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 ARISAWA Akihiro <ari at mbf dot ocn dot ne dot jp>
35 Vincent Bernat <bernat at luffy dot cx>
36 Han Boetes <han at mijncomputer dot nl>
37 Robert J. Chassell <bob at rattlesnake dot com>
38 Romain Francoise <romain at orebokech dot com>
39 Ami Fischman <ami at fischman dot org>
40 Friedrich Delgado Friedrichs <friedel at nomaden dot org>
41 IRIE Tetsuya <irie at t dot email dot ne dot jp>
42 Yoshiaki Kasahara <kasahara at nc dot kyushu-u dot ac dot jp>
43 Jurej Kubelka <Juraj dot Kubelka at email dot cz>
44 David Lichteblau <david at lichteblau dot com>
45 Xavier Mallard <zedek at gnu-rox dot org>
46 Istvan Marko <mi-mtty at kismala dot com>
47 Ted Morse <morse at ciholas dot com>
48 Dan Nicolaescu <dann at ics dot uci dot edu>
49 Gergely Nagy <algernon at debian dot org>
50 Mark Plaksin <happy at mcplaksin dot org>
51 Francisco Borges <borges at let dot rug dot nl>
52 Frank Ruell <stoerte at dreamwarrior dot net>
53 Dan Waber <dwaber at logolalia dot com>
56 Richard Stallman was kind enough to review an earlier version of my
63 The multi-tty mailing list (discussion & bug reports):
65 Address: multi-tty@lists.fnord.hu
66 Signup: http://lists.fnord.hu/mailman/listinfo/multi-tty
67 Archive: http://news.gmane.org/gmane.emacs.multi-tty/
69 Commit notifications (read-only):
71 Address: multi-tty-commits@lists.fnord.hu
72 Signup: http://lists.fnord.hu/mailman/listinfo/multi-tty-commits
78 The branch is now very stable and almost full-featured. All of the
79 major problems have been fixed, only a few minor issues remain. (It
80 still needs to be ported to Windows/Mac/DOS, though.) Both multiple
81 tty device support and simultaneous X and tty frame support works
82 fine. Emacsclient has been extended to support opening new tty and X
83 frames. It has been changed open new Emacs frames by default.
85 The multi-tty branch has been scheduled for inclusion in the next
86 major release of Emacs (version 23). I expect the merge into the
87 development trunk to occur sometime during next year (2005), after the
88 merge of the Unicode branch.
90 Tested on GNU/Linux, Solaris 8, FreeBSD and OpenBSD. Please let me
91 know if you succeed or fail to use it on other platforms---I'll have a
92 few tricky test cases for you.
96 * GTK support. If you compile your Emacs with the GTK
97 toolkit, some functionality of multi-tty will be lost.
98 Current releases of GTK have limitations and bugs that
99 prevent full-blown multi-display support in Emacs. Use the
100 Lucid toolkit if you want to see a complete feature set.
102 * The single-kboard mode.
104 If your multi-tty Emacs session seems to be frozen, you
105 probably have a recursive editing session or a pending
106 minibuffer prompt (which is a kind of recursive editing) on
107 another display. To unfreeze your session, switch to that
108 display and complete the recursive edit, for example by
109 pressing C-] (`abort-recursive-edit').
111 I am sorry to say that currently there is no way to break
112 out of this "single-kboard mode" from a frozen display. If
113 you are unable to switch to the display that locks the
114 others (for example because it is on a remote computer),
115 then you can use emacsclient to break out of all recursive
118 emacsclient -e '(top-level)'
120 Note that this (perhaps) unintuitive behaviour is by design.
121 Single-kboard mode is required because of an intrinsic Emacs
122 limitation that is very hard to eliminate. (This limitation
123 is related to the single-threaded nature of Emacs.)
125 I plan to implement better user notification and support for
126 breaking out of single-kboard mode from locked displays.
