Commit | Line | Data |
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3eb25fda MM |
1 | /* Generic serial interface functions. |
2 | ||
6aba47ca DJ |
3 | Copyright (C) 1992, 1993, 1994, 1995, 1996, 1998, 1999, 2000, 2001, 2003, |
4 | 2004, 2005, 2006, 2007 Free Software Foundation, Inc. | |
3eb25fda MM |
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 | |
a9762ec7 | 10 | the Free Software Foundation; either version 3 of the License, or |
3eb25fda MM |
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 | |
a9762ec7 | 19 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
3eb25fda MM |
20 | |
21 | #include "defs.h" | |
22 | #include "serial.h" | |
a07ff70c | 23 | #include "ser-base.h" |
3eb25fda | 24 | #include "event-loop.h" |
a07ff70c | 25 | |
0ea3f30e | 26 | #include "gdb_select.h" |
a07ff70c | 27 | #include "gdb_string.h" |
248697b2 | 28 | #include <sys/time.h> |
b4505029 MM |
29 | #ifdef USE_WIN32API |
30 | #include <winsock2.h> | |
31 | #endif | |
3eb25fda | 32 | |
401e7faf | 33 | |
3eb25fda MM |
34 | static timer_handler_func push_event; |
35 | static handler_func fd_event; | |
36 | ||
37 | /* Event handling for ASYNC serial code. | |
38 | ||
39 | At any time the SERIAL device either: has an empty FIFO and is | |
40 | waiting on a FD event; or has a non-empty FIFO/error condition and | |
41 | is constantly scheduling timer events. | |
42 | ||
43 | ASYNC only stops pestering its client when it is de-async'ed or it | |
44 | is told to go away. */ | |
45 | ||
46 | /* Value of scb->async_state: */ | |
47 | enum { | |
48 | /* >= 0 (TIMER_SCHEDULED) */ | |
49 | /* The ID of the currently scheduled timer event. This state is | |
50 | rarely encountered. Timer events are one-off so as soon as the | |
51 | event is delivered the state is shanged to NOTHING_SCHEDULED. */ | |
52 | FD_SCHEDULED = -1, | |
53 | /* The fd_event() handler is scheduled. It is called when ever the | |
54 | file descriptor becomes ready. */ | |
55 | NOTHING_SCHEDULED = -2 | |
56 | /* Either no task is scheduled (just going into ASYNC mode) or a | |
57 | timer event has just gone off and the current state has been | |
58 | forced into nothing scheduled. */ | |
59 | }; | |
60 | ||
61 | /* Identify and schedule the next ASYNC task based on scb->async_state | |
62 | and scb->buf* (the input FIFO). A state machine is used to avoid | |
63 | the need to make redundant calls into the event-loop - the next | |
64 | scheduled task is only changed when needed. */ | |
65 | ||
66 | void | |
67 | reschedule (struct serial *scb) | |
68 | { | |
69 | if (serial_is_async_p (scb)) | |
70 | { | |
71 | int next_state; | |
72 | switch (scb->async_state) | |
73 | { | |
74 | case FD_SCHEDULED: | |
75 | if (scb->bufcnt == 0) | |
76 | next_state = FD_SCHEDULED; | |
77 | else | |
78 | { | |
79 | delete_file_handler (scb->fd); | |
80 | next_state = create_timer (0, push_event, scb); | |
81 | } | |
82 | break; | |
83 | case NOTHING_SCHEDULED: | |
84 | if (scb->bufcnt == 0) | |
85 | { | |
86 | add_file_handler (scb->fd, fd_event, scb); | |
87 | next_state = FD_SCHEDULED; | |
88 | } | |
89 | else | |
90 | { | |
91 | next_state = create_timer (0, push_event, scb); | |
92 | } | |
93 | break; | |
94 | default: /* TIMER SCHEDULED */ | |
95 | if (scb->bufcnt == 0) | |
96 | { | |
