Async message-send

[Manuel Giraud via "Emacs development discussions." <emacs-devel@gnu.org>]

Hi,

I'm (again) trying to make an async version of 'message-send'.  Reading
the elisp manual, I found that maybe I could use a "condition variable"
to make the communication between a sender thread and a house-keeping
thread.  Here is a working example of what I had in mind:

--8<---------------cut here---------------start------------->8---
;;; -*- lexical-binding:t -*-
;;; Toy example with thread and condition variable

(defvar done-workers nil)

(defun worker (mutex cv token)
  `(lambda ()
     (if (zerop (mod (random 100) 2))
	 ;; Error case: notify without adding me to the done-workers
	 ;; list.
	 (with-mutex ,mutex
	   (condition-notify ,cv))
       (with-current-buffer (get-buffer-create "foobar")
	 (insert "I'm done… ")
	 (with-mutex ,mutex
	   (push ,token done-workers)
	   (condition-notify ,cv))))))

(defun house-keeper (mutex cv token)
  `(lambda ()
     (with-mutex ,mutex
       (condition-wait ,cv)
       (cond ((member ,token done-workers)
	      (with-current-buffer (get-buffer-create "foobar")
		(insert "okay\n"))
	      (setq done-workers (remove ,token done-workers)))
	     (t (message "There was an error"))))))

(defun +my-command ()
  (interactive)
  (let* ((mutex (make-mutex))
	 (cv (make-condition-variable mutex))
	 (token (random 100)))
    (make-thread (worker mutex cv token))
    (make-thread (house-keeper mutex cv token))))
--8<---------------cut here---------------end--------------->8---

Before trying to apply this pattern to 'message-send', do you think this
approach could have any flaws?  Thanks.
-- 
Manuel Giraud