Computer

"Making each Actor run in a separate Thread:

To make each Actor run in a separate Thread, we need to modify the Actor class to implement the Runnable interface, and move the existing game loop from the GamePanel class to the Actor class. We can then start a new Thread for each Actor in the GamePanel class, and call the start() method on the Thread object.

Here's an example of how the modified Actor class might look:

java

public class Actor implements Runnable {

    private int x;

    private int y;

    private int dx;

    private int dy;

    private Image image;

    public Actor(int x, int y, Image image) {

        this.x = x;

        this.y = y;

        this.image = image;

    }

    public void move() {

        x += dx;

        y += dy;

    }

    public void setVelocity(int dx, int dy) {

        this.dx = dx;

        this.dy = dy;

    }

    public void draw(Graphics g) {

        g.drawImage(image, x, y, null);

    }

    @Override

    public void run() {

        while (true) {

            move();

            try {

                Thread.sleep(50);

            } catch (InterruptedException e) {

                e.printStackTrace();

            }

        }

    }

}

And here's an example of how the modified GamePanel class might create and start a Thread for each Actor:

java

Copy code

public class GamePanel extends JPanel {

    private List<Actor> actors = new ArrayList<>();

    public void addActor(Actor actor) {

        actors.add(actor);

        new Thread(actor).start();

    }

    @Override

    protected void paintComponent(Graphics g) {

        super.paintComponent(g);

        for (Actor actor : actors) {

            actor.draw(g);

        }

    }

}

Thread-safety issues:

One thread-safety issue that we might encounter with the current implementation is the concurrent modification of the actors list in the GamePanel class. If we add or remove an Actor from the list while the game loop is running, we might get a ConcurrentModificationException.

Another issue might be the access to shared variables between threads, such as the x and y variables of the Actor class. If two threads try to modify these variables at the same time, we might get unexpected results.

Making the program thread-safe:

To make the program thread-safe, we can use the synchronized keyword to ensure that only one thread can access a shared resource at a time. We can synchronize access to the actors list in the GamePanel class, and to the x and y variables in the Actor class."