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28d440ab KL |
1 | -*- coding: utf-8; -*- |
2 | GOAL | |
3 | ---- | |
4 | ||
5 | The ultimate goal of this branch is to implement support for opening | |
6 | multiple, different tty devices and simultaneous X and tty frames from | |
7 | a single Emacs session. | |
8 | ||
9 | WHO IS DOING IT | |
10 | --------------- | |
11 | ||
12 | I'm Károly Lőrentey. My address: lorentey@elte.hu. | |
13 | ||
14 | Patches or suggestions are welcome! | |
15 | ||
6548cf00 | 16 | Retrieving the latest version of the branch: |
4f0359de KL |
17 | |
18 | tla register-archive lorentey@elte.hu--2004 http://lorentey.web.elte.hu/arch/2004/ | |
19 | tla get lorentey@elte.hu--2004/emacs--multi-tty--0 <directory> | |
20 | ||
21 | (I use tla 1.1.) | |
22 | ||
28d440ab KL |
23 | |
24 | STATUS | |
25 | ------ | |
26 | ||
52c2ee2a KL |
27 | Basic multi-tty support is there; there are some rough edges, but it |
28 | already seems to be usable. Emacsclient has been extended to support | |
29 | opening a new terminal frame. | |
28d440ab | 30 | |
bc279d67 KL |
31 | To try it out, compile Emacs with the following commands |
32 | ||
33 | mkdir +build | |
34 | cd +build | |
35 | ../configure --with-x-toolkit=no --without-x | |
36 | make bootstrap | |
37 | ||
38 | then start up the emacs server (src/emacs, M-x server-start), and then | |
6548cf00 | 39 | (from a shell prompt on another terminal) start emacsclient with |
28d440ab | 40 | |
bc279d67 | 41 | lib-src/emacsclient -h |
28d440ab | 42 | |
52c2ee2a KL |
43 | You'll hopefully have two fully working frames on separate terminals. |
44 | If you exit emacs, both terminals should be restored to their previous | |
c33d2d42 | 45 | states. You can close the newly opened frame and return to the shell |
53fed860 | 46 | without exiting Emacs by pressing C-x 5 0, i.e., delete-frame. |
52c2ee2a KL |
47 | |
48 | X, Mac, Windows and DOS support is broken, probably doesn't even | |
49 | compile -- this will be solved later. | |
6548cf00 KL |
50 | |
51 | Tested under GNU/Linux only. | |
28d440ab KL |
52 | |
53 | NEWS | |
54 | ---- | |
55 | ||
56 | For the NEWS file: | |
57 | ||
58 | ** Support for multiple terminal devices has been added. You can | |
59 | specify a terminal device (`tty' parameter) and a terminal type | |
6548cf00 | 60 | (`tty-type' parameter) to `make-terminal-frame'. `tty' must be a |
52c2ee2a KL |
61 | terminal device created by the updated emacsclient, or there will |
62 | be problems with terminal input and window resizes. (The kernel | |
6548cf00 KL |
63 | notifies processes about pending input or terminal resizes only on |
64 | the controlling terminal, so we need emacsclient to sit on the real | |
65 | terminal device, create SIGIO signals upon terminal input, and | |
66 | forward SIGWINCH signals to us.) | |
67 | ||
68 | You can test for the presence of multiple terminal support by | |
69 | testing for the `multi-tty' feature. | |
70 | ||
71 | ** A make-frame-on-tty function has been added to make it easier to | |
72 | create frames on new terminals. | |
28d440ab | 73 | |
9628b887 KL |
74 | ** Emacsclient has been extended to support opening a new terminal |
75 | frame. | |
28d440ab KL |
76 | |
77 | CHANGELOG | |
78 | --------- | |
79 | ||
80 | See arch logs. | |
81 | ||
82 | ||
6548cf00 KL |
83 | DIARY OF CHANGES |
84 | ---------------- | |
85 | ||
86 | (ex-TODO items with explanations.) | |
28d440ab KL |
87 | |
88 | -- Introduce a new abstraction for terminal devices. | |
89 | ||
90 | (Done, see struct tty_output. The abstraction is not yet | |
