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; |
75ee5925 PA |
167 | |
168 | do | |
169 | { | |
170 | nr = scb->ops->read_prim (scb, BUFSIZ); | |
171 | } | |
172 | while (nr < 0 && errno == EINTR); | |
173 | ||
3eb25fda MM |
174 | if (nr == 0) |
175 | { | |
176 | scb->bufcnt = SERIAL_EOF; | |
177 | } | |
178 | else if (nr > 0) | |
179 | { | |
180 | scb->bufcnt = nr; | |
181 | scb->bufp = scb->buf; | |
182 | } | |
183 | else | |
184 | { | |
185 | scb->bufcnt = SERIAL_ERROR; | |
186 | } | |
187 | } | |
ddefb60f | 188 | run_async_handler_and_reschedule (scb); |
3eb25fda MM |
189 | } |
190 | ||
191 | /* PUSH_EVENT: The input FIFO is non-empty (or there is a pending | |
192 | error). Nag the client until all the data has been read. In the | |
193 | case of errors, the client will need to close or de-async the | |
c378eb4e | 194 | device before naging stops. */ |
3eb25fda MM |
195 | |
196 | static void | |
197 | push_event (void *context) | |
198 | { | |
19ba03f4 | 199 | struct serial *scb = (struct serial *) context; |
433759f7 | 200 | |
3eb25fda | 201 | scb->async_state = NOTHING_SCHEDULED; /* Timers are one-off */ |
ddefb60f | 202 | run_async_handler_and_reschedule (scb); |
3eb25fda MM |
203 | } |
204 | ||
b4505029 | 205 | /* Wait for input on scb, with timeout seconds. Returns 0 on success, |
c378eb4e | 206 | otherwise SERIAL_TIMEOUT or SERIAL_ERROR. */ |
b4505029 MM |
207 | |
208 | static int | |
209 | ser_base_wait_for (struct serial *scb, int timeout) | |
210 | { | |
211 | while (1) | |
212 | { | |
213 | int numfds; | |
214 | struct timeval tv; | |
215 | fd_set readfds, exceptfds; | |
216 | ||
217 | /* NOTE: Some OS's can scramble the READFDS when the select() | |
218 | call fails (ex the kernel with Red Hat 5.2). Initialize all | |
c378eb4e | 219 | arguments before each call. */ |
b4505029 MM |
220 | |
221 | tv.tv_sec = timeout; | |
222 | tv.tv_usec = 0; | |
223 | ||
224 | FD_ZERO (&readfds); | |
225 | FD_ZERO (&exceptfds); | |
226 | FD_SET (scb->fd, &readfds); | |
227 | FD_SET (scb->fd, &exceptfds); | |
228 | ||
229 | if (timeout >= 0) | |
0ea3f30e | 230 | numfds = gdb_select (scb->fd + 1, &readfds, 0, &exceptfds, &tv); |
b4505029 | 231 | else |
0ea3f30e | 232 | numfds = gdb_select (scb->fd + 1, &readfds, 0, &exceptfds, 0); |
b4505029 MM |
233 | |
234 | if (numfds <= 0) | |
235 | { | |
236 | if (numfds == 0) | |
237 | return SERIAL_TIMEOUT; | |
238 | else if (errno == EINTR) | |
239 | continue; | |
240 | else | |
c378eb4e MS |
241 | return SERIAL_ERROR; /* Got an error from select or |
242 | poll. */ | |
b4505029 MM |
243 | } |
244 | ||
245 | return 0; | |
246 | } | |
247 | } | |
248 | ||
3347eb1a | 249 | /* Read any error output we might have. */ |
250 | ||
251 | static void | |
252 | ser_base_read_error_fd (struct serial *scb, int close_fd) | |
253 | { | |
254 | if (scb->error_fd != -1) | |
255 | { | |
256 | ssize_t s; | |
257 | char buf[GDB_MI_MSG_WIDTH + 1]; | |
258 | ||
259 | for (;;) | |
260 | { | |
261 | char *current; | |
262 | char *newline; | |
263 | int to_read = GDB_MI_MSG_WIDTH; | |
264 | int num_bytes = -1; | |
265 | ||
266 | if (scb->ops->avail) | |
267 | num_bytes = (scb->ops->avail)(scb, scb->error_fd); | |
268 | ||
269 | if (num_bytes != -1) | |
270 | to_read = (num_bytes < to_read) ? num_bytes : to_read; | |
271 | ||
272 | if (to_read == 0) | |
273 | break; | |
274 | ||
275 | s = read (scb->error_fd, &buf, to_read); | |
