volatile失效了么？

public class ThreadTest {

    public static volatile int count = 0;

    public static AtomicInteger atomicCount = new AtomicInteger(0);

    public static void main(String[] args) throws InterruptedException {
        Thread thread = new Thread(new Runnable() {
            @Override
            public void run() {
                int j = 0;
                while (j < 100000) {
                    Thread threadA = new Thread(() -> {
                        int i = 0;
                        while (i < 100) {
                            count++;
                            atomicCount.incrementAndGet();
                            i++;
                        }
                    });
                    threadA.start();
                    j++;
                }
            }

        }, "thread");
        thread.start();
        thread.join();
        System.out.println("count结果：" + count);
        System.out.println("atomicCount结果：" + atomicCount.get());
        System.out.println("main--stop");
    }


}

　　执行结果：

count结果：9999944
atomicCount结果：10000000
main--stop