Commit | Line | Data |
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3eb25fda MM |
1 | /* Generic serial interface functions. |
2 | ||
0b302171 JB |
3 | Copyright (C) 1992-1996, 1998-2001, 2003-2012 Free Software |
4 | 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" |
3347eb1a | 28 | #include "gdb_assert.h" |
248697b2 | 29 | #include <sys/time.h> |
b4505029 MM |
30 | #ifdef USE_WIN32API |
31 | #include <winsock2.h> | |
32 | #endif | |
3eb25fda | 33 | |
401e7faf | 34 | |
3eb25fda MM |
35 | static timer_handler_func push_event; |
36 | static handler_func fd_event; | |
37 | ||
38 | /* Event handling for ASYNC serial code. | |
39 | ||
40 | At any time the SERIAL device either: has an empty FIFO and is | |
41 | waiting on a FD event; or has a non-empty FIFO/error condition and | |
42 | is constantly scheduling timer events. | |
43 | ||
44 | ASYNC only stops pestering its client when it is de-async'ed or it | |
c378eb4e | 45 | is told to go away. */ |
3eb25fda MM |
46 | |
47 | /* Value of scb->async_state: */ | |
48 | enum { | |
49 | /* >= 0 (TIMER_SCHEDULED) */ | |
c378eb4e | 50 | /* The ID of the currently scheduled timer event. This state is |
3eb25fda | 51 | rarely encountered. Timer events are one-off so as soon as the |
c378eb4e | 52 | event is delivered the state is shanged to NOTHING_SCHEDULED. */ |
3eb25fda MM |
53 | FD_SCHEDULED = -1, |
54 | /* The fd_event() handler is scheduled. It is called when ever the | |
c378eb4e | 55 | file descriptor becomes ready. */ |
3eb25fda MM |
56 | NOTHING_SCHEDULED = -2 |
57 | /* Either no task is scheduled (just going into ASYNC mode) or a | |
58 | timer event has just gone off and the current state has been | |
c378eb4e | 59 | forced into nothing scheduled. */ |
3eb25fda MM |
60 | }; |
61 | ||
62 | /* Identify and schedule the next ASYNC task based on scb->async_state | |
63 | and scb->buf* (the input FIFO). A state machine is used to avoid | |
64 | the need to make redundant calls into the event-loop - the next | |
c378eb4e | 65 | scheduled task is only changed when needed. */ |
3eb25fda | 66 | |
a26d8d11 | 67 | static void |
3eb25fda MM |
68 | reschedule (struct serial *scb) |
69 | { | |
70 | if (serial_is_async_p (scb)) | |
71 | { | |
72 | int next_state; | |
433759f7 | 73 | |
3eb25fda MM |
74 | switch (scb->async_state) |
75 | { | |
76 | case FD_SCHEDULED: | |
77 | if (scb->bufcnt == 0) | |
78 | next_state = FD_SCHEDULED; | |
79 | else | |
80 | { | |
81 | delete_file_handler (scb->fd); | |
82 | next_state = create_timer (0, push_event, scb); | |
83 | } | |
84 | break; | |
85 | case NOTHING_SCHEDULED: | |
86 | if (scb->bufcnt == 0) | |
87 | { | |
88 | add_file_handler (scb->fd, fd_event, scb); | |
89 | next_state = FD_SCHEDULED; | |
90 | } | |
91 | else | |
92 | { | |
93 | next_state = create_timer (0, push_event, scb); | |
94 | } | |
95 | break; | |
96 | default: /* TIMER SCHEDULED */ | |
97 | if (scb->bufcnt == 0) | |
98 | { | |
99 | delete_timer (scb->async_state); | |
100 | add_file_handler (scb->fd, fd_event, scb); | |
