in_thread (Borges::Session)

    # File lib/Borges/RequestHandler/Session.rb, line 155
      def in_thread(&block)
        val = nil

        if Thread.current[:in_handler_thread] then
          #val = handle_request(req)
          val = block.call

        else
          start_handler_thread unless defined? @thread

          @session_mutex.synchronize do
            response_lock = Mutex.new.lock # unlocked by #perform_request
            #@thread[:request] = req
            @thread[:block] = block
            @thread[:response_done] = response_lock
            @thread_mutex.unlock
            response_lock.lock
            val = @thread[:return]
          end

        end

        return val
      end