276 | if ((s == -1) || (s == 0 && !close_fd)) | |
277 | break; | |
278 | ||
279 | if (s == 0 && close_fd) | |
280 | { | |
281 | /* End of file. */ | |
282 | close (scb->error_fd); | |
283 | scb->error_fd = -1; | |
284 | break; | |
285 | } | |
286 | ||
287 | /* In theory, embedded newlines are not a problem. | |
288 | But for MI, we want each output line to have just | |
289 | one newline for legibility. So output things | |
290 | in newline chunks. */ | |
291 | gdb_assert (s > 0 && s <= GDB_MI_MSG_WIDTH); | |
292 | buf[s] = '\0'; | |
293 | current = buf; | |
294 | while ((newline = strstr (current, "\n")) != NULL) | |
295 | { | |
296 | *newline = '\0'; | |
297 | fputs_unfiltered (current, gdb_stderr); | |
298 | fputs_unfiltered ("\n", gdb_stderr); | |
299 | current = newline + 1; | |
300 | } | |
301 | ||
302 | fputs_unfiltered (current, gdb_stderr); | |
303 | } | |
304 | } | |
305 | } | |
306 | ||
b4505029 MM |
307 | /* Read a character with user-specified timeout. TIMEOUT is number of seconds |
308 | to wait, or -1 to wait forever. Use timeout of 0 to effect a poll. Returns | |
309 | char if successful. Returns -2 if timeout expired, EOF if line dropped | |
c378eb4e | 310 | dead, or -3 for any other error (see errno in that case). */ |
b4505029 MM |
311 | |
312 | static int | |
313 | do_ser_base_readchar (struct serial *scb, int timeout) | |
314 | { | |
315 | int status; | |
316 | int delta; | |
317 | ||
318 | /* We have to be able to keep the GUI alive here, so we break the | |
319 | original timeout into steps of 1 second, running the "keep the | |
320 | GUI alive" hook each time through the loop. | |
321 | ||
322 | Also, timeout = 0 means to poll, so we just set the delta to 0, | |
323 | so we will only go through the loop once. */ | |
324 | ||
325 | delta = (timeout == 0 ? 0 : 1); | |
326 | while (1) | |
327 | { | |
328 | /* N.B. The UI may destroy our world (for instance by calling | |
329 | remote_stop,) in which case we want to get out of here as | |
330 | quickly as possible. It is not safe to touch scb, since | |
331 | someone else might have freed it. The | |
332 | deprecated_ui_loop_hook signals that we should exit by | |
333 | returning 1. */ | |
334 | ||
335 | if (deprecated_ui_loop_hook) | |
336 | { | |
337 | if (deprecated_ui_loop_hook (0)) | |
338 | return SERIAL_TIMEOUT; | |
339 | } | |
340 | ||
341 | status = ser_base_wait_for (scb, delta); | |
342 | if (timeout > 0) | |
343 | timeout -= delta; | |
344 | ||
345 | /* If we got a character or an error back from wait_for, then we can | |
c378eb4e | 346 | break from the loop before the timeout is completed. */ |
b4505029 MM |
347 | if (status != SERIAL_TIMEOUT) |
348 | break; | |
349 | ||
350 | /* If we have exhausted the original timeout, then generate | |
c378eb4e | 351 | a SERIAL_TIMEOUT, and pass it out of the loop. */ |
b4505029 MM |
352 | else if (timeout == 0) |
353 | { | |
354 | status = SERIAL_TIMEOUT; | |
355 | break; | |
356 | } | |
3347eb1a | 357 | |
358 | /* We also need to check and consume the stderr because it could | |
359 | come before the stdout for some stubs. If we just sit and wait | |
360 | for stdout, we would hit a deadlock for that case. */ | |
361 | ser_base_read_error_fd (scb, 0); | |
b4505029 MM |
362 | } |
363 | ||
364 | if (status < 0) | |
365 | return status; | |
366 | ||
75ee5925 PA |
367 | do |
368 | { | |
369 | status = scb->ops->read_prim (scb, BUFSIZ); | |
370 | } | |
