1 ;;; timer.el --- run a function with args at some time in future
3 ;; Copyright (C) 1996, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008,
4 ;; 2009, 2010 Free Software Foundation, Inc.
9 ;; This file is part of GNU Emacs.
11 ;; GNU Emacs is free software: you can redistribute it and/or modify
12 ;; it under the terms of the GNU General Public License as published by
13 ;; the Free Software Foundation, either version 3 of the License, or
14 ;; (at your option) any later version.
16 ;; GNU Emacs is distributed in the hope that it will be useful,
17 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
18 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 ;; GNU General Public License for more details.
21 ;; You should have received a copy of the GNU General Public License
22 ;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>.
26 ;; This package gives you the capability to run Emacs Lisp commands at
27 ;; specified times in the future, either as one-shots or periodically.
31 ;; Layout of a timer vector:
32 ;; [triggered-p high-seconds low-seconds usecs repeat-delay
33 ;; function args idle-delay]
34 ;; triggered-p is nil if the timer is active (waiting to be triggered),
35 ;; t if it is inactive ("already triggered", in theory)
37 (eval-when-compile (require 'cl))
42 (:constructor timer-create ())
46 high-seconds low-seconds usecs repeat-delay function args idle-delay)
48 (defun timerp (object)
49 "Return t if OBJECT is a timer."
50 (and (vectorp object) (= (length object) 8)))
52 ;; Pseudo field `time'.
53 (defun timer--time (timer)
54 (list (timer--high-seconds timer)
55 (timer--low-seconds timer)
56 (timer--usecs timer)))
60 (or (timerp timer) (error "Invalid timer"))
61 (setf (timer--high-seconds timer) (pop time))
62 (setf (timer--low-seconds timer)
63 (if (consp time) (car time) time))
64 (setf (timer--usecs timer) (or (and (consp time) (consp (cdr time))
69 (defun timer-set-time (timer time &optional delta)
70 "Set the trigger time of TIMER to TIME.
71 TIME must be in the internal format returned by, e.g., `current-time'.
72 If optional third argument DELTA is a positive number, make the timer
73 fire repeatedly that many seconds apart."
74 (setf (timer--time timer) time)
75 (setf (timer--repeat-delay timer) (and (numberp delta) (> delta 0) delta))
78 (defun timer-set-idle-time (timer secs &optional repeat)
79 "Set the trigger idle time of TIMER to SECS.
80 SECS may be an integer, floating point number, or the internal
81 time format (HIGH LOW USECS) returned by, e.g., `current-idle-time'.
82 If optional third argument REPEAT is non-nil, make the timer
83 fire each time Emacs is idle for that many seconds."
85 (setf (timer--time timer) secs)
86 (setf (timer--time timer) '(0 0 0))
87 (timer-inc-time timer secs))
88 (setf (timer--repeat-delay timer) repeat)
91 (defun timer-next-integral-multiple-of-time (time secs)
92 "Yield the next value after TIME that is an integral multiple of SECS.
93 More precisely, the next value, after TIME, that is an integral multiple
94 of SECS seconds since the epoch. SECS may be a fraction."
95 (let ((time-base (ash 1 16)))
96 ;; Use floating point, taking care to not lose precision.
97 (let* ((float-time-base (float time-base))
99 (time-usec (+ (* million
100 (+ (* float-time-base (nth 0 time))
103 (secs-usec (* million secs))
104 (mod-usec (mod time-usec secs-usec))
105 (next-usec (+ (- time-usec mod-usec) secs-usec))
106 (time-base-million (* float-time-base million)))
107 (list (floor next-usec time-base-million)
108 (floor (mod next-usec time-base-million) million)
109 (floor (mod next-usec million))))))
111 (defun timer-relative-time (time secs &optional usecs)
112 "Advance TIME by SECS seconds and optionally USECS microseconds.
