;; -*- lexical-binding:t -*-

(defun wait-forever (filename)
  (unwind-protect
      (condition-case e
	  (let* ((mutex (make-mutex))
		 (cvar (make-condition-variable mutex)))
	    (with-mutex mutex
	      (write-region "WAITING" nil filename nil 0)
	      (while t
		(condition-wait cvar))))
	(quit
	 (write-region "QUIT" nil filename nil 0)))
    (kill-emacs)))

(defun spawn-child-then-wait (filename)
  (make-thread (lambda ()
		 (write-region " TERMINATING2" nil filename t 0)))
  (unwind-protect
      (condition-case e
	  (let* ((mutex (make-mutex))
		 (cvar (make-condition-variable mutex)))
	    (with-mutex mutex
	      (write-region "WAITING1" nil filename nil 0)
	      (while t
		(condition-wait cvar))))
	(quit
	 (write-region "QUIT1" nil filename nil 0)))
    (kill-emacs)))

(defun two-threads-waiting (filename)
  (make-thread
   (lambda ()
     (unwind-protect
	 (condition-case e
	     (let* ((mutex (make-mutex))
		    (cvar (make-condition-variable mutex)))
	       (with-mutex mutex
		 (write-region " WAITING2" nil filename t 0)
		 (while t
		   (condition-wait cvar))))
	   (quit
	    (write-region "QUIT2" nil filename nil 0)))
       (kill-emacs))))
  (unwind-protect
      (condition-case e
	  (let* ((mutex (make-mutex))
		 (cvar (make-condition-variable mutex)))
	    (with-mutex mutex
	      (write-region "WAITING1" nil filename nil 0)
	      (while t
		(condition-wait cvar))))
	(quit
	 (write-region " QUIT1" nil filename t 0)))
    (kill-emacs)))