128 * Mac, Windows and DOS support is broken, doesn't even
129 compile. Multiple display support will probably not provide
130 new Emacs features on these systems, but the multi-tty
131 branch changed a few low-level interfaces, and the
132 system-dependent source files need to be adapted
133 accordingly. The changes are mostly trivial, so almost
134 anyone can help, if only by compiling the branch and
135 reporting the compiler errors. (It is not worth to do this
139 HOW TO GET THE BRANCH
140 ---------------------
142 The branch uses GNU Arch (http://www.gnuarch.org) for version control.
144 Retrieving the latest version of the branch:
146 tla register-archive -f http://lorentey.hu/arch/2004/
147 tla get lorentey@elte.hu--2004/emacs--multi-tty <directory>
149 This incantation uses my private archive mirror that is hosted on a
150 relatively low-bandwidth site; if you are outside Hungary, you will
151 probably want to you use my secondary mirror: (Note that the -f option
152 will overwrite the archive location if you have previously registered
155 tla register-archive -f http://aszt.inf.elte.hu/~lorentey/mirror/arch/2004
156 tla get lorentey@elte.hu--2004/emacs--multi-tty <directory>
158 http://aszt.inf.elte.hu/~lorentey/mirror/arch/2004
160 The Arch supermirror provides mirroring services for all public Arch
161 repositories. We have a mirror there, too, if you prefer.
163 tla register-archive -f http://mirrors.sourcecontrol.net/lorentey%40elte.hu--2004
164 tla get lorentey@elte.hu--2004/emacs--multi-tty <directory>
166 My GPG key id is 0FB27A3F; it is available from
167 hkp://wwwkeys.eu.pgp.net/, or from my homepage at
168 http://lorentey.hu/rolam/gpg.html)
170 Don't worry if the above checkout takes a few minutes to complete;
171 once you have a source tree, updating it to the latest revision will
172 be _much_ faster. Use the following command for the update:
176 You can find more information about Arch on http://wiki.gnuarch.org/.
177 It's a wonderful source control system, I highly recommend it.
179 If you don't have tla, the branch has a homepage from which you can
180 download conventional patches against Emacs CVS HEAD:
182 http://lorentey.hu/project/emacs.html
187 If you run Debian, or a distribution based on Debian, you are welcome
188 to use our binary packages; put these lines in your /etc/apt/sources.list:
191 deb http://aszt.inf.elte.hu/~lorentey/mirror/apt ./
192 deb-src http://aszt.inf.elte.hu/~lorentey/mirror/apt ./
194 Note that these packages are intended solely to provide an easy way to
195 test the new multi-tty features. They are not to be taken as Emacs
196 releases, and it's a mistake to expect robust operation or any kind of
197 timely support for them. Do not install them, unless you'd like to
198 have your editor crash on you.
204 The multi-tty branch is compiled the same way as Emacs itself:
206 make maintainer-clean # (If you have compiled Emacs before)
208 ./configure <your favourite options>
212 If you have strange compilation errors, they may be caused by old
213 *.elc files that are left over from an earlier bootstrap. The `make
214 maintainer-clean' target deletes them, so it is a good idea to run
215 that before reporting a bug. (Emacs requires a clean recompilation
216 after certain kinds of source code changes.)
221 To test the multi-tty branch, start up the Emacs server with the
227 and then (from a shell prompt on another terminal) start emacsclient
229 emacsclient -t /optional/file/names... (for a tty frame)
230 emacsclient /optional/file/names... (for an X frame)
232 (Make sure both emacs and emacsclient are multi-tty versions.)
233 You'll hopefully have two fully working, independent frames on
234 separate terminals. The new frame is closed automatically when you
235 finish editing the specified files (C-x #), but delete-frame (C-x 5 0)
236 also works. Of course, you can create frames on more than two tty
239 Creating new frames on the same tty with C-x 5 2 works, and they
240 behave the same way as in previous Emacs versions. If you exit emacs,
241 all terminals should be restored to their previous states.
243 This is work in progress, and probably full of bugs. It is a good
244 idea to run emacs from gdb, so that you'll have a live instance to
245 debug if something goes wrong. Please send me your bug reports on our
246 mailing list: multi-tty@lists.fnord.hu
251 I think the best way to use the new Emacs is to have it running inside
252 a disconnected GNU screen session, and always use emacsclient for
253 normal work. One advantage of this is that not a single keystroke of
254 your work will be lost if the display device that you are using
255 crashes, or the network connection times out, or whatever. (I had an
256 extremely unstable X server for some time while I was developing these
257 patches, and running Emacs this way has saved me a number of M-x
258 recover-session invocations.)