113 SECS may be either an integer or a floating point number."
114 ;; FIXME: we should just use (time-add time (list 0 secs usecs))
115 (let ((high (car time))
116 (low (if (consp (cdr time)) (nth 1 time) (cdr time)))
117 (micro (if (numberp (car-safe (cdr-safe (cdr time))))
121 (if usecs (setq micro (+ micro usecs)))
123 (setq micro (+ micro (floor (* 1000000 (- secs (floor secs)))))))
124 (setq low (+ low (floor secs)))
127 ;; `/' rounds towards zero while `mod' returns a positive number,
128 ;; so we can't rely on (= a (+ (* 100 (/ a 100)) (mod a 100))).
129 (setq low (+ low (/ micro 1000000) (if (< micro 0) -1 0)))
130 (setq micro (mod micro 1000000))
131 (setq high (+ high (/ low 65536) (if (< low 0) -1 0)))
132 (setq low (logand low 65535))
134 (list high low (and (/= micro 0) micro))))
136 (defun timer--time-less-p (t1 t2)
137 "Say whether time value T1 is less than time value T2."
138 ;; FIXME just use time-less-p.
139 (destructuring-bind (high1 low1 micro1) (timer--time t1)
140 (destructuring-bind (high2 low2 micro2) (timer--time t2)
145 (< micro1 micro2))))))))
147 (defun timer-inc-time (timer secs &optional usecs)
148 "Increment the time set in TIMER by SECS seconds and USECS microseconds.
149 SECS may be a fraction. If USECS is omitted, that means it is zero."
150 (setf (timer--time timer)
151 (timer-relative-time (timer--time timer) secs usecs)))
153 (defun timer-set-time-with-usecs (timer time usecs &optional delta)
154 "Set the trigger time of TIMER to TIME plus USECS.
155 TIME must be in the internal format returned by, e.g., `current-time'.
156 The microsecond count from TIME is ignored, and USECS is used instead.
157 If optional fourth argument DELTA is a positive number, make the timer
158 fire repeatedly that many seconds apart."
159 (setf (timer--time timer) time)
160 (setf (timer--usecs timer) usecs)
161 (setf (timer--repeat-delay timer) (and (numberp delta) (> delta 0) delta))
163 (make-obsolete 'timer-set-time-with-usecs
164 "use `timer-set-time' and `timer-inc-time' instead."
167 (defun timer-set-function (timer function &optional args)
168 "Make TIMER call FUNCTION with optional ARGS when triggering."
170 (error "Invalid timer"))
171 (setf (timer--function timer) function)
172 (setf (timer--args timer) args)
175 (defun timer--activate (timer &optional triggered-p reuse-cell idle)
176 (if (and (timerp timer)
177 (integerp (timer--high-seconds timer))
178 (integerp (timer--low-seconds timer))
179 (integerp (timer--usecs timer))
180 (timer--function timer))
181 (let ((timers (if idle timer-idle-list timer-list))
183 ;; Skip all timers to trigger before the new one.
184 (while (and timers (timer--time-less-p (car timers) timer))
186 timers (cdr timers)))
189 (setcar reuse-cell timer)
190 (setcdr reuse-cell timers))
191 (setq reuse-cell (cons timer timers)))
192 ;; Insert new timer after last which possibly means in front of queue.
194 (setcdr last reuse-cell)
196 (setq timer-idle-list reuse-cell)
197 (setq timer-list reuse-cell)))
198 (setf (timer--triggered timer) triggered-p)
199 (setf (timer--idle-delay timer) idle)
201 (error "Invalid or uninitialized timer")))
203 (defun timer-activate (timer &optional triggered-p reuse-cell idle)
204 "Put TIMER on the list of active timers.
206 If TRIGGERED-P is t, that means to make the timer inactive
207 \(put it on the list, but mark it as already triggered).
208 To remove from the list, use `cancel-timer'.
210 REUSE-CELL, if non-nil, is a cons cell to reuse instead
211 of allocating a new one."
212 (timer--activate timer triggered-p reuse-cell nil))
214 (defun timer-activate-when-idle (timer &optional dont-wait reuse-cell)
215 "Arrange to activate TIMER whenever Emacs is next idle.
216 If optional argument DONT-WAIT is non-nil, then enable the
217 timer to activate immediately, or at the right time, if Emacs
220 REUSE-CELL, if non-nil, is a cons cell to reuse instead
221 of allocating a new one."
