C#

static class Parameters
{
  private static int x1; // only getters of x1 and x2 will be visible to outside world
  private static int x2;  
  private static bool isInit;
  private static readonly object Locker = new object();

  public static bool isInited()
  {
   lock(Locker)
    {
    return isInit;
    }
  }

  public static int X1()
  {
    if(!isInited()) throw new Exception("init first");
    return x1;
     
  }

  public static int X2()
  {
    lock(Locker)
    {
     if(!isInited()) throw new Exception("init first");
     return x2;
    }
    
  }

  public static void init(int x, int y)
  {
    lock(Locker)
    {
      if(isInit) return;
      isInit = true;
      x1 = x;
      x2 = y; 
    }
  }

  public static void Deinit()
  {

    lock(Locker)
    {
      if(!isInit) return;
      isInit = false;
      x1 = 0;
      x2 = 0;
    }
  }


}