260 I use the following two bash functions to handle my Emacs sessions:
262 ,----[ ~/.bash_profile
263 | # Usage: preload_emacs <name> [<waitp>]
265 | # Preloads the Emacs instance called NAME in a detached screen
266 | # session. Does nothing if the instance is already running. If WAITP
267 | # is non-empty, the function waits until the server starts up and
268 | # creates its socket; otherwise it returns immediately.
269 | function preload_emacs {
272 | local screendir="/var/run/screen/S-$USER"
273 | local serverdir="/tmp/emacs$UID"
274 | local emacs=emacs # Or wherever you installed your multi-tty Emacs
276 | if [ -z "$name" ]; then
277 | echo "Usage: preload_emacs <name> [<waitp>]" >&2
281 | if [ ! -e "$screendir"/*."$name" ]; then
282 | if [ -e "$serverdir/$name" ]; then
283 | # Delete leftover socket (for the wait option)
284 | rm "$serverdir/$name"
286 | screen -dmS "$name" "$emacs" -nw --eval "(setq server-name \"$name\")" -f server-start
288 | if [ ! -z "$waitp" ]; then
289 | while [ ! -e "$serverdir/$name" ]; do sleep 0.1; done
294 | # Usage: connect_emacs <name> <args>...
296 | # Connects to the Emacs instance called NAME. Starts up the instance
297 | # if it is not already running. The rest of the arguments are passed
299 | function connect_emacs {
303 | if [ -z "$name" ]; then
304 | echo "Usage: connect_emacs <name> <args>..." >&2
306 | preload_emacs "$name" wait
307 | emacsclient -s "$name" "$@"
310 | export -f preload_emacs connect_emacs
312 | # Preload editor and gnus sessions for speedy initial connects.
313 | preload_emacs editor
318 | alias gnus="connect_emacs gnus"
319 | alias edit="connect_emacs editor"
320 | alias et="connect_emacs editor -t"
328 For the NEWS file: (Needs work)
330 ** Support for multiple terminal devices has been added.
332 *** You can specify a terminal device (`tty' parameter) and a terminal
333 type (`tty-type' parameter) to `make-terminal-frame'.
335 *** You can test for the presence of multiple terminal support by
336 testing for the `multi-tty' feature.
338 *** Emacsclient has been extended to support opening a new terminal
339 frame. Its behaviour has been changed to open a new Emacs frame by
340 default. Use the -c option to get the old behavior of opening
341 files in the currently selected Emacs frame.
343 *** A make-frame-on-tty function has been added to make it easier to
344 create frames on new terminals.
346 *** New functions: frame-tty-name, frame-tty-type for accessing
347 terminal parameters, and delete-tty for closing the terminal
350 *** talk.el has been extended for multiple tty support.
353 ** Support for simultaneous graphical and terminal frames has been
356 *** The function `make-frame-on-display' now works during a terminal
357 session, and `make-frame-on-tty' works during a graphical session.
359 *** The `window-system' variable has been made frame-local.
361 *** The new `initial-window-system' variable contains the
362 `window-system' value for the first frame.
371 (The rest of this file consists of my development notes and as such it
372 is probably not very interesting for anyone else.)
377 ** The single-keyboard mode of MULTI_KBOARD is extremely confusing
378 sometimes; Emacs does not respond to stimuli from other keyboards.
379 At least a beep or a message would be important, if the single-mode
380 is still required to prevent interference. (Reported by Dan
383 Update: selecting a region with the mouse enables single_kboard
384 under X. This is very confusing.
386 Update: After discussions with Richard, this will be resolved by
387 having locked displays warn the user to wait, and introducing a
388 complex protocol to remotely bail out of single-kboard mode by
391 Update: Warning the user is not trivial to implement, as Emacs has
392 only one echo area. Ideally the warning should not be displayed on
393 the display that is locking the others. Perhaps the high
394 probability of user confusion caused by single_kboard mode deserves
395 a special case in the display code. Alternatively, it might be
396 good enough to signal single_kboard mode by changing the modelines
397 or some other frame-local display element on the locked out displays.
399 ** normal-erase-is-backspace-mode in simple.el needs to be updated for
400 multi-tty (rep. by Dan Waber).
