// blocking. This value is what AbstractQueuedSynchronizer uses.
  private static final long SPIN_THRESHOLD_NANOS = 1000L;

  @VisibleForTesting
  static String atomicHelperTypeForTest() {
    return ATOMIC_HELPER.atomicHelperTypeForTest();
  }

  private abstract static class AtomicHelper {
    /** Non-volatile write of the thread to the {@link Waiter#thread} field. */