97 | delete_timer (scb->async_state); | |
98 | add_file_handler (scb->fd, fd_event, scb); | |
99 | next_state = FD_SCHEDULED; | |
100 | } | |
101 | else | |
102 | next_state = scb->async_state; | |
103 | break; | |
104 | } | |
105 | if (serial_debug_p (scb)) | |
106 | { | |
107 | switch (next_state) | |
108 | { | |
109 | case FD_SCHEDULED: | |
110 | if (scb->async_state != FD_SCHEDULED) | |
111 | fprintf_unfiltered (gdb_stdlog, "[fd%d->fd-scheduled]\n", | |
112 | scb->fd); | |
113 | break; | |
114 | default: /* TIMER SCHEDULED */ | |
115 | if (scb->async_state == FD_SCHEDULED) | |
116 | fprintf_unfiltered (gdb_stdlog, "[fd%d->timer-scheduled]\n", | |
117 | scb->fd); | |
118 | break; | |
119 | } | |
120 | } | |
121 | scb->async_state = next_state; | |
122 | } | |
123 | } | |
124 | ||
125 | /* FD_EVENT: This is scheduled when the input FIFO is empty (and there | |
126 | is no pending error). As soon as data arrives, it is read into the | |
127 | input FIFO and the client notified. The client should then drain | |
128 | the FIFO using readchar(). If the FIFO isn't immediatly emptied, | |
129 | push_event() is used to nag the client until it is. */ | |
130 | ||
131 | static void | |
132 | fd_event (int error, void *context) | |
133 | { | |
134 | struct serial *scb = context; | |
135 | if (error != 0) | |
136 | { | |
137 | scb->bufcnt = SERIAL_ERROR; | |
138 | } | |
139 | else if (scb->bufcnt == 0) | |
140 | { | |
141 | /* Prime the input FIFO. The readchar() function is used to | |
142 | pull characters out of the buffer. See also | |
143 | generic_readchar(). */ | |
144 | int nr; | |
b4505029 | 145 | nr = scb->ops->read_prim (scb, BUFSIZ); |
3eb25fda MM |
146 | if (nr == 0) |
147 | { | |
148 | scb->bufcnt = SERIAL_EOF; | |
149 | } | |
150 | else if (nr > 0) | |
151 | { | |
152 | scb->bufcnt = nr; | |
153 | scb->bufp = scb->buf; | |
154 | } | |
155 | else | |
156 | { | |
157 | scb->bufcnt = SERIAL_ERROR; | |
158 | } | |
159 | } | |
160 | scb->async_handler (scb, scb->async_context); | |
161 | reschedule (scb); | |
162 | } | |
163 | ||
164 | /* PUSH_EVENT: The input FIFO is non-empty (or there is a pending | |
165 | error). Nag the client until all the data has been read. In the | |
166 | case of errors, the client will need to close or de-async the | |
167 | device before naging stops. */ | |
168 | ||
169 | static void | |
170 | push_event (void *context) | |
171 | { | |
172 | struct serial *scb = context; | |
173 | scb->async_state = NOTHING_SCHEDULED; /* Timers are one-off */ | |
174 | scb->async_handler (scb, scb->async_context); | |
175 | /* re-schedule */ | |
176 | reschedule (scb); | |
177 | } | |
178 | ||
b4505029 MM |
179 | /* Wait for input on scb, with timeout seconds. Returns 0 on success, |
180 | otherwise SERIAL_TIMEOUT or SERIAL_ERROR. */ | |
181 | ||
182 | static int | |
183 | ser_base_wait_for (struct serial *scb, int timeout) | |
184 | { | |
185 | while (1) | |
186 | { | |
187 | int numfds; | |
188 | struct timeval tv; | |
189 | fd_set readfds, exceptfds; | |
190 | ||
191 | /* NOTE: Some OS's can scramble the READFDS when the select() | |
192 | call fails (ex the kernel with Red Hat 5.2). Initialize all | |
193 | arguments before each call. */ | |
194 | ||
195 | tv.tv_sec = timeout; | |
196 | tv.tv_usec = 0; | |
197 | ||