402 ** Hunt down display-related functions in frame.el and extend them all
403 to accept display ids.
405 ** rif->flush_display_optional (NULL) calls should be replaced by a
408 ** Have a look at fatal_error_hook.
410 ** Have a look at set_frame_matrix_frame.
412 ** Check if we got term-setup-hook right.
414 ** I think tip_frame should be display-local.
416 ** Check display reference count handling in x_create_tip_frame.
418 ** make-frame does not correctly handle extra parameters in its
421 (frame-parameter (make-frame (list (cons 'foobar 42))) 'foobar)
424 (This is likely an error in the CVS trunk.)
426 ** Fix set-input-mode for multi-tty. It's a truly horrible interface;
427 what if we'd blow it up into several separate functions (with a
428 compatibility definition)?
430 ** The terminal customization files in term/*.el tend to change global
431 parameters, which may confuse Emacs with multiple displays. Change
432 them to tweak only frame-local settings, if possible.
434 ** Dan Nicolaescu suggests that -nw should be added as an alias for -t
435 in emacsclient. Good idea. (Alas, implementing this is not
436 trivial, getopt_long does not seem to support two-letter ``short''
437 options. Patches are welcome.) :-)
439 ** Mark Plaksin suggests that emacsclient should accept the same
440 X-related command-line arguments as Emacs. Most of the X-related
441 argument-handling is done in Lisp, so this should be quite easy to
444 ** Gergely Nagy suggests that C-x # should only kill the current
445 frame, not any other emacsclient frame that may have the same file
446 opened for editing. I think I agree with him.
448 ** Very strange bug: visible-bell does not work on secondary
449 terminals in xterm and konsole. The screen does flicker a bit,
450 but it's so quick it isn't noticable.
452 ** Clean up the frame-local variable system. I think it's ugly and
453 error-prone. But maybe I just haven't yet fully understood it.
455 ** Move baud_rate to struct display.
457 ** Implement support for starting an interactive Emacs session without
458 an initial frame. (The user would connect to it and open frames
459 later, with emacsclient.)
461 ** Fix Mac support (I can't do this entirely myself). Note that the
462 current state of Mac-specific source files in the multi-tty tree
463 are not useful; before starting work on Mac support, revert to
464 pristine, pre-multi-tty versions.
466 ** Fix W32 support (I can't do this entirely myself). Note that the
467 current state of W32-specific source files in the multi-tty tree
468 are not useful; before starting work on W32 support, revert to
469 pristine, pre-multi-tty versions.
471 ** Fix DOS support (I can't do this entirely myself). Note that the
472 current state of DOS-specific source files in the multi-tty tree
473 are not useful; before starting work on DOS support, revert to
474 pristine, pre-multi-tty versions.
476 ** Do a grep on XXX and ?? for more issues.
478 ** Understand Emacs's low-level input system (it's black magic) :-)
479 What exactly does interrupt_input do? I tried to disable it for
480 raw secondary tty support, but it does not seem to do anything
481 useful. (Update: Look again. X unconditionally enables this, maybe
482 that's why raw terminal support is broken again. I really do need
483 to understand input.)
485 ** Maybe standard-display-table should be display-local.
490 (ex-TODO items with explanations.)
492 -- Introduce a new struct for terminal devices.
494 (Done, see struct tty_output. The list of members is not yet
497 -- Change the bootstrap procedure to initialize tty_list.
499 (Done, but needs review.)
501 -- Change make-terminal-frame to support specifying another tty.
503 (Done, new frame parameters: `tty' and `tty-type'.)
505 -- Implement support for reading from multiple terminals.
507 (Done, read_avail_input tries to read from each terminal, until one
508 succeeds. MULTI_KBOARD is not used. Secondary terminals don't send
511 (Update: They do, now.)
513 (Update2: After enabling X, they don't.)
515 -- other-frame should cycle through the frames on the `current'
518 (Done, by trivially modifiying next_frame and prev_frame.)
520 -- Support different terminal sizes.
524 -- Make sure terminal resizes are handled gracefully. (Could be
527 (Done. We don't get automatic SIGWINCH for additional ttys,
530 -- Extend emacsclient to automatically open a new tty when it connects
533 (Done. It's an ugly hack, needs more work.)
535 -- Redisplay must refresh the topmost frame on *all* terminals, not
536 just the initial terminal.
