*
 * <p>jsr166e note: This class is targeted to be placed in java.util.concurrent.atomic.
 *
 * @since 1.8
 * @author Doug Lea
 */
final class LongAdder extends Striped64 implements Serializable, LongAddable {
  @GwtIncompatible @J2ktIncompatible   private static final long serialVersionUID = 7249069246863182397L;

  /** Version of plus for use in retryUpdate */
  @Override
  final long fn(long v, long x) {

   * need compare-and-swap.
   */
  static final class LockFreeBitArray {
    private static final int LONG_ADDRESSABLE_BITS = 6;
    final AtomicLongArray data;
    private final LongAddable bitCount;

    LockFreeBitArray(long bits) {
      checkArgument(bits > 0, "data length is zero!");
      // Avoid delegating to this(long[]), since AtomicLongArray(long[]) will clone its input and