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1 ;;; timer.el --- run a function with args at some time in future
3 ;; Copyright (C) 1996, 2001-2014 Free Software Foundation, Inc.
5 ;; Maintainer: FSF
6 ;; Package: emacs
8 ;; This file is part of GNU Emacs.
10 ;; GNU Emacs is free software: you can redistribute it and/or modify
11 ;; it under the terms of the GNU General Public License as published by
12 ;; the Free Software Foundation, either version 3 of the License, or
13 ;; (at your option) any later version.
15 ;; GNU Emacs is distributed in the hope that it will be useful,
16 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
17 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 ;; GNU General Public License for more details.
20 ;; You should have received a copy of the GNU General Public License
21 ;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>.
23 ;;; Commentary:
25 ;; This package gives you the capability to run Emacs Lisp commands at
26 ;; specified times in the future, either as one-shots or periodically.
28 ;;; Code:
30 (eval-when-compile (require 'cl-lib))
32 (cl-defstruct (timer
33 (:constructor nil)
34 (:copier nil)
35 (:constructor timer-create ())
36 (:type vector)
37 (:conc-name timer--))
38 ;; nil if the timer is active (waiting to be triggered),
39 ;; non-nil if it is inactive ("already triggered", in theory).
40 (triggered t)
41 ;; Time of next trigger: for normal timers, absolute time, for idle timers,
42 ;; time relative to idle-start.
43 high-seconds low-seconds usecs
44 ;; For normal timers, time between repetitions, or nil. For idle timers,
45 ;; non-nil iff repeated.
46 repeat-delay
47 function args ;What to do when triggered.
48 idle-delay ;If non-nil, this is an idle-timer.
49 psecs)
51 (defun timerp (object)
52 "Return t if OBJECT is a timer."
53 (and (vectorp object) (= (length object) 9)))
55 (defsubst timer--check (timer)
56 (or (timerp timer) (signal 'wrong-type-argument (list #'timerp timer))))
58 (defun timer--time-setter (timer time)
59 (timer--check timer)
60 (setf (timer--high-seconds timer) (pop time))
61 (let ((low time) (usecs 0) (psecs 0))
62 (when (consp time)
63 (setq low (pop time))
64 (when time
65 (setq usecs (pop time))
66 (when time
67 (setq psecs (car time)))))
68 (setf (timer--low-seconds timer) low)
69 (setf (timer--usecs timer) usecs)
70 (setf (timer--psecs timer) psecs)
71 time))
73 ;; Pseudo field `time'.
74 (defun timer--time (timer)
75 (declare (gv-setter timer--time-setter))
76 (list (timer--high-seconds timer)
77 (timer--low-seconds timer)
78 (timer--usecs timer)
79 (timer--psecs timer)))
81 (defun timer-set-time (timer time &optional delta)
82 "Set the trigger time of TIMER to TIME.
83 TIME must be in the internal format returned by, e.g., `current-time'.
84 If optional third argument DELTA is a positive number, make the timer
85 fire repeatedly that many seconds apart."
86 (setf (timer--time timer) time)
87 (setf (timer--repeat-delay timer) (and (numberp delta) (> delta 0) delta))
88 timer)
90 (defun timer-set-idle-time (timer secs &optional repeat)
91 ;; FIXME: Merge with timer-set-time.
92 "Set the trigger idle time of TIMER to SECS.
93 SECS may be an integer, floating point number, or the internal
94 time format returned by, e.g., `current-idle-time'.
95 If optional third argument REPEAT is non-nil, make the timer
96 fire each time Emacs is idle for that many seconds."
97 (setf (timer--time timer) (if (consp secs) secs (seconds-to-time secs)))
98 (setf (timer--repeat-delay timer) repeat)
99 timer)
101 (defun timer-next-integral-multiple-of-time (time secs)
102 "Yield the next value after TIME that is an integral multiple of SECS.
103 More precisely, the next value, after TIME, that is an integral multiple
104 of SECS seconds since the epoch. SECS may be a fraction."
