1 -*- coding: utf-8; mode: text; -*-
5 This branch implements support for opening multiple, different tty
6 devices and simultaneous X and tty frames from a single Emacs session.
9 Emacs is notoriously slow at startup, so most people use another
10 editor or emacsclient for quick editing jobs from the console.
11 Unfortunately, emacsclient was very awkward to use, because it did not
12 support opening a new Emacs frame on the current virtual console.
13 Now, with multi-tty support, it can do that. (Emacsclient starts up
16 Some Gnus users (including me) run Gnus in an X frame in its own Emacs
17 instance, which they typically leave running for weeks. It would be
18 nice if they could connect to this instance from a remote ssh session
19 and check their messages without opening a remote X frame or resorting
25 I'm Károly Lőrentey. My address: lorentey@elte.hu.
27 Comments, bug reports, suggestions and patches are welcome; send them
28 to multi-tty@lists.fnord.hu.
30 The following is a (sadly incomplete) list of people who have
31 contributed to the project by testing, submitting patches, bug
32 reports, and suggestions. Thanks!
34 Bernard Adrian <bernadrian@free.fr>
35 ARISAWA Akihiro <ari@mbf.ocn.ne.jp>
36 Vincent Bernat <bernat@luffy.cx>
37 Han Boetes <han@mijncomputer.nl>
38 Francisco Borges <borges@let.rug.nl>
39 Damien Cassou <damien.cassou@laposte.net>
40 Robert J. Chassell <bob@rattlesnake.com>
41 Romain Francoise <romain@orebokech.com>
42 Ami Fischman <ami@fischman.org>
43 Friedrich Delgado Friedrichs <friedel@nomaden.org>
44 IRIE Tetsuya <irie@t.email.ne.jp>
45 Yoshiaki Kasahara <kasahara@nc.kyushu-u.ac.jp>
46 Bas Kok <nekkobassu@yahoo.com>
47 Jurej Kubelka <Juraj.Kubelka@email.cz>
48 David Lichteblau <david@lichteblau.com>
49 Xavier Mallard <zedek@gnu-rox.org>
50 Istvan Marko <mi-mtty@kismala.com>
51 Ted Morse <morse@ciholas.com>
52 Gergely Nagy <algernon@debian.org>
53 Dan Nicolaescu <dann@ics.uci.edu>
54 Kalle Olavi Niemitalo <kon@iki.fi>
55 Mark Plaksin <happy@mcplaksin.org>
56 Frank Ruell <stoerte@dreamwarrior.net>
57 Tom Schutzer-Weissmann <trmsw@yahoo.co.uk>
58 Joakim Verona <joakim@verona.se>
59 Dan Waber <dwaber@logolalia.com>
62 Richard Stallman was kind enough to review an earlier version of my
69 The multi-tty mailing list (discussion & bug reports):
71 Address: multi-tty@lists.fnord.hu
72 Signup: http://lists.fnord.hu/mailman/listinfo/multi-tty
73 Archive: http://news.gmane.org/gmane.emacs.multi-tty/
75 Commit notifications (read-only):
77 Address: multi-tty-commits@lists.fnord.hu
78 Signup: http://lists.fnord.hu/mailman/listinfo/multi-tty-commits
84 The branch is now very stable and almost full-featured. All of the
85 major problems have been fixed, only a few minor issues remain. (It
86 still needs to be ported to Windows/Mac/DOS, though.) Both multiple
87 tty device support and simultaneous X and tty frame support works
88 fine. Emacsclient has been extended to support opening new tty and X
89 frames. It has been changed open new Emacs frames by default.
91 The multi-tty branch has been scheduled for inclusion in the next
92 major release of Emacs (version 23). I expect the merge into the
93 development trunk to occur sometime during next year (2006), after the
94 merge of the Unicode branch.
96 Tested on GNU/Linux, Solaris 8, FreeBSD and OpenBSD. Please let me
97 know if you succeed or fail to use it on other platforms---I'll have a
98 few tricky test cases for you.
102 * GTK support. If you compile your Emacs with the GTK
103 toolkit, some functionality of multi-tty will be lost. In
104 particular, you will not be able to work on multiple X
105 displays at once. Current releases of GTK have limitations
106 and bugs that prevent full-blown multi-display support in
107 Emacs. (GTK crashes when Emacs tries to disconnect from an
108 X server.) Use the Lucid toolkit if you want to see a
109 complete feature set.
111 * The single-kboard mode.
113 If your multi-tty Emacs session seems to be frozen, you
114 probably have a recursive editing session or a pending
115 minibuffer prompt (which is a kind of recursive editing) on
116 another display. To unfreeze your session, switch to that
117 display and complete the recursive edit, for example by
118 pressing C-] (`abort-recursive-edit').
120 I am sorry to say that currently there is no way to break
121 out of this "single-kboard mode" from a frozen display. If
122 you are unable to switch to the display that locks the
123 others (for example because it is on a remote computer),
124 then you can use emacsclient to break out of all recursive
127 emacsclient -e '(top-level)'
129 Note that this (perhaps) unintuitive behaviour is by design.
130 Single-kboard mode is required because of an intrinsic Emacs
131 limitation that is very hard to eliminate. (This limitation
132 is related to the single-threaded nature of Emacs.)
134 I plan to implement better user notification and support for
135 breaking out of single-kboard mode from locked displays.
137 * Mac, Windows and DOS support is broken, doesn't even
138 compile. Multiple display support will probably not provide
139 new Emacs features on these systems, but the multi-tty
140 branch changed a few low-level interfaces, and the
141 system-dependent source files need to be adapted
142 accordingly. The changes are mostly trivial, so almost
143 anyone can help, if only by compiling the branch and
144 reporting the compiler errors.
