ok i understand what's going on. i need to rewrite the font-lock after-change
functions to use text properties instead of extents, and add some additional
trickiness for deletes. as it is, you're getting 7900 extents in the buffer
generated by 7900 text-insertion operations, and each insertion operation needs
to adjust the endpoint of all following extents ... you get the N^2 idea.
i'll fix this within a couple of days and send a patch.
thanks once again for the investigative work, chris.
stephen, perhaps we could learn from this eposide and write up some info for bug
reporters (e.g. about profiling etc.) about actively working with someone so
that the bug actually has a high chance of getting fixed.
ben
Chris Holt wrote:
Stephen J. Turnbull writes:
> >>>>> "Ben" == Ben Wing <ben(a)666.com> writes:
>
> Ben> indeed i did change this and i can't see why those calls to
> Ben> make-extent should have such a slowdown effect.
>
> I was afraid of that.
>
> Ben> [b] someone broke the redisplay extent optimization code.
>
> Can you give me some function names or other ways to localize
> dangerous changes for `cvs annotate'? I consider this a priority item
> for the release. Slow font-lock sucks badly for too many people.
>
> Ben> but even more to the point, redisplay should not even be
> Ben> getting called at all.
>
> The only thing I can think of off-hand is that Andy has done several
> "set-yet-another-dirty-flag" fixes for the widget code. Andy?
>
> Chris, do you have the progress bar enabled? It may not matter if
> it's invisible, depending on where those flags are getting set. (NB:
> Matt Tucker's password buffer bug is a background font-lock problem.)
>
Okay. I've got some more information.
If I use beta32, which is an interesting data point because it's the first
xemacs that has the progress bar (or at least a visible progress bar in my
environment) it looks like the options.el file is being loaded several
times. However, the time to save the customization file is still pretty
fast. I'm afraid I don't even have the menubar enabled, let alone the
progress bar.
Also, it doesn't seem like the font-lock-after-change-function is getting
called any more now than before. Both weigh in at 7934 calls.
Oh, and font-lock-always-fontify-immediately is definitely nil. I couldn't
imagine having that variable set to t. :-) In fact, I even commented out the
check in font-lock-after-change-function to make sure.
Here's my methodology:
(define-key global-map [(control c) (control f)]
(function (lambda ()
(interactive)
(if (profiling-active-p)
(progn
(stop-profiling)
(message "...Finished profiling"))
(message "Profiling...")
(clear-profiling-info)
(start-profiling)))))
I used the above function to control start/stop of profile. The experiment
entailed going to a customization buffer with lazy-shot, changing something,
and profiling the save of the customization file. Although the profile
includes me hitting "C-c C-f" a couple of times, plus a C-g, they're way
in
the noise.
Here's my results:
; Trial #1: Out-of-the-box font-lock.el version b43. Stopped save before
; completion. font-lock-after-change-function looks like this:
(defun font-lock-after-change-function (beg end old-len)
(when font-lock-mode
(let ((ex (make-extent beg end)))
(set-extent-property ex 'detachable nil)
(set-extent-property ex 'end-open nil)
(let ((exs (gethash (current-buffer) font-lock-pending-extent-table)))