222 (timer--activate timer (not dont-wait) reuse-cell 'idle))
224 (defalias 'disable-timeout 'cancel-timer)
226 (defun cancel-timer (timer)
227 "Remove TIMER from the list of active timers."
229 (error "Invalid timer"))
230 (setq timer-list (delq timer timer-list))
231 (setq timer-idle-list (delq timer timer-idle-list))
234 (defun cancel-timer-internal (timer)
235 "Remove TIMER from the list of active timers or idle timers.
236 Only to be used in this file. It returns the cons cell
237 that was removed from the timer list."
238 (let ((cell1 (memq timer timer-list))
239 (cell2 (memq timer timer-idle-list)))
241 (setq timer-list (delq timer timer-list)))
243 (setq timer-idle-list (delq timer timer-idle-list)))
246 (defun cancel-function-timers (function)
247 "Cancel all timers which would run FUNCTION.
248 This affects ordinary timers such as are scheduled by `run-at-time',
249 and idle timers such as are scheduled by `run-with-idle-timer'."
250 (interactive "aCancel timers of function: ")
251 (dolist (timer timer-list)
252 (if (eq (timer--function timer) function)
253 (setq timer-list (delq timer timer-list))))
254 (dolist (timer timer-idle-list)
255 (if (eq (timer--function timer) function)
256 (setq timer-idle-list (delq timer timer-idle-list)))))
258 ;; Record the last few events, for debugging.
259 (defvar timer-event-last nil
260 "Last timer that was run.")
261 (defvar timer-event-last-1 nil
262 "Next-to-last timer that was run.")
263 (defvar timer-event-last-2 nil
264 "Third-to-last timer that was run.")
266 (defvar timer-max-repeats 10
267 "*Maximum number of times to repeat a timer, if many repeats are delayed.
268 Timer invocations can be delayed because Emacs is suspended or busy,
269 or because the system's time changes. If such an occurrence makes it
270 appear that many invocations are overdue, this variable controls
271 how many will really happen.")
273 (defun timer-until (timer time)
274 "Calculate number of seconds from when TIMER will run, until TIME.
275 TIMER is a timer, and stands for the time when its next repeat is scheduled.
276 TIME is a time-list."
277 ;; FIXME: (float-time (time-subtract (timer--time timer) time))
278 (let ((high (- (car time) (timer--high-seconds timer)))
279 (low (- (nth 1 time) (timer--low-seconds timer))))
280 (+ low (* high 65536))))
282 (defun timer-event-handler (timer)
283 "Call the handler for the timer TIMER.
284 This function is called, by name, directly by the C code."
285 (setq timer-event-last-2 timer-event-last-1)
286 (setq timer-event-last-1 timer-event-last)
287 (setq timer-event-last timer)
288 (let ((inhibit-quit t))
290 (let (retrigger cell)
291 ;; Delete from queue. Record the cons cell that was used.
292 (setq cell (cancel-timer-internal timer))
293 ;; Re-schedule if requested.
294 (if (timer--repeat-delay timer)
295 (if (timer--idle-delay timer)
296 (timer-activate-when-idle timer nil cell)
297 (timer-inc-time timer (timer--repeat-delay timer) 0)
298 ;; If real time has jumped forward,
299 ;; perhaps because Emacs was suspended for a long time,
300 ;; limit how many times things get repeated.
301 (if (and (numberp timer-max-repeats)
302 (< 0 (timer-until timer (current-time))))
303 (let ((repeats (/ (timer-until timer (current-time))
304 (timer--repeat-delay timer))))
305 (if (> repeats timer-max-repeats)
306 (timer-inc-time timer (* (timer--repeat-delay timer)
308 (timer-activate timer t cell)
311 ;; We do this after rescheduling so that the handler function
312 ;; can cancel its own timer successfully with cancel-timer.
314 ;; Timer functions should not change the current buffer.
315 ;; If they do, all kinds of nasty surprises can happen,
316 ;; and it can be hellish to track down their source.
318 (apply (timer--function timer) (timer--args timer)))
321 (setf (timer--triggered timer) nil)))
322 (error "Bogus timer event"))))
324 ;; This function is incompatible with the one in levents.el.