538 (Done, but introduced an ugly redisplay problems. Ugh.)
540 -- Fix redisplay problems.
542 (Done; it turned out that the entire Wcm structure must be moved
543 inside tty_output. Why didn't I catch this earlier?)
545 -- Provide a way for emacsclient to tell Emacs that the tty has been
548 (Done, simply forward the SIGWINCH signal.)
550 -- Each keypress should automatically select the frame corresponding
551 to the terminal that it was coming from. This means that Emacs
552 must know from which terminal the last keyboard event came from.
554 (Done, it was quite simple, the input event system already
555 supported multiple frames.)
557 -- Fix SIGIO issue with secondary terminals.
559 (Done, emacsclient signals Emacs after writing to the proxy pseudo
560 terminal. Note that this means that multi-tty does not work with
563 (Update: This is bullshit. There is a read_input_waiting function,
564 extend that somehow.)
566 (Update of update: The first update was not right either, extending
567 read_input_waiting was not necessary. Secondary ttys do seem to
568 send signals on input.)
570 (Update^3: Not any more.)
572 -- Make make-terminal-frame look up the `tty' and `tty-type' frame
573 parameters from the currently selected terminal before the global
578 -- Put all cached terminal escape sequences into struct tty_output.
579 Currently, they are still stored in global variables, so we don't
580 really support multiple terminal types.
582 (Done. It was not fun.)
584 -- Implement sane error handling after initialization. (Currently
585 emacs exits if you specify a bad terminal type.) The helpful error
586 messages must still be provided when Emacs starts.
590 -- Implement terminal deletion, i.e., deleting local frames, closing
591 the tty device and restoring its previous state without exiting
594 (Done, but at the moment only called when an error happens during
595 initialization. There is a memory corruption error around this
596 somewhere.) (Update: now it is fully enabled.)
598 -- Implement automatic deletion of terminals when the last frame on
599 that terminal is closed.
603 -- Restore tty screen after closing the terminal.
605 (Done, we do the same as Emacs 21.2 for all terminals.)
607 -- 'TERM=dumb src/emacs' does not restore the terminal state.
611 -- C-g should work on secondary terminals.
613 (Done, but the binding is not configurable.)
615 -- Deal with SIGHUP in Emacs and in emacsclient. (After this, the
616 server-frames may be removed from server.el.)
618 (Done, nothing to do. It seems that Emacs does not receive SIGHUP
619 from secondary ttys, which is actually a good thing.) (Update: I
620 think it would be a bad idea to remove server-frames.)
622 -- Change emacsclient/server.el to support the -t argument better,
623 i.e. automatically close the socket when the frame is closed.
625 (Seems to be working OK.)
627 -- Fix mysterious memory corruption error with tty deletion. To
628 trigger it, try the following shell command:
630 while true; do TERM=no-such-terminal-definition emacsclient -h; done
632 Emacs usually dumps core after a few dozen iterations. (The bug
633 seems to be related to the xfreeing or bzeroing of
634 tty_output.Wcm. Maybe there are outside references to struct Wcm?
635 Why were these vars collected into a struct before multi-tty
638 (Done. Whew. It turned out that the problem had nothing to do
639 with hypothetical external references to Wcm, or any other
640 tty_output component; it was simply that delete_tty closed the
641 filehandles of secondary ttys twice, resulting in fclose doubly
642 freeing memory. Utterly trivial matter. I love the C's memory
643 management, it puts hair on your chest.)
645 -- Support raw secondary terminals. (Note that SIGIO works only on
646 the controlling terminal.) Hint: extend read_input_waiting for
647 multiple ttys and hopefully this will be fixed.
649 (Done, it seems to have been working already for some time. It
650 seems F_SETOWN does work, after all. Not sure what made it fail
651 earlier, but it seems to be fixed (there were several changes
652 around request_sigio, maybe one of them did it).
653 read_input_waiting is only used in sys_select, don't change
654 it.) (Update: After adding X support, it's broken again.)
655 (Update^2: No it isn't.) :-)
657 -- Find out why does Emacs abort when it wants to close its
658 controlling tty. Hint: chan_process[] array. Hey, maybe
659 noninterrupt-IO would work, too? Update: no, there is no process
662 (Done. Added add/delete_keyboard_wait_descriptor to
663 term_init/delete_tty. The hint was right, in a way.)
