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3eb25fda MM |
1 | /* Generic serial interface functions. |
2 | ||
3 | Copyright 1992, 1993, 1994, 1995, 1996, 1998, 1999, 2000, 2001, | |
4 | 2003, 2004, 2005 Free Software Foundation, Inc. | |
5 | ||
6 | This file is part of GDB. | |
7 | ||
8 | This program is free software; you can redistribute it and/or modify | |
9 | it under the terms of the GNU General Public License as published by | |
10 | the Free Software Foundation; either version 2 of the License, or | |
11 | (at your option) any later version. | |
12 | ||
13 | This program is distributed in the hope that it will be useful, | |
14 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
16 | GNU General Public License for more details. | |
17 | ||
18 | You should have received a copy of the GNU General Public License | |
19 | along with this program; if not, write to the Free Software | |
20 | Foundation, Inc., 59 Temple Place - Suite 330, | |
21 | Boston, MA 02111-1307, USA. */ | |
22 | ||
23 | #include "defs.h" | |
24 | #include "serial.h" | |
25 | #include "ser-unix.h" | |
26 | #include "event-loop.h" | |
b4505029 MM |
27 | #ifdef USE_WIN32API |
28 | #include <winsock2.h> | |
29 | #endif | |
3eb25fda | 30 | |
401e7faf MK |
31 | #include "gdb_string.h" |
32 | ||
3eb25fda MM |
33 | static timer_handler_func push_event; |
34 | static handler_func fd_event; | |
35 | ||
36 | /* Event handling for ASYNC serial code. | |
37 | ||
38 | At any time the SERIAL device either: has an empty FIFO and is | |
39 | waiting on a FD event; or has a non-empty FIFO/error condition and | |
40 | is constantly scheduling timer events. | |
41 | ||
42 | ASYNC only stops pestering its client when it is de-async'ed or it | |
43 | is told to go away. */ | |
44 | ||
45 | /* Value of scb->async_state: */ | |
46 | enum { | |
47 | /* >= 0 (TIMER_SCHEDULED) */ | |
48 | /* The ID of the currently scheduled timer event. This state is | |
49 | rarely encountered. Timer events are one-off so as soon as the | |
50 | event is delivered the state is shanged to NOTHING_SCHEDULED. */ | |
51 | FD_SCHEDULED = -1, | |
52 | /* The fd_event() handler is scheduled. It is called when ever the | |
53 | file descriptor becomes ready. */ | |
54 | NOTHING_SCHEDULED = -2 | |
55 | /* Either no task is scheduled (just going into ASYNC mode) or a | |
56 | timer event has just gone off and the current state has been | |
57 | forced into nothing scheduled. */ | |
58 | }; | |
59 | ||
60 | /* Identify and schedule the next ASYNC task based on scb->async_state | |
61 | and scb->buf* (the input FIFO). A state machine is used to avoid | |
62 | the need to make redundant calls into the event-loop - the next | |
63 | scheduled task is only changed when needed. */ | |
64 | ||
65 | void | |
66 | reschedule (struct serial *scb) | |
67 | { | |
68 | if (serial_is_async_p (scb)) | |
69 | { | |
70 | int next_state; | |
71 | switch (scb->async_state) | |
72 | { | |
73 | case FD_SCHEDULED: | |
74 | if (scb->bufcnt == 0) | |
75 | next_state = FD_SCHEDULED; | |
76 | else | |
77 | { | |
78 | delete_file_handler (scb->fd); | |
79 | next_state = create_timer (0, push_event, scb); | |
80 | } | |
81 | break; | |
82 | case NOTHING_SCHEDULED: | |
83 | if (scb->bufcnt == 0) | |
84 | { | |
85 | add_file_handler (scb->fd, fd_event, scb); | |
86 | next_state = FD_SCHEDULED; | |
87 | } | |
88 | else | |
89 | { | |
90 | next_state = create_timer (0, push_event, scb); | |
91 | } | |
92 | break; | |
93 | default: /* TIMER SCHEDULED */ | |
94 | if (scb->bufcnt == 0) | |
95 | { | |
96 | delete_timer (scb->async_state); | |
97 | add_file_handler (scb->fd, fd_event, scb); | |
98 | next_state = FD_SCHEDULED; | |
99 | } | |
100 | else | |
101 | next_state = scb->async_state; | |
102 | break; | |
103 | } | |
104 | if (serial_debug_p (scb)) | |
105 | { | |
106 | switch (next_state) | |
