这是要测试的线程不安全的类

正常情况下,使用下面线程池测试上面的代码,结果并不是100,也就是说明线程不安全

但使用下面的这个代码,结果总是100,也就是线程安全,但明明是不安全的呀

public static void main(String[] args) throws InterruptedException {
            El el = new El();
            final int threadSize = 100;

            final CountDownLatch countDownLatch = new CountDownLatch(threadSize);
            ExecutorService executorService = Executors.newCachedThreadPool();
            for (int i = 0; i < threadSize; i++) {
                executorService.execute(() -> {
                    el.add();
                    countDownLatch.countDown();
                });
            }
            Thread.sleep(100);
            System.out.println(el.get());

            //另一个测试代码
           Runnable r = new Runnable() {

                @Override
                public  void run() {

                        el.add();


                }
            };
            Thread threads[]=new Thread[100];
            for (int i = 0; i < 100; i++) {

                threads[i] = new Thread(r," " + i);
            }
            for (int i = 0; i < 100; i++) {
                threads[i].start();
            }


            Thread.sleep(1000);
            System.out.println(el.get());

        }

EL类

public class El {
    public int count = 0;

    public  void add() {

           count += 1;

       }

    public int get() {
        return count;
    }
}