Commit | Line | Data |
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3eb25fda MM |
1 | /* Generic serial interface functions. |
2 | ||
618f726f | 3 | Copyright (C) 1992-2016 Free Software Foundation, Inc. |
3eb25fda MM |
4 | |
5 | This file is part of GDB. | |
6 | ||
7 | This program is free software; you can redistribute it and/or modify | |
8 | it under the terms of the GNU General Public License as published by | |
a9762ec7 | 9 | the Free Software Foundation; either version 3 of the License, or |
3eb25fda MM |
10 | (at your option) any later version. |
11 | ||
12 | This program is distributed in the hope that it will be useful, | |
13 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | GNU General Public License for more details. | |
16 | ||
17 | You should have received a copy of the GNU General Public License | |
a9762ec7 | 18 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
3eb25fda MM |
19 | |
20 | #include "defs.h" | |
21 | #include "serial.h" | |
a07ff70c | 22 | #include "ser-base.h" |
3eb25fda | 23 | #include "event-loop.h" |
a07ff70c | 24 | |
0ea3f30e | 25 | #include "gdb_select.h" |
438e1e42 | 26 | #include "gdb_sys_time.h" |
b4505029 MM |
27 | #ifdef USE_WIN32API |
28 | #include <winsock2.h> | |
29 | #endif | |
3eb25fda | 30 | |
401e7faf | 31 | |
3eb25fda MM |
32 | static timer_handler_func push_event; |
33 | static handler_func fd_event; | |
34 | ||
35 | /* Event handling for ASYNC serial code. | |
36 | ||
37 | At any time the SERIAL device either: has an empty FIFO and is | |
38 | waiting on a FD event; or has a non-empty FIFO/error condition and | |
39 | is constantly scheduling timer events. | |
40 | ||
41 | ASYNC only stops pestering its client when it is de-async'ed or it | |
c378eb4e | 42 | is told to go away. */ |
3eb25fda MM |
43 | |
44 | /* Value of scb->async_state: */ | |
45 | enum { | |
46 | /* >= 0 (TIMER_SCHEDULED) */ | |
c378eb4e | 47 | /* The ID of the currently scheduled timer event. This state is |
3eb25fda | 48 | rarely encountered. Timer events are one-off so as soon as the |
c378eb4e | 49 | event is delivered the state is shanged to NOTHING_SCHEDULED. */ |
3eb25fda MM |
50 | FD_SCHEDULED = -1, |
51 | /* The fd_event() handler is scheduled. It is called when ever the | |
c378eb4e | 52 | file descriptor becomes ready. */ |
3eb25fda MM |
53 | NOTHING_SCHEDULED = -2 |
54 | /* Either no task is scheduled (just going into ASYNC mode) or a | |
55 | timer event has just gone off and the current state has been | |
c378eb4e | 56 | forced into nothing scheduled. */ |
3eb25fda MM |
57 | }; |
58 | ||
59 | /* Identify and schedule the next ASYNC task based on scb->async_state | |
60 | and scb->buf* (the input FIFO). A state machine is used to avoid | |
61 | the need to make redundant calls into the event-loop - the next | |
c378eb4e | 62 | scheduled task is only changed when needed. */ |
3eb25fda | 63 | |
a26d8d11 | 64 | static void |
3eb25fda MM |
65 | reschedule (struct serial *scb) |
66 | { | |
67 | if (serial_is_async_p (scb)) | |
68 | { | |
69 | int next_state; | |
433759f7 | 70 | |
3eb25fda MM |
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 | ||
ddefb60f PA |
124 | /* Run the SCB's async handle, and reschedule, if the handler doesn't |
125 | close SCB. */ | |
126 | ||
127 | static void | |
128 | run_async_handler_and_reschedule (struct serial *scb) | |
129 | { | |
130 | int is_open; | |
131 | ||
132 | /* Take a reference, so a serial_close call within the handler | |
133 | doesn't make SCB a dangling pointer. */ | |
134 | serial_ref (scb); | |
135 | ||
136 | /* Run the handler. */ | |