147 HOW TO GET THE BRANCH
148 ---------------------
150 The branch uses Bazaar 1 (http://bazaar.canonical.com) for version control.
152 Retrieving the latest version of the branch:
154 baz register-archive -f http://aszt.inf.elte.hu/~lorentey/mirror/arch/2004
155 baz get lorentey@elte.hu--2004/emacs--multi-tty <directory>
157 This incantation uses an archive mirror that is hosted on a
158 high-bandwidth site. Please note that on average there is a two-hour
159 delay for commits to arrive on this mirror. My primary mirror is on the
160 low-bandwidth http://lorentey.hu/ site:
162 baz register-archive -f http://lorentey.hu/arch/2004/
163 baz get lorentey@elte.hu--2004/emacs--multi-tty <directory>
165 This is "instantly" updated, but very slow from outside Hungary.
166 (By "instantly" I mean as soon as I connect the notebook I work on to
167 a network. It could take days.)
169 The Arch supermirror provides mirroring services for all public Arch
170 repositories. We have a mirror there, too, if you prefer.
172 baz register-archive -f http://mirrors.sourcecontrol.net/lorentey%40elte.hu--2004
173 baz get lorentey@elte.hu--2004/emacs--multi-tty <directory>
175 My GPG key id is 0FB27A3F; it is available from
176 hkp://wwwkeys.eu.pgp.net/, or from my homepage at
177 http://lorentey.hu/rolam/gpg.html)
179 Don't worry if the above checkout takes a few minutes to complete;
180 once you have a source tree, updating it to the latest revision will
181 be _much_ faster. Use the following command for the update:
185 You can find more information about Bazaar on
186 http://bazaar.canonical.com/. It's a distributed source control
187 system that is somewhat less broken than competing projects.
189 If you don't have Bazaar, the branch has a homepage from which you can
190 download conventional patches against Emacs CVS HEAD:
192 http://lorentey.hu/project/emacs.html
194 I suggest you use Bazaar whenever feasible.
200 If you run Debian, or a distribution based on Debian, you are welcome
201 to use our binary packages; put these lines in your /etc/apt/sources.list:
204 deb http://aszt.inf.elte.hu/~lorentey/mirror/apt unstable multi-tty
205 deb-src http://aszt.inf.elte.hu/~lorentey/mirror/apt unstable multi-tty
207 Note that these packages are intended solely to provide an easy way to
208 test the new multi-tty features. They are not to be taken as Emacs
209 releases, and it's a mistake to expect robust operation or any kind of
210 timely support for them. Do not install them, unless you'd like to
211 have your editor crash on you.
217 The multi-tty branch is compiled the same way as Emacs itself:
219 make maintainer-clean # (If you have compiled Emacs before)
221 ./configure --without-gtk <your favourite options>
225 If you have strange compilation errors, they may be caused by old
226 *.elc files that are left over from an earlier bootstrap. The `make
227 maintainer-clean' target deletes them, so it is a good idea to run
228 that before reporting a bug. (Emacs requires a clean recompilation
229 after certain kinds of source code changes.)
234 To test the multi-tty branch, start up the Emacs server with the
240 and then (from a shell prompt on another terminal) start emacsclient
242 emacsclient -t /optional/file/names... (for a tty frame)
243 emacsclient /optional/file/names... (for an X frame)
245 (Make sure both emacs and emacsclient are multi-tty versions.)
246 You'll hopefully have two fully working, independent frames on
247 separate terminals. The new frame is closed automatically when you
248 finish editing the specified files (C-x #), but delete-frame (C-x 5 0)
249 also works. Of course, you can create frames on more than two tty
252 Creating new frames on the same tty with C-x 5 2 (make-frame-command)
253 works, and they behave the same way as in previous Emacs versions. If
254 you exit emacs, all terminals should be restored to their previous
257 This is work in progress, and probably full of bugs. It is a good
258 idea to run emacs from gdb, so that you'll have a live instance to
259 debug if something goes wrong. Please send me your bug reports on our
260 mailing list: multi-tty@lists.fnord.hu
265 I think the best way to use the new Emacs is to have it running inside
266 a disconnected GNU screen session, and always use emacsclient for
267 normal work. One advantage of this is that not a single keystroke of
268 your work will be lost if the display device that you are using
269 crashes, or the network connection times out, or whatever. (I had an
270 extremely unstable X server for some time while I was developing these
271 patches, and running Emacs this way has saved me a number of M-x
272 recover-session invocations.)
274 I use the following two bash scripts to handle my Emacs sessions:
276 -------------------------------------------------------connect-emacs--
278 # Usage: connect-emacs <name> <args>...
280 # Connects to the Emacs instance called NAME. Starts up the instance
281 # if it is not already running. The rest of the arguments are passed
287 if [ -z "$name" ]; then
288 echo "Usage: connect_emacs <name> <args>..." >&2
291 preload-emacs "$name" wait
292 /usr/bin/emacsclient.emacs-multi-tty -s "$name" "$@"
293 ----------------------------------------------------------------------
295 -------------------------------------------------------preload-emacs--
297 # Usage: preload-emacs <name> [<waitp>]
299 # Preloads the Emacs instance called NAME in a detached screen
300 # session. Does nothing if the instance is already running. If WAITP
301 # is non-empty, the function waits until the server starts up and
302 # creates its socket; otherwise it returns immediately.
306 screendir="/var/run/screen/S-$USER"
307 serverdir="/tmp/emacs$UID"
308 emacs=/usr/bin/emacs-multi-tty # Or wherever you installed your multi-tty Emacs
310 if [ -z "$name" ]; then
311 echo "Usage: preload_emacs <name> [<waitp>]" >&2
315 if [ ! -e "$screendir"/*."$name" ]; then
316 if [ -e "$serverdir/$name" ]; then
317 # Delete leftover socket (for the wait option)
318 rm "$serverdir/$name"
320 screen -dmS "$name" "$emacs" -nw --eval "(setq server-name \"$name\")" -f server-start
322 if [ ! -z "$waitp" ]; then
323 while [ ! -e "$serverdir/$name" ]; do sleep 0.1; done
325 ----------------------------------------------------------------------
327 I have the following in my profile to have two instances automatically
328 preloaded for editing and email:
333 It is useful to set up short aliases for connect-emacs. I use the
336 alias edit="connect-emacs editor"
338 alias et="connect-emacs editor -t"
339 alias gnus="connect-emacs gnus"
351 For the NEWS file: (Needs much, much work)
353 ** Support for multiple terminal devices has been added.
