Commit | Line | Data |
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b5a0ac70 | 1 | /* Event loop machinery for GDB, the GNU debugger. |
b811d2c2 | 2 | Copyright (C) 1999-2020 Free Software Foundation, Inc. |
b5a0ac70 SS |
3 | Written by Elena Zannoni <ezannoni@cygnus.com> of Cygnus Solutions. |
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 |
b5a0ac70 SS |
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 | |
371d5dec | 18 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
b5a0ac70 | 19 | |
400b5eca TT |
20 | #include "gdbsupport/common-defs.h" |
21 | #include "gdbsupport/event-loop.h" | |
409a3f64 | 22 | |
98029d02 TT |
23 | #include <chrono> |
24 | ||
b5a0ac70 | 25 | #ifdef HAVE_POLL |
409a3f64 | 26 | #if defined (HAVE_POLL_H) |
9e0b60a8 | 27 | #include <poll.h> |
409a3f64 AC |
28 | #elif defined (HAVE_SYS_POLL_H) |
29 | #include <sys/poll.h> | |
30 | #endif | |
44f45770 | 31 | #endif |
409a3f64 | 32 | |
9e0b60a8 | 33 | #include <sys/types.h> |
268a13a5 | 34 | #include "gdbsupport/gdb_sys_time.h" |
06cc9596 | 35 | #include "gdbsupport/gdb_select.h" |
c2c6d25f | 36 | |
371d5dec MS |
37 | /* Tell create_file_handler what events we are interested in. |
38 | This is used by the select version of the event loop. */ | |
01f69b38 DE |
39 | |
40 | #define GDB_READABLE (1<<1) | |
41 | #define GDB_WRITABLE (1<<2) | |
42 | #define GDB_EXCEPTION (1<<3) | |
43 | ||
c2c6d25f | 44 | /* Information about each file descriptor we register with the event |
371d5dec | 45 | loop. */ |
c2c6d25f JM |
46 | |
47 | typedef struct file_handler | |
48 | { | |
371d5dec MS |
49 | int fd; /* File descriptor. */ |
50 | int mask; /* Events we want to monitor: POLLIN, etc. */ | |
c2c6d25f | 51 | int ready_mask; /* Events that have been seen since |
371d5dec MS |
52 | the last time. */ |
53 | handler_func *proc; /* Procedure to call when fd is ready. */ | |
54 | gdb_client_data client_data; /* Argument to pass to proc. */ | |
55 | int error; /* Was an error detected on this fd? */ | |
56 | struct file_handler *next_file; /* Next registered file descriptor. */ | |
c2c6d25f JM |
57 | } |
58 | file_handler; | |
59 | ||
b5a0ac70 SS |
60 | /* Gdb_notifier is just a list of file descriptors gdb is interested in. |
61 | These are the input file descriptor, and the target file | |
371d5dec | 62 | descriptor. We have two flavors of the notifier, one for platforms |
b5a0ac70 | 63 | that have the POLL function, the other for those that don't, and |
371d5dec | 64 | only support SELECT. Each of the elements in the gdb_notifier list is |
b5a0ac70 | 65 | basically a description of what kind of events gdb is interested |
371d5dec | 66 | in, for each fd. */ |
b5a0ac70 | 67 | |
392a587b | 68 | /* As of 1999-04-30 only the input file descriptor is registered with the |
371d5dec | 69 | event loop. */ |
b5a0ac70 | 70 | |
44f45770 | 71 | /* Do we use poll or select ? */ |
b5a0ac70 | 72 | #ifdef HAVE_POLL |
44f45770 EZ |
73 | #define USE_POLL 1 |
74 | #else | |
75 | #define USE_POLL 0 | |
76 | #endif /* HAVE_POLL */ | |
77 | ||
78 | static unsigned char use_poll = USE_POLL; | |
b5a0ac70 | 79 | |
011825f0 MM |
80 | #ifdef USE_WIN32API |
81 | #include <windows.h> | |
82 | #include <io.h> | |
83 | #endif | |
84 | ||
b5a0ac70 SS |
85 | static struct |
