    
                    //餓漢式：在使用前進行初始化，執行緒安全
//                    System.out.println(System.currentTimeMillis() + ":"  + Hungry.getInstance());
                    
                    //懶漢式：執行緒不安全，需要使用synchronized關鍵字（會較低效率）
//                    System.out.println(System.currentTimeMillis() + ":"  + LazeOne.getInstance());
                    
                    //懶漢式-內部類/程式碼塊：執行緒安全的；注意：使用靜態內部類注意載入順序，只有用到才會載入內部類
                    System.out.println(System.currentTimeMillis() + ":"  + LazeTwo.getInstance());
                    
                }
            }.start();
            
            latch.countDown();
        }
        
        System.out.println("總耗時："+ (System.currentTimeMillis() - time));
    }
}