137 | scb->async_handler (scb, scb->async_context); | |
138 | ||
139 | is_open = serial_is_open (scb); | |
140 | serial_unref (scb); | |
141 | ||
142 | /* Get ready for more, if not already closed. */ | |
143 | if (is_open) | |
144 | reschedule (scb); | |
145 | } | |
146 | ||
3eb25fda MM |
147 | /* FD_EVENT: This is scheduled when the input FIFO is empty (and there |
148 | is no pending error). As soon as data arrives, it is read into the | |
149 | input FIFO and the client notified. The client should then drain | |
150 | the FIFO using readchar(). If the FIFO isn't immediatly emptied, | |
c378eb4e | 151 | push_event() is used to nag the client until it is. */ |
3eb25fda MM |
152 | |
153 | static void | |
154 | fd_event (int error, void *context) | |
155 | { | |
19ba03f4 | 156 | struct serial *scb = (struct serial *) context; |
3eb25fda MM |
157 | if (error != 0) |
158 | { | |
159 | scb->bufcnt = SERIAL_ERROR; | |
160 | } | |
161 | else if (scb->bufcnt == 0) | |
162 | { | |
163 | /* Prime the input FIFO. The readchar() function is used to | |
164 | pull characters out of the buffer. See also | |
c378eb4e | 165 | generic_readchar(). */ |
3eb25fda | 166 | int nr; |
b4505029 | 167 | nr = scb->ops->read_prim (scb, BUFSIZ); |
3eb25fda MM |
168 | if (nr == 0) |
169 | { | |
170 | scb->bufcnt = SERIAL_EOF; | |
171 | } | |
172 | else if (nr > 0) | |
173 | { | |
174 | scb->bufcnt = nr; | |
175 | scb->bufp = scb->buf; | |
176 | } | |
177 | else | |
178 | { | |
179 | scb->bufcnt = SERIAL_ERROR; | |
180 | } | |
181 | } | |
ddefb60f | 182 | run_async_handler_and_reschedule (scb); |
3eb25fda MM |
183 | } |
184 | ||
185 | /* PUSH_EVENT: The input FIFO is non-empty (or there is a pending | |
186 | error). Nag the client until all the data has been read. In the | |
187 | case of errors, the client will need to close or de-async the | |
c378eb4e | 188 | device before naging stops. */ |
3eb25fda MM |
189 | |
190 | static void | |
191 | push_event (void *context) | |
192 | { | |
19ba03f4 | 193 | struct serial *scb = (struct serial *) context; |
433759f7 | 194 | |
3eb25fda | 195 | scb->async_state = NOTHING_SCHEDULED; /* Timers are one-off */ |
ddefb60f | 196 | run_async_handler_and_reschedule (scb); |
3eb25fda MM |
197 | } |
198 | ||
b4505029 | 199 | /* Wait for input on scb, with timeout seconds. Returns 0 on success, |
c378eb4e | 200 | otherwise SERIAL_TIMEOUT or SERIAL_ERROR. */ |
b4505029 MM |
201 | |
202 | static int | |
203 | ser_base_wait_for (struct serial *scb, int timeout) | |
204 | { | |
205 | while (1) | |
206 | { | |
207 | int numfds; | |
208 | struct timeval tv; | |
209 | fd_set readfds, exceptfds; | |
210 | ||
211 | /* NOTE: Some OS's can scramble the READFDS when the select() | |
212 | call fails (ex the kernel with Red Hat 5.2). Initialize all | |
c378eb4e | 213 | arguments before each call. */ |
b4505029 MM |
214 | |
215 | tv.tv_sec = timeout; | |
216 | tv.tv_usec = 0; | |
217 | ||
218 | FD_ZERO (&readfds); | |
219 | FD_ZERO (&exceptfds); | |
220 | FD_SET (scb->fd, &readfds); | |
221 | FD_SET (scb->fd, &exceptfds); | |
222 | ||
223 | if (timeout >= 0) | |
0ea3f30e | 224 | numfds = gdb_select (scb->fd + 1, &readfds, 0, &exceptfds, &tv); |
b4505029 | 225 | else |
0ea3f30e | 226 | numfds = gdb_select (scb->fd + 1, &readfds, 0, &exceptfds, 0); |
b4505029 MM |
227 | |
228 | if (numfds <= 0) | |
229 | { | |
230 | if (numfds == 0) | |
231 | return SERIAL_TIMEOUT; | |
232 | else if (errno == EINTR) | |
233 | continue; | |
234 | else | |
c378eb4e MS |
235 | return SERIAL_ERROR; /* Got an error from select or |
236 | poll. */ | |
b4505029 MM |
237 | } |
238 | ||
239 | return 0; | |
240 | } | |