355 *** You can specify a terminal device (`tty' parameter) and a terminal
356 type (`tty-type' parameter) to `make-terminal-frame'.
358 *** You can test for the presence of multiple terminal support by
359 testing for the `multi-tty' feature.
361 *** Emacsclient has been extended to support opening a new terminal
362 frame. Its behaviour has been changed to open a new Emacs frame by
363 default. Use the -c option to get the old behavior of opening
364 files in the currently selected Emacs frame.
366 *** A make-frame-on-tty function has been added to make it easier to
367 create frames on new terminals.
369 *** New functions: frame-tty-name, frame-tty-type, delete-tty,
370 terminal-local-value, set-terminal-local-value
372 terminal-id, terminal-parameters, terminal-parameter,
373 set-terminal-parameter
375 *** New variables: global-key-translation-map
377 *** The keymaps key-translation-map and function-key-map are now
380 ** Support for simultaneous graphical and terminal frames has been
383 *** The function `make-frame-on-display' now works during a terminal
384 session, and `make-frame-on-tty' works during a graphical session.
386 *** The `window-system' variable has been made frame-local.
388 *** The new `initial-window-system' variable contains the
389 `window-system' value for the first frame.
391 *** talk.el has been extended for multiple tty support.
393 *** C-z now invokes `suspend-frame', C-x C-c now invokes
394 `save-buffers-kill-frame'.
398 (The rest of this file consists of my development notes and as such it
399 is probably not very interesting for anyone else.)
404 ** Trouble: `setenv' doesn't actually set environment variables in the
405 Emacs process. This defeats the purpose of the elaborate
406 `server-with-environment' magic around the `tgetent' call in
409 ** (Possibly) create hooks in struct device for creating frames on a
410 specific terminal, and eliminate the hackish terminal-related frame
411 parameters (display, tty, tty-type).
417 ** Move Fsend_string_to_terminal to term.c, and declare get_named_tty
418 as static, removing it from dispextern.h.
419 Move fatal to emacs.c and declare it somewhere.
421 ** Search for `suspend-emacs' references and replace them with
422 `suspend-frame', if necessary. Ditto for `save-buffers-kill-emacs'
423 vs. `save-buffers-kill-display'.
425 ** Emacs crashes when a tty frame is resized so that there is no space
426 for all its windows. (Tom Schutzer-Weissmann)
428 ** Report GTK multi-display problems to GTK maintainers. For extra
431 Currently you can not connect to new X displays when you compile
432 Emacs with GTK support. If you want to play around with GTK
433 multidisplay (and don't mind core dumps), you can edit src/config.h
434 and define HAVE_GTK_MULTIDISPLAY there by hand.
436 ** Audit `face-valid-attribute-values' usage in customize and
437 elsewhere. Its return value depends on the current window system.
438 Replace static initializers using it with runtime functions. For
439 example, custom's buttons are broken on non-initial device types.
441 ** Possibly turn off the double C-g feature when there is an X frame.
442 C.f. (emacs)Emergency Escape.
444 ** frames-on-display-list should also accept frames.
446 ** I smell something funny around pop_kboard's "deleted kboard" case.
447 Determine what are the circumstances of this case, and fix any
448 bug that comes to light.
450 ** Consider the `tty-type' frame parameter and the `display-tty-type'
451 function. They serve the exact same purpose. I think it may be
452 a good idea to eliminate one of them, preferably `tty-type'.
454 ** The handling of lisp/term/*.el, and frame creation in general, is a
455 big, big mess. How come the terminal-specific file is loaded by
456 tty-create-frame-with-faces? I don't think it is necessary to load
457 these files for each frame; once per terminal should be enough.
458 Update: lisp/term/*.el is not loaded repeatedly anymore, but
459 faces.el still needs to be cleaned up.
461 ** Fix frame-set-background-mode in this branch. It was recently
462 changed in CVS, and frame.el in multi-tty has not yet been adapted
463 for the changes. (It needs to look at
464 default-frame-background-mode.) (Update: maybe it is fixed now;
465 needs testing.) (Note that the byte compiler has this to say about
468 term/rxvt.el:309:17:Warning: assignment to free variable
469 `default-frame-background-mode'
471 ** I think `(set-)terminal-local-value' and the terminal parameter
472 mechanism should be integrated into a single framework.
474 (Update: `(set-)terminal-local-value' is now eliminated, but the
475 terminal-local variables should still be accessible as terminal
476 parameters. This also applies to `display-name' and similar
479 ** Add the following hooks: after-delete-frame-hook (for server.el,
480 instead of delete-frame-functions),
481 after-delete-terminal-functions, after-create-terminal-functions.
483 ** Fix set-input-mode for multi-tty. It's a truly horrible interface;
484 what if we'd blow it up into several separate functions (with a
485 compatibility definition)?
487 ** BULK RENAME: The `display-' prefix of new Lisp-level functions
488 conflicts with stuff like `display-time-mode'. Use `device-'
489 or `terminal-' instead. I think I prefer `terminal-'.
491 It turns out that most of the offending Lisp functions were defined
492 in the trunk. Therefore, compatibility aliases should be defined
493 for the following names:
495 display-color-cells terminal-color-cells
496 display-color-p terminal-color-p
497 display-graphic-p terminal-graphic-p
498 display-grayscale-p terminal-grayscale-p
499 display-images-p terminal-images-p
500 display-mm-height terminal-mm-height
501 display-mm-width terminal-mm-width
502 display-mouse-p terminal-mouse-p
503 display-multi-font-p terminal-multi-font-p
504 display-multi-frame-p terminal-multi-frame-p
505 display-pixel-height terminal-pixel-height
506 display-pixel-width terminal-pixel-width
507 display-pixels-per-inch terminal-pixels-per-inch
508 display-planes terminal-planes
509 display-popup-menus-p terminal-popup-menus-p
510 display-save-under terminal-save-under
511 display-screens terminal-screens
512 display-supports-face-attributes-p terminal-supports-face-attributes-p
513 display-visual-class terminal-visual-class
514 framep-on-display framep-on-terminal
515 frames-on-display-list frames-on-terminal-list
517 The following functions were introduced in the multi-tty branch, and
518 can be renamed without aliases:
520 display-controlling-tty-p terminal-controlling-tty-p
521 display-list terminal-list
522 display-live-p terminal-live-p
523 display-name terminal-name
524 display-tty-type terminal-tty-type
525 frame-display terminal-of-frame
526 delete-display delete-terminal
528 ** The single-keyboard mode of MULTI_KBOARD is extremely confusing
529 sometimes; Emacs does not respond to stimuli from other keyboards.