665 -- Issue with SIGIO: it needs to be disabled during redisplay. See if
666 fcntl kernel behaviour could be emulated by emacsclient.
668 (Done. Simply disabled the SIGIO emulation hack in emacsclient.)
669 (Update: it was added back.) (Update^2: and removed again.)
671 -- server.el: There are issues with saving files in buffers of closed
672 clients. Try editing a file with emacsclient -f, and (without
673 saving it) do a delete-frame. The frame is closed without
674 question, and a surprising confirmation prompt appears in another
677 (Done. delete-frame now asks for confirmation if it still has
678 pending buffers, and modified buffers don't seem to be deleted.)
680 -- emacsclient.el, server.el: Handle eval or file open errors when
685 -- Make parts of struct tty_output accessible from Lisp. The device
686 name and the type is sufficient.
688 (Done, see frame-tty-name and frame-tty-type.)
690 -- Export delete_tty to the Lisp environment, for emacsclient.
692 (Done, see delete-tty.)
694 -- Get rid of the accessor macros in termchar.h, or define macros for
699 -- Move device-specific parameters (like costs) commonly used by
700 device backends to a common, device-dependent structure.
702 (Done. See struct display_method in termhooks.h.)
706 (Done. Well, it seems to be working.)
708 -- Allow simultaneous X and tty frames. (Handling input could be
709 tricky. Or maybe not.)
711 (Done. Allowed, that is. It is currently extremely unstable, to
712 the point of being unusable. The rif variable causes constant
713 core dumps. Handling input is indeed tricky.)
715 -- Rewrite multi-tty input in terms of MULTI_KBOARD.
717 (Done. In fact, there was no need to rewrite anything, I just
718 added a kboard member to tty_display_info, and initialized the
719 frame's kboard from there.)
721 -- Fix rif issue with X-tty combo sessions. IMHO the best thing to do
722 is to get rid of that global variable (and use the value value in
723 display_method, which is guaranteed to be correct).
725 (Done, did exactly that. Core dumps during combo sessions became
726 much rarer. In fact, I have not yet met a single one.)
728 -- Add multi-tty support to talk.el.
732 -- Clean up the source of emacsclient. It is a mess.
734 (Done, eliminated stupid proxy-pty kludge.)
736 -- Fix faces on tty frames during X-tty combo sessions. There is an
737 init_frame_faces call in init_sys_modes, see if there is a problem
740 (Done, there was a stupid mistake in
741 Ftty_supports_face_attributes_p. Colors are broken, though.)
743 -- C-x 5 2, C-x 5 o, C-x 5 0 on an emacsclient frame unexpectedly
744 exits emacsclient. This is a result of trying to be clever with
745 delete-frame-functions.
747 (Fixed, added delete-tty-after-functions, and changed server.el to
750 -- Something with (maybe) multi-keyboard support broke function keys
751 and arrows on ttys during X+tty combo sessions. Debug this.
753 (I can't reproduce it, maybe the terminal type was wrong.)
755 -- Fix input from raw ttys (again).
757 (Now it seems to work all right.)
759 -- During an X-tty combo session, a (message "Hello") from a tty frame
760 goes to the X frame. Fix this.
762 (Done. There was a safeguard against writing to the initial
763 terminal frame during bootstrap which prevented echo_area_display
764 from working correctly on a tty frame during a combo session.)
766 -- If there are no frames on its controlling terminal, Emacs should
767 exit if the user presses C-c there.
769 (Done, as far as possible. See the SIGTERM comment in
770 interrupt_signal on why this seems to be impossible to solve this
773 -- During an X session, Emacs seems to read from stdin. Also, Emacs
774 fails to start without a controlling tty.
776 (Fixed by replacing the troublesome termcap display with a dummy
777 bootstrap display during bootstrap.
779 -- Do tty output through struct display, like graphical display
784 -- Define an output_initial value for output_method for the initial
785 frame that is dumped with Emacs. Checking for this frame (e.g. in
786 cmd_error_internal) is ugly.
788 (Done, broking interactive temacs.)
790 -- The command `emacsclient -t -e '(delete-frame)'' fails to exit.