86 | { | |
371d5dec | 87 | /* Ptr to head of file handler list. */ |
b5a0ac70 SS |
88 | file_handler *first_file_handler; |
89 | ||
4e63d0ac PA |
90 | /* Next file handler to handle, for the select variant. To level |
91 | the fairness across event sources, we serve file handlers in a | |
92 | round-robin-like fashion. The number and order of the polled | |
93 | file handlers may change between invocations, but this is good | |
94 | enough. */ | |
95 | file_handler *next_file_handler; | |
96 | ||
44f45770 | 97 | #ifdef HAVE_POLL |
371d5dec | 98 | /* Ptr to array of pollfd structures. */ |
b5a0ac70 SS |
99 | struct pollfd *poll_fds; |
100 | ||
4e63d0ac PA |
101 | /* Next file descriptor to handle, for the poll variant. To level |
102 | the fairness across event sources, we poll the file descriptors | |
103 | in a round-robin-like fashion. The number and order of the | |
104 | polled file descriptors may change between invocations, but | |
105 | this is good enough. */ | |
106 | int next_poll_fds_index; | |
107 | ||
371d5dec | 108 | /* Timeout in milliseconds for calls to poll(). */ |
44f45770 EZ |
109 | int poll_timeout; |
110 | #endif | |
b5a0ac70 SS |
111 | |
112 | /* Masks to be used in the next call to select. | |
371d5dec | 113 | Bits are set in response to calls to create_file_handler. */ |
58a2c44a | 114 | fd_set check_masks[3]; |
b5a0ac70 | 115 | |
371d5dec | 116 | /* What file descriptors were found ready by select. */ |
58a2c44a | 117 | fd_set ready_masks[3]; |
b5a0ac70 | 118 | |
371d5dec MS |
119 | /* Number of file descriptors to monitor (for poll). */ |
120 | /* Number of valid bits (highest fd value + 1) (for select). */ | |
b5a0ac70 SS |
121 | int num_fds; |
122 | ||
371d5dec | 123 | /* Time structure for calls to select(). */ |
44f45770 | 124 | struct timeval select_timeout; |
c2c6d25f | 125 | |
371d5dec | 126 | /* Flag to tell whether the timeout should be used. */ |
c2c6d25f | 127 | int timeout_valid; |
6426a772 | 128 | } |
b5a0ac70 SS |
129 | gdb_notifier; |
130 | ||
371d5dec MS |
131 | /* Structure associated with a timer. PROC will be executed at the |
132 | first occasion after WHEN. */ | |
c2c6d25f JM |
133 | struct gdb_timer |
134 | { | |
dcb07cfa | 135 | std::chrono::steady_clock::time_point when; |
c2c6d25f JM |
136 | int timer_id; |
137 | struct gdb_timer *next; | |
371d5dec MS |
138 | timer_handler_func *proc; /* Function to call to do the work. */ |
139 | gdb_client_data client_data; /* Argument to async_handler_func. */ | |
ae462839 | 140 | }; |
c2c6d25f | 141 | |
371d5dec MS |
142 | /* List of currently active timers. It is sorted in order of |
143 | increasing timers. */ | |
c2c6d25f JM |
144 | static struct |
145 | { | |
371d5dec | 146 | /* Pointer to first in timer list. */ |
c2c6d25f JM |
147 | struct gdb_timer *first_timer; |
148 | ||
371d5dec | 149 | /* Id of the last timer created. */ |
c2c6d25f JM |
150 | int num_timers; |
151 | } | |
152 | timer_list; | |
153 | ||
50d01748 PA |
154 | static void create_file_handler (int fd, int mask, handler_func *proc, |
155 | gdb_client_data client_data); | |
50d01748 | 156 | static int gdb_wait_for_event (int); |
70b66289 PA |
157 | static int update_wait_timeout (void); |
158 | static int poll_timers (void); | |
b5a0ac70 | 159 | \f |
