[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 Remove emacs_mswindows_quit_check_disallowed_p(), superseded by in_modal_loop.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/event-tty.c	Fri Feb 07 01:43:07 2003 +0000
+++ b/src/event-tty.c	Fri Feb 07 11:50:54 2003 +0000
@@ -1,7 +1,7 @@
 /* The event_stream interface for tty's.
    Copyright (C) 1994, 1995 Board of Trustees, University of Illinois.
    Copyright (C) 1995 Sun Microsystems, Inc.
-   Copyright (C) 1995, 2002 Ben Wing.
+   Copyright (C) 1995, 2002, 2003 Ben Wing.
 
 This file is part of XEmacs.
 
@@ -69,7 +69,8 @@
   /* timeout events have nil as channel */
   SET_EVENT_TYPE (emacs_event, timeout_event);
   SET_EVENT_TIMESTAMP_ZERO (emacs_event); /* #### */
-  SET_EVENT_TIMEOUT_INTERVAL_ID (emacs_event, pop_low_level_timeout (&tty_timer_queue, 0));
+  SET_EVENT_TIMEOUT_INTERVAL_ID (emacs_event,
+				 pop_low_level_timeout (&tty_timer_queue, 0));
   SET_EVENT_TIMEOUT_FUNCTION (emacs_event, Qnil);
   SET_EVENT_TIMEOUT_OBJECT (emacs_event, Qnil);
 }
@@ -77,9 +78,9 @@
 
 
 static int
-emacs_tty_event_pending_p (int user_p)
+emacs_tty_event_pending_p (int how_many)
 {
-  if (!user_p)
+  if (!how_many)
     {
       EMACS_TIME sometime;
       /* see if there's a pending timeout. */
@@ -87,10 +88,14 @@
       if (tty_timer_queue &&
 	  EMACS_TIME_EQUAL_OR_GREATER (sometime, tty_timer_queue->time))
 	return 1;
+
+      return poll_fds_for_input (non_fake_input_wait_mask);
     }
 
-  return poll_fds_for_input (user_p ? tty_only_mask :
-			     non_fake_input_wait_mask);
+  /* #### Not right!  We need to *count* the number of pending events, which
+     means we need to have a dispatch queue and drain the pending events,
+     using drain_tty_devices(). */
+  return poll_fds_for_input (tty_only_mask);
 }
 
 static void