[xemacs-hg @ 2003-02-07 11:50:50 by ben] fixes for menu crashes + better preemption behavior This contains two related changes: (1) Fix problems with reentrant calling of lwlib and associated crashes when selecting menu items. (2) Improve redisplay handling of preemption. Turn on lazy lock and hold down page-down or page-up and you'll see what I mean. They are related because they both touch on the code that retrieves events and handles the internal queues. console-msw.h, event-msw.c, event-stream.c, events.h, menubar-msw.c, menubar-x.c, menubar.h: mswindows_protect_modal_loop() has been generalized to event_stream_protect_modal_loop(), and moved to event-stream.c. mswindows_in_modal_loop ->in_modal_loop likewise. Changes in event-msw.c and menubar-msw.c for the new names and calling format (use structures instead of static variables in menubar-msw.c). Delete former in_menu_callback and use in_modal_loop in its place. Remove emacs_mswindows_quit_check_disallowed_p(), superseded by in_modal_loop. Use event_stream_protect_modal_loop() in pre_activate_callback() so that we get no lwlib reentrancy. Rearrange some of the code in event-msw.c to be grouped better. Make mswindows_drain_windows_queue() respect in_modal_loop and do nothing if so. cmdloop.c, event-stream.c: Don't conditionalize on LWLIB_MENUBARS_LUCID when giving error when in_modal_loop, and give better error. event-Xt.c, event-gtk.c: If in_modal_loop, only retrieve process and timeout events. Don't retrieve any X events because processing them can lead to reentrancy in lwlib -> death. event-stream.c: Remove unused parameter to check_event_stream_ok() and change all callers. lisp.h, event-stream.c: Rearrange some functions for increased clarity -- in particular, group all the input-pending/QUIT-related stuff together, and put right next to next-event stuff, to which it's related. Add the concept of "HOW_MANY" -- when asking whether user input is pending, you can ask if at least HOW_MANY events are pending, not just if any are. Add parameter to detect_input_pending() for this. Change recursive_sit_for from a Lisp_Object (which could only be Qt or Qnil) to an int, like it should be. event-Xt.c, event-gtk.c, event-xlike-inc.c: New file. Abstract out similar code in event_{Xt/gtk}_pending_p() and write only once, using include-file tricks. Rewrite this function to implement HOW_MANY and only process events when not in_modal_loop. event-msw.c: Implement HOW_MANY and only process events when not in_modal_loop. event-tty.c: Implement HOW_MANY. redisplay.c: Add var `max-preempts' to control maximum number of preempts. (#### perhaps not useful) Rewrite preemption check so that, rather than preempting when any user events are available, only preempt when a certain number (currently 4) of them are backed up. This effectively allows redisplay to proceed to completion in the presence of a fast auto-repeat (usually the auto-repeating is generated dynamically as necessary), and you get much better display behavior with lazy-lock active. event-unixoid.c: Comment changes. event-stream.c: Rewrite discard-input much more simply and safely using the drain-queue functions. I think the old version might loop forever if called when in_modal_loop. SEMI-UNRELATED CHANGES: ----------------------- event-stream.c: Turn QUIT-checking back on when running the pre-idle hook so it can be quit out of. indent.c: Document exact functioning of `vertical-motion' better, and its differences from GNU Emacs.

--- a/src/redisplay.c	Fri Feb 07 01:43:07 2003 +0000
+++ b/src/redisplay.c	Fri Feb 07 11:50:54 2003 +0000
@@ -1,7 +1,7 @@
 /* Display generation from window structure and buffer text.
    Copyright (C) 1994, 1995, 1996 Board of Trustees, University of Illinois.
    Copyright (C) 1995 Free Software Foundation, Inc.
-   Copyright (C) 1995, 1996, 2000, 2001, 2002 Ben Wing.
+   Copyright (C) 1995, 1996, 2000, 2001, 2002, 2003 Ben Wing.
    Copyright (C) 1995 Sun Microsystems, Inc.
    Copyright (C) 1996 Chuck Thompson.
 
@@ -314,14 +314,17 @@
 
 /* This used to be 10 but 30 seems to give much better performance. */
 #define INIT_MAX_PREEMPTS	30
-static int max_preempts;
+static Fixnum max_preempts;
+
+#define QUEUED_EVENTS_REQUIRED_FOR_PREEMPTION 4
 
 #define REDISPLAY_PREEMPTION_CHECK					\
 ((void)									\
  (preempted =								\
   (!disable_preemption &&						\
    ((preemption_count < max_preempts) || !NILP (Vexecuting_macro)) &&	\
-   (!INTERACTIVE || detect_input_pending ()))))
+   (!INTERACTIVE || 							\
+    detect_input_pending (QUEUED_EVENTS_REQUIRED_FOR_PREEMPTION)))))
 
 /*
  * Redisplay global variables.
@@ -9606,7 +9609,6 @@
 {
   disable_preemption = 0;
   preemption_count = 0;
-  max_preempts = INIT_MAX_PREEMPTS;
 
 #ifndef PDUMP
   if (!initialized)
@@ -9734,6 +9736,11 @@
 */ );
   cache_adjustment = 2;
 
+  DEFVAR_INT ("maximum-preempts", &max_preempts /*
+Maximum number of times redisplay can be preempted by user input.
+*/ );
+  max_preempts = INIT_MAX_PREEMPTS;
+
   DEFVAR_INT_MAGIC ("pixel-vertical-clip-threshold", &vertical_clip /*
 Minimum pixel height for clipped bottom display line.
 A clipped line shorter than this won't be displayed.