b5a0ac70 SS |
160 | /* Process one high level event. If nothing is ready at this time, |
161 | wait for something to happen (via gdb_wait_for_event), then process | |
11cf8741 | 162 | it. Returns >0 if something was done otherwise returns <0 (this |
e0dd0826 | 163 | can happen if there are no event sources to wait for). */ |
11cf8741 | 164 | |
99656a61 | 165 | int |
e0dd0826 | 166 | gdb_do_one_event (void) |
b5a0ac70 | 167 | { |
50d01748 PA |
168 | static int event_source_head = 0; |
169 | const int number_of_sources = 3; | |
170 | int current = 0; | |
171 | ||
70b66289 PA |
172 | /* First let's see if there are any asynchronous signal handlers |
173 | that are ready. These would be the result of invoking any of the | |
174 | signal handlers. */ | |
175 | if (invoke_async_signal_handlers ()) | |
50d01748 PA |
176 | return 1; |
177 | ||
178 | /* To level the fairness across event sources, we poll them in a | |
179 | round-robin fashion. */ | |
180 | for (current = 0; current < number_of_sources; current++) | |
11cf8741 | 181 | { |
70b66289 PA |
182 | int res; |
183 | ||
50d01748 PA |
184 | switch (event_source_head) |
185 | { | |
186 | case 0: | |
70b66289 PA |
187 | /* Are any timers that are ready? */ |
188 | res = poll_timers (); | |
50d01748 PA |
189 | break; |
190 | case 1: | |
191 | /* Are there events already waiting to be collected on the | |
192 | monitored file descriptors? */ | |
70b66289 | 193 | res = gdb_wait_for_event (0); |
50d01748 PA |
194 | break; |
195 | case 2: | |
196 | /* Are there any asynchronous event handlers ready? */ | |
70b66289 | 197 | res = check_async_event_handlers (); |
50d01748 | 198 | break; |
80bd5fab PA |
199 | default: |
200 | internal_error (__FILE__, __LINE__, | |
201 | "unexpected event_source_head %d", | |
202 | event_source_head); | |
50d01748 PA |
203 | } |
204 | ||
205 | event_source_head++; | |
206 | if (event_source_head == number_of_sources) | |
207 | event_source_head = 0; | |
7e5cd2de | 208 | |
70b66289 PA |
209 | if (res > 0) |
210 | return 1; | |
211 | } | |
7e5cd2de | 212 | |
50d01748 PA |
213 | /* Block waiting for a new event. If gdb_wait_for_event returns -1, |
214 | we should get out because this means that there are no event | |
215 | sources left. This will make the event loop stop, and the | |
216 | application exit. */ | |
7e5cd2de | 217 | |
50d01748 PA |
218 | if (gdb_wait_for_event (1) < 0) |
219 | return -1; | |
7e5cd2de | 220 | |
50d01748 PA |
221 | /* If gdb_wait_for_event has returned 1, it means that one event has |
222 | been handled. We break out of the loop. */ | |
11cf8741 JM |
223 | return 1; |
224 | } | |
225 | ||
b5a0ac70 SS |
226 | \f |
227 | ||
085dd6e6 JM |
228 | /* Wrapper function for create_file_handler, so that the caller |
229 | doesn't have to know implementation details about the use of poll | |
371d5dec | 230 | vs. select. */ |
c5aa993b | 231 | void |
6426a772 | 232 | add_file_handler (int fd, handler_func * proc, gdb_client_data client_data) |
085dd6e6 JM |
233 | { |
234 | #ifdef HAVE_POLL | |
44f45770 EZ |
235 | struct pollfd fds; |
236 | #endif | |
237 | ||
238 | if (use_poll) | |
239 | { | |
240 | #ifdef HAVE_POLL | |
371d5dec MS |
241 | /* Check to see if poll () is usable. If not, we'll switch to |
242 | use select. This can happen on systems like | |