(push ex exs)
(puthash (current-buffer) exs font-lock-pending-extent-table)))
(if font-lock-always-fontify-immediately
(font-lock-fontify-pending-extents))))
)))
(profile-results)
Function Name Ticks %/Total Call Count
=============================== ===== ======= ==========
prin1 2788 74.987 427
princ 868 23.346 674
(in garbage collection) 24 0.646
#<compiled-function (symbol) "...(119)" [spec now requests comment symbol
#theme-value custom-requests standard-value boundp force-value rogue
saved-variable-comment user set princ
'( prin1 saved-value t nil )] 6>
5 0.134 14798
make-extent 4 0.108 3038
car-safe 3 0.081 15871
read 3 0.081 7
font-lock-after-change-function 2 0.054 3038
#<compiled-function (ex) "...(52)" [extent-live-p ex extent-detached-p
#extent-start-position beg extent-end-position end 0 1 detach-extent
#put-range-table t font-lock-range-table] 5>
2 0.054 3038
car 2 0.054 15871
get 2 0.054 15873
quote 1 0.027 31969
not 1 0.027 15871
#<subr when> 1 0.027 15871
itimer-restart 1 0.027 2
memq 1 0.027 15875
let 1 0.027 15871
run-hook-with-args 1 0.027 9
mapc-internal 1 0.027 2
syntactically-sectionize 1 0.027 1
gethash 1 0.027 3038
and 1 0.027 15874
when 1 0.027 15871
boundp 1 0.027 14141
set-extent-property 1 0.027 6077
mapatoms 1 0.027 2
----------------------------------------------------------------
Total 3718 100.00
One tick = 1 ms
nil
; Trial #2: Comment out everything but the extent stuff. Stopped save before
; completion. New font-lock-after-change-function:
(defun font-lock-after-change-function (beg end old-len)
(when font-lock-mode
(let ((ex (make-extent beg end)))
(set-extent-property ex 'detachable nil)
(set-extent-property ex 'end-open nil)
; (let ((exs (gethash (current-buffer)
; font-lock-pending-extent-table)))
; (push ex exs)
; (puthash (current-buffer) exs font-lock-pending-extent-table)))
; (if font-lock-always-fontify-immediately
; (font-lock-fontify-pending-extents))))
)))
(profile-results)
Function Name Ticks %/Total Call Count
=============================== ===== ======= ==========
prin1 2902 75.357 427
princ 875 22.721 673
(in garbage collection) 26 0.675
#<compiled-function (symbol) "...(119)" [spec now requests comment symbol
#theme-value custom-requests standard-value boundp force-value rogue
saved-variable-comment user set princ
'( prin1 saved-value t nil )] 6>
5 0.130 15663
make-extent 5 0.130 3117
set-extent-property 5 0.130 6207
quote 3 0.078 39995
car-safe 3 0.078 16781
(in redisplay) 3 0.078
#<subr when> 3 0.078 19884
read 3 0.078 16
let 3 0.078 19885
eq 2 0.052 17002
font-lock-after-change-function 2 0.052 3103
get 2 0.052 16783
insert-file-contents-internal 1 0.026 1
car 1 0.026 16781
lazy-shot-after-change-function 1 0.026 3103
when 1 0.026 19884
redisplay-echo-area 1 0.026 12
(lambda (object) (let ((spec (car-safe (get object (quote theme-value)))))
(when (and (not (memq object ignored-special)) (eq (car spec) (quote user)) (eq
(second spec) (quote reset))) (unless started-writing (setq started-writing t)
(unless (bolp) (princ
)) (princ () (princ (quote custom-reset-variables)) (princ
'() (prin1 object) (princ ) (prin1 (third spec)) (princ ))))))
1 0.026 16781
boundp 1 0.026 15014
put-char-table 1 0.026 17
mapatoms 1 0.026 2
----------------------------------------------------------------
Total 3851 100.00
One tick = 1 ms
nil
; Trial #3: Comment out everything but the actual make-extent. This time,
; the save did run to completion.
