@tindex redisplay-preemption-period
@defvar redisplay-preemption-period
-This variable controls how often Emacs checks for new input during
-redisplay. The default setting is to check for input every 0.1
-seconds after redisplay has started. If input arrives, redisplay
-stops, and all available input is processed before redisplay starts over.
- If this variable is set to @code{nil}, redisplay--once started--is never
-preempted by input.
+This variable specifies how many seconds Emacs waits between checks
+for new input during redisplay. (The default is 0.1 seconds.) If
+input has arrived when Emacs checks, it pre-empts redisplay and
+processes the available input before trying again to redisplay.
+
+If this variable is @code{nil}, Emacs does not check for input during
+redisplay, and redisplay cannot be preempted by input.
@emph{Note} that this variable is only available if Emacs is built
with support for sub-second timers.
regardless of whether input is available.
@end defvar
+@tindex sit-for
You can request a display update, but only if no input is pending,
with @code{(sit-for 0)}. To force a display update even when input is
-pending, do this:
-
-@example
-(let ((redisplay-dont-pause t))
- (sit-for 0))
-@end example
+pending, use @code{(sit-for -1)}.
@node Truncation
@section Truncation