public class order
{
	int    m_type = nan;
	float  m_param;
}

public class exchange
{
	static private order m_order = new order;

	// Put an order
	synchronized bool put(order a)
	{
		if ( m_order.m_type == nan )
		{
			m_order = a;
			return true;
		}
		else
		{
			return false;
		}
	}

	// Get an order
	synchronized order get()
	{
		return m_order;
	}

	// Delete an order.
	synchronized void delete()
	{
		m_order.m_type = nan;
	}
}

extern void object::Slave4( )
{
	exchange list();
	order    todo;

	while ( true )
	{
		while ( true )
		{
			todo = list.get();
			if ( todo.m_type != nan )  break;
			wait(1);
		}

		if ( todo.m_type == 1 )
		{
			message("move("+todo.m_param+")");
			move(todo.m_param);
		}
		else if ( todo.m_type == 2 )
		{
			message("turn("+todo.m_param+")");
			turn(todo.m_param);
		}
		else
		{
			message("Unknown order");
		}
		list.delete();
	}
}