107 | { | |
108 | case FD_SCHEDULED: | |
109 | if (scb->async_state != FD_SCHEDULED) | |
110 | fprintf_unfiltered (gdb_stdlog, "[fd%d->fd-scheduled]\n", | |
111 | scb->fd); | |
112 | break; | |
113 | default: /* TIMER SCHEDULED */ | |
114 | if (scb->async_state == FD_SCHEDULED) | |
115 | fprintf_unfiltered (gdb_stdlog, "[fd%d->timer-scheduled]\n", | |
116 | scb->fd); | |
117 | break; | |
118 | } | |
119 | } | |
120 | scb->async_state = next_state; | |
121 | } | |
122 | } | |
123 | ||
124 | /* FD_EVENT: This is scheduled when the input FIFO is empty (and there | |
125 | is no pending error). As soon as data arrives, it is read into the | |
126 | input FIFO and the client notified. The client should then drain | |
127 | the FIFO using readchar(). If the FIFO isn't immediatly emptied, | |
128 | push_event() is used to nag the client until it is. */ | |
129 | ||
130 | static void | |
131 | fd_event (int error, void *context) | |
132 | { | |
133 | struct serial *scb = context; | |
134 | if (error != 0) | |
135 | { | |
136 | scb->bufcnt = SERIAL_ERROR; | |
137 | } | |
138 | else if (scb->bufcnt == 0) | |
139 | { | |
140 | /* Prime the input FIFO. The readchar() function is used to | |
141 | pull characters out of the buffer. See also | |
142 | generic_readchar(). */ | |
143 | int nr; | |
b4505029 | 144 | nr = scb->ops->read_prim (scb, BUFSIZ); |
3eb25fda MM |
145 | if (nr == 0) |
146 | { | |
147 | scb->bufcnt = SERIAL_EOF; | |
148 | } | |
149 | else if (nr > 0) | |
150 | { | |
151 | scb->bufcnt = nr; | |
152 | scb->bufp = scb->buf; | |
153 | } | |
154 | else | |
155 | { | |
156 | scb->bufcnt = SERIAL_ERROR; | |
157 | } | |
158 | } | |
159 | scb->async_handler (scb, scb->async_context); | |
160 | reschedule (scb); | |
161 | } | |
162 | ||
163 | /* PUSH_EVENT: The input FIFO is non-empty (or there is a pending | |
164 | error). Nag the client until all the data has been read. In the | |
165 | case of errors, the client will need to close or de-async the | |
166 | device before naging stops. */ | |
167 | ||
168 | static void | |
169 | push_event (void *context) | |
170 | { | |
171 | struct serial *scb = context; | |
172 | scb->async_state = NOTHING_SCHEDULED; /* Timers are one-off */ | |
173 | scb->async_handler (scb, scb->async_context); | |
174 | /* re-schedule */ | |
175 | reschedule (scb); | |
176 | } | |
177 | ||
b4505029 MM |
178 | /* Wait for input on scb, with timeout seconds. Returns 0 on success, |
179 | otherwise SERIAL_TIMEOUT or SERIAL_ERROR. */ | |
180 | ||
181 | static int | |
182 | ser_base_wait_for (struct serial *scb, int timeout) | |
183 | { | |
184 | while (1) | |
185 | { | |
186 | int numfds; | |
187 | struct timeval tv; | |
188 | fd_set readfds, exceptfds; | |
189 | ||
190 | /* NOTE: Some OS's can scramble the READFDS when the select() | |
191 | call fails (ex the kernel with Red Hat 5.2). Initialize all | |
192 | arguments before each call. */ | |
193 | ||
194 | tv.tv_sec = timeout; | |
195 | tv.tv_usec = 0; | |
196 | ||
197 | FD_ZERO (&readfds); | |
198 | FD_ZERO (&exceptfds); | |
199 | FD_SET (scb->fd, &readfds); | |
200 | FD_SET (scb->fd, &exceptfds); | |
201 | ||
202 | if (timeout >= 0) | |
203 | numfds = select (scb->fd + 1, &readfds, 0, &exceptfds, &tv); | |
204 | else | |
205 | numfds = select (scb->fd + 1, &readfds, 0, &exceptfds, 0); | |
206 | ||
207 | if (numfds <= 0) | |
208 | { | |
209 | if (numfds == 0) | |
210 | return SERIAL_TIMEOUT; | |
211 | else if (errno == EINTR) | |
212 | continue; | |
213 | else | |
214 | return SERIAL_ERROR; /* Got an error from select or poll */ | |
215 | } | |
216 | ||
217 | return 0; | |
218 | } | |
219 | } | |
220 | ||
221 | /* Read a character with user-specified timeout. TIMEOUT is number of seconds | |
222 | to wait, or -1 to wait forever. Use timeout of 0 to effect a poll. Returns | |