325 (defun timeout-event-p (event)
326 "Non-nil if EVENT is a timeout event."
327 (and (listp event) (eq (car event) 'timer-event)))
330 (declare-function diary-entry-time "diary-lib" (s))
332 (defun run-at-time (time repeat function &rest args)
333 "Perform an action at time TIME.
334 Repeat the action every REPEAT seconds, if REPEAT is non-nil.
335 TIME should be one of: a string giving an absolute time like
336 \"11:23pm\" (the acceptable formats are those recognized by
337 `diary-entry-time'; note that such times are interpreted as times
338 today, even if in the past); a string giving a relative time like
339 \"2 hours 35 minutes\" (the acceptable formats are those
340 recognized by `timer-duration'); nil meaning now; a number of
341 seconds from now; a value from `encode-time'; or t (with non-nil
342 REPEAT) meaning the next integral multiple of REPEAT. REPEAT may
343 be an integer or floating point number. The action is to call
344 FUNCTION with arguments ARGS.
346 This function returns a timer object which you can use in `cancel-timer'."
347 (interactive "sRun at time: \nNRepeat interval: \naFunction: ")
350 (and (numberp repeat) (< 0 repeat))
351 (error "Invalid repetition interval"))
353 ;; Special case: nil means "now" and is useful when repeating.
355 (setq time (current-time)))
357 ;; Special case: t means the next integral multiple of REPEAT.
358 (if (and (eq time t) repeat)
359 (setq time (timer-next-integral-multiple-of-time (current-time) repeat)))
361 ;; Handle numbers as relative times in seconds.
363 (setq time (timer-relative-time (current-time) time)))
365 ;; Handle relative times like "2 hours 35 minutes"
367 (let ((secs (timer-duration time)))
369 (setq time (timer-relative-time (current-time) secs)))))
371 ;; Handle "11:23pm" and the like. Interpret it as meaning today
372 ;; which admittedly is rather stupid if we have passed that time
373 ;; already. (Though only Emacs hackers hack Emacs at that time.)
377 (let ((hhmm (diary-entry-time time))
381 (encode-time 0 (% hhmm 100) (/ hhmm 100) (nth 3 now)
382 (nth 4 now) (nth 5 now) (nth 8 now)))))))
385 (error "Invalid time format"))
387 (let ((timer (timer-create)))
388 (timer-set-time timer time repeat)
389 (timer-set-function timer function args)
390 (timer-activate timer)
393 (defun run-with-timer (secs repeat function &rest args)
394 "Perform an action after a delay of SECS seconds.
395 Repeat the action every REPEAT seconds, if REPEAT is non-nil.
396 SECS and REPEAT may be integers or floating point numbers.
397 The action is to call FUNCTION with arguments ARGS.
399 This function returns a timer object which you can use in `cancel-timer'."
400 (interactive "sRun after delay (seconds): \nNRepeat interval: \naFunction: ")
401 (apply 'run-at-time secs repeat function args))
403 (defun add-timeout (secs function object &optional repeat)
404 "Add a timer to run SECS seconds from now, to call FUNCTION on OBJECT.
405 If REPEAT is non-nil, repeat the timer every REPEAT seconds.
406 This function is for compatibility; see also `run-with-timer'."
407 (run-with-timer secs repeat function object))
409 (defun run-with-idle-timer (secs repeat function &rest args)
410 "Perform an action the next time Emacs is idle for SECS seconds.
411 The action is to call FUNCTION with arguments ARGS.
412 SECS may be an integer, a floating point number, or the internal
413 time format (HIGH LOW USECS) returned by, e.g., `current-idle-time'.
414 If Emacs is currently idle, and has been idle for N seconds (N < SECS),
415 then it will call FUNCTION in SECS - N seconds from now.
417 If REPEAT is non-nil, do the action each time Emacs has been idle for
418 exactly SECS seconds (that is, only once for each time Emacs becomes idle).
