Re: The history of sit_for vs sit-for

[Kim Storm <storm@cua.dk>]

Hi Stefan

Maybe this thread will explain why and how...

http://lists.gnu.org/archive/html/emacs-devel/2006-07/msg00401.html

Kim

On 2014-05-29 16:18, Stefan Monnier wrote:
> Hi Yidong and Kim,
>
> Around July 2006, a whole bunch of sit-for related changes were made
> resulting among other things in moving `sit-for' to Elisp (while
> keeping a `sit_for' implemented in C as well).
>
> Do you guys remember what this was about?
> We're having problems still with sit-for, because it uses `read-event'
> and then pushes those back to unread-command-events and this bumps into
> various problems in corner cases.
>
> It seems that the C version `sit_for' does not suffer from those
> problems, so I'm strongly tempted to move `sit-for' back to C, but I'd
> rather not just go back to some old problem.
>
> See appended some of the relevant commit messages, in the hopes that it
> might help your memory.
>
>
>          Stefan
>
>
> revno: 72101
> committer: Chong Yidong <cyd@stupidchicken.com>
> timestamp: Wed 2006-07-26 18:18:26 +0000
> message:
>    	* subr.el (sit-for): Use new SECONDS arg of read-event instead of
>    	a timer.
> ------------------------------------------------------------
> revno: 72059
> committer: Richard M. Stallman <rms@gnu.org>
> timestamp: Mon 2006-07-24 17:01:08 +0000
> message:
>    (dolist, dotimes): Use interned symbols for iteration.
>    (--dotimes-limit--, --dolist-tail--): New defvars.
>    (looking-back): Doc fix.
> ------------------------------------------------------------
> revno: 71924
> committer: Chong Yidong <cyd@stupidchicken.com>
> timestamp: Tue 2006-07-18 01:34:48 +0000
> message:
>    	* subr.el (sit-for): Just sleep-for if noninteractive.
> ------------------------------------------------------------
> revno: 71738
> committer: Kim F. Storm <storm@cua.dk>
> timestamp: Tue 2006-07-11 00:17:43 +0000
> message:
>    (sit-for): Doc fix.  Specify normal arg list using fn-form.
>    Remove special case for seconds < 0.  Use (redisplay t) instead.
> ------------------------------------------------------------
> revno: 71735
> committer: Kim F. Storm <storm@cua.dk>
> timestamp: Mon 2006-07-10 23:54:17 +0000
> message:
>    (Fredisplay): Doc fix.
> ------------------------------------------------------------
> revno: 71734
> committer: Kim F. Storm <storm@cua.dk>
> timestamp: Mon 2006-07-10 23:52:38 +0000
> message:
>    (Fredisplay): Add FORCE argument to force redisplay when
>    input is available.  Fix test for redisplay_dont_pause non-nil.
>    Specbind redisplay-dont-pause to t if FORCE non-nil.
> ------------------------------------------------------------
> revno: 71726
> committer: Chong Yidong <cyd@stupidchicken.com>
> timestamp: Mon 2006-07-10 18:52:13 +0000
> message:
>    	* subr.el (sit-for): New function.
>    
>    	* play/hanoi.el (hanoi-sit-for): Check sit-for return value.
> ------------------------------------------------------------
> revno: 71724
> committer: Chong Yidong <cyd@stupidchicken.com>
> timestamp: Mon 2006-07-10 18:51:31 +0000
> message:
>    	* puresize.h (BASE_PURESIZE): Increment to 1211000.
>    
>    	* dispnew.c (Fredisplay): New function, equivalent to (sit-for 0).
>    	(Fsit_for): Function deleted.
>    
>    	* keyboard.c (command_loop_1, Fexecute_extended_command): Call
>    	sit_for instead of Fsit_for.
>    
>    	* minibuf.c (temp_echo_area_glyphs): Likewise.
> ------------------------------------------------------------
> revno: 71536
> committer: Kim F. Storm <storm@cua.dk>
> timestamp: Mon 2006-07-03 15:00:28 +0000
> message:
>    (sit_for): Fix preempt condition.
> ------------------------------------------------------------
> revno: 71341
> committer: Kim F. Storm <storm@cua.dk>
> timestamp: Sat 2006-06-17 00:11:59 +0000
> message:
>    (update_frame): Check for input pending on entry.
>    (update_window, update_frame_1): Break loop if input is detected.
> ------------------------------------------------------------
> revno: 71296
> committer: Kim F. Storm <storm@cua.dk>
> timestamp: Tue 2006-06-13 22:06:22 +0000
> message:
>    (sit_for): Undo 2006-06-01 change.  Instead, a
>    negative time forces redisplay even when input is available.
>    (Fsit_for): Doc fix.
> ------------------------------------------------------------
> revno: 71286
> committer: Kim F. Storm <storm@cua.dk>
> timestamp: Mon 2006-06-12 22:32:47 +0000
> message:
>    Modify preemptive redisplay to be based on periodic checks for input.
>    (PERIODIC_PREEMPTION_CHECKING): Define to 1 iff EMACS_HAS_USECS.
>    (Vredisplay_preemption_period): New variable.
>    (syms_of_display): DEFVAR_LISP and initialize it.
>    (preemption_period, preemption_next_check): New variables.
>    (update_frame, update_single_window): Initialize them based on
>    Vredisplay_preemption_period if !force_p.
>    (update_window, update_frame_1): Use them to determine when to
>    check for input.
> ------------------------------------------------------------
> revno: 71174
> committer: David Kastrup <dak@gnu.org>
> timestamp: Sun 2006-06-04 15:07:25 +0000
> message:
>    Mention `redisplay-dont-pause' in doc string of
>    `sit-for'.
> ------------------------------------------------------------
> revno: 71104
> committer: Richard M. Stallman <rms@gnu.org>
> timestamp: Thu 2006-06-01 21:04:58 +0000
> message:
>    Whitespace changes.
> ------------------------------------------------------------
> revno: 71101
> committer: Kim F. Storm <storm@cua.dk>
> timestamp: Thu 2006-06-01 13:53:19 +0000
> message:
>    (sit_for): Perform redisplay even if input is pending
>    when redisplay-dont-pause is non-nil.
>
>