/**
     * Returns an Unsafe. Suitable for use in a 3rd party package. Replace with a simple call to
     * Unsafe.getUnsafe when integrating into a JDK.
     *
     * @return an Unsafe instance if successful
     */
    private static Unsafe getUnsafe() {
      try {
        return Unsafe.getUnsafe();
      } catch (SecurityException tryReflectionInstead) {
        // We'll try reflection instead.
      }
      try {

        } catch (UnsupportedOperationException e) {
          return OFFSET_UNSAFE_APPROACH_IS_UNAVAILABLE;
        }
      }

      private static @Nullable Unsafe getUnsafe() {
        try {
          return Unsafe.getUnsafe();
        } catch (SecurityException e) {
          // that's okay; try reflection instead
        }
        try {
          return doPrivileged(

    static final long VALUE_OFFSET;
    static final long WAITER_THREAD_OFFSET;
    static final long WAITER_NEXT_OFFSET;

    static {
      Unsafe unsafe = null;
      try {
        unsafe = Unsafe.getUnsafe();
      } catch (SecurityException tryReflectionInstead) {
        try {
          unsafe =
              doPrivileged(
                  (PrivilegedExceptionAction<Unsafe>)
                      () -> {