101 | next_state = FD_SCHEDULED; | |
102 | } | |
103 | else | |
104 | next_state = scb->async_state; | |
105 | break; | |
106 | } | |
107 | if (serial_debug_p (scb)) | |
108 | { | |
109 | switch (next_state) | |
110 | { | |
111 | case FD_SCHEDULED: | |
112 | if (scb->async_state != FD_SCHEDULED) | |
113 | fprintf_unfiltered (gdb_stdlog, "[fd%d->fd-scheduled]\n", | |
114 | scb->fd); | |
115 | break; | |
116 | default: /* TIMER SCHEDULED */ | |
117 | if (scb->async_state == FD_SCHEDULED) | |
118 | fprintf_unfiltered (gdb_stdlog, "[fd%d->timer-scheduled]\n", | |
119 | scb->fd); | |
120 | break; | |
121 | } | |
122 | } | |
123 | scb->async_state = next_state; | |
124 | } | |
125 | } | |
126 | ||
ddefb60f PA |
127 | /* Run the SCB's async handle, and reschedule, if the handler doesn't |
128 | close SCB. */ | |
129 | ||
130 | static void | |
131 | run_async_handler_and_reschedule (struct serial *scb) | |
132 | { | |
133 | int is_open; | |
134 | ||
135 | /* Take a reference, so a serial_close call within the handler | |
136 | doesn't make SCB a dangling pointer. */ | |
137 | serial_ref (scb); | |
138 | ||
139 | /* Run the handler. */ | |
140 | scb->async_handler (scb, scb->async_context); | |
141 | ||
142 | is_open = serial_is_open (scb); | |
143 | serial_unref (scb); | |
144 | ||
145 | /* Get ready for more, if not already closed. */ | |
146 | if (is_open) | |
147 | reschedule (scb); | |
148 | } | |
149 | ||
3eb25fda MM |
150 | /* FD_EVENT: This is scheduled when the input FIFO is empty (and there |
151 | is no pending error). As soon as data arrives, it is read into the | |
152 | input FIFO and the client notified. The client should then drain | |
153 | the FIFO using readchar(). If the FIFO isn't immediatly emptied, | |
c378eb4e | 154 | push_event() is used to nag the client until it is. */ |
3eb25fda MM |
155 | |
156 | static void | |
157 | fd_event (int error, void *context) | |
158 | { | |
159 | struct serial *scb = context; | |
160 | if (error != 0) | |
161 | { | |
162 | scb->bufcnt = SERIAL_ERROR; | |
163 | } | |
164 | else if (scb->bufcnt == 0) | |
165 | { | |
166 | /* Prime the input FIFO. The readchar() function is used to | |
167 | pull characters out of the buffer. See also | |
c378eb4e | 168 | generic_readchar(). */ |
3eb25fda | 169 | int nr; |
b4505029 | 170 | nr = scb->ops->read_prim (scb, BUFSIZ); |
3eb25fda MM |
171 | if (nr == 0) |
172 | { | |
173 | scb->bufcnt = SERIAL_EOF; | |
174 | } | |
175 | else if (nr > 0) | |
176 | { | |
177 | scb->bufcnt = nr; | |
178 | scb->bufp = scb->buf; | |
179 | } | |
180 | else | |
181 | { | |
182 | scb->bufcnt = SERIAL_ERROR; | |
183 | } | |
184 | } | |
ddefb60f | 185 | run_async_handler_and_reschedule (scb); |
3eb25fda MM |
186 | } |
187 | ||
188 | /* PUSH_EVENT: The input FIFO is non-empty (or there is a pending | |
189 | error). Nag the client until all the data has been read. In the | |
190 | case of errors, the client will need to close or de-async the | |
c378eb4e | 191 | device before naging stops. */ |
3eb25fda MM |
192 | |
193 | static void | |
