class Concurrent::Collection::AtomicReferenceMapBackend

def initialize_table
  until current_table ||= table
    if (size_ctrl = size_control) == NOW_RESIZING
      Thread.pass # lost initialization race; just spin
    else
      try_in_resize_lock(current_table, size_ctrl) do
        initial_size = size_ctrl > 0 ? size_ctrl : DEFAULT_CAPACITY
        current_table = self.table = Table.new(initial_size)
        initial_size - (initial_size >> 2) # 75% load factor
      end
    end
  end
  current_table
end