530 At least a beep or a message would be important, if the single-mode
531 is still required to prevent interference. (Reported by Dan
534 Update: selecting a region with the mouse enables single_kboard
535 under X. This is very confusing.
537 Update: After discussions with Richard Stallman, this will be
538 resolved by having locked displays warn the user to wait, and
539 introducing a complex protocol to remotely bail out of
540 single-kboard mode by pressing C-g.
542 Update: Warning the user is not trivial to implement, as Emacs has
543 only one echo area, shared by all frames. Ideally the warning
544 should not be displayed on the display that is locking the others.
545 Perhaps the high probability of user confusion caused by
546 single_kboard mode deserves a special case in the display code.
547 Alternatively, it might be good enough to signal single_kboard mode
548 by changing the modelines or some other frame-local display element
549 on the locked out displays.
551 ** The session management module is prone to crashes when the X
552 connection is closed and then later I try to connect to a new X
555 #0 0xb7ebc806 in SmcGetIceConnection () from /usr/X11R6/lib/libSM.so.6
556 #1 0x080e6641 in x_session_check_input (bufp=0xbf86c9c0) at xsmfns.c:144
557 #2 0x080d3bbc in XTread_socket (device=0xa722ff8, expected=1, hold_quit=0xbf86ca90) at xterm.c:7037
558 #3 0x080fa404 in read_avail_input (expected=1) at keyboard.c:6696
559 #4 0x080fa4ca in handle_async_input () at keyboard.c:6900
560 #5 0x080d51fa in x_term_init (display_name=162628899, xrm_option=0x0, resource_name=0x857068c "emacs") at xterm.c:10622
561 #6 0x080d920e in x_display_info_for_name (name=162628899) at xfns.c:3975
562 #7 0x080d92f9 in check_x_display_info (object=1) at xfns.c:274
563 #8 0x080d97b8 in Fx_create_frame (parms=151221485) at xfns.c:3016
564 #9 0x0815bf72 in Ffuncall (nargs=2, args=0xbf86ceec) at eval.c:2851
566 I installed a workaround to prevent this. The X session manager is
567 only contacted when the very first display in the Emacs session is
568 an X display. Also, x_delete_display() on this display aborts
569 session management, and XTread_socket only calls
570 x_session_check_input when it is called for the display that the
571 session was opened on. While this does not really fix the bug, it
572 makes it much less frequent, because session manager support will
573 not normally be enabled when Emacs can survive the shutdown of the
576 See if xsmfns.c should be updated.
578 ** Hunt down display-related functions in frame.el and extend them all
579 to accept display ids.
581 ** rif->flush_display_optional (NULL) calls should be replaced by a
584 ** The set-locale-environment hack (adding the DISPLAY option) should
585 be replaced with a clean design.
587 ** standard-display-table should be display-local.
588 standard-display-european should be display-local.
590 ** With iswitchb-default-method set to 'always-frame, only frames on
591 the current display should be considered. This might involve
592 extending `get-buffer-window'.
594 ** Have a look at Vlocale_coding_system. Seems like it would be a
595 tedious job to localize it, although most references use it for
596 interfacing with libc and are therefore OK with the global
599 Exceptions found so far: x-select-text and
600 x-cut-buffer-or-selection-value.
602 ** Have a look at fatal_error_hook.
604 ** Have a look at set_frame_matrix_frame.
606 ** Check if we got term-setup-hook right.
608 ** I think tip_frame should be display-local.
610 ** Check display reference count handling in x_create_tip_frame.
612 ** make-frame does not correctly handle extra parameters in its
615 (frame-parameter (make-frame (list (cons 'foobar 42))) 'foobar)
618 (This is likely an error in the CVS trunk.)
620 ** Dan Nicolaescu suggests that -nw should be added as an alias for -t
621 in emacsclient. Good idea. (Alas, implementing this is not
622 trivial, getopt_long does not seem to support two-letter ``short''
623 options. Patches are welcome.)
625 ** Mark Plaksin suggests that emacsclient should accept the same
626 X-related command-line arguments as Emacs. Most of the X-related
627 argument-handling is done in Lisp, so this should be quite easy to
630 ** Gergely Nagy suggests that C-x # should only kill the current
631 frame, not any other emacsclient frame that may have the same file
632 opened for editing. I think I agree with him.
634 ** Very strange bug: visible-bell does not work on secondary
635 terminals in xterm and konsole. The screen does flicker a bit,
636 but it's so quick it isn't noticable.
638 ** Move baud_rate to struct display.
640 ** Implement support for starting an interactive Emacs session without
641 an initial frame. (The user would connect to it and open frames
642 later, with emacsclient.)
644 ** Fix Mac support (I can't do this entirely myself). Note that the
645 current state of Mac-specific source files in the multi-tty tree
646 are not useful; before starting work on Mac support, revert to
647 pristine, pre-multi-tty versions.
649 ** Fix W32 support (I can't do this entirely myself). Note that the
650 current state of W32-specific source files in the multi-tty tree
651 are not useful; before starting work on W32 support, revert to
652 pristine, pre-multi-tty versions.
654 ** Fix DOS support (I can't do this entirely myself). Note that the
655 current state of DOS-specific source files in the multi-tty tree
656 are not useful; before starting work on DOS support, revert to
657 pristine, pre-multi-tty versions.
659 ** Do a grep on XXX and ?? for more issues.
661 ** Understand Emacs's low-level input system (it's black magic) :-)
662 What exactly does interrupt_input do? I tried to disable it for
663 raw secondary tty support, but it does not seem to do anything
664 useful. (Update: Look again. X unconditionally enables this, maybe
665 that's why raw terminal support is broken again. I really do need
666 to understand input.)