(defun font-lock-after-change-function (beg end old-len)
(when font-lock-mode
(let ((ex (make-extent beg end)))
; (set-extent-property ex 'detachable nil)
; (set-extent-property ex 'end-open nil)
; (let ((exs (gethash (current-buffer)
; font-lock-pending-extent-table)))
; (push ex exs)
; (puthash (current-buffer) exs font-lock-pending-extent-table)))
; (if font-lock-always-fontify-immediately
; (font-lock-fontify-pending-extents))))
)))
(profile-results)
Function Name Ticks %/Total Call Count
=============================== ===== ======= ==========
prin1 177 53.636 659
princ 49 14.848 1054
(in garbage collection) 43 13.030
get 6 1.818 33565
custom-save-face-internal 5 1.515 16782
#<compiled-function (symbol) "...(119)" [spec now requests comment symbol
#theme-value custom-requests standard-value boundp force-value rogue
saved-variable-comment user set princ
'( prin1 saved-value t nil )] 6>
4 1.212 16781
eq 3 0.909 33889
#<subr when> 3 0.909 41968
read 3 0.909 28
when 3 0.909 41968
find-face 3 0.909 16738
scan-sexps 2 0.606 2
quote 2 0.606 67458
car 2 0.606 33888
car-safe 2 0.606 33563
memq 2 0.606 33567
let 2 0.606 41969
if 2 0.606 41970
make-extent 2 0.606 8422
mapatoms 2 0.606 4
not 1 0.303 33563
font-lock-after-change-function 1 0.303 8405
widget-default-create 1 0.303 6
(in redisplay) 1 0.303
check-menu-syntax 1 0.303 278
byte-compile-constant 1 0.303 324
load-average 1 0.303 2
next-command-event 1 0.303 1
(lambda (object) (let ((spec (car-safe (get object (quote theme-value)))))
(when (and (not (memq object ignored-special)) (eq (car spec) (quote user)) (eq
(second spec) (quote reset))) (unless started-writing (setq started-writing t)
(unless (bolp) (princ
)) (princ () (princ (quote custom-reset-variables)) (princ
'() (prin1 object) (princ ) (prin1 (third spec)) (princ ))))))
1 0.303 16781
second 1 0.303 324
and 1 0.303 33566
redisplay-echo-area 1 0.303 21
boundp 1 0.303 16114
----------------------------------------------------------------
Total 330 100.00
One tick = 1 ms
nil
; Trial #4: Used the old version of font-lock-after-change-function. This
; one also ran to completion (obviously).
(profile-results)
Function Name Ticks %/Total Call Count
=============================== ===== ======= ==========
(in garbage collection) 41 27.703
prin1 27 18.243 659
#<compiled-function (symbol) "...(119)" [spec now requests comment symbol
#theme-value custom-requests standard-value boundp force-value rogue
saved-variable-comment user set princ
'( prin1 saved-value t nil )] 6>
7 4.730 16786
read 7 4.730 28
custom-save-face-internal 7 4.730 16787
quote 5 3.378 67478
memq 4 2.703 33577
let 4 2.703 33574
get 4 2.703 33575
princ 4 2.703 1054
(in redisplay) 3 2.027
boundp 3 2.027 16118
mapatoms 3 2.027 4
eq 2 1.351 33899
car 2 1.351 33898
car-safe 2 1.351 33573
if 2 1.351 33575
when 2 1.351 33573
re-search-forward 2 1.351 438
put-nonduplicable-text-property 2 1.351 714
byte-compile-out-toplevel 1 0.676 1
font-lock-after-change-function 1 0.676 8405
key-binding 1 0.676 1
#<subr when> 1 0.676 33573
lazy-shot-after-change-function 1 0.676 8405
set-marker-insertion-type 1 0.676 21
crypt-write-file-hook 1 0.676 1
insert-string 1 0.676 19
kill-all-local-variables 1 0.676 2
(lambda (object) (let ((spec (car-safe (get object (quote theme-face)))))
(when (and (not (memq object ignored-special)) (eq (car spec) (quote user)) (eq
(second spec) (quote reset))) (unless started-writing (setq started-writing t)
(unless (bolp) (princ
)) (princ () (princ (quote custom-reset-faces)) (princ
'() (prin1 object) (princ ) (prin1 (third spec)) (princ ))))))
1 0.676 16787
and 1 0.676 33576
redisplay-echo-area 1 0.676 19
extent-start-position 1 0.676 8412
put-text-property 1 0.676 379
next-single-property-change 1 0.676 376
----------------------------------------------------------------
Total 148 100.00
One tick = 1 ms
nil
Analysis
--------
Well, I'm not an xemacs expert, but it looks to this layman that the print
functions don't get along well with extents, for whatever reason. The number
of calls to prin1 and princ (and whatever anonymous compiled function that
called them) in the last two trials were exactly the same, and higher than
in the first two, but the time spent in them was far less, especially in
Trial 4. Hmmm...
Hope this helps,
Chris
--
ben
I'm sometimes slow in getting around to reading my mail, so if you
want to reach me faster, call 520-661-6661.
See
http://www.666.com/ben/chronic-pain/ for the hell I've been
through.