105 (let* ((trillion 1e12)
106 (time-sec (+ (nth 1 time)
107 (* 65536.0 (nth 0 time))))
108 (delta-sec (mod (- time-sec) secs))
109 (next-sec (+ time-sec (ffloor delta-sec)))
110 (next-sec-psec (ffloor (* trillion (mod delta-sec 1))))
111 (sub-time-psec (+ (or (nth 3 time) 0)
112 (* 1e6 (nth 2 time))))
113 (psec-diff (- sub-time-psec next-sec-psec)))
114 (if (and (<= next-sec time-sec) (< 0 psec-diff))
115 (setq next-sec-psec (+ sub-time-psec
116 (mod (- psec-diff) (* trillion secs)))))
117 (setq next-sec (+ next-sec (floor next-sec-psec trillion)))
118 (setq next-sec-psec (mod next-sec-psec trillion))
119 (list (floor next-sec 65536)
120 (floor (mod next-sec 65536))
121 (floor next-sec-psec 1000000)
122 (floor (mod next-sec-psec 1000000)))))
124 (defun timer-relative-time (time secs &optional usecs psecs)
125 "Advance TIME by SECS seconds and optionally USECS microseconds
126 and PSECS picoseconds. SECS may be either an integer or a
127 floating point number."
128 (let ((delta (if (floatp secs)
129 (seconds-to-time secs)
130 (list (floor secs 65536) (mod secs 65536)))))
131 (if (or usecs psecs)
132 (setq delta (time-add delta (list 0 0 (or usecs 0) (or psecs 0)))))
133 (time-add time delta)))
135 (defun timer--time-less-p (t1 t2)
136 "Say whether time value T1 is less than time value T2."
137 (time-less-p (timer--time t1) (timer--time t2)))
139 (defun timer-inc-time (timer secs &optional usecs psecs)
140 "Increment the time set in TIMER by SECS seconds, USECS microseconds,
141 and PSECS picoseconds. SECS may be a fraction. If USECS or PSECS are
142 omitted, they are treated as zero."
143 (setf (timer--time timer)
144 (timer-relative-time (timer--time timer) secs usecs psecs)))
146 (defun timer-set-time-with-usecs (timer time usecs &optional delta)
147 "Set the trigger time of TIMER to TIME plus USECS.
148 TIME must be in the internal format returned by, e.g., `current-time'.
149 The microsecond count from TIME is ignored, and USECS is used instead.
150 If optional fourth argument DELTA is a positive number, make the timer
151 fire repeatedly that many seconds apart."
152 (declare (obsolete "use `timer-set-time' and `timer-inc-time' instead."
153 "22.1"))
154 (setf (timer--time timer) time)
155 (setf (timer--usecs timer) usecs)
156 (setf (timer--psecs timer) 0)
157 (setf (timer--repeat-delay timer) (and (numberp delta) (> delta 0) delta))
158 timer)
160 (defun timer-set-function (timer function &optional args)
161 "Make TIMER call FUNCTION with optional ARGS when triggering."
162 (timer--check timer)
163 (setf (timer--function timer) function)
164 (setf (timer--args timer) args)
165 timer)
167 (defun timer--activate (timer &optional triggered-p reuse-cell idle)
168 (if (and (timerp timer)
169 (integerp (timer--high-seconds timer))
170 (integerp (timer--low-seconds timer))
171 (integerp (timer--usecs timer))
172 (integerp (timer--psecs timer))
173 (timer--function timer))
174 (let ((timers (if idle timer-idle-list timer-list))
175 last)
176 ;; Skip all timers to trigger before the new one.
177 (while (and timers (timer--time-less-p (car timers) timer))
178 (setq last timers
179 timers (cdr timers)))
180 (if reuse-cell
181 (progn
182 (setcar reuse-cell timer)
183 (setcdr reuse-cell timers))
184 (setq reuse-cell (cons timer timers)))
185 ;; Insert new timer after last which possibly means in front of queue.
186 (setf (cond (last (cdr last))
187 (idle timer-idle-list)
188 (t timer-list))
189 reuse-cell)
190 (setf (timer--triggered timer) triggered-p)
191 (setf (timer--idle-delay timer) idle)
192 nil)
193 (error "Invalid or uninitialized timer")))
195 (defun timer-activate (timer &optional triggered-p reuse-cell)
196 "Insert TIMER into `timer-list'.
197 If TRIGGERED-P is t, make TIMER inactive (put it on the list, but
198 mark it as already triggered). To remove it, use `cancel-timer'.