794 -- frame-creation-function should always create a frame that is on the
795 same display as the selected frame. Maybe frame-creation-function
796 should simply be removed and make-frame changed to do the right
799 (Done, with a nice hack. frame-creation-function is now frame-local.)
801 -- Fix C-g on raw ttys.
803 (Done. I disabled the interrupt/quit keys on all secondary
804 terminals, so Emacs sees C-g as normal input. This looks like an
805 overkill, because emacsclient has extra code to pass SIGINT to
806 Emacs, so C-g should remain the interrupt/quit key on emacsclient
807 frames. See the next entry why implementing this distinction would
810 -- Make sure C-g goes to the right frame with ttys. This is hard, as
811 SIGINT doesn't have a tty parameter. :-(
813 (Done, the previous change fixes this as a pleasant side effect.)
815 -- I have seen a case when Emacs with multiple ttys fell into a loop
816 eating 100% of CPU time. Strace showed this loop:
819 kill(30284, SIGIO) = 0
820 --- SIGIO (I/O possible) @ 0 (0) ---
821 ioctl(6, FIONREAD, [0]) = -1 EIO (Input/output error)
822 ioctl(5, FIONREAD, [0]) = -1 EIO (Input/output error)
823 ioctl(0, FIONREAD, [0]) = 0
824 sigreturn() = ? (mask now [])
825 gettimeofday({1072842297, 747760}, NULL) = 0
826 gettimeofday({1072842297, 747806}, NULL) = 0
827 select(9, [0 3 5 6], NULL, NULL, {0, 0}) = 2 (in [5 6], left {0, 0})
828 select(9, [0 3 5 6], NULL, NULL, {0, 0}) = 2 (in [5 6], left {0, 0})
829 gettimeofday({1072842297, 748245}, NULL) = 0
831 I have seen something similar with a single X frame, but have not
832 been able to reproduce it for debugging.
834 Update: This may have been caused by checking for nread != 0
835 instead of nread > 0 after calling read_socket_hook in
838 (Fixed. This was caused by unconditionally including stdin in
839 input_wait_mask in init_process. The select call in
840 wait_reading_process_input always returned immediately, indicating
841 that there is pending input from stdin, which nobody read.
843 Note that the above strace output seems to be an unrelated but
844 similar bug. I think that is now fixed.)
846 -- Exiting Emacs while there are emacsclient frames doesn't restore the
847 ttys to their default states.
849 (This seems to be fixed by some previous change.)
851 -- Allow opening an X session after -nw.
855 -- Fix color handling during tty+X combo sessions. (It seems that tty
856 sessions automatically convert the face colors to terminal colors
857 when the face is loaded. This conversion must happen instead on
858 the fly in write_glyphs, which might be problematic, as color
859 approximation is currently done in lisp (term/tty-colors.el).)
860 (Update: hm, colors seem to work fine if I start emacs with -nw and
861 then create an X frame. Maybe it's just a small buglet somewhere.)
863 (Seems to be fixed. The problem was in startup.el, it did not
864 initialize tty colors when the initial window system was
867 -- emacs -nw --eval '(y-or-n-p "Foobar")' segfaults. (Reported by
870 (Fixed, there was a keyboard initialization problem.)
872 -- Fix interactive use of temacs. There are face-related SEGVs, most
873 likely because of changes in realize_default_face, realize_face.
877 -- Don't exit Emacs when the last X connection fails during a
878 multi-display session.
882 -- Dan Nicolaescu noticed that starting emacsclient on the same
883 terminal device that is the controlling tty of the Emacs process
884 gives unexpected results.
888 -- Istvan Marko reported that Emacs hang on ttys if it was started
891 (Fixed. There was a bug in the multi-tty version of
892 narrow_foreground_group. tcsetpgrp blocks if it is called from a
893 process that is not in the same process group as the tty.)
895 -- emacsclient -t from an Emacs term buffer does not work, complains
896 about face problems. This can even lock up Emacs (if the recursive
897 frame sets single_kboard). Update: the face problems are caused by
898 bugs in term.el, not in multi-tty. The lockup is caused by
899 single_kboard mode, and is not easily resolvable. The best thing to
900 do is to simply refuse to create a tty frame of type `eterm'.