194 | push_event (void *context) | |
195 | { | |
196 | struct serial *scb = context; | |
433759f7 | 197 | |
3eb25fda | 198 | scb->async_state = NOTHING_SCHEDULED; /* Timers are one-off */ |
ddefb60f | 199 | run_async_handler_and_reschedule (scb); |
3eb25fda MM |
200 | } |
201 | ||
b4505029 | 202 | /* Wait for input on scb, with timeout seconds. Returns 0 on success, |
c378eb4e | 203 | otherwise SERIAL_TIMEOUT or SERIAL_ERROR. */ |
b4505029 MM |
204 | |
205 | static int | |
206 | ser_base_wait_for (struct serial *scb, int timeout) | |
207 | { | |
208 | while (1) | |
209 | { | |
210 | int numfds; | |
211 | struct timeval tv; | |
212 | fd_set readfds, exceptfds; | |
213 | ||
214 | /* NOTE: Some OS's can scramble the READFDS when the select() | |
215 | call fails (ex the kernel with Red Hat 5.2). Initialize all | |
c378eb4e | 216 | arguments before each call. */ |
b4505029 MM |
217 | |
218 | tv.tv_sec = timeout; | |
219 | tv.tv_usec = 0; | |
220 | ||
221 | FD_ZERO (&readfds); | |
222 | FD_ZERO (&exceptfds); | |
223 | FD_SET (scb->fd, &readfds); | |
224 | FD_SET (scb->fd, &exceptfds); | |
225 | ||
226 | if (timeout >= 0) | |
0ea3f30e | 227 | numfds = gdb_select (scb->fd + 1, &readfds, 0, &exceptfds, &tv); |
b4505029 | 228 | else |
0ea3f30e | 229 | numfds = gdb_select (scb->fd + 1, &readfds, 0, &exceptfds, 0); |
b4505029 MM |
230 | |
231 | if (numfds <= 0) | |
232 | { | |
233 | if (numfds == 0) | |
234 | return SERIAL_TIMEOUT; | |
235 | else if (errno == EINTR) | |
236 | continue; | |
237 | else | |
c378eb4e MS |
238 | return SERIAL_ERROR; /* Got an error from select or |
239 | poll. */ | |
b4505029 MM |
240 | } |
241 | ||
242 | return 0; | |
243 | } | |
244 | } | |
245 | ||
3347eb1a | 246 | /* Read any error output we might have. */ |
247 | ||
248 | static void | |
249 | ser_base_read_error_fd (struct serial *scb, int close_fd) | |
250 | { | |
251 | if (scb->error_fd != -1) | |
252 | { | |
253 | ssize_t s; | |
254 | char buf[GDB_MI_MSG_WIDTH + 1]; | |
255 | ||
256 | for (;;) | |
257 | { | |
258 | char *current; | |
259 | char *newline; | |
260 | int to_read = GDB_MI_MSG_WIDTH; | |
261 | int num_bytes = -1; | |
262 | ||
263 | if (scb->ops->avail) | |
264 | num_bytes = (scb->ops->avail)(scb, scb->error_fd); | |
265 | ||
266 | if (num_bytes != -1) | |
267 | to_read = (num_bytes < to_read) ? num_bytes : to_read; | |
268 | ||
269 | if (to_read == 0) | |
270 | break; | |
271 | ||
272 | s = read (scb->error_fd, &buf, to_read); | |
273 | if ((s == -1) || (s == 0 && !close_fd)) | |
274 | break; | |
275 | ||
276 | if (s == 0 && close_fd) | |
277 | { | |
278 | /* End of file. */ | |
279 | close (scb->error_fd); | |
280 | scb->error_fd = -1; | |
281 | break; | |
282 | } | |
283 | ||
284 | /* In theory, embedded newlines are not a problem. | |
285 | But for MI, we want each output line to have just | |
286 | one newline for legibility. So output things | |
287 | in newline chunks. */ | |
288 | gdb_assert (s > 0 && s <= GDB_MI_MSG_WIDTH); | |
289 | buf[s] = '\0'; | |
290 | current = buf; | |
