Java语言多个程序什么时候会做到同时运行

public class MultiThreadExample extends Thread {
    public static void main(String[] args) {
        // 创建第一个线程并启动
        Thread thread1 = new MultiThreadExample();
        thread1.start();

        // 创建第二个线程并启动
        Thread thread2 = new MultiThreadExample();
        thread2.start();
    }

    @Override
    public void run() {
        // 执行线程中的代码块或函数
        System.out.println("线程正在运行");
    }
}

public class MultiThreadCommunicationExample {
    public static void main(String[] args) {
        Data data = new Data();

        // 创建并启动第一个线程
        Thread thread1 = new Thread(() -> {
            synchronized (data) {
                System.out.println("线程1正在运行");
                data.setFlag(true);
                data.notify();
            }
        });
        thread1.start();

        // 创建并启动第二个线程
        Thread thread2 = new Thread(() -> {
            synchronized (data) {
                while (!data.isFlag()) {
                    try {
                        data.wait();
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                }
                System.out.println("线程2正在运行");
            }
        });
        thread2.start();
    }

    static class Data {
        private boolean flag = false;

        public boolean isFlag() {
            return flag;
        }

        public void setFlag(boolean flag) {
            this.flag = flag;
        }
    }
}