为什么 Java 中的非线程安全计数器总是返回正确的值

我试图通过递增Executor服务任务中的计数并使用倒计时锁存来等待所有线程启动和停止，然后在读取主线程中的值之前，来模拟一个非线程安全的计数器类.

问题是，当我运行它时，最后的System.out总是返回10作为正确的计数值.当我运行它时，我希望看到一些其他的值，因为这10个线程可能会看到不同的值.

我的代码如下.知道这里发生了什么吗？我在Java 17和IntelliJ Idea上运行它.

Couner.java

public class Counter {

    private int counter = 0;

    public void incrementCounter() {
        counter += 1;
    }

    public int getCounter() {
        return counter;
    }
}

#Main.Java#

import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

public class Main {
    public static void main(String[] args) throws InterruptedException {
        ExecutorService executorService = Executors.newFixedThreadPool(10);

        CountDownLatch startSignal = new CountDownLatch(10);
        CountDownLatch doneSignal = new CountDownLatch(10);
        Counter counter = new Counter();
        for (int i=0; i<10; i++) {
            executorService.submit(() -> {
                try {
                    startSignal.countDown();
                    startSignal.await();
                } catch (InterruptedException e) {
                    throw new RuntimeException(e);
                }

                counter.incrementCounter();
                doneSignal.countDown();
            });
        }

        doneSignal.await();
        System.out.println("Finished: " + counter.getCounter());
        executorService.shutdownNow();
    }
}