291 | while ((newline = strstr (current, "\n")) != NULL) | |
292 | { | |
293 | *newline = '\0'; | |
294 | fputs_unfiltered (current, gdb_stderr); | |
295 | fputs_unfiltered ("\n", gdb_stderr); | |
296 | current = newline + 1; | |
297 | } | |
298 | ||
299 | fputs_unfiltered (current, gdb_stderr); | |
300 | } | |
301 | } | |
302 | } | |
303 | ||
b4505029 MM |
304 | /* Read a character with user-specified timeout. TIMEOUT is number of seconds |
305 | to wait, or -1 to wait forever. Use timeout of 0 to effect a poll. Returns | |
306 | char if successful. Returns -2 if timeout expired, EOF if line dropped | |
c378eb4e | 307 | dead, or -3 for any other error (see errno in that case). */ |
b4505029 MM |
308 | |
309 | static int | |
310 | do_ser_base_readchar (struct serial *scb, int timeout) | |
311 | { | |
312 | int status; | |
313 | int delta; | |
314 | ||
315 | /* We have to be able to keep the GUI alive here, so we break the | |
316 | original timeout into steps of 1 second, running the "keep the | |
317 | GUI alive" hook each time through the loop. | |
318 | ||
319 | Also, timeout = 0 means to poll, so we just set the delta to 0, | |
320 | so we will only go through the loop once. */ | |
321 | ||
322 | delta = (timeout == 0 ? 0 : 1); | |
323 | while (1) | |
324 | { | |
325 | /* N.B. The UI may destroy our world (for instance by calling | |
326 | remote_stop,) in which case we want to get out of here as | |
327 | quickly as possible. It is not safe to touch scb, since | |
328 | someone else might have freed it. The | |
329 | deprecated_ui_loop_hook signals that we should exit by | |
330 | returning 1. */ | |
331 | ||
332 | if (deprecated_ui_loop_hook) | |
333 | { | |
334 | if (deprecated_ui_loop_hook (0)) | |
335 | return SERIAL_TIMEOUT; | |
336 | } | |
337 | ||
338 | status = ser_base_wait_for (scb, delta); | |
339 | if (timeout > 0) | |
340 | timeout -= delta; | |
341 | ||
342 | /* If we got a character or an error back from wait_for, then we can | |
c378eb4e | 343 | break from the loop before the timeout is completed. */ |
b4505029 MM |
344 | if (status != SERIAL_TIMEOUT) |
345 | break; | |
346 | ||
347 | /* If we have exhausted the original timeout, then generate | |
c378eb4e | 348 | a SERIAL_TIMEOUT, and pass it out of the loop. */ |
b4505029 MM |
349 | else if (timeout == 0) |
350 | { | |
351 | status = SERIAL_TIMEOUT; | |
352 | break; | |
353 | } | |
3347eb1a | 354 | |
355 | /* We also need to check and consume the stderr because it could | |
356 | come before the stdout for some stubs. If we just sit and wait | |
357 | for stdout, we would hit a deadlock for that case. */ | |
358 | ser_base_read_error_fd (scb, 0); | |
b4505029 MM |
359 | } |
360 | ||
361 | if (status < 0) | |
362 | return status; | |
363 | ||
364 | status = scb->ops->read_prim (scb, BUFSIZ); | |
365 | ||
366 | if (status <= 0) | |
367 | { | |
368 | if (status == 0) | |
d41ebd5d | 369 | return SERIAL_EOF; |
b4505029 MM |
370 | else |
371 | /* Got an error from read. */ | |
372 | return SERIAL_ERROR; | |
373 | } | |
374 | ||
