/**
 * Defines an interface for SimRunThread to communicate
 * back with the frontend.
 */
public interface ThreadedFrontend {
	/**
	 * Indicates that run is completed
	 * @param code Code for program stop (this is not the program exit code)
	 * @param o An object (for ERROR, this would be an exception, null for others)
	 */
	void runDone(int code, Object o);

	/**
	 * Signals the GUI to update the display status
	 * This is called after each instruction is executed
	 */
	void updateStatus();
}