91 | complete.) | |
92 | ||
28d440ab KL |
93 | -- Change the bootstrap procedure to initialize tty_list. |
94 | ||
95 | (Done, but needs review.) | |
96 | ||
28d440ab KL |
97 | -- Change make-terminal-frame to support specifying another tty. |
98 | ||
99 | (Done, new frame parameters: `tty' and `tty-type'.) | |
100 | ||
9628b887 KL |
101 | -- Implement support for reading from multiple terminals. |
102 | ||
103 | (Done, read_avail_input tries to read from each terminal, until one | |
6548cf00 KL |
104 | succeeds. MULTIKBOARD is not used. Secondary terminals don't send |
105 | SIGIO!) | |
9628b887 KL |
106 | |
107 | -- other-frame should cycle through the frames on the `current' | |
6548cf00 | 108 | terminal only. |
9628b887 | 109 | |
6548cf00 | 110 | (Done, by trivially modifiying next_frame and prev_frame.) |
9628b887 KL |
111 | |
112 | -- Support different terminal sizes. | |
113 | ||
114 | (Done, no problem.) | |
115 | ||
116 | -- Make sure terminal resizes are handled gracefully. (Could be | |
117 | problematic.) | |
118 | ||
6548cf00 KL |
119 | (Done. We don't get automatic SIGWINCH for additional ttys, |
120 | though.) | |
9628b887 KL |
121 | |
122 | -- Extend emacsclient to automatically open a new tty when it connects | |
123 | to Emacs. | |
124 | ||
125 | (Done. It's an ugly hack, needs more work.) | |
126 | ||
52c2ee2a KL |
127 | -- Redisplay must refresh the topmost frame on *all* terminals, not |
128 | just the initial terminal. | |
9628b887 | 129 | |
52c2ee2a | 130 | (Done, but introduced an ugly redisplay problems. Ugh.) |
9628b887 | 131 | |
6548cf00 KL |
132 | -- Fix redisplay problems. |
133 | ||
52c2ee2a KL |
134 | (Done; it turned out that the entire Wcm structure must be moved |
135 | inside tty_output. Why didn't I catch this earlier?) | |
6548cf00 KL |
136 | |
137 | -- Provide a way for emacsclient to tell Emacs that the tty has been | |
138 | resized. | |
139 | ||
140 | (Done, simply forward the SIGWINCH signal.) | |
141 | ||
142 | -- Each keypress should automatically select the frame corresponding | |
143 | to the terminal that it was coming from. This means that Emacs | |
144 | must know from which terminal the last keyboard event came from. | |
6548cf00 | 145 | |
52c2ee2a KL |
146 | (Done, it was quite simple, the input event system already |
147 | supported multiple frames.) | |
6548cf00 KL |
148 | |
149 | -- Fix SIGIO issue with secondary terminals. | |
150 | ||
151 | (Done, emacsclient signals Emacs after writing to the proxy pseudo | |
52c2ee2a KL |
152 | terminal. Note that this means that multi-tty does not work with |
153 | raw ttys!) | |
28d440ab | 154 | |
fca177d4 KL |
155 | -- Make make-terminal-frame look up the `tty' and `tty-type' frame |
156 | parameters from the currently selected terminal before the global | |
157 | default. | |
158 | ||
159 | (Done.) | |
160 | ||
161 | -- Put all cached terminal escape sequences into struct tty_output. | |
162 | Currently, they are still stored in global variables, so we don't | |
163 | really support multiple terminal types. | |
164 | ||
52c2ee2a | 165 | (Done. It was not fun.) |
fca177d4 KL |
166 | |
167 | -- Implement sane error handling after initialization. (Currently | |
6548cf00 KL |
168 | emacs exits if you specify a bad terminal type.) The helpful error |
169 | messages must still be provided when Emacs starts. | |
170 | ||
fca177d4 KL |
171 | (Done.) |
172 | ||
173 | -- Implement terminal deletion, i.e., deleting local frames, closing | |
174 | the tty device and restoring its previous state without exiting | |
175 | Emacs. | |
