share/contrib/timeout.lisp

   1 ;; stopme command, only for sbcl
   2 (in-package :maxima)
   3
   4 ;; stopme and  time_constrained are the same except that
   5 ;; time_constrained, in case of timeout simply returns
   6 ;; the expression Aborted.
   7 ;; stopme gives a message, and returns it. The message contains the unevaluated expr.
   8 ;; There are too many other variants possible to cover them all.
   9 ;; You may want a slightly different behavior. e.g. return unevaluated expr only.
  10 ;; (Mathematica returns "$Aborted" for timeout.)
  11
  12 #+sbcl
  13 (defmspec $stopme(args) ;; usage:  stopme (do x:x+1, 2) ; stops infinite loop after 2 sec
  14   (let* ((evalme(cadr args))              ;  not evaluated !
  15          (timelimit (meval (caddr args))) ; evaluate the time limit
  16          (v (sb-ext::make-timer ;; the timer program
  17              (lambda()
  18                (let ((msg `((mtext) ,evalme "   timed out after " ,timelimit " seconds")))
  19                (mformat t "~m" msg)
  20                (throw 'stopme msg ))))))
  21     (catch 'stopme
  22       (progn
  23         (sb-ext::schedule-timer v timelimit)
  24         (prog1 (meval evalme)
  25           (sb-ext::unschedule-timer v)) ))))
  26
  27 #+sbcl
  28 (defmspec $time_constrained(args)       ;; usage:  stopme (do x:x+1, 2) ; stops infinite loop after 2 sec
  29   (let* ((evalme(cadr args))              ;  not evaluated !
  30          (timelimit (meval (caddr args))) ; evaluate the time limit
  31          (v (sb-ext::make-timer ;; the timer program
  32              (lambda()(throw 'stopme '$Aborted
  33                              ;;evalme ;; just return unevaluated.
  34                              ) ))))
  35     (catch 'stopme
  36       (progn
  37         (sb-ext::schedule-timer v timelimit)
  38         (prog1 (meval evalme)
  39           (sb-ext::unschedule-timer v)) ))))
  40
  41 #-sbcl (format t "~%time_constrained and stopme
  42 are currently unimplemented
  43 in your lisp.
  44 Available in sbcl versions of Maxima. ~%")