198 | FD_ZERO (&readfds); | |
199 | FD_ZERO (&exceptfds); | |
200 | FD_SET (scb->fd, &readfds); | |
201 | FD_SET (scb->fd, &exceptfds); | |
202 | ||
203 | if (timeout >= 0) | |
0ea3f30e | 204 | numfds = gdb_select (scb->fd + 1, &readfds, 0, &exceptfds, &tv); |
b4505029 | 205 | else |
0ea3f30e | 206 | numfds = gdb_select (scb->fd + 1, &readfds, 0, &exceptfds, 0); |
b4505029 MM |
207 | |
208 | if (numfds <= 0) | |
209 | { | |
210 | if (numfds == 0) | |
211 | return SERIAL_TIMEOUT; | |
212 | else if (errno == EINTR) | |
213 | continue; | |
214 | else | |
215 | return SERIAL_ERROR; /* Got an error from select or poll */ | |
216 | } | |
217 | ||
218 | return 0; | |
219 | } | |
220 | } | |
221 | ||
222 | /* Read a character with user-specified timeout. TIMEOUT is number of seconds | |
223 | to wait, or -1 to wait forever. Use timeout of 0 to effect a poll. Returns | |
224 | char if successful. Returns -2 if timeout expired, EOF if line dropped | |
225 | dead, or -3 for any other error (see errno in that case). */ | |
226 | ||
227 | static int | |
228 | do_ser_base_readchar (struct serial *scb, int timeout) | |
229 | { | |
230 | int status; | |
231 | int delta; | |
232 | ||
233 | /* We have to be able to keep the GUI alive here, so we break the | |
234 | original timeout into steps of 1 second, running the "keep the | |
235 | GUI alive" hook each time through the loop. | |
236 | ||
237 | Also, timeout = 0 means to poll, so we just set the delta to 0, | |
238 | so we will only go through the loop once. */ | |
239 | ||
240 | delta = (timeout == 0 ? 0 : 1); | |
241 | while (1) | |
242 | { | |
243 | /* N.B. The UI may destroy our world (for instance by calling | |
244 | remote_stop,) in which case we want to get out of here as | |
245 | quickly as possible. It is not safe to touch scb, since | |
246 | someone else might have freed it. The | |
247 | deprecated_ui_loop_hook signals that we should exit by | |
248 | returning 1. */ | |
249 | ||
250 | if (deprecated_ui_loop_hook) | |
251 | { | |
252 | if (deprecated_ui_loop_hook (0)) | |
253 | return SERIAL_TIMEOUT; | |
254 | } | |
255 | ||
256 | status = ser_base_wait_for (scb, delta); | |
257 | if (timeout > 0) | |
258 | timeout -= delta; | |
259 | ||
260 | /* If we got a character or an error back from wait_for, then we can | |
261 | break from the loop before the timeout is completed. */ | |
262 | if (status != SERIAL_TIMEOUT) | |
263 | break; | |
264 | ||
265 | /* If we have exhausted the original timeout, then generate | |
266 | a SERIAL_TIMEOUT, and pass it out of the loop. */ | |
267 | else if (timeout == 0) | |
268 | { | |
269 | status = SERIAL_TIMEOUT; | |
270 | break; | |
271 | } | |
272 | } | |
273 | ||
274 | if (status < 0) | |
275 | return status; | |
276 | ||
277 | status = scb->ops->read_prim (scb, BUFSIZ); | |
278 | ||
279 | if (status <= 0) | |
280 | { | |
281 | if (status == 0) | |
282 | /* 0 chars means timeout. (We may need to distinguish between EOF | |
283 | & timeouts someday.) */ | |
284 | return SERIAL_TIMEOUT; | |
285 | else | |
286 | /* Got an error from read. */ | |
287 | return SERIAL_ERROR; | |
288 | } | |
289 | ||
290 | scb->bufcnt = status; | |
291 | scb->bufcnt--; | |
292 | scb->bufp = scb->buf; | |
293 | return *scb->bufp++; | |
294 | } | |
295 | ||