200 REUSE-CELL, if non-nil, is a cons cell to reuse when inserting
201 TIMER into `timer-list' (usually a cell removed from that list by
202 `cancel-timer-internal'; using this reduces consing for repeat
203 timers). If nil, allocate a new cell."
204 (timer--activate timer triggered-p reuse-cell nil))
206 (defun timer-activate-when-idle (timer &optional dont-wait reuse-cell)
207 "Insert TIMER into `timer-idle-list'.
208 This arranges to activate TIMER whenever Emacs is next idle.
209 If optional argument DONT-WAIT is non-nil, set TIMER to activate
210 immediately \(see below\), or at the right time, if Emacs is
211 already idle.
213 REUSE-CELL, if non-nil, is a cons cell to reuse when inserting
214 TIMER into `timer-idle-list' (usually a cell removed from that
215 list by `cancel-timer-internal'; using this reduces consing for
216 repeat timers). If nil, allocate a new cell.
218 Using non-nil DONT-WAIT is not recommended when activating an
219 idle timer from an idle timer handler, if the timer being
220 activated has an idleness time that is smaller or equal to
221 the time of the current timer. That's because the activated
222 timer will fire right away."
223 (timer--activate timer (not dont-wait) reuse-cell 'idle))
225 (defalias 'disable-timeout 'cancel-timer)
227 (defun cancel-timer (timer)
228 "Remove TIMER from the list of active timers."
229 (timer--check timer)
230 (setq timer-list (delq timer timer-list))
231 (setq timer-idle-list (delq timer timer-idle-list))
232 nil)
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)))
240 (if cell1
241 (setq timer-list (delq timer timer-list)))
242 (if cell2
243 (setq timer-idle-list (delq timer timer-idle-list)))
244 (or cell1 cell2)))
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 (defcustom 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."
272 :type 'integer
273 :group 'internal)
275 (defun timer-until (timer time)
276 "Calculate number of seconds from when TIMER will run, until TIME.
277 TIMER is a timer, and stands for the time when its next repeat is scheduled.
278 TIME is a time-list."
279 (- (float-time time) (float-time (timer--time timer))))
281 (defun timer-event-handler (timer)
282 "Call the handler for the timer TIMER.
283 This function is called, by name, directly by the C code."
284 (setq timer-event-last-2 timer-event-last-1)
285 (setq timer-event-last-1 timer-event-last)
286 (setq timer-event-last timer)
287 (let ((inhibit-quit t))
288 (timer--check timer)
289 (let ((retrigger nil)
290 (cell
291 ;; Delete from queue. Record the cons cell that was used.
292 (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)
307 repeats)))))
308 ;; Place it back on the timer-list before running
309 ;; timer--function, so it can cancel-timer itself.
310 (timer-activate timer t cell)
311 (setq retrigger t)))
312 ;; Run handler.
313 (condition-case-unless-debug err
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.
317 (save-current-buffer
318 (apply (timer--function timer) (timer--args timer)))
319 (error (message "Error running timer%s: %S"
320 (if (symbolp (timer--function timer))
321 (format " `%s'" (timer--function timer)) "")
322 err)))
323 (when (and retrigger
324 ;; If the timer's been canceled, don't "retrigger" it
325 ;; since it might still be in the copy of timer-list kept
326 ;; by keyboard.c:timer_check (bug#14156).
327 (memq timer timer-list))
328 (setf (timer--triggered timer) nil)))))
330 ;; This function is incompatible with the one in levents.el.
331 (defun timeout-event-p (event)
332 "Non-nil if EVENT is a timeout event."
333 (and (listp event) (eq (car event) 'timer-event)))
336 (declare-function diary-entry-time "diary-lib" (s))
338 (defun run-at-time (time repeat function &rest args)
339 "Perform an action at time TIME.
340 Repeat the action every REPEAT seconds, if REPEAT is non-nil.
341 TIME should be one of: a string giving an absolute time like
342 \"11:23pm\" (the acceptable formats are those recognized by
343 `diary-entry-time'; note that such times are interpreted as times
344 today, even if in the past); a string giving a relative time like
345 \"2 hours 35 minutes\" (the acceptable formats are those
346 recognized by `timer-duration'); nil meaning now; a number of
347 seconds from now; a value from `encode-time'; or t (with non-nil
348 REPEAT) meaning the next integral multiple of REPEAT. REPEAT may
349 be an integer or floating point number. The action is to call
350 FUNCTION with arguments ARGS.
352 This function returns a timer object which you can use in `cancel-timer'."
353 (interactive "sRun at time: \nNRepeat interval: \naFunction: ")
355 (or (null repeat)
356 (and (numberp repeat) (< 0 repeat))
357 (error "Invalid repetition interval"))
359 ;; Special case: nil means "now" and is useful when repeating.
