多线程测试用例

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(){
                    
                    //所有线程执行到这里进行阻塞，count=0时，所有线程从该位置同时触发执行
                    try {
                        latch.await();
                    } catch (InterruptedException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    }
                    
                    //饿汉式：在使用前进行初始化，线程安全
//                    System.out.println(System.currentTimeMillis() + ":"  + Hungry.getInstance());
                    
                    //懒汉式：线程不安全，需要使用synchronized关键字（会较低效率）
//                    System.out.println(System.currentTimeMillis() + ":"  + LazeOne.getInstance());
                    
                    //懒汉式-内部类/代码块：线程安全的；注意：使用静态内部类注意加载顺序，只有用到才会加载内部类
                    System.out.println(System.currentTimeMillis() + ":"  + LazeTwo.getInstance());
                    
                }
            }.start();
            
            latch.countDown();
        }
        
        System.out.println("总耗时："+ (System.currentTimeMillis() - time));
    }
}