223 | char if successful. Returns -2 if timeout expired, EOF if line dropped | |
224 | dead, or -3 for any other error (see errno in that case). */ | |
225 | ||
226 | static int | |
227 | do_ser_base_readchar (struct serial *scb, int timeout) | |
228 | { | |
229 | int status; | |
230 | int delta; | |
231 | ||
232 | /* We have to be able to keep the GUI alive here, so we break the | |
233 | original timeout into steps of 1 second, running the "keep the | |
234 | GUI alive" hook each time through the loop. | |
235 | ||
236 | Also, timeout = 0 means to poll, so we just set the delta to 0, | |
237 | so we will only go through the loop once. */ | |
238 | ||
239 | delta = (timeout == 0 ? 0 : 1); | |
240 | while (1) | |
241 | { | |
242 | /* N.B. The UI may destroy our world (for instance by calling | |
243 | remote_stop,) in which case we want to get out of here as | |
244 | quickly as possible. It is not safe to touch scb, since | |
245 | someone else might have freed it. The | |
246 | deprecated_ui_loop_hook signals that we should exit by | |
247 | returning 1. */ | |
248 | ||
249 | if (deprecated_ui_loop_hook) | |
250 | { | |
251 | if (deprecated_ui_loop_hook (0)) | |
252 | return SERIAL_TIMEOUT; | |
253 | } | |
254 | ||
255 | status = ser_base_wait_for (scb, delta); | |
256 | if (timeout > 0) | |
257 | timeout -= delta; | |
258 | ||
259 | /* If we got a character or an error back from wait_for, then we can | |
260 | break from the loop before the timeout is completed. */ | |
261 | if (status != SERIAL_TIMEOUT) | |
262 | break; | |
263 | ||
264 | /* If we have exhausted the original timeout, then generate | |
265 | a SERIAL_TIMEOUT, and pass it out of the loop. */ | |
266 | else if (timeout == 0) | |
267 | { | |
268 | status = SERIAL_TIMEOUT; | |
269 | break; | |
270 | } | |
271 | } | |
272 | ||
273 | if (status < 0) | |
274 | return status; | |
275 | ||
276 | status = scb->ops->read_prim (scb, BUFSIZ); | |
277 | ||
278 | if (status <= 0) | |
279 | { | |
280 | if (status == 0) | |
281 | /* 0 chars means timeout. (We may need to distinguish between EOF | |
282 | & timeouts someday.) */ | |
283 | return SERIAL_TIMEOUT; | |
284 | else | |
285 | /* Got an error from read. */ | |
286 | return SERIAL_ERROR; | |
287 | } | |
288 | ||
289 | scb->bufcnt = status; | |
290 | scb->bufcnt--; | |
291 | scb->bufp = scb->buf; | |
292 | return *scb->bufp++; | |
293 | } | |
294 | ||
295 | /* Perform operations common to both old and new readchar. */ | |
296 | ||
297 | /* Return the next character from the input FIFO. If the FIFO is | |
298 | empty, call the SERIAL specific routine to try and read in more | |
299 | characters. | |
300 | ||
301 | Initially data from the input FIFO is returned (fd_event() | |
302 | pre-reads the input into that FIFO. Once that has been emptied, | |
303 | further data is obtained by polling the input FD using the device | |
304 | specific readchar() function. Note: reschedule() is called after | |
305 | every read. This is because there is no guarentee that the lower | |
306 | level fd_event() poll_event() code (which also calls reschedule()) | |
307 | will be called. */ | |
308 | ||
309 | int | |
310 | generic_readchar (struct serial *scb, int timeout, | |
311 | int (do_readchar) (struct serial *scb, int timeout)) | |
312 | { | |
313 | int ch; | |
314 | if (scb->bufcnt > 0) | |
315 | { | |
316 | ch = *scb->bufp; | |
317 | scb->bufcnt--; | |
318 | scb->bufp++; | |
319 | } | |
320 | else if (scb->bufcnt < 0) | |
321 | { | |
322 | /* Some errors/eof are are sticky. */ | |
323 | ch = scb->bufcnt; | |
324 | } | |
325 | else | |
326 | { | |
327 | ch = do_readchar (scb, timeout); | |
328 | if (ch < 0) | |
329 | { | |
330 | switch ((enum serial_rc) ch) | |
331 | { | |
332 | case SERIAL_EOF: | |
333 | case SERIAL_ERROR: | |
334 | /* Make the error/eof stick. */ | |
335 | scb->bufcnt = ch; | |
336 | break; | |