241 | } | |
242 | ||
3347eb1a | 243 | /* Read any error output we might have. */ |
244 | ||
245 | static void | |
246 | ser_base_read_error_fd (struct serial *scb, int close_fd) | |
247 | { | |
248 | if (scb->error_fd != -1) | |
249 | { | |
250 | ssize_t s; | |
251 | char buf[GDB_MI_MSG_WIDTH + 1]; | |
252 | ||
253 | for (;;) | |
254 | { | |
255 | char *current; | |
256 | char *newline; | |
257 | int to_read = GDB_MI_MSG_WIDTH; | |
258 | int num_bytes = -1; | |
259 | ||
260 | if (scb->ops->avail) | |
261 | num_bytes = (scb->ops->avail)(scb, scb->error_fd); | |
262 | ||
263 | if (num_bytes != -1) | |
264 | to_read = (num_bytes < to_read) ? num_bytes : to_read; | |
265 | ||
266 | if (to_read == 0) | |
267 | break; | |
268 | ||
269 | s = read (scb->error_fd, &buf, to_read); | |
270 | if ((s == -1) || (s == 0 && !close_fd)) | |
271 | break; | |
272 | ||
273 | if (s == 0 && close_fd) | |
274 | { | |
275 | /* End of file. */ | |
276 | close (scb->error_fd); | |
277 | scb->error_fd = -1; | |
278 | break; | |
279 | } | |
280 | ||
281 | /* In theory, embedded newlines are not a problem. | |
282 | But for MI, we want each output line to have just | |
283 | one newline for legibility. So output things | |
284 | in newline chunks. */ | |
285 | gdb_assert (s > 0 && s <= GDB_MI_MSG_WIDTH); | |
286 | buf[s] = '\0'; | |
287 | current = buf; | |
288 | while ((newline = strstr (current, "\n")) != NULL) | |
289 | { | |
290 | *newline = '\0'; | |
291 | fputs_unfiltered (current, gdb_stderr); | |
292 | fputs_unfiltered ("\n", gdb_stderr); | |
293 | current = newline + 1; | |
294 | } | |
295 | ||
296 | fputs_unfiltered (current, gdb_stderr); | |
297 | } | |
298 | } | |
299 | } | |
300 | ||
b4505029 MM |
301 | /* Read a character with user-specified timeout. TIMEOUT is number of seconds |
302 | to wait, or -1 to wait forever. Use timeout of 0 to effect a poll. Returns | |
303 | char if successful. Returns -2 if timeout expired, EOF if line dropped | |
c378eb4e | 304 | dead, or -3 for any other error (see errno in that case). */ |
b4505029 MM |
305 | |
306 | static int | |
307 | do_ser_base_readchar (struct serial *scb, int timeout) | |
308 | { | |
309 | int status; | |
310 | int delta; | |
311 | ||
312 | /* We have to be able to keep the GUI alive here, so we break the | |
313 | original timeout into steps of 1 second, running the "keep the | |
314 | GUI alive" hook each time through the loop. | |
315 | ||
316 | Also, timeout = 0 means to poll, so we just set the delta to 0, | |
317 | so we will only go through the loop once. */ | |
318 | ||
319 | delta = (timeout == 0 ? 0 : 1); | |
320 | while (1) | |
321 | { | |
322 | /* N.B. The UI may destroy our world (for instance by calling | |
323 | remote_stop,) in which case we want to get out of here as | |
324 | quickly as possible. It is not safe to touch scb, since | |
325 | someone else might have freed it. The | |
326 | deprecated_ui_loop_hook signals that we should exit by | |
327 | returning 1. */ | |
328 | ||
329 | if (deprecated_ui_loop_hook) | |
330 | { | |
331 | if (deprecated_ui_loop_hook (0)) | |
332 | return SERIAL_TIMEOUT; | |
333 | } | |
334 | ||
335 | status = ser_base_wait_for (scb, delta); | |
336 | if (timeout > 0) | |
337 | timeout -= delta; | |
338 | ||
339 | /* If we got a character or an error back from wait_for, then we can | |
c378eb4e | 340 | break from the loop before the timeout is completed. */ |
b4505029 MM |
341 | if (status != SERIAL_TIMEOUT) |
342 | break; | |
343 | ||
344 | /* If we have exhausted the original timeout, then generate | |
c378eb4e | 345 | a SERIAL_TIMEOUT, and pass it out of the loop. */ |