7e5cd2de EZ |
243 | m68k-motorola-sys, `poll' cannot be used to wait for `stdin'. |
244 | On m68k-motorola-sysv, tty's are not stream-based and not | |
371d5dec | 245 | `poll'able. */ |
7e5cd2de EZ |
246 | fds.fd = fd; |
247 | fds.events = POLLIN; | |
248 | if (poll (&fds, 1, 0) == 1 && (fds.revents & POLLNVAL)) | |
249 | use_poll = 0; | |
44f45770 | 250 | #else |
8e65ff28 | 251 | internal_error (__FILE__, __LINE__, |
e2e0b3e5 | 252 | _("use_poll without HAVE_POLL")); |
44f45770 EZ |
253 | #endif /* HAVE_POLL */ |
254 | } | |
255 | if (use_poll) | |
256 | { | |
257 | #ifdef HAVE_POLL | |
258 | create_file_handler (fd, POLLIN, proc, client_data); | |
085dd6e6 | 259 | #else |
8e65ff28 | 260 | internal_error (__FILE__, __LINE__, |
e2e0b3e5 | 261 | _("use_poll without HAVE_POLL")); |
085dd6e6 | 262 | #endif |
44f45770 EZ |
263 | } |
264 | else | |
371d5dec MS |
265 | create_file_handler (fd, GDB_READABLE | GDB_EXCEPTION, |
266 | proc, client_data); | |
085dd6e6 JM |
267 | } |
268 | ||
b5a0ac70 | 269 | /* Add a file handler/descriptor to the list of descriptors we are |
371d5dec MS |
270 | interested in. |
271 | ||
272 | FD is the file descriptor for the file/stream to be listened to. | |
273 | ||
274 | For the poll case, MASK is a combination (OR) of POLLIN, | |
275 | POLLRDNORM, POLLRDBAND, POLLPRI, POLLOUT, POLLWRNORM, POLLWRBAND: | |
276 | these are the events we are interested in. If any of them occurs, | |
277 | proc should be called. | |
278 | ||
279 | For the select case, MASK is a combination of READABLE, WRITABLE, | |
280 | EXCEPTION. PROC is the procedure that will be called when an event | |
281 | occurs for FD. CLIENT_DATA is the argument to pass to PROC. */ | |
282 | ||
085dd6e6 | 283 | static void |
371d5dec MS |
284 | create_file_handler (int fd, int mask, handler_func * proc, |
285 | gdb_client_data client_data) | |
b5a0ac70 SS |
286 | { |
287 | file_handler *file_ptr; | |
288 | ||
371d5dec MS |
289 | /* Do we already have a file handler for this file? (We may be |
290 | changing its associated procedure). */ | |
b5a0ac70 SS |
291 | for (file_ptr = gdb_notifier.first_file_handler; file_ptr != NULL; |
292 | file_ptr = file_ptr->next_file) | |
293 | { | |
294 | if (file_ptr->fd == fd) | |
295 | break; | |
296 | } | |
297 | ||
371d5dec MS |
298 | /* It is a new file descriptor. Add it to the list. Otherwise, just |
299 | change the data associated with it. */ | |
b5a0ac70 SS |
300 | if (file_ptr == NULL) |
301 | { | |
8d749320 | 302 | file_ptr = XNEW (file_handler); |
b5a0ac70 SS |
303 | file_ptr->fd = fd; |
304 | file_ptr->ready_mask = 0; | |
305 | file_ptr->next_file = gdb_notifier.first_file_handler; | |
306 | gdb_notifier.first_file_handler = file_ptr; | |
b5a0ac70 | 307 | |
05a6c72c KS |
308 | if (use_poll) |
309 | { | |
b5a0ac70 | 310 | #ifdef HAVE_POLL |
05a6c72c KS |
311 | gdb_notifier.num_fds++; |
312 | if (gdb_notifier.poll_fds) | |
313 | gdb_notifier.poll_fds = | |
314 | (struct pollfd *) xrealloc (gdb_notifier.poll_fds, | |
315 | (gdb_notifier.num_fds | |
316 | * sizeof (struct pollfd))); | |
317 | else | |
318 | gdb_notifier.poll_fds = | |
8d749320 | 319 | XNEW (struct pollfd); |
05a6c72c KS |
320 | (gdb_notifier.poll_fds + gdb_notifier.num_fds - 1)->fd = fd; |