667 (Update: I am starting to understand the read_key_sequence->read-char
668 ->kbd_buffer_get_event->read_avail_input->read_socket_hook path. Yay!)
670 ** flow-ctrl.el must be updated.
672 ** Fix stuff_char for multi-tty. Doesn't seem to be of high priority.
677 (ex-TODO items with explanations.)
679 -- Introduce a new struct for terminal devices.
681 (Done, see struct tty_output. The list of members is not yet
684 -- Change the bootstrap procedure to initialize tty_list.
686 (Done, but needs review.)
688 -- Change make-terminal-frame to support specifying another tty.
690 (Done, new frame parameters: `tty' and `tty-type'.)
692 -- Implement support for reading from multiple terminals.
694 (Done, read_avail_input tries to read from each terminal, until one
695 succeeds. MULTI_KBOARD is not used. Secondary terminals don't send
698 (Update: They do, now.)
700 (Update2: After enabling X, they don't.)
702 -- other-frame should cycle through the frames on the `current'
705 (Done, by trivially modifiying next_frame and prev_frame.)
707 -- Support different terminal sizes.
711 -- Make sure terminal resizes are handled gracefully. (Could be
714 (Done. We don't get automatic SIGWINCH for additional ttys,
717 -- Extend emacsclient to automatically open a new tty when it connects
720 (Done. It's an ugly hack, needs more work.)
722 -- Redisplay must refresh the topmost frame on *all* terminals, not
723 just the initial terminal.
725 (Done, but introduced an ugly redisplay problems. Ugh.)
727 -- Fix redisplay problems.
729 (Done; it turned out that the entire Wcm structure must be moved
730 inside tty_output. Why didn't I catch this earlier?)
732 -- Provide a way for emacsclient to tell Emacs that the tty has been
735 (Done, simply forward the SIGWINCH signal.)
737 -- Each keypress should automatically select the frame corresponding
738 to the terminal that it was coming from. This means that Emacs
739 must know from which terminal the last keyboard event came from.
741 (Done, it was quite simple, the input event system already
742 supported multiple frames.)
744 -- Fix SIGIO issue with secondary terminals.
746 (Done, emacsclient signals Emacs after writing to the proxy pseudo
747 terminal. Note that this means that multi-tty does not work with
750 (Update: This is bullshit. There is a read_input_waiting function,
751 extend that somehow.)
753 (Update of update: The first update was not right either, extending
754 read_input_waiting was not necessary. Secondary ttys do seem to
755 send signals on input.)
757 (Update^3: Not any more.)
759 -- Make make-terminal-frame look up the `tty' and `tty-type' frame
760 parameters from the currently selected terminal before the global
765 -- Put all cached terminal escape sequences into struct tty_output.
766 Currently, they are still stored in global variables, so we don't
767 really support multiple terminal types.
769 (Done. It was not fun.)
771 -- Implement sane error handling after initialization. (Currently
772 emacs exits if you specify a bad terminal type.) The helpful error
773 messages must still be provided when Emacs starts.
777 -- Implement terminal deletion, i.e., deleting local frames, closing
778 the tty device and restoring its previous state without exiting
781 (Done, but at the moment only called when an error happens during
782 initialization. There is a memory corruption error around this
783 somewhere.) (Update: now it is fully enabled.)
785 -- Implement automatic deletion of terminals when the last frame on
786 that terminal is closed.
790 -- Restore tty screen after closing the terminal.
792 (Done, we do the same as Emacs 21.2 for all terminals.)
794 -- 'TERM=dumb src/emacs' does not restore the terminal state.
798 -- C-g should work on secondary terminals.
800 (Done, but the binding is not configurable.)
802 -- Deal with SIGHUP in Emacs and in emacsclient. (After this, the
803 server-frames may be removed from server.el.)
805 (Done, nothing to do. It seems that Emacs does not receive SIGHUP
806 from secondary ttys, which is actually a good thing.) (Update: I
807 think it would be a bad idea to remove server-frames.)
809 -- Change emacsclient/server.el to support the -t argument better,
810 i.e. automatically close the socket when the frame is closed.
812 (Seems to be working OK.)
814 -- Fix mysterious memory corruption error with tty deletion. To
815 trigger it, try the following shell command:
817 while true; do TERM=no-such-terminal-definition emacsclient -h; done
819 Emacs usually dumps core after a few dozen iterations. (The bug
820 seems to be related to the xfreeing or bzeroing of
821 tty_output.Wcm. Maybe there are outside references to struct Wcm?
822 Why were these vars collected into a struct before multi-tty
825 (Done. Whew. It turned out that the problem had nothing to do
826 with hypothetical external references to Wcm, or any other
827 tty_output component; it was simply that delete_tty closed the
828 filehandles of secondary ttys twice, resulting in fclose doubly
829 freeing memory. Utterly trivial matter. I love the C's memory
830 management, it puts hair on your chest.)
832 -- Support raw secondary terminals. (Note that SIGIO works only on
833 the controlling terminal.) Hint: extend read_input_waiting for
834 multiple ttys and hopefully this will be fixed.
836 (Done, it seems to have been working already for some time. It
837 seems F_SETOWN does work, after all. Not sure what made it fail
838 earlier, but it seems to be fixed (there were several changes
839 around request_sigio, maybe one of them did it).
840 read_input_waiting is only used in sys_select, don't change
841 it.) (Update: After adding X support, it's broken again.)
842 (Update^2: No it isn't.) :-)
844 -- Find out why does Emacs abort when it wants to close its
845 controlling tty. Hint: chan_process[] array. Hey, maybe
846 noninterrupt-IO would work, too? Update: no, there is no process
849 (Done. Added add/delete_keyboard_wait_descriptor to
850 term_init/delete_tty. The hint was right, in a way.)
852 -- Issue with SIGIO: it needs to be disabled during redisplay. See if
853 fcntl kernel behaviour could be emulated by emacsclient.
855 (Done. Simply disabled the SIGIO emulation hack in emacsclient.)
856 (Update: it was added back.) (Update^2: and removed again.)
