    # File lib/phusion_passenger/abstract_request_handler.rb, line 333
            def soft_shutdown
                    @select_timeout = @soft_termination_linger_time
                    @graceful_termination_pipe[1].close rescue nil
                    if @detach_key && @pool_account_username && @pool_account_password
                            client = MessageClient.new(@pool_account_username, @pool_account_password)
                            begin
                                    client.detach(@detach_key)
                            ensure
                                    client.close
                            end
                    end
            end