296 | /* Perform operations common to both old and new readchar. */ | |
297 | ||
298 | /* Return the next character from the input FIFO. If the FIFO is | |
299 | empty, call the SERIAL specific routine to try and read in more | |
300 | characters. | |
301 | ||
302 | Initially data from the input FIFO is returned (fd_event() | |
303 | pre-reads the input into that FIFO. Once that has been emptied, | |
304 | further data is obtained by polling the input FD using the device | |
305 | specific readchar() function. Note: reschedule() is called after | |
306 | every read. This is because there is no guarentee that the lower | |
307 | level fd_event() poll_event() code (which also calls reschedule()) | |
308 | will be called. */ | |
309 | ||
310 | int | |
311 | generic_readchar (struct serial *scb, int timeout, | |
312 | int (do_readchar) (struct serial *scb, int timeout)) | |
313 | { | |
314 | int ch; | |
315 | if (scb->bufcnt > 0) | |
316 | { | |
317 | ch = *scb->bufp; | |
318 | scb->bufcnt--; | |
319 | scb->bufp++; | |
320 | } | |
321 | else if (scb->bufcnt < 0) | |
322 | { | |
323 | /* Some errors/eof are are sticky. */ | |
324 | ch = scb->bufcnt; | |
325 | } | |
326 | else | |
327 | { | |
328 | ch = do_readchar (scb, timeout); | |
329 | if (ch < 0) | |
330 | { | |
331 | switch ((enum serial_rc) ch) | |
332 | { | |
333 | case SERIAL_EOF: | |
334 | case SERIAL_ERROR: | |
335 | /* Make the error/eof stick. */ | |
336 | scb->bufcnt = ch; | |
337 | break; | |
338 | case SERIAL_TIMEOUT: | |
339 | scb->bufcnt = 0; | |
340 | break; | |
341 | } | |
342 | } | |
343 | } | |
65cc4390 VP |
344 | /* Read any error output we might have. */ |
345 | if (scb->error_fd != -1) | |
346 | { | |
347 | ssize_t s; | |
348 | char buf[81]; | |
349 | ||
350 | for (;;) | |
351 | { | |
352 | char *current; | |
353 | char *newline; | |
354 | int to_read = 80; | |
355 | ||
356 | int num_bytes = -1; | |
357 | if (scb->ops->avail) | |
358 | num_bytes = (scb->ops->avail)(scb, scb->error_fd); | |
359 | if (num_bytes != -1) | |
360 | to_read = (num_bytes < to_read) ? num_bytes : to_read; | |
361 | ||
362 | if (to_read == 0) | |
363 | break; | |
364 | ||
365 | s = read (scb->error_fd, &buf, to_read); | |
366 | if (s == -1) | |
367 | break; | |
368 | ||
369 | /* In theory, embedded newlines are not a problem. | |
370 | But for MI, we want each output line to have just | |
371 | one newline for legibility. So output things | |
372 | in newline chunks. */ | |
373 | buf[s] = '\0'; | |
374 | current = buf; | |
375 | while ((newline = strstr (current, "\n")) != NULL) | |
376 | { | |
377 | *newline = '\0'; | |
378 | fputs_unfiltered (current, gdb_stderr); | |
379 | fputs_unfiltered ("\n", gdb_stderr); | |
380 | current = newline + 1; | |
381 | } | |
382 | fputs_unfiltered (current, gdb_stderr); | |
383 | } | |
384 | } | |
385 | ||
b4505029 MM |
386 | reschedule (scb); |
387 | return ch; | |
388 | } | |
389 | ||
390 | int | |
391 | ser_base_readchar (struct serial *scb, int timeout) | |
392 | { | |
393 | return generic_readchar (scb, timeout, do_ser_base_readchar); | |
394 | } | |
395 | ||
3eb25fda | 396 | int |
dd5da072 | 397 | ser_base_write (struct serial *scb, const char *str, int len) |
3eb25fda MM |
398 | { |
399 | int cc; | |
400 | ||
401 | while (len > 0) | |
402 | { | |