858 -- server.el: There are issues with saving files in buffers of closed
859 clients. Try editing a file with emacsclient -f, and (without
860 saving it) do a delete-frame. The frame is closed without
861 question, and a surprising confirmation prompt appears in another
864 (Done. delete-frame now asks for confirmation if it still has
865 pending buffers, and modified buffers don't seem to be deleted.)
867 -- emacsclient.el, server.el: Handle eval or file open errors when
872 -- Make parts of struct tty_output accessible from Lisp. The device
873 name and the type is sufficient.
875 (Done, see frame-tty-name and frame-tty-type.)
877 -- Export delete_tty to the Lisp environment, for emacsclient.
879 (Done, see delete-tty.)
881 -- Get rid of the accessor macros in termchar.h, or define macros for
886 -- Move device-specific parameters (like costs) commonly used by
887 device backends to a common, device-dependent structure.
889 (Done. See struct display_method in termhooks.h.)
893 (Done. Well, it seems to be working.)
895 -- Allow simultaneous X and tty frames. (Handling input could be
896 tricky. Or maybe not.)
898 (Done. Allowed, that is. It is currently extremely unstable, to
899 the point of being unusable. The rif variable causes constant
900 core dumps. Handling input is indeed tricky.)
902 -- Rewrite multi-tty input in terms of MULTI_KBOARD.
904 (Done. In fact, there was no need to rewrite anything, I just
905 added a kboard member to tty_display_info, and initialized the
906 frame's kboard from there.)
908 -- Fix rif issue with X-tty combo sessions. IMHO the best thing to do
909 is to get rid of that global variable (and use the value value in
910 display_method, which is guaranteed to be correct).
912 (Done, did exactly that. Core dumps during combo sessions became
913 much rarer. In fact, I have not yet met a single one.)
915 -- Add multi-tty support to talk.el.
919 -- Clean up the source of emacsclient. It is a mess.
921 (Done, eliminated stupid proxy-pty kludge.)
923 -- Fix faces on tty frames during X-tty combo sessions. There is an
924 init_frame_faces call in init_sys_modes, see if there is a problem
927 (Done, there was a stupid mistake in
928 Ftty_supports_face_attributes_p. Colors are broken, though.)
930 -- C-x 5 2, C-x 5 o, C-x 5 0 on an emacsclient frame unexpectedly
931 exits emacsclient. This is a result of trying to be clever with
932 delete-frame-functions.
934 (Fixed, added delete-tty-after-functions, and changed server.el to
937 -- Something with (maybe) multi-keyboard support broke function keys
938 and arrows on ttys during X+tty combo sessions. Debug this.
940 (I can't reproduce it, maybe the terminal type was wrong.)
942 -- Fix input from raw ttys (again).
944 (Now it seems to work all right.)
946 -- During an X-tty combo session, a (message "Hello") from a tty frame
947 goes to the X frame. Fix this.
949 (Done. There was a safeguard against writing to the initial
950 terminal frame during bootstrap which prevented echo_area_display
951 from working correctly on a tty frame during a combo session.)
953 -- If there are no frames on its controlling terminal, Emacs should
954 exit if the user presses C-c there.
956 (Done, as far as possible. See the SIGTERM comment in
957 interrupt_signal on why this seems to be impossible to solve this
960 -- During an X session, Emacs seems to read from stdin. Also, Emacs
961 fails to start without a controlling tty.
963 (Fixed by replacing the troublesome termcap display with a dummy
964 bootstrap display during bootstrap.
966 -- Do tty output through struct display, like graphical display
971 -- Define an output_initial value for output_method for the initial
972 frame that is dumped with Emacs. Checking for this frame (e.g. in
973 cmd_error_internal) is ugly.
975 (Done, breaking interactive temacs.)
977 -- The command `emacsclient -t -e '(delete-frame)'' fails to exit.
981 -- frame-creation-function should always create a frame that is on the
982 same display as the selected frame. Maybe frame-creation-function
983 should simply be removed and make-frame changed to do the right
986 (Done, with a nice hack. frame-creation-function is now frame-local.)
988 -- Fix C-g on raw ttys.
990 (Done. I disabled the interrupt/quit keys on all secondary
991 terminals, so Emacs sees C-g as normal input. This looks like an
992 overkill, because emacsclient has extra code to pass SIGINT to
993 Emacs, so C-g should remain the interrupt/quit key on emacsclient
994 frames. See the next entry why implementing this distinction would
997 -- Make sure C-g goes to the right frame with ttys. This is hard, as
998 SIGINT doesn't have a tty parameter. :-(
1000 (Done, the previous change fixes this as a pleasant side effect.)
1002 -- I have seen a case when Emacs with multiple ttys fell into a loop
1003 eating 100% of CPU time. Strace showed this loop:
1006 kill(30284, SIGIO) = 0
1007 --- SIGIO (I/O possible) @ 0 (0) ---
1008 ioctl(6, FIONREAD, [0]) = -1 EIO (Input/output error)
1009 ioctl(5, FIONREAD, [0]) = -1 EIO (Input/output error)
1010 ioctl(0, FIONREAD, [0]) = 0
1011 sigreturn() = ? (mask now [])
1012 gettimeofday({1072842297, 747760}, NULL) = 0
1013 gettimeofday({1072842297, 747806}, NULL) = 0
1014 select(9, [0 3 5 6], NULL, NULL, {0, 0}) = 2 (in [5 6], left {0, 0})
1015 select(9, [0 3 5 6], NULL, NULL, {0, 0}) = 2 (in [5 6], left {0, 0})
1016 gettimeofday({1072842297, 748245}, NULL) = 0
1018 I have seen something similar with a single X frame, but have not
1019 been able to reproduce it for debugging.
1021 Update: This may have been caused by checking for nread != 0
1022 instead of nread > 0 after calling read_socket_hook in
1025 (Fixed. This was caused by unconditionally including stdin in
1026 input_wait_mask in init_process. The select call in
1027 wait_reading_process_input always returned immediately, indicating
1028 that there is pending input from stdin, which nobody read.
1030 Note that the above strace output seems to be an unrelated but
1031 similar bug. I think that is now fixed.)
1033 -- Exiting Emacs while there are emacsclient frames doesn't restore the
1034 ttys to their default states.
