xx-define-background-function-wrapper.el

(defmacro define-background-function-wrapper (bg-function fn)
  (let ((is-loading-sym (intern (concat "*" (symbol-name bg-function) "-is-loading*"))))
    `(progn
       (defvar ,is-loading-sym nil)
       (defun ,bg-function ()
         (interactive)
         (when ,is-loading-sym
           (message ,(concat (symbol-name fn) " is already loading")))
         (setq ,is-loading-sym t)
         (make-thread (lambda ()
                        (unwind-protect
                            (,fn)
                          (setq ,is-loading-sym nil))))))))