Re: Old/unused display bits

[Eli Zaretskii]

> Date: Fri, 25 Jan 2013 16:22:09 +0400
> From: Dmitry Antipov <address@hidden>
> CC: Eli Zaretskii <address@hidden>
> 
> IIUC these bits are either the leftovers from old
> code or has no real users; can we get rid of them?

Kim, is there a reason to keep this?

> === modified file 'src/dispnew.c'
> --- src/dispnew.c     2013-01-23 20:07:28 +0000
> +++ src/dispnew.c     2013-01-25 10:49:31 +0000
> @@ -107,12 +107,6 @@
>  static void adjust_frame_glyphs_for_window_redisplay (struct frame *);
>  static void adjust_frame_glyphs_for_frame_redisplay (struct frame *);
>  
> -
> -/* Redisplay preemption timers.  */
> -
> -static EMACS_TIME preemption_period;
> -static EMACS_TIME preemption_next_check;
> -
>  /* True upon entry to redisplay means do not assume anything about
>     current contents of actual terminal frame; clear and redraw it.  */
>  
> @@ -122,9 +116,8 @@
>  
>  bool display_completed;
>  
> -Lisp_Object Qdisplay_table, Qredisplay_dont_pause;
> +Lisp_Object Qdisplay_table;
>  
> -
>  /* The currently selected frame.  In a single-frame version, this
>     variable always equals the_only_frame.  */
>  
> @@ -3078,23 +3071,10 @@
>    bool paused_p;
>    struct window *root_window = XWINDOW (f->root_window);
>  
> -  if (redisplay_dont_pause)
> -    force_p = 1;
> -  else if (NILP (Vredisplay_preemption_period))
> -    force_p = 1;
> -  else if (!force_p && NUMBERP (Vredisplay_preemption_period))
> +  if (!force_p && detect_input_pending_ignore_squeezables ())
>      {
> -      double p = XFLOATINT (Vredisplay_preemption_period);
> -
> -      if (detect_input_pending_ignore_squeezables ())
> -     {
> -       paused_p = 1;
> -       goto do_pause;
> -     }
> -
> -      preemption_period = EMACS_TIME_FROM_DOUBLE (p);
> -      preemption_next_check = add_emacs_time (current_emacs_time (),
> -                                           preemption_period);
> +      paused_p = 1;
> +      goto do_pause;
>      }
>  
>    if (FRAME_WINDOW_P (f))
> @@ -3230,18 +3210,6 @@
>        /* Record that this is not a frame-based redisplay.  */
>        set_frame_matrix_frame (NULL);
>  
> -      if (redisplay_dont_pause)
> -     force_p = 1;
> -      else if (NILP (Vredisplay_preemption_period))
> -     force_p = 1;
> -      else if (!force_p && NUMBERP (Vredisplay_preemption_period))
> -     {
> -       double p = XFLOATINT (Vredisplay_preemption_period);
> -       preemption_period = EMACS_TIME_FROM_DOUBLE (p);
> -       preemption_next_check = add_emacs_time (current_emacs_time (),
> -                                               preemption_period);
> -     }
> -
>        /* Update W.  */
>        update_begin (f);
>        update_window (w, force_p);
> @@ -3394,9 +3362,7 @@
>  {
>    struct glyph_matrix *desired_matrix = w->desired_matrix;
>    bool paused_p;
> -#if !PERIODIC_PREEMPTION_CHECKING
>    int preempt_count = baud_rate / 2400 + 1;
> -#endif
>    struct redisplay_interface *rif = FRAME_RIF (XFRAME (WINDOW_FRAME (w)));
>  #ifdef GLYPH_DEBUG
>    /* Check that W's frame doesn't have glyph matrices.  */
> @@ -3404,10 +3370,8 @@
>  #endif
>  
>    /* Check pending input the first time so that we can quickly return.  */
> -#if !PERIODIC_PREEMPTION_CHECKING
>    if (!force_p)
>      detect_input_pending_ignore_squeezables ();
> -#endif
>  
>    /* If forced to complete the update, or if no input is pending, do
>       the update.  */
> @@ -3418,9 +3382,7 @@
>        struct glyph_row *header_line_row;
>        int yb;
>        bool changed_p = 0, mouse_face_overwritten_p = 0;
> -#if ! PERIODIC_PREEMPTION_CHECKING
>        int n_updated = 0;
> -#endif
>  
>        rif->update_window_begin_hook (w);
>        yb = window_text_bottom_y (w);
> @@ -3484,22 +3446,8 @@
>              detect_input_pending.  If it's done too often,
>              scrolling large windows with repeated scroll-up
>              commands will too quickly pause redisplay.  */
> -#if PERIODIC_PREEMPTION_CHECKING
> -         if (!force_p)
> -           {
> -             EMACS_TIME tm = current_emacs_time ();
> -             if (EMACS_TIME_LT (preemption_next_check, tm))
> -               {
> -                 preemption_next_check = add_emacs_time (tm,
> -                                                         preemption_period);
> -                 if (detect_input_pending_ignore_squeezables ())
> -                   break;
> -               }
> -           }
> -#else
>           if (!force_p && ++n_updated % preempt_count == 0)
>             detect_input_pending_ignore_squeezables ();