371 | while (status < 0 && errno == EINTR); | |
b4505029 MM |
372 | |
373 | if (status <= 0) | |
374 | { | |
375 | if (status == 0) | |
d41ebd5d | 376 | return SERIAL_EOF; |
b4505029 MM |
377 | else |
378 | /* Got an error from read. */ | |
379 | return SERIAL_ERROR; | |
380 | } | |
381 | ||
382 | scb->bufcnt = status; | |
383 | scb->bufcnt--; | |
384 | scb->bufp = scb->buf; | |
385 | return *scb->bufp++; | |
386 | } | |
387 | ||
c378eb4e | 388 | /* Perform operations common to both old and new readchar. */ |
b4505029 MM |
389 | |
390 | /* Return the next character from the input FIFO. If the FIFO is | |
391 | empty, call the SERIAL specific routine to try and read in more | |
392 | characters. | |
393 | ||
394 | Initially data from the input FIFO is returned (fd_event() | |
395 | pre-reads the input into that FIFO. Once that has been emptied, | |
396 | further data is obtained by polling the input FD using the device | |
397 | specific readchar() function. Note: reschedule() is called after | |
398 | every read. This is because there is no guarentee that the lower | |
399 | level fd_event() poll_event() code (which also calls reschedule()) | |
c378eb4e | 400 | will be called. */ |
b4505029 MM |
401 | |
402 | int | |
403 | generic_readchar (struct serial *scb, int timeout, | |
404 | int (do_readchar) (struct serial *scb, int timeout)) | |
405 | { | |
406 | int ch; | |
407 | if (scb->bufcnt > 0) | |
408 | { | |
409 | ch = *scb->bufp; | |
410 | scb->bufcnt--; | |
411 | scb->bufp++; | |
412 | } | |
413 | else if (scb->bufcnt < 0) | |
414 | { | |
c378eb4e | 415 | /* Some errors/eof are are sticky. */ |
b4505029 MM |
416 | ch = scb->bufcnt; |
417 | } | |
418 | else | |
419 | { | |
420 | ch = do_readchar (scb, timeout); | |
421 | if (ch < 0) | |
422 | { | |
423 | switch ((enum serial_rc) ch) | |
424 | { | |
425 | case SERIAL_EOF: | |
426 | case SERIAL_ERROR: | |
c378eb4e | 427 | /* Make the error/eof stick. */ |
b4505029 MM |
428 | scb->bufcnt = ch; |
429 | break; | |
430 | case SERIAL_TIMEOUT: | |
431 | scb->bufcnt = 0; | |
432 | break; | |
433 | } | |
434 | } | |
435 | } | |
65cc4390 | 436 | |
3347eb1a | 437 | /* Read any error output we might have. */ |
438 | ser_base_read_error_fd (scb, 1); | |
65cc4390 | 439 | |
b4505029 MM |
440 | reschedule (scb); |
441 | return ch; | |
442 | } | |
443 | ||
444 | int | |
445 | ser_base_readchar (struct serial *scb, int timeout) | |
446 | { | |
447 | return generic_readchar (scb, timeout, do_ser_base_readchar); | |
448 | } | |
449 | ||
3eb25fda | 450 | int |
c628b528 | 451 | ser_base_write (struct serial *scb, const void *buf, size_t count) |
3eb25fda | 452 | { |
19ba03f4 | 453 | const char *str = (const char *) buf; |
3eb25fda MM |
454 | int cc; |
455 | ||
c628b528 | 456 | while (count > 0) |
3eb25fda | 457 | { |
c628b528 | 458 | cc = scb->ops->write_prim (scb, str, count); |
3eb25fda MM |
459 | |
460 | if (cc < 0) | |
75ee5925 PA |
461 | { |
462 | if (errno == EINTR) | |
463 | continue; | |
464 | return 1; | |
465 | } | |
c628b528 | 466 | count -= cc; |
3eb25fda MM |
467 | str += cc; |
468 | } | |
469 | return 0; | |
470 | } | |
471 | ||
472 | int | |
dd5da072 | 473 | ser_base_flush_output (struct serial *scb) |
3eb25fda MM |
474 | { |
475 | return 0; | |
476 | } | |
477 | ||
478 | int | |
dd5da072 | 479 | ser_base_flush_input (struct serial *scb) |
3eb25fda MM |
480 | { |
481 | if (scb->bufcnt >= 0) | |
482 | { | |
483 | scb->bufcnt = 0; | |