9628b887 | 176 | |
fca177d4 KL |
177 | (Done, but at the moment only called when an error happens during |
178 | initialization. There is a memory corruption error around this | |
179 | somewhere.) | |
180 | ||
8303ba32 KL |
181 | -- Implement automatic deletion of terminals when the last frame on |
182 | that terminal is closed. | |
183 | ||
184 | (Done.) | |
185 | ||
fca177d4 KL |
186 | |
187 | THINGS TO DO | |
188 | ------------ | |
189 | ||
190 | ** Fix mysterious memory corruption error with tty deletion. To | |
191 | trigger it, try the following shell command: | |
192 | ||
193 | while true; do TERM=no-such-terminal-definition emacsclient -h; done | |
194 | ||
195 | Emacs usually dumps core after a few dozen iterations. (The bug | |
196 | seems to be related to the xfree()ing or bzero()ing of | |
52c2ee2a KL |
197 | tty_output.Wcm or some other tty_output part. Maybe there are |
198 | outside references to struct Wcm? Why were these vars collected | |
199 | into a struct before multi-tty support?) | |
fca177d4 | 200 | |
52c2ee2a | 201 | The bug does not seem to happen if the error occurs before terminal |
fca177d4 | 202 | initialization or if I comment out all xfree()s in delete_frame. |
52c2ee2a KL |
203 | Update: yes it does, although it is much rarer. Or maybe it's |
204 | another bug. | |
fca177d4 | 205 | |
8303ba32 KL |
206 | ** Change emacsclient/server.el to support the -h argument better, |
207 | i.e. automatically close the socket when the frame is closed. | |
28d440ab | 208 | |
8303ba32 KL |
209 | ** Export delete_tty to the Lisp environment, for emacsclient. |
210 | ||
c33d2d42 KL |
211 | ** Restore tty screen after closing the terminal. |
212 | ||
213 | ** 'TERM=dumb src/emacs' does not restore the terminal state. | |
214 | ||
8303ba32 | 215 | ** C-g should work on secondary terminals. |
28d440ab | 216 | |
6548cf00 KL |
217 | ** Make parts of struct tty_output accessible from Lisp. The device |
218 | name and the type is sufficient. | |
28d440ab | 219 | |
c33d2d42 KL |
220 | ** Find out why does Emacs abort when it wants to close its |
221 | controlling tty. | |
222 | ||
28d440ab KL |
223 | ** Implement support for starting an interactive Emacs session without |
224 | an initial frame. (The user would connect to it and open frames | |
fca177d4 | 225 | later, with emacsclient.) Not necessarily a good idea. |
28d440ab | 226 | |
6548cf00 | 227 | ** Support raw secondary terminals. (This one is tricky, SIGIO works |
52c2ee2a KL |
228 | only on the controlling terminal. The emacsclient solution works |
229 | nicely, so this is not that important anyway.) | |
6548cf00 KL |
230 | |
231 | ** What does interrupt_input do? I tried to disable it for raw | |
52c2ee2a | 232 | secondary tty support, but it does not seem to do anything useful. |
6548cf00 | 233 | |
52c2ee2a KL |
234 | ** Move optimalization parameters (costs) from union output_data to |
235 | a backend-neutral per-device structure. | |
28d440ab | 236 | |
c33d2d42 KL |
237 | ** Find out the best way to support suspending Emacs with multiple |
238 | ttys. | |
239 | ||
240 | ** Do tty output through term_hooks, like all other display backends. | |
6548cf00 | 241 | |
52c2ee2a KL |
242 | ** Fix X support. |
243 | ||
28d440ab KL |
244 | ** Allow simultaneous X and tty frames. |
245 | ||
246 | ** Fix Mac support (I can't do this myself). | |
247 | ||
248 | ** Fix W32 support (I can't do this myself). | |
249 | ||
250 | ** Fix DOS support (I can't do this myself). | |
251 | ||
252 | ||
253 | ||
254 | ;;; arch-tag: 8da1619e-2e79-41a8-9ac9-a0485daad17d |