> -#endif
>           changed_p |= update_window_line (w, vpos,
>                                            &mouse_face_overwritten_p);
>  
> @@ -4531,13 +4479,11 @@
>    if (preempt_count <= 0)
>      preempt_count = 1;
>  
> -#if !PERIODIC_PREEMPTION_CHECKING
>    if (!force_p && detect_input_pending_ignore_squeezables ())
>      {
>        pause_p = 1;
>        goto do_pause;
>      }
> -#endif
>  
>    /* If we cannot insert/delete lines, it's no use trying it.  */
>    if (!FRAME_LINE_INS_DEL_OK (f))
> @@ -4578,21 +4524,8 @@
>               }
>           }
>  
> -#if PERIODIC_PREEMPTION_CHECKING
> -       if (!force_p)
> -         {
> -           EMACS_TIME tm = current_emacs_time ();
> -           if (EMACS_TIME_LT (preemption_next_check, tm))
> -             {
> -               preemption_next_check = add_emacs_time (tm, 
> preemption_period);
> -               if (detect_input_pending_ignore_squeezables ())
> -                 break;
> -             }
> -         }
> -#else
>         if (!force_p && (i - 1) % preempt_count == 0)
>           detect_input_pending_ignore_squeezables ();
> -#endif
>  
>         update_frame_line (f, i);
>       }
> @@ -4698,9 +4631,7 @@
>       }
>      }
>  
> -#if !PERIODIC_PREEMPTION_CHECKING
>   do_pause:
> -#endif
>  
>    clear_desired_matrices (f);
>    return pause_p;
> @@ -5893,33 +5824,19 @@
>  
>  DEFUN ("redisplay", Fredisplay, Sredisplay, 0, 1, 0,
>         doc: /* Perform redisplay.
> -Optional arg FORCE, if non-nil, prevents redisplay from being
> -preempted by arriving input, even if `redisplay-dont-pause' is nil.
> -If `redisplay-dont-pause' is non-nil (the default), redisplay is never
> -preempted by arriving input, so FORCE does nothing.
> +Optional arg FORCE does nothing and used for backward compatibility.
>  
>  Return t if redisplay was performed, nil if redisplay was preempted
>  immediately by pending input.  */)
>    (Lisp_Object force)
>  {
> -  ptrdiff_t count;
> -
>    swallow_events (1);
> -  if ((detect_input_pending_run_timers (1)
> -       && NILP (force) && !redisplay_dont_pause)
> -      || !NILP (Vexecuting_kbd_macro))
> +  if (detect_input_pending_run_timers (1) || !NILP (Vexecuting_kbd_macro))
>      return Qnil;
> -
> -  count = SPECPDL_INDEX ();
> -  if (!NILP (force) && !redisplay_dont_pause)
> -    specbind (Qredisplay_dont_pause, Qt);
>    redisplay_preserve_echo_area (2);
> -  unbind_to (count, Qnil);
>    return Qt;
>  }
>  
> -
> -
>  /***********************************************************************
>                        Other Lisp Functions
>   ***********************************************************************/
> @@ -6335,7 +6252,6 @@
>    staticpro (&frame_and_buffer_state);
>  
>    DEFSYM (Qdisplay_table, "display-table");
> -  DEFSYM (Qredisplay_dont_pause, "redisplay-dont-pause");
>  
>    DEFVAR_INT ("baud-rate", baud_rate,
>             doc: /* The output baud rate of the terminal.
> @@ -6406,19 +6322,6 @@
>  See `buffer-display-table' for more information.  */);
>    Vstandard_display_table = Qnil;
>  
> -  DEFVAR_BOOL ("redisplay-dont-pause", redisplay_dont_pause,
> -            doc: /* Non-nil means display update isn't paused when input is 
> detected.  */);
> -  redisplay_dont_pause = 1;
> -
> -#if PERIODIC_PREEMPTION_CHECKING
> -  DEFVAR_LISP ("redisplay-preemption-period", Vredisplay_preemption_period,
> -            doc: /* Period in seconds between checking for input during 
> redisplay.
> -This has an effect only if `redisplay-dont-pause' is nil; in that
> -case, arriving input preempts redisplay until the input is processed.
> -If the value is nil, redisplay is never preempted.  */);
> -  Vredisplay_preemption_period = make_float (0.10);
> -#endif
> -
>  #ifdef CANNOT_DUMP
>    if (noninteractive)
>  #endif
> 
> === modified file 'src/xdisp.c'
> --- src/xdisp.c       2013-01-24 05:41:28 +0000
> +++ src/xdisp.c       2013-01-25 10:51:24 +0000
> @@ -10697,14 +10697,9 @@
>                needs to run hooks.  */
>             && !NILP (Vrun_hooks))
>           {
> -           /* Must update other windows.  Likewise as in other
> -              cases, don't let this update be interrupted by
> -              pending input.  */
> -           ptrdiff_t count = SPECPDL_INDEX ();
> -           specbind (Qredisplay_dont_pause, Qt);
> +           /* Must update other windows.  */
>             windows_or_buffers_changed = 1;
>             redisplay_internal ();
> -           unbind_to (count, Qnil);
>           }
>         else if (FRAME_WINDOW_P (f) && n == 0)
>           {
>