337 | case SERIAL_TIMEOUT: | |
338 | scb->bufcnt = 0; | |
339 | break; | |
340 | } | |
341 | } | |
342 | } | |
343 | reschedule (scb); | |
344 | return ch; | |
345 | } | |
346 | ||
347 | int | |
348 | ser_base_readchar (struct serial *scb, int timeout) | |
349 | { | |
350 | return generic_readchar (scb, timeout, do_ser_base_readchar); | |
351 | } | |
352 | ||
3eb25fda | 353 | int |
dd5da072 | 354 | ser_base_write (struct serial *scb, const char *str, int len) |
3eb25fda MM |
355 | { |
356 | int cc; | |
357 | ||
358 | while (len > 0) | |
359 | { | |
b4505029 | 360 | cc = scb->ops->write_prim (scb, str, len); |
3eb25fda MM |
361 | |
362 | if (cc < 0) | |
363 | return 1; | |
364 | len -= cc; | |
365 | str += cc; | |
366 | } | |
367 | return 0; | |
368 | } | |
369 | ||
370 | int | |
dd5da072 | 371 | ser_base_flush_output (struct serial *scb) |
3eb25fda MM |
372 | { |
373 | return 0; | |
374 | } | |
375 | ||
376 | int | |
dd5da072 | 377 | ser_base_flush_input (struct serial *scb) |
3eb25fda MM |
378 | { |
379 | if (scb->bufcnt >= 0) | |
380 | { | |
381 | scb->bufcnt = 0; | |
382 | scb->bufp = scb->buf; | |
383 | return 0; | |
384 | } | |
385 | else | |
386 | return SERIAL_ERROR; | |
387 | } | |
388 | ||
389 | int | |
dd5da072 | 390 | ser_base_send_break (struct serial *scb) |
3eb25fda MM |
391 | { |
392 | return 0; | |
393 | } | |
394 | ||
395 | int | |
dd5da072 | 396 | ser_base_drain_output (struct serial *scb) |
3eb25fda MM |
397 | { |
398 | return 0; | |
399 | } | |
400 | ||
401 | void | |
dd5da072 | 402 | ser_base_raw (struct serial *scb) |
3eb25fda MM |
403 | { |
404 | return; /* Always in raw mode */ | |
405 | } | |
406 | ||
407 | serial_ttystate | |
dd5da072 | 408 | ser_base_get_tty_state (struct serial *scb) |
3eb25fda MM |
409 | { |
410 | /* allocate a dummy */ | |
411 | return (serial_ttystate) XMALLOC (int); | |
412 | } | |
413 | ||
414 | int | |
dd5da072 | 415 | ser_base_set_tty_state (struct serial *scb, serial_ttystate ttystate) |
3eb25fda MM |
416 | { |
417 | return 0; | |
418 | } | |
419 | ||
420 | int | |
dd5da072 MM |
421 | ser_base_noflush_set_tty_state (struct serial *scb, |
422 | serial_ttystate new_ttystate, | |
423 | serial_ttystate old_ttystate) | |
3eb25fda MM |
424 | { |
425 | return 0; | |
426 | } | |
427 | ||
428 | void | |
dd5da072 MM |
429 | ser_base_print_tty_state (struct serial *scb, |
430 | serial_ttystate ttystate, | |
431 | struct ui_file *stream) | |
3eb25fda MM |
432 | { |
433 | /* Nothing to print. */ | |
434 | return; | |
435 | } | |
436 | ||
437 | int | |
dd5da072 | 438 | ser_base_setbaudrate (struct serial *scb, int rate) |
3eb25fda MM |
439 | { |
440 | return 0; /* Never fails! */ | |
441 | } | |
442 | ||
443 | int | |
dd5da072 | 444 | ser_base_setstopbits (struct serial *scb, int num) |
3eb25fda MM |
445 | { |
446 | return 0; /* Never fails! */ | |
447 | } | |
448 | ||
449 | /* Put the SERIAL device into/out-of ASYNC mode. */ | |
450 | ||
451 | void | |
dd5da072 | 452 | ser_base_async (struct serial *scb, |
3eb25fda MM |
453 | int async_p) |
454 | { | |
455 | if (async_p) | |
456 | { | |
457 | /* Force a re-schedule. */ | |
458 | scb->async_state = NOTHING_SCHEDULED; | |
459 | if (serial_debug_p (scb)) | |
460 | fprintf_unfiltered (gdb_stdlog, "[fd%d->asynchronous]\n", | |
461 | scb->fd); | |
462 | reschedule (scb); | |
463 | } | |
464 | else | |
465 | { | |
466 | if (serial_debug_p (scb)) | |
467 | fprintf_unfiltered (gdb_stdlog, "[fd%d->synchronous]\n", | |
468 | scb->fd); | |
469 | /* De-schedule whatever tasks are currently scheduled. */ | |
470 | switch (scb->async_state) | |
471 | { | |
472 | case FD_SCHEDULED: | |
473 | delete_file_handler (scb->fd); | |
474 | break; | |
475 | case NOTHING_SCHEDULED: | |
476 | break; | |
477 | default: /* TIMER SCHEDULED */ | |
478 | delete_timer (scb->async_state); | |
479 | break; | |
480 | } | |
481 | } | |
482 | } |