321 | (gdb_notifier.poll_fds + gdb_notifier.num_fds - 1)->events = mask; | |
322 | (gdb_notifier.poll_fds + gdb_notifier.num_fds - 1)->revents = 0; | |
44f45770 | 323 | #else |
05a6c72c | 324 | internal_error (__FILE__, __LINE__, |
e2e0b3e5 | 325 | _("use_poll without HAVE_POLL")); |
44f45770 | 326 | #endif /* HAVE_POLL */ |
05a6c72c | 327 | } |
44f45770 | 328 | else |
05a6c72c KS |
329 | { |
330 | if (mask & GDB_READABLE) | |
331 | FD_SET (fd, &gdb_notifier.check_masks[0]); | |
332 | else | |
333 | FD_CLR (fd, &gdb_notifier.check_masks[0]); | |
334 | ||
335 | if (mask & GDB_WRITABLE) | |
336 | FD_SET (fd, &gdb_notifier.check_masks[1]); | |
337 | else | |
338 | FD_CLR (fd, &gdb_notifier.check_masks[1]); | |
339 | ||
340 | if (mask & GDB_EXCEPTION) | |
341 | FD_SET (fd, &gdb_notifier.check_masks[2]); | |
342 | else | |
343 | FD_CLR (fd, &gdb_notifier.check_masks[2]); | |
344 | ||
345 | if (gdb_notifier.num_fds <= fd) | |
346 | gdb_notifier.num_fds = fd + 1; | |
347 | } | |
44f45770 | 348 | } |
05a6c72c KS |
349 | |
350 | file_ptr->proc = proc; | |
351 | file_ptr->client_data = client_data; | |
352 | file_ptr->mask = mask; | |
b5a0ac70 SS |
353 | } |
354 | ||
4e63d0ac PA |
355 | /* Return the next file handler to handle, and advance to the next |
356 | file handler, wrapping around if the end of the list is | |
357 | reached. */ | |
358 | ||
359 | static file_handler * | |
360 | get_next_file_handler_to_handle_and_advance (void) | |
361 | { | |
362 | file_handler *curr_next; | |
363 | ||
364 | /* The first time around, this is still NULL. */ | |
365 | if (gdb_notifier.next_file_handler == NULL) | |
366 | gdb_notifier.next_file_handler = gdb_notifier.first_file_handler; | |
367 | ||
368 | curr_next = gdb_notifier.next_file_handler; | |
369 | gdb_assert (curr_next != NULL); | |
370 | ||
371 | /* Advance. */ | |
372 | gdb_notifier.next_file_handler = curr_next->next_file; | |
373 | /* Wrap around, if necessary. */ | |
374 | if (gdb_notifier.next_file_handler == NULL) | |
375 | gdb_notifier.next_file_handler = gdb_notifier.first_file_handler; | |
376 | ||
377 | return curr_next; | |
378 | } | |
379 | ||
b5a0ac70 | 380 | /* Remove the file descriptor FD from the list of monitored fd's: |
371d5dec | 381 | i.e. we don't care anymore about events on the FD. */ |
b5a0ac70 | 382 | void |
c2c6d25f | 383 | delete_file_handler (int fd) |
b5a0ac70 SS |
384 | { |
385 | file_handler *file_ptr, *prev_ptr = NULL; | |
58a2c44a EZ |
386 | int i; |
387 | #ifdef HAVE_POLL | |
388 | int j; | |
b5a0ac70 | 389 | struct pollfd *new_poll_fds; |
b5a0ac70 SS |
390 | #endif |
391 | ||
371d5dec | 392 | /* Find the entry for the given file. */ |
b5a0ac70 SS |
393 | |
394 | for (file_ptr = gdb_notifier.first_file_handler; file_ptr != NULL; | |
395 | file_ptr = file_ptr->next_file) | |
396 | { | |
397 | if (file_ptr->fd == fd) | |
398 | break; | |
399 | } | |
400 | ||
401 | if (file_ptr == NULL) | |
402 | return; | |
403 | ||
44f45770 EZ |
404 | if (use_poll) |
405 | { | |
b5a0ac70 | 406 | #ifdef HAVE_POLL |
371d5dec MS |
407 | /* Create a new poll_fds array by copying every fd's information |
408 | but the one we want to get rid of. */ | |
b5a0ac70 | 409 | |
371d5dec MS |
410 | new_poll_fds = (struct pollfd *) |
411 | xmalloc ((gdb_notifier.num_fds - 1) * sizeof (struct pollfd)); | |