420 This function returns a timer object which you can use in `cancel-timer'."
422 (list (read-from-minibuffer "Run after idle (seconds): " nil nil t)
423 (y-or-n-p "Repeat each time Emacs is idle? ")
424 (intern (completing-read "Function: " obarray 'fboundp t))))
425 (let ((timer (timer-create)))
426 (timer-set-function timer function args)
427 (timer-set-idle-time timer secs repeat)
428 (timer-activate-when-idle timer t)
431 (defun with-timeout-handler (tag)
432 "This is the timer function used for the timer made by `with-timeout'."
433 (throw tag 'timeout))
435 (defvar with-timeout-timers nil
436 "List of all timers used by currently pending `with-timeout' calls.")
438 (defmacro with-timeout (list &rest body)
439 "Run BODY, but if it doesn't finish in SECONDS seconds, give up.
440 If we give up, we run the TIMEOUT-FORMS and return the value of the last one.
441 The timeout is checked whenever Emacs waits for some kind of external
442 event (such as keyboard input, input from subprocesses, or a certain time);
443 if the program loops without waiting in any way, the timeout will not
445 \n(fn (SECONDS TIMEOUT-FORMS...) BODY)"
447 (let ((seconds (car list))
448 (timeout-forms (cdr list)))
449 `(let ((with-timeout-tag (cons nil nil))
450 with-timeout-value with-timeout-timer
451 (with-timeout-timers with-timeout-timers))
452 (if (catch with-timeout-tag
454 (setq with-timeout-timer
455 (run-with-timer ,seconds nil
456 'with-timeout-handler
458 (push with-timeout-timer with-timeout-timers)
459 (setq with-timeout-value (progn . ,body))
461 (progn . ,timeout-forms)
462 (cancel-timer with-timeout-timer)
463 with-timeout-value))))
465 (defun with-timeout-suspend ()
466 "Stop the clock for `with-timeout'. Used by debuggers.
467 The idea is that the time you spend in the debugger should not
468 count against these timeouts.
470 The value is a list that the debugger can pass to `with-timeout-unsuspend'
471 when it exits, to make these timers start counting again."
472 (mapcar (lambda (timer)
474 (list timer (time-subtract (timer--time timer) (current-time))))
475 with-timeout-timers))
477 (defun with-timeout-unsuspend (timer-spec-list)
478 "Restart the clock for `with-timeout'.
479 The argument should be a value previously returned by `with-timeout-suspend'."
480 (dolist (elt timer-spec-list)
481 (let ((timer (car elt))
483 (timer-set-time timer (time-add (current-time) delay))
484 (timer-activate timer))))
486 (defun y-or-n-p-with-timeout (prompt seconds default-value)
487 "Like (y-or-n-p PROMPT), with a timeout.
488 If the user does not answer after SECONDS seconds, return DEFAULT-VALUE."
489 (with-timeout (seconds default-value)
492 (defconst timer-duration-words
493 (list (cons "microsec" 0.000001)
494 (cons "microsecond" 0.000001)
495 (cons "millisec" 0.001)
496 (cons "millisecond" 0.001)
501 (cons "hour" (* 60 60))
502 (cons "day" (* 24 60 60))
503 (cons "week" (* 7 24 60 60))
504 (cons "fortnight" (* 14 24 60 60))
505 (cons "month" (* 30 24 60 60)) ; Approximation
506 (cons "year" (* 365.25 24 60 60)) ; Approximation
508 "Alist mapping temporal words to durations in seconds.")
510 (defun timer-duration (string)
511 "Return number of seconds specified by STRING, or nil if parsing fails."
514 (case-fold-search t))
516 "[ \t]*\\([0-9.]+\\)?[ \t]*\\([a-z]+[a-rt-z]\\)s?[ \t]*"
518 (let ((count (if (match-beginning 1)
519 (string-to-number (match-string 1 string))
521 (itemsize (cdr (assoc (match-string 2 string)
522 timer-duration-words))))
524 (setq start (match-end 0)
525 secs (+ secs (* count itemsize)))
527 start (length string)))))
528 (if (= start (length string))
530 (if (string-match-p "\\`[0-9.]+\\'" string)
531 (string-to-number string)))))
535 ;;; timer.el ends here