b4505029 | 403 | cc = scb->ops->write_prim (scb, str, len); |
3eb25fda MM |
404 | |
405 | if (cc < 0) | |
406 | return 1; | |
407 | len -= cc; | |
408 | str += cc; | |
409 | } | |
410 | return 0; | |
411 | } | |
412 | ||
413 | int | |
dd5da072 | 414 | ser_base_flush_output (struct serial *scb) |
3eb25fda MM |
415 | { |
416 | return 0; | |
417 | } | |
418 | ||
419 | int | |
dd5da072 | 420 | ser_base_flush_input (struct serial *scb) |
3eb25fda MM |
421 | { |
422 | if (scb->bufcnt >= 0) | |
423 | { | |
424 | scb->bufcnt = 0; | |
425 | scb->bufp = scb->buf; | |
426 | return 0; | |
427 | } | |
428 | else | |
429 | return SERIAL_ERROR; | |
430 | } | |
431 | ||
432 | int | |
dd5da072 | 433 | ser_base_send_break (struct serial *scb) |
3eb25fda MM |
434 | { |
435 | return 0; | |
436 | } | |
437 | ||
438 | int | |
dd5da072 | 439 | ser_base_drain_output (struct serial *scb) |
3eb25fda MM |
440 | { |
441 | return 0; | |
442 | } | |
443 | ||
444 | void | |
dd5da072 | 445 | ser_base_raw (struct serial *scb) |
3eb25fda MM |
446 | { |
447 | return; /* Always in raw mode */ | |
448 | } | |
449 | ||
450 | serial_ttystate | |
dd5da072 | 451 | ser_base_get_tty_state (struct serial *scb) |
3eb25fda MM |
452 | { |
453 | /* allocate a dummy */ | |
454 | return (serial_ttystate) XMALLOC (int); | |
455 | } | |
456 | ||
457 | int | |
dd5da072 | 458 | ser_base_set_tty_state (struct serial *scb, serial_ttystate ttystate) |
3eb25fda MM |
459 | { |
460 | return 0; | |
461 | } | |
462 | ||
463 | int | |
dd5da072 MM |
464 | ser_base_noflush_set_tty_state (struct serial *scb, |
465 | serial_ttystate new_ttystate, | |
466 | serial_ttystate old_ttystate) | |
3eb25fda MM |
467 | { |
468 | return 0; | |
469 | } | |
470 | ||
471 | void | |
dd5da072 MM |
472 | ser_base_print_tty_state (struct serial *scb, |
473 | serial_ttystate ttystate, | |
474 | struct ui_file *stream) | |
3eb25fda MM |
475 | { |
476 | /* Nothing to print. */ | |
477 | return; | |
478 | } | |
479 | ||
480 | int | |
dd5da072 | 481 | ser_base_setbaudrate (struct serial *scb, int rate) |
3eb25fda MM |
482 | { |
483 | return 0; /* Never fails! */ | |
484 | } | |
485 | ||
486 | int | |
dd5da072 | 487 | ser_base_setstopbits (struct serial *scb, int num) |
3eb25fda MM |
488 | { |
489 | return 0; /* Never fails! */ | |
490 | } | |
491 | ||
492 | /* Put the SERIAL device into/out-of ASYNC mode. */ | |
493 | ||
494 | void | |
dd5da072 | 495 | ser_base_async (struct serial *scb, |
3eb25fda MM |
496 | int async_p) |
497 | { | |
498 | if (async_p) | |
499 | { | |
500 | /* Force a re-schedule. */ | |
501 | scb->async_state = NOTHING_SCHEDULED; | |
502 | if (serial_debug_p (scb)) | |
503 | fprintf_unfiltered (gdb_stdlog, "[fd%d->asynchronous]\n", | |
504 | scb->fd); | |
505 | reschedule (scb); | |
506 | } | |
507 | else | |
508 | { | |
509 | if (serial_debug_p (scb)) | |
510 | fprintf_unfiltered (gdb_stdlog, "[fd%d->synchronous]\n", | |
511 | scb->fd); | |
512 | /* De-schedule whatever tasks are currently scheduled. */ | |
513 | switch (scb->async_state) | |
514 | { | |
515 | case FD_SCHEDULED: | |
516 | delete_file_handler (scb->fd); | |
517 | break; | |
518 | case NOTHING_SCHEDULED: | |
519 | break; | |
520 | default: /* TIMER SCHEDULED */ | |
521 | delete_timer (scb->async_state); | |
522 | break; | |
523 | } | |
524 | } | |
525 | } |