code: public boolean compareAndSet(final long expectedValue, final long updateValue)
      {
          return UnsafeAccess.UNSAFE.compareAndSwapLong(byteArray, addressOffset, expectedValue, updateValue);
      }
docs: Compare the current value to expected and if true then set to the update value atomically.
  
  @param expectedValue for the counter.
  @param updateValue   for the counter.
  @return true if successful otherwise false.