375 | scb->bufcnt = status; | |
376 | scb->bufcnt--; | |
377 | scb->bufp = scb->buf; | |
378 | return *scb->bufp++; | |
379 | } | |
380 | ||
c378eb4e | 381 | /* Perform operations common to both old and new readchar. */ |
b4505029 MM |
382 | |
383 | /* Return the next character from the input FIFO. If the FIFO is | |
384 | empty, call the SERIAL specific routine to try and read in more | |
385 | characters. | |
386 | ||
387 | Initially data from the input FIFO is returned (fd_event() | |
388 | pre-reads the input into that FIFO. Once that has been emptied, | |
389 | further data is obtained by polling the input FD using the device | |
390 | specific readchar() function. Note: reschedule() is called after | |
391 | every read. This is because there is no guarentee that the lower | |
392 | level fd_event() poll_event() code (which also calls reschedule()) | |
c378eb4e | 393 | will be called. */ |
b4505029 MM |
394 | |
395 | int | |
396 | generic_readchar (struct serial *scb, int timeout, | |
397 | int (do_readchar) (struct serial *scb, int timeout)) | |
398 | { | |
399 | int ch; | |
400 | if (scb->bufcnt > 0) | |
401 | { | |
402 | ch = *scb->bufp; | |
403 | scb->bufcnt--; | |
404 | scb->bufp++; | |
405 | } | |
406 | else if (scb->bufcnt < 0) | |
407 | { | |
c378eb4e | 408 | /* Some errors/eof are are sticky. */ |
b4505029 MM |
409 | ch = scb->bufcnt; |
410 | } | |
411 | else | |
412 | { | |
413 | ch = do_readchar (scb, timeout); | |
414 | if (ch < 0) | |
415 | { | |
416 | switch ((enum serial_rc) ch) | |
417 | { | |
418 | case SERIAL_EOF: | |
419 | case SERIAL_ERROR: | |
c378eb4e | 420 | /* Make the error/eof stick. */ |
b4505029 MM |
421 | scb->bufcnt = ch; |
422 | break; | |
423 | case SERIAL_TIMEOUT: | |
424 | scb->bufcnt = 0; | |
425 | break; | |
426 | } | |
427 | } | |
428 | } | |
65cc4390 | 429 | |
3347eb1a | 430 | /* Read any error output we might have. */ |
431 | ser_base_read_error_fd (scb, 1); | |
65cc4390 | 432 | |
b4505029 MM |
433 | reschedule (scb); |
434 | return ch; | |
435 | } | |
436 | ||
437 | int | |
438 | ser_base_readchar (struct serial *scb, int timeout) | |
439 | { | |
440 | return generic_readchar (scb, timeout, do_ser_base_readchar); | |
441 | } | |
442 | ||
3eb25fda | 443 | int |
dd5da072 | 444 | ser_base_write (struct serial *scb, const char *str, int len) |
3eb25fda MM |
445 | { |
446 | int cc; | |
447 | ||
448 | while (len > 0) | |
449 | { | |
b4505029 | 450 | cc = scb->ops->write_prim (scb, str, len); |
3eb25fda MM |
451 | |
452 | if (cc < 0) | |
453 | return 1; | |
454 | len -= cc; | |
455 | str += cc; | |
456 | } | |
457 | return 0; | |
458 | } | |
459 | ||
460 | int | |
dd5da072 | 461 | ser_base_flush_output (struct serial *scb) |
3eb25fda MM |
462 | { |
463 | return 0; | |
464 | } | |
465 | ||
466 | int | |
dd5da072 | 467 | ser_base_flush_input (struct serial *scb) |
3eb25fda MM |
468 | { |
469 | if (scb->bufcnt >= 0) | |
470 | { | |
471 | scb->bufcnt = 0; | |
472 | scb->bufp = scb->buf; | |
473 | return 0; | |
474 | } | |
475 | else | |
476 | return SERIAL_ERROR; | |
