class Fluent::Plugin::ForwardOutput::Node::SocketCache

def dec_ref(key = Thread.current.object_id)
  @mutex.synchronize do
    if @active_socks[key]
      @active_socks[key].ref -= 1
    elsif @inactive_socks[key]
      @inactive_socks[key].ref -= 1
    else
      @log.warn("Not found key for dec_ref: #{key}")
    end
  end
end