[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 Remove emacs_mswindows_quit_check_disallowed_p(), superseded by in_modal_loop.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.

/* code is all from loser.c and loser.el by Mly

Copyright (C) 2002 Richard Mlynarik <mly@pobox.com>

This is part of XEmacs

Compile this file.  Run it in the background giving it a command line
argument PORT which is a positive integer 1024 < PORT < 32768 (avoid the
numbers assigned in /etc/services).

Then start up a fresh (you're going to crash) XEmacs.  Execute the following

(defun lose (port)
  (interactive "nUrk: ")
  (require 'comint)
  (while t
    (condition-case e
        (let* ((name "*lose*")
	       (b (get-buffer-create name)))
          (switch-to-buffer b)
          (comint-mode)
          (comint-exec b name (cons "127.0.0.1" port) nil '())
          (process-send-string (get-buffer-process b) "\377\373\001")
          (process-send-string (get-buffer-process b) "\377\373\001"))
      (error (message "URK: %s" e)) (sit-for 1))))

Then M-x lose RET PORT RET and you lose big (in XEmacs 21.1, anyway).
Note: the error messages are proper functioning.  What should eventually
happen after a number of SIGPIPEs is that you get a SIGSEGV and life is
bad and XEmacs is dead.
*/

#include <arpa/inet.h>

int
main (int argc, char **argv)
{
  struct sockaddr_in junk;
  int s;

  memset (&junk, 0, sizeof (junk));

  junk.sin_family = AF_INET;
  junk.sin_addr.s_addr = htonl (INADDR_ANY); /* un*x sucks */
  junk.sin_port = htons (atoi (argv[1])); /* un*x blows */

  s = socket (PF_INET, SOCK_STREAM, 0);

  bind (s, (struct sockaddr *)&junk, sizeof (junk));

  listen (s, 1);
  
  for (;;)
  {
    int loser = accept (s, NULL, 0);
    close (loser);
  }
}