477 | } | |
478 | ||
479 | int | |
dd5da072 | 480 | ser_base_send_break (struct serial *scb) |
3eb25fda MM |
481 | { |
482 | return 0; | |
483 | } | |
484 | ||
485 | int | |
dd5da072 | 486 | ser_base_drain_output (struct serial *scb) |
3eb25fda MM |
487 | { |
488 | return 0; | |
489 | } | |
490 | ||
491 | void | |
dd5da072 | 492 | ser_base_raw (struct serial *scb) |
3eb25fda | 493 | { |
c378eb4e | 494 | return; /* Always in raw mode. */ |
3eb25fda MM |
495 | } |
496 | ||
497 | serial_ttystate | |
dd5da072 | 498 | ser_base_get_tty_state (struct serial *scb) |
3eb25fda | 499 | { |
c378eb4e | 500 | /* Allocate a dummy. */ |
3eb25fda MM |
501 | return (serial_ttystate) XMALLOC (int); |
502 | } | |
503 | ||
1e182ce8 UW |
504 | serial_ttystate |
505 | ser_base_copy_tty_state (struct serial *scb, serial_ttystate ttystate) | |
506 | { | |
507 | /* Allocate another dummy. */ | |
508 | return (serial_ttystate) XMALLOC (int); | |
509 | } | |
510 | ||
3eb25fda | 511 | int |
dd5da072 | 512 | ser_base_set_tty_state (struct serial *scb, serial_ttystate ttystate) |
3eb25fda MM |
513 | { |
514 | return 0; | |
515 | } | |
516 | ||
517 | int | |
dd5da072 MM |
518 | ser_base_noflush_set_tty_state (struct serial *scb, |
519 | serial_ttystate new_ttystate, | |
520 | serial_ttystate old_ttystate) | |
3eb25fda MM |
521 | { |
522 | return 0; | |
523 | } | |
524 | ||
525 | void | |
dd5da072 MM |
526 | ser_base_print_tty_state (struct serial *scb, |
527 | serial_ttystate ttystate, | |
528 | struct ui_file *stream) | |
3eb25fda MM |
529 | { |
530 | /* Nothing to print. */ | |
531 | return; | |
532 | } | |
533 | ||
534 | int | |
dd5da072 | 535 | ser_base_setbaudrate (struct serial *scb, int rate) |
3eb25fda | 536 | { |
c378eb4e | 537 | return 0; /* Never fails! */ |
3eb25fda MM |
538 | } |
539 | ||
540 | int | |
dd5da072 | 541 | ser_base_setstopbits (struct serial *scb, int num) |
3eb25fda | 542 | { |
c378eb4e | 543 | return 0; /* Never fails! */ |
3eb25fda MM |
544 | } |
545 | ||
546 | /* Put the SERIAL device into/out-of ASYNC mode. */ | |
547 | ||
548 | void | |
dd5da072 | 549 | ser_base_async (struct serial *scb, |
3eb25fda MM |
550 | int async_p) |
551 | { | |
552 | if (async_p) | |
553 | { | |
c378eb4e | 554 | /* Force a re-schedule. */ |
3eb25fda MM |
555 | scb->async_state = NOTHING_SCHEDULED; |
556 | if (serial_debug_p (scb)) | |
557 | fprintf_unfiltered (gdb_stdlog, "[fd%d->asynchronous]\n", | |
558 | scb->fd); | |
559 | reschedule (scb); | |
560 | } | |
561 | else | |
562 | { | |
563 | if (serial_debug_p (scb)) | |
564 | fprintf_unfiltered (gdb_stdlog, "[fd%d->synchronous]\n", | |
565 | scb->fd); | |
c378eb4e | 566 | /* De-schedule whatever tasks are currently scheduled. */ |
3eb25fda MM |
567 | switch (scb->async_state) |
568 | { | |
569 | case FD_SCHEDULED: | |
570 | delete_file_handler (scb->fd); | |
571 | break; | |
572 | case NOTHING_SCHEDULED: | |
573 | break; | |
574 | default: /* TIMER SCHEDULED */ | |
575 | delete_timer (scb->async_state); | |
576 | break; | |
577 | } | |
578 | } | |
579 | } |