902 (Fixed, changed emacsclient to check for TERM=eterm. The face
903 complaints seem to be caused by bugs in term.el; they are not
904 related to multi-tty.)
906 -- Find out the best way to support suspending Emacs with multiple
907 ttys. My guess: disable it on the controlling tty, but from other
908 ttys pass it on to emacsclient somehow. (It is (I hope) trivial to
909 extend emacsclient to handle suspend/resume. A `kill -STOP' almost
912 (Done. I needed to play with signal handling and the server
913 protocol a bit to make emacsclient behave as a normal UNIX program
914 wrt foreground/background process groups.)
916 -- There is a flicker during the startup of `emacs -nw'; it's as if
917 the terminal is initialized, reset and then initialialized again.
918 Debug this. (Hint: narrow_foreground_group is called twice during
923 -- Robert Chassell has found serious copy-paste bugs with the
924 multi-tty branch. There seem to be redisplay bugs while copying
925 from X to a terminal frame. Copying accented characters do not
928 (Patch-124 should fix this, by changing the interprogram-*-function
929 variables to be frame-local, as suggested by Mark Plaksin
930 (thanks!). I think that the redisplay bugs are in fact not bugs,
931 but delays caused by single_kboard --> perhaps MULTI_KBOARD should
934 -- frame-creation-function was removed, which might be a bad idea.
935 Think up a compatible solution.
937 (It was an internal interface that may be changed when necessary.)
939 -- Change Lisp code not to (getenv "TERM"); use the `tty-type' frame
940 parameter or the frame-tty-type function instead. (M-x tags-search
941 "TERM" helps with this.) Update: Actually, all getenv invocations
942 should be checked for multi-tty compatibility, and an interface
943 must be implemented to get the remote client's environment.
945 (Done. Only getenv calls in lisp/term/*.el were changed; other
946 calls should be mostly left as they are.)
948 -- Add an elaborate mechanism for display-local variables. (There are
949 already a few of these; search for `terminal-local' in the Elisp
952 (Not needed. Display-local variables could be emulated by
953 frame-local variables.)
955 -- Emacs assumes that all terminal frames have the same locale
956 settings as Emacs itself. This may lead to bogus results in a
957 multi-locale setup. (E.g., while logging in from a remote client
958 with a different locale.)
959 (Update after new bugreport by Friedrich Delgado Friedrichs:
960 (at least) the structs terminal_coding and keyboard_coding in
961 coding.c must be moved to struct display, and the Lisp interface
962 [set-]keyboard-coding-system must be adapted for the change.)
964 (Fixed. Emacs now uses the locale settings as seen by the
965 emacsclient process for server tty frames.)
968 -- Make `struct display' accessible to Lisp programs. Accessor functions:
970 (displayp OBJECT): Returns t if OBJECT is a display.
971 => Implemented as display-live-p.
973 (display-list): Returns list of currently active displays.
976 (selected-display): Returns the display object of the selected frame.
977 => Not strictly necessary, but implemented anyway.
979 (frame-display FRAME): Returns the display object of FRAME.
982 (display-frames DISPLAY): Returns a list of frames on DISPLAY.
983 => Already implemented, see frames-on-display-list.
985 (display-type DISPLAY): Returns the type of DISPLAY, as a
986 symbol. (See `framep'.)
987 => Implemented as display-live-p.
989 (display-device DISPLAY): Returns the name of the device that
990 DISPLAY uses, as a string. (E.g: "/dev/pts/16", or
992 => Implemented as display-name.
996 See next issue why this is necessary.
998 (Update: The consensus on emacs-devel seems to be to do this via
999 integer identifiers. That's fine by me.)
1003 -- The following needs to be supported:
1010 The cleanest way to solve this is to allow multiple displays on the
1011 same terminal device; each new emacsclient process should create
1012 its own display. As displays are currently identified by their
1013 device names, this is not possible until struct display becomes
1014 accessible as a Lisp-level object.
1018 -- Miles Bader suggests that C-x C-c on an emacsclient frame should
1019 only close the frame, not exit the entire Emacs session. Update:
1020 see above for a function that does this. Maybe this should be the
1023 (Done. This is the new default. No complaints so far.)
1026 ;;; arch-tag: 8da1619e-2e79-41a8-9ac9-a0485daad17d