class Concurrent::ThreadLocals

def locals!
  thread = Thread.current
  locals = thread.thread_variable_get(:concurrent_thread_locals)
  unless locals
    locals = thread.thread_variable_set(:concurrent_thread_locals, [])
    weak_synchronize do
      @all_arrays[locals.object_id] = locals
    end
    # When the thread goes out of scope, we should delete the associated locals:
    ObjectSpace.define_finalizer(thread, thread_fiber_finalizer(locals.object_id))
  end
  locals
end