b4505029 MM |
346 | else if (timeout == 0) |
347 | { | |
348 | status = SERIAL_TIMEOUT; | |
349 | break; | |
350 | } | |
3347eb1a | 351 | |
352 | /* We also need to check and consume the stderr because it could | |
353 | come before the stdout for some stubs. If we just sit and wait | |
354 | for stdout, we would hit a deadlock for that case. */ | |
355 | ser_base_read_error_fd (scb, 0); | |
b4505029 MM |
356 | } |
357 | ||
358 | if (status < 0) | |
359 | return status; | |
360 | ||
361 | status = scb->ops->read_prim (scb, BUFSIZ); | |
362 | ||
363 | if (status <= 0) | |
364 | { | |
365 | if (status == 0) | |
d41ebd5d | 366 | return SERIAL_EOF; |
b4505029 MM |
367 | else |
368 | /* Got an error from read. */ | |
369 | return SERIAL_ERROR; | |
370 | } | |
371 | ||
372 | scb->bufcnt = status; | |
373 | scb->bufcnt--; | |
374 | scb->bufp = scb->buf; | |
375 | return *scb->bufp++; | |
376 | } | |
377 | ||
c378eb4e | 378 | /* Perform operations common to both old and new readchar. */ |
b4505029 MM |
379 | |
380 | /* Return the next character from the input FIFO. If the FIFO is | |
381 | empty, call the SERIAL specific routine to try and read in more | |
382 | characters. | |
383 | ||
384 | Initially data from the input FIFO is returned (fd_event() | |
385 | pre-reads the input into that FIFO. Once that has been emptied, | |
386 | further data is obtained by polling the input FD using the device | |
387 | specific readchar() function. Note: reschedule() is called after | |
388 | every read. This is because there is no guarentee that the lower | |
389 | level fd_event() poll_event() code (which also calls reschedule()) | |
c378eb4e | 390 | will be called. */ |
b4505029 MM |
391 | |
392 | int | |
393 | generic_readchar (struct serial *scb, int timeout, | |
394 | int (do_readchar) (struct serial *scb, int timeout)) | |
395 | { | |
396 | int ch; | |
397 | if (scb->bufcnt > 0) | |
398 | { | |
399 | ch = *scb->bufp; | |
400 | scb->bufcnt--; | |
401 | scb->bufp++; | |
402 | } | |
403 | else if (scb->bufcnt < 0) | |
404 | { | |
c378eb4e | 405 | /* Some errors/eof are are sticky. */ |
b4505029 MM |
406 | ch = scb->bufcnt; |
407 | } | |
408 | else | |
409 | { | |
410 | ch = do_readchar (scb, timeout); | |
411 | if (ch < 0) | |
412 | { | |
413 | switch ((enum serial_rc) ch) | |
414 | { | |
415 | case SERIAL_EOF: | |
416 | case SERIAL_ERROR: | |
c378eb4e | 417 | /* Make the error/eof stick. */ |
b4505029 MM |
418 | scb->bufcnt = ch; |
419 | break; | |
420 | case SERIAL_TIMEOUT: | |
421 | scb->bufcnt = 0; | |
422 | break; | |
423 | } | |
424 | } | |
425 | } | |
65cc4390 | 426 | |
3347eb1a | 427 | /* Read any error output we might have. */ |
428 | ser_base_read_error_fd (scb, 1); | |
65cc4390 | 429 | |
b4505029 MM |
430 | reschedule (scb); |
431 | return ch; | |
432 | } | |
433 | ||
434 | int | |
435 | ser_base_readchar (struct serial *scb, int timeout) | |
436 | { | |
437 | return generic_readchar (scb, timeout, do_ser_base_readchar); | |
438 | } | |
439 | ||
3eb25fda | 440 | int |
c628b528 | 441 | ser_base_write (struct serial *scb, const void *buf, size_t count) |
3eb25fda | 442 | { |
19ba03f4 | 443 | const char *str = (const char *) buf; |
3eb25fda MM |
444 | int cc; |
445 | ||
c628b528 | 446 | while (count > 0) |
3eb25fda | 447 | { |
c628b528 | 448 | cc = scb->ops->write_prim (scb, str, count); |
3eb25fda MM |
449 | |
450 | if (cc < 0) | |
451 | return 1; | |
c628b528 | 452 | count -= cc; |
3eb25fda MM |
453 | str += cc; |
454 | } | |
455 | return 0; | |
456 | } | |
457 | ||
458 | int | |
dd5da072 | 459 | ser_base_flush_output (struct serial *scb) |
3eb25fda MM |
460 | { |