360 (if (null time)
361 (setq time (current-time)))
363 ;; Special case: t means the next integral multiple of REPEAT.
364 (if (and (eq time t) repeat)
365 (setq time (timer-next-integral-multiple-of-time (current-time) repeat)))
367 ;; Handle numbers as relative times in seconds.
368 (if (numberp time)
369 (setq time (timer-relative-time (current-time) time)))
371 ;; Handle relative times like "2 hours 35 minutes"
372 (if (stringp time)
373 (let ((secs (timer-duration time)))
374 (if secs
375 (setq time (timer-relative-time (current-time) secs)))))
377 ;; Handle "11:23pm" and the like. Interpret it as meaning today
378 ;; which admittedly is rather stupid if we have passed that time
379 ;; already. (Though only Emacs hackers hack Emacs at that time.)
380 (if (stringp time)
381 (progn
382 (require 'diary-lib)
383 (let ((hhmm (diary-entry-time time))
384 (now (decode-time)))
385 (if (>= hhmm 0)
386 (setq time
387 (encode-time 0 (% hhmm 100) (/ hhmm 100) (nth 3 now)
388 (nth 4 now) (nth 5 now) (nth 8 now)))))))
390 (or (consp time)
391 (error "Invalid time format"))
393 (let ((timer (timer-create)))
394 (timer-set-time timer time repeat)
395 (timer-set-function timer function args)
396 (timer-activate timer)
397 timer))
399 (defun run-with-timer (secs repeat function &rest args)
400 "Perform an action after a delay of SECS seconds.
401 Repeat the action every REPEAT seconds, if REPEAT is non-nil.
402 SECS and REPEAT may be integers or floating point numbers.
403 The action is to call FUNCTION with arguments ARGS.
405 This function returns a timer object which you can use in `cancel-timer'."
406 (interactive "sRun after delay (seconds): \nNRepeat interval: \naFunction: ")
407 (apply 'run-at-time secs repeat function args))
409 (defun add-timeout (secs function object &optional repeat)
410 "Add a timer to run SECS seconds from now, to call FUNCTION on OBJECT.
411 If REPEAT is non-nil, repeat the timer every REPEAT seconds.
412 This function is for compatibility; see also `run-with-timer'."
413 (run-with-timer secs repeat function object))
415 (defun run-with-idle-timer (secs repeat function &rest args)
416 "Perform an action the next time Emacs is idle for SECS seconds.
417 The action is to call FUNCTION with arguments ARGS.
418 SECS may be an integer, a floating point number, or the internal
419 time format returned by, e.g., `current-idle-time'.
420 If Emacs is currently idle, and has been idle for N seconds (N < SECS),
421 then it will call FUNCTION in SECS - N seconds from now. Using
422 SECS <= N is not recommended if this function is invoked from an idle
423 timer, because FUNCTION will then be called immediately.
425 If REPEAT is non-nil, do the action each time Emacs has been idle for
426 exactly SECS seconds (that is, only once for each time Emacs becomes idle).
428 This function returns a timer object which you can use in `cancel-timer'."
429 (interactive
430 (list (read-from-minibuffer "Run after idle (seconds): " nil nil t)
431 (y-or-n-p "Repeat each time Emacs is idle? ")
432 (intern (completing-read "Function: " obarray 'fboundp t))))
433 (let ((timer (timer-create)))
434 (timer-set-function timer function args)
435 (timer-set-idle-time timer secs repeat)
436 (timer-activate-when-idle timer t)
437 timer))
439 (defvar with-timeout-timers nil
440 "List of all timers used by currently pending `with-timeout' calls.")
442 (defmacro with-timeout (list &rest body)
443 "Run BODY, but if it doesn't finish in SECONDS seconds, give up.
444 If we give up, we run the TIMEOUT-FORMS and return the value of the last one.
445 The timeout is checked whenever Emacs waits for some kind of external
446 event (such as keyboard input, input from subprocesses, or a certain time);
447 if the program loops without waiting in any way, the timeout will not
448 be detected.