1036 (This seems to be fixed by some previous change.)
1038 -- Allow opening an X session after -nw.
1042 -- Fix color handling during tty+X combo sessions. (It seems that tty
1043 sessions automatically convert the face colors to terminal colors
1044 when the face is loaded. This conversion must happen instead on
1045 the fly in write_glyphs, which might be problematic, as color
1046 approximation is currently done in lisp (term/tty-colors.el).)
1047 (Update: hm, colors seem to work fine if I start emacs with -nw and
1048 then create an X frame. Maybe it's just a small buglet somewhere.)
1050 (Seems to be fixed. The problem was in startup.el, it did not
1051 initialize tty colors when the initial window system was
1054 -- emacs -nw --eval '(y-or-n-p "Foobar")' segfaults. (Reported by
1057 (Fixed, there was a keyboard initialization problem.)
1059 -- Fix interactive use of temacs. There are face-related SEGVs, most
1060 likely because of changes in realize_default_face, realize_face.
1064 -- Don't exit Emacs when the last X connection fails during a
1065 multi-display session.
1069 -- Dan Nicolaescu noticed that starting emacsclient on the same
1070 terminal device that is the controlling tty of the Emacs process
1071 gives unexpected results.
1075 -- Istvan Marko reported that Emacs hang on ttys if it was started
1076 from a shell script.
1078 (Fixed. There was a bug in the multi-tty version of
1079 narrow_foreground_group. tcsetpgrp blocks if it is called from a
1080 process that is not in the same process group as the tty.)
1082 -- emacsclient -t from an Emacs term buffer does not work, complains
1083 about face problems. This can even lock up Emacs (if the recursive
1084 frame sets single_kboard). Update: the face problems are caused by
1085 bugs in term.el, not in multi-tty. The lockup is caused by
1086 single_kboard mode, and is not easily resolvable. The best thing to
1087 do is to simply refuse to create a tty frame of type `eterm'.
1089 (Fixed, changed emacsclient to check for TERM=eterm. The face
1090 complaints seem to be caused by bugs in term.el; they are not
1091 related to multi-tty.)
1093 -- Find out the best way to support suspending Emacs with multiple
1094 ttys. My guess: disable it on the controlling tty, but from other
1095 ttys pass it on to emacsclient somehow. (It is (I hope) trivial to
1096 extend emacsclient to handle suspend/resume. A `kill -STOP' almost
1099 (Done. I needed to play with signal handling and the server
1100 protocol a bit to make emacsclient behave as a normal UNIX program
1101 wrt foreground/background process groups.)
1103 -- There is a flicker during the startup of `emacs -nw'; it's as if
1104 the terminal is initialized, reset and then initialialized again.
1105 Debug this. (Hint: narrow_foreground_group is called twice during
1110 -- Robert Chassell has found serious copy-paste bugs with the
1111 multi-tty branch. There seem to be redisplay bugs while copying
1112 from X to a terminal frame. Copying accented characters do not
1115 (Patch-124 should fix this, by changing the interprogram-*-function
1116 variables to be frame-local, as suggested by Mark Plaksin
1117 (thanks!). I think that the redisplay bugs are in fact not bugs,
1118 but delays caused by single_kboard --> perhaps MULTI_KBOARD should
1121 -- frame-creation-function was removed, which might be a bad idea.
1122 Think up a compatible solution.
1124 (It was an internal interface that may be changed when necessary.)
1126 -- Change Lisp code not to (getenv "TERM"); use the `tty-type' frame
1127 parameter or the frame-tty-type function instead. (M-x tags-search
1128 "TERM" helps with this.) Update: Actually, all getenv invocations
1129 should be checked for multi-tty compatibility, and an interface
1130 must be implemented to get the remote client's environment.
1132 (Done. Only getenv calls in lisp/term/*.el were changed; other
1133 calls should be mostly left as they are.)
1135 -- Add an elaborate mechanism for display-local variables. (There are
1136 already a few of these; search for `terminal-local' in the Elisp
1139 (Not needed. Display-local variables could be emulated by
1140 frame-local variables.)
1142 -- Emacs assumes that all terminal frames have the same locale
1143 settings as Emacs itself. This may lead to bogus results in a
1144 multi-locale setup. (E.g., while logging in from a remote client
1145 with a different locale.)
1146 (Update after new bugreport by Friedrich Delgado Friedrichs:
1147 (at least) the structs terminal_coding and keyboard_coding in
1148 coding.c must be moved to struct display, and the Lisp interface
1149 [set-]keyboard-coding-system must be adapted for the change.)
1151 (Fixed. Emacs now uses the locale settings as seen by the
1152 emacsclient process for server tty frames.)
1153 (Update: Not really; Vlocale_coding_system is still global.)
1155 -- Make `struct display' accessible to Lisp programs. Accessor functions:
1157 (displayp OBJECT): Returns t if OBJECT is a display.
1158 => Implemented as display-live-p.
1160 (display-list): Returns list of currently active displays.
1163 (selected-display): Returns the display object of the selected frame.
1164 => Not strictly necessary, but implemented anyway.
1166 (frame-display FRAME): Returns the display object of FRAME.
1169 (display-frames DISPLAY): Returns a list of frames on DISPLAY.
1170 => Already implemented, see frames-on-display-list.
1172 (display-type DISPLAY): Returns the type of DISPLAY, as a
1173 symbol. (See `framep'.)
1174 => Implemented as display-live-p.
1176 (display-device DISPLAY): Returns the name of the device that
1177 DISPLAY uses, as a string. (E.g: "/dev/pts/16", or
1179 => Implemented as display-name.
1183 See next issue why this is necessary.
1185 (Update: The consensus on emacs-devel seems to be to do this via
1186 integer identifiers. That's fine by me.)
1190 -- The following needs to be supported:
1197 The cleanest way to solve this is to allow multiple displays on the
1198 same terminal device; each new emacsclient process should create
1199 its own display. As displays are currently identified by their
1200 device names, this is not possible until struct display becomes
1201 accessible as a Lisp-level object.