461 | return 0; | |
462 | } | |
463 | ||
464 | int | |
dd5da072 | 465 | ser_base_flush_input (struct serial *scb) |
3eb25fda MM |
466 | { |
467 | if (scb->bufcnt >= 0) | |
468 | { | |
469 | scb->bufcnt = 0; | |
470 | scb->bufp = scb->buf; | |
471 | return 0; | |
472 | } | |
473 | else | |
474 | return SERIAL_ERROR; | |
475 | } | |
476 | ||
477 | int | |
dd5da072 | 478 | ser_base_send_break (struct serial *scb) |
3eb25fda MM |
479 | { |
480 | return 0; | |
481 | } | |
482 | ||
483 | int | |
dd5da072 | 484 | ser_base_drain_output (struct serial *scb) |
3eb25fda MM |
485 | { |
486 | return 0; | |
487 | } | |
488 | ||
489 | void | |
dd5da072 | 490 | ser_base_raw (struct serial *scb) |
3eb25fda | 491 | { |
c378eb4e | 492 | return; /* Always in raw mode. */ |
3eb25fda MM |
493 | } |
494 | ||
495 | serial_ttystate | |
dd5da072 | 496 | ser_base_get_tty_state (struct serial *scb) |
3eb25fda | 497 | { |
c378eb4e | 498 | /* Allocate a dummy. */ |
70ba0933 | 499 | return (serial_ttystate) XNEW (int); |
3eb25fda MM |
500 | } |
501 | ||
1e182ce8 UW |
502 | serial_ttystate |
503 | ser_base_copy_tty_state (struct serial *scb, serial_ttystate ttystate) | |
504 | { | |
505 | /* Allocate another dummy. */ | |
70ba0933 | 506 | return (serial_ttystate) XNEW (int); |
1e182ce8 UW |
507 | } |
508 | ||
3eb25fda | 509 | int |
dd5da072 | 510 | ser_base_set_tty_state (struct serial *scb, serial_ttystate ttystate) |
3eb25fda MM |
511 | { |
512 | return 0; | |
513 | } | |
514 | ||
515 | int | |
dd5da072 MM |
516 | ser_base_noflush_set_tty_state (struct serial *scb, |
517 | serial_ttystate new_ttystate, | |
518 | serial_ttystate old_ttystate) | |
3eb25fda MM |
519 | { |
520 | return 0; | |
521 | } | |
522 | ||
523 | void | |
dd5da072 MM |
524 | ser_base_print_tty_state (struct serial *scb, |
525 | serial_ttystate ttystate, | |
526 | struct ui_file *stream) | |
3eb25fda MM |
527 | { |
528 | /* Nothing to print. */ | |
529 | return; | |
530 | } | |
531 | ||
532 | int | |
dd5da072 | 533 | ser_base_setbaudrate (struct serial *scb, int rate) |
3eb25fda | 534 | { |
c378eb4e | 535 | return 0; /* Never fails! */ |
3eb25fda MM |
536 | } |
537 | ||
538 | int | |
dd5da072 | 539 | ser_base_setstopbits (struct serial *scb, int num) |
3eb25fda | 540 | { |
c378eb4e | 541 | return 0; /* Never fails! */ |
3eb25fda MM |
542 | } |
543 | ||
236af5e3 YG |
544 | /* Implement the "setparity" serial_ops callback. */ |
545 | ||
546 | int | |
547 | ser_base_setparity (struct serial *scb, int parity) | |
548 | { | |
549 | return 0; /* Never fails! */ | |
550 | } | |
551 | ||
3eb25fda MM |
552 | /* Put the SERIAL device into/out-of ASYNC mode. */ |
553 | ||
554 | void | |
dd5da072 | 555 | ser_base_async (struct serial *scb, |
3eb25fda MM |
556 | int async_p) |
557 | { | |
558 | if (async_p) | |
559 | { | |
c378eb4e | 560 | /* Force a re-schedule. */ |
3eb25fda MM |
561 | scb->async_state = NOTHING_SCHEDULED; |
562 | if (serial_debug_p (scb)) | |
563 | fprintf_unfiltered (gdb_stdlog, "[fd%d->asynchronous]\n", | |
564 | scb->fd); | |
565 | reschedule (scb); | |
566 | } | |
567 | else | |
568 | { | |
569 | if (serial_debug_p (scb)) | |
570 | fprintf_unfiltered (gdb_stdlog, "[fd%d->synchronous]\n", | |
571 | scb->fd); | |
c378eb4e | 572 | /* De-schedule whatever tasks are currently scheduled. */ |
3eb25fda MM |
573 | switch (scb->async_state) |
574 | { | |
575 | case FD_SCHEDULED: | |
576 | delete_file_handler (scb->fd); | |
577 | break; | |
578 | case NOTHING_SCHEDULED: | |
579 | break; | |
580 | default: /* TIMER SCHEDULED */ | |
581 | delete_timer (scb->async_state); | |
582 | break; | |
583 | } | |
584 | } | |
585 | } |