449 \n(fn (SECONDS TIMEOUT-FORMS...) BODY)"
450 (declare (indent 1) (debug ((form body) body)))
451 (let ((seconds (car list))
452 (timeout-forms (cdr list))
453 (timeout (make-symbol "timeout")))
454 `(let ((-with-timeout-value-
455 (catch ',timeout
456 (let* ((-with-timeout-timer-
457 (run-with-timer ,seconds nil
458 (lambda () (throw ',timeout ',timeout))))
459 (with-timeout-timers
460 (cons -with-timeout-timer- with-timeout-timers)))
461 (unwind-protect
462 (progn ,@body)
463 (cancel-timer -with-timeout-timer-))))))
464 ;; It is tempting to avoid the `if' altogether and instead run
465 ;; timeout-forms in the timer, just before throwing `timeout'.
466 ;; But that would mean that timeout-forms are run in the deeper
467 ;; dynamic context of the timer, with inhibit-quit set etc...
468 (if (eq -with-timeout-value- ',timeout)
469 (progn ,@timeout-forms)
470 -with-timeout-value-))))
472 (defun with-timeout-suspend ()
473 "Stop the clock for `with-timeout'. Used by debuggers.
474 The idea is that the time you spend in the debugger should not
475 count against these timeouts.
477 The value is a list that the debugger can pass to `with-timeout-unsuspend'
478 when it exits, to make these timers start counting again."
479 (mapcar (lambda (timer)
480 (cancel-timer timer)
481 (list timer (time-subtract (timer--time timer) (current-time))))
482 with-timeout-timers))
484 (defun with-timeout-unsuspend (timer-spec-list)
485 "Restart the clock for `with-timeout'.
486 The argument should be a value previously returned by `with-timeout-suspend'."
487 (dolist (elt timer-spec-list)
488 (let ((timer (car elt))
489 (delay (cadr elt)))
490 (timer-set-time timer (time-add (current-time) delay))
491 (timer-activate timer))))
493 (defun y-or-n-p-with-timeout (prompt seconds default-value)
494 "Like (y-or-n-p PROMPT), with a timeout.
495 If the user does not answer after SECONDS seconds, return DEFAULT-VALUE."
496 (with-timeout (seconds default-value)
497 (y-or-n-p prompt)))
499 (defconst timer-duration-words
500 (list (cons "microsec" 0.000001)
501 (cons "microsecond" 0.000001)
502 (cons "millisec" 0.001)
503 (cons "millisecond" 0.001)
504 (cons "sec" 1)
505 (cons "second" 1)
506 (cons "min" 60)
507 (cons "minute" 60)
508 (cons "hour" (* 60 60))
509 (cons "day" (* 24 60 60))
510 (cons "week" (* 7 24 60 60))
511 (cons "fortnight" (* 14 24 60 60))
512 (cons "month" (* 30 24 60 60)) ; Approximation
513 (cons "year" (* 365.25 24 60 60)) ; Approximation
515 "Alist mapping temporal words to durations in seconds.")
517 (defun timer-duration (string)
518 "Return number of seconds specified by STRING, or nil if parsing fails."
519 (let ((secs 0)
520 (start 0)
521 (case-fold-search t))
522 (while (string-match
523 "[ \t]*\\([0-9.]+\\)?[ \t]*\\([a-z]+[a-rt-z]\\)s?[ \t]*"
524 string start)
525 (let ((count (if (match-beginning 1)
526 (string-to-number (match-string 1 string))
528 (itemsize (cdr (assoc (match-string 2 string)
529 timer-duration-words))))
530 (if itemsize
531 (setq start (match-end 0)
532 secs (+ secs (* count itemsize)))
533 (setq secs nil
534 start (length string)))))
535 (if (= start (length string))
536 secs
537 (if (string-match-p "\\`[0-9.]+\\'" string)
538 (string-to-number string)))))
540 (defun internal-timer-start-idle ()
541 "Mark all idle-time timers as once again candidates for running."
542 (dolist (timer timer-idle-list)
543 (if (timerp timer) ;; FIXME: Why test?
544 (setf (timer--triggered timer) nil))))
546 (provide 'timer)
548 ;;; timer.el ends here