1205 -- Miles Bader suggests that C-x C-c on an emacsclient frame should
1206 only close the frame, not exit the entire Emacs session. Update:
1207 see above for a function that does this. Maybe this should be the
1210 (Done. This is the new default. No complaints so far.)
1212 -- Clean up the frame-local variable system. I think it's ugly and
1213 error-prone. But maybe I just haven't yet fully understood it.
1215 (Nothing to do. It doesn't seem ugly any more. It's rather clever.)
1217 -- Support multiple character locales. A version of
1218 `set-locale-environment' needs to be written for setting up
1219 display-local settings on ttys. I think calling
1220 set-display-table-and-terminal-coding-system and
1221 set-keyboard-coding-system would be enough. The language
1222 environment itself should remain a global setting.
1224 (Done, by an ugly hack.)
1226 -- The terminal customization files in term/*.el tend to change global
1227 parameters, which may confuse Emacs with multiple displays. Change
1228 them to tweak only frame-local settings, if possible. (They tend
1229 to call define-key to set function key sequences a lot.)
1231 (Done, by making `function-key-map' terminal-local (i.e., part of
1232 struct kboard). This has probably covered all the remaining problems.)
1234 -- Make `function-key-map' and `key-translation-map' terminal-local.
1238 -- Implement `terminal-local-value' and `set-terminal-local-value' to
1239 allow deterministic access to terminal local bindings. The
1240 encode-kb package can not set up `key-translation-map' without
1241 these. The terminal-local bindings seem to be independent of what
1246 -- xt-mouse.el needs to be adapted for multi-tty. It currently
1247 signals an error on kill-emacs under X, which prevents the user
1248 from exiting Emacs. (Reported by Mnemonikk on freenode.)
1253 -- Having {reset,init}_all_sys_modes in set-input-mode breaks arrow
1254 keys on non-selected terminals under screen, and sometimes on other
1255 terminal types as well. The other function keys continue to work
1256 fine. Sometimes faces on these screens become garbled.
1258 This only seems to affect displays that are of the same terminfo
1259 type as the selected one. Interestingly, in screen Emacs normally
1260 reports the up arrow key as `M-o A', but after the above SNAFU, it
1261 complains about `M-[ a'. UNIX ttys are a complete mystery to me,
1262 but it seems the reset-reinitialize cycle somehow leaves the
1263 non-selected terminals in a different state than usual. I have no
1264 idea how this could happen.
1266 Currently set-input-mode resets only the currently selected
1267 terminal, which seems to somehow work around the problem.
1271 Dan Nicolaescu <dann@ics.uci.edu> writes:
1272 > Some terminals have 2 modes for cursor keys: Application Mode where
1273 > the cursor keys transmit the codes defined in the terminfo entry, and
1274 > Cursor mode. Applications have to send the smkx and rmkx terminfo
1275 > strings to switch between the 2 modes. So Emacs (and emacsclient) have
1276 > to send smkx when initializing and rmkx when quitting (or on
1279 (I think patch-370 fixed this.)
1281 -- This long-standing bug (first reported by Han Boetes) seems to come
1282 and go all the time. It is time to track it down and fix it.
1287 # From another xterm:
1288 emacsclient -e '(y-or-n-p "Do you want me to crash? ")'
1289 # Notice how the answer ends up in the *scratch* buffer
1293 (Fixed in patch-414 after detailed analysis by Kalle Olavi Niemitalo.)
1295 -- normal-erase-is-backspace-mode in simple.el needs to be updated for
1296 multi-tty (rep. by Dan Waber). (The Delete key is broken on X
1299 (Fixed in patch-427.)
1301 -- I think keyboard-translate-table should be made terminal-local.
1303 (Done in patch-431.)
1305 -- The semantics of terminal-local variables are confusing; it is not
1306 clear what binding is in effect in any given time. See if
1307 current_kboard (or at least the terminal-local bindings exported to
1308 Lisp) might be changed to be tied to the selected frame instead.
1309 Currently, `function-key-map' and `key-translation-map' may be
1310 accessed reliably only using the hackish
1311 `(set-)terminal-local-value' functions.
1313 Perhaps there should be a difference between `last-command' &co.
1314 and these more conventional configuration variables.
1315 (E.g. `symbol-value' would use current_kboard to access
1316 `last-command', but SELECTED_FRAME()->display->kboard to get the
1317 value of `function-key-map'.
1319 (Fixed in patch-434.)
1321 -- If the first key pressed on a new tty terminal is a function key,
1322 it is not recognized correctly. May be related to the bug below.
1324 (Seems to have been fixed as a side effect of patch-434. "The bug
1325 below" was the set-input-mode madness.)
1327 (Update: this bug was fixed for good in patch-449. It was tracked
1328 down to a bug in `read_key_sequence': it failed to reinitialize its
1329 local function-key-map/key-translation-map references when it
1330 switched keyboards. I don't understand why did this bug only
1331 appear on brand new frames, though!)
1333 -- Disable connecting to a new X display when we use the GTK toolkit.
1335 (Disabled in patch-450.)
1337 -- Implement automatic forwarding of client environment variables to
1338 forked processes, as discussed on the multi-tty list. Terminal
1339 parameters are now accessible in C code, so the biggest obstacle is
1340 gone. The `getenv_internal' and `child_setup' functions in
1341 callproc.c must be changed to support the following variable:
1343 terminal-local-environment-variables is a variable defined in ...
1345 Enable or disable terminal-local environment variables.
1347 If set to t, `getenv', `setenv' and subprocess creation
1348 functions use the environment variables of the emacsclient
1349 process that created the selected frame, ignoring
1350 `process-environment'.
1352 If set to nil, Emacs uses `process-environment' and ignores
1353 the client environment.
1355 Otherwise, `terminal-local-environment-variables' should be a
1356 list of variable names (represented by Lisp strings) to look
1357 up in the client environment. The rest will come from
1358 `process-environment'.
1360 (Implemented in patch-461; `terminal-getenv', `terminal-setenv' and
1361 `with-terminal-environment' are now replaced by extensions to
1362 `getenv' and `setenv', and the new `local-environment-variables'
1365 ;;; arch-tag: 8da1619e-2e79-41a8-9ac9-a0485daad17d