484 | scb->bufp = scb->buf; | |
485 | return 0; | |
486 | } | |
487 | else | |
488 | return SERIAL_ERROR; | |
489 | } | |
490 | ||
491 | int | |
dd5da072 | 492 | ser_base_send_break (struct serial *scb) |
3eb25fda MM |
493 | { |
494 | return 0; | |
495 | } | |
496 | ||
497 | int | |
dd5da072 | 498 | ser_base_drain_output (struct serial *scb) |
3eb25fda MM |
499 | { |
500 | return 0; | |
501 | } | |
502 | ||
503 | void | |
dd5da072 | 504 | ser_base_raw (struct serial *scb) |
3eb25fda | 505 | { |
c378eb4e | 506 | return; /* Always in raw mode. */ |
3eb25fda MM |
507 | } |
508 | ||
509 | serial_ttystate | |
dd5da072 | 510 | ser_base_get_tty_state (struct serial *scb) |
3eb25fda | 511 | { |
c378eb4e | 512 | /* Allocate a dummy. */ |
70ba0933 | 513 | return (serial_ttystate) XNEW (int); |
3eb25fda MM |
514 | } |
515 | ||
1e182ce8 UW |
516 | serial_ttystate |
517 | ser_base_copy_tty_state (struct serial *scb, serial_ttystate ttystate) | |
518 | { | |
519 | /* Allocate another dummy. */ | |
70ba0933 | 520 | return (serial_ttystate) XNEW (int); |
1e182ce8 UW |
521 | } |
522 | ||
3eb25fda | 523 | int |
dd5da072 | 524 | ser_base_set_tty_state (struct serial *scb, serial_ttystate ttystate) |
3eb25fda MM |
525 | { |
526 | return 0; | |
527 | } | |
528 | ||
529 | int | |
dd5da072 MM |
530 | ser_base_noflush_set_tty_state (struct serial *scb, |
531 | serial_ttystate new_ttystate, | |
532 | serial_ttystate old_ttystate) | |
3eb25fda MM |
533 | { |
534 | return 0; | |
535 | } | |
536 | ||
537 | void | |
dd5da072 MM |
538 | ser_base_print_tty_state (struct serial *scb, |
539 | serial_ttystate ttystate, | |
540 | struct ui_file *stream) | |
3eb25fda MM |
541 | { |
542 | /* Nothing to print. */ | |
543 | return; | |
544 | } | |
545 | ||
546 | int | |
dd5da072 | 547 | ser_base_setbaudrate (struct serial *scb, int rate) |
3eb25fda | 548 | { |
c378eb4e | 549 | return 0; /* Never fails! */ |
3eb25fda MM |
550 | } |
551 | ||
552 | int | |
dd5da072 | 553 | ser_base_setstopbits (struct serial *scb, int num) |
3eb25fda | 554 | { |
c378eb4e | 555 | return 0; /* Never fails! */ |
3eb25fda MM |
556 | } |
557 | ||
236af5e3 YG |
558 | /* Implement the "setparity" serial_ops callback. */ |
559 | ||
560 | int | |
561 | ser_base_setparity (struct serial *scb, int parity) | |
562 | { | |
563 | return 0; /* Never fails! */ | |
564 | } | |
565 | ||
3eb25fda MM |
566 | /* Put the SERIAL device into/out-of ASYNC mode. */ |
567 | ||
568 | void | |
dd5da072 | 569 | ser_base_async (struct serial *scb, |
3eb25fda MM |
570 | int async_p) |
571 | { | |
572 | if (async_p) | |
573 | { | |
c378eb4e | 574 | /* Force a re-schedule. */ |
3eb25fda MM |
575 | scb->async_state = NOTHING_SCHEDULED; |
576 | if (serial_debug_p (scb)) | |
577 | fprintf_unfiltered (gdb_stdlog, "[fd%d->asynchronous]\n", | |
578 | scb->fd); | |
579 | reschedule (scb); | |
580 | } | |
581 | else | |
582 | { | |
583 | if (serial_debug_p (scb)) | |
584 | fprintf_unfiltered (gdb_stdlog, "[fd%d->synchronous]\n", | |
585 | scb->fd); | |
c378eb4e | 586 | /* De-schedule whatever tasks are currently scheduled. */ |
3eb25fda MM |
587 | switch (scb->async_state) |
588 | { | |
589 | case FD_SCHEDULED: | |
590 | delete_file_handler (scb->fd); | |
591 | break; | |
592 | case NOTHING_SCHEDULED: | |
593 | break; | |
594 | default: /* TIMER SCHEDULED */ | |
595 | delete_timer (scb->async_state); | |
596 | break; | |
597 | } | |
598 | } | |
599 | } |