import java.awt.Dimension;

/*
* Goal: maintain a fixed ratio between length and width.
* This version is thread-safe
*/

public class ThreadSafeAspectRatio {
  // Get rid of the AtomicIntegers; thread-safety is now
  // provided with synchronized blocks
  private int length = 0;
  private int width = 0;

  public ThreadSafeAspectRatio(int l,int w) {
    this.length = l;
    this.width = w;
  }

  // use a synchronized block to ensure that the length and
  // width are set atomically
  public synchronized void setLength(int newLength) {    
    double ratio = ((double)length) / width;
    length = newLength;
    width = (int) ((double) newLength / ratio);
  }

  // To preserve the aspect ratio invariant, we must return
  // the length and width together
  public synchronized Dimension getDimension() {
    return new Dimension (length,width);
  }
}