b5a0ac70 | 412 | |
44f45770 | 413 | for (i = 0, j = 0; i < gdb_notifier.num_fds; i++) |
b5a0ac70 | 414 | { |
44f45770 EZ |
415 | if ((gdb_notifier.poll_fds + i)->fd != fd) |
416 | { | |
417 | (new_poll_fds + j)->fd = (gdb_notifier.poll_fds + i)->fd; | |
418 | (new_poll_fds + j)->events = (gdb_notifier.poll_fds + i)->events; | |
3e43a32a MS |
419 | (new_poll_fds + j)->revents |
420 | = (gdb_notifier.poll_fds + i)->revents; | |
44f45770 EZ |
421 | j++; |
422 | } | |
b5a0ac70 | 423 | } |
b8c9b27d | 424 | xfree (gdb_notifier.poll_fds); |
44f45770 EZ |
425 | gdb_notifier.poll_fds = new_poll_fds; |
426 | gdb_notifier.num_fds--; | |
427 | #else | |
8e65ff28 | 428 | internal_error (__FILE__, __LINE__, |
e2e0b3e5 | 429 | _("use_poll without HAVE_POLL")); |
44f45770 | 430 | #endif /* HAVE_POLL */ |
b5a0ac70 | 431 | } |
44f45770 EZ |
432 | else |
433 | { | |
434 | if (file_ptr->mask & GDB_READABLE) | |
435 | FD_CLR (fd, &gdb_notifier.check_masks[0]); | |
436 | if (file_ptr->mask & GDB_WRITABLE) | |
437 | FD_CLR (fd, &gdb_notifier.check_masks[1]); | |
438 | if (file_ptr->mask & GDB_EXCEPTION) | |
439 | FD_CLR (fd, &gdb_notifier.check_masks[2]); | |
b5a0ac70 | 440 | |
371d5dec | 441 | /* Find current max fd. */ |
b5a0ac70 | 442 | |
44f45770 | 443 | if ((fd + 1) == gdb_notifier.num_fds) |
b5a0ac70 | 444 | { |
44f45770 EZ |
445 | gdb_notifier.num_fds--; |
446 | for (i = gdb_notifier.num_fds; i; i--) | |
447 | { | |
448 | if (FD_ISSET (i - 1, &gdb_notifier.check_masks[0]) | |
449 | || FD_ISSET (i - 1, &gdb_notifier.check_masks[1]) | |
450 | || FD_ISSET (i - 1, &gdb_notifier.check_masks[2])) | |
451 | break; | |
452 | } | |
453 | gdb_notifier.num_fds = i; | |
b5a0ac70 SS |
454 | } |
455 | } | |
b5a0ac70 | 456 | |
cff3e48b | 457 | /* Deactivate the file descriptor, by clearing its mask, |
371d5dec | 458 | so that it will not fire again. */ |
cff3e48b JM |
459 | |
460 | file_ptr->mask = 0; | |
461 | ||
4e63d0ac PA |
462 | /* If this file handler was going to be the next one to be handled, |
463 | advance to the next's next, if any. */ | |
464 | if (gdb_notifier.next_file_handler == file_ptr) | |
465 | { | |
466 | if (file_ptr->next_file == NULL | |
467 | && file_ptr == gdb_notifier.first_file_handler) | |
468 | gdb_notifier.next_file_handler = NULL; | |
469 | else | |
470 | get_next_file_handler_to_handle_and_advance (); | |
471 | } | |
472 | ||
371d5dec | 473 | /* Get rid of the file handler in the file handler list. */ |
b5a0ac70 SS |
474 | if (file_ptr == gdb_notifier.first_file_handler) |
475 | gdb_notifier.first_file_handler = file_ptr->next_file; | |
476 | else | |
477 | { | |
478 | for (prev_ptr = gdb_notifier.first_file_handler; | |
9e0b60a8 | 479 | prev_ptr->next_file != file_ptr; |
b5a0ac70 SS |
480 | prev_ptr = prev_ptr->next_file) |
481 | ; | |
482 | prev_ptr->next_file = file_ptr->next_file; | |
483 | } | |
b8c9b27d | 484 | xfree (file_ptr); |
b5a0ac70 SS |
485 | } |
486 | ||
487 | /* Handle the given event by calling the procedure associated to the | |
70b66289 PA |
488 | corresponding file handler. */ |
489 | ||
b5a0ac70 | 490 | static void |
70b66289 | 491 | handle_file_event (file_handler *file_ptr, int ready_mask) |
b5a0ac70 | 492 | { |
c2c6d25f JM |
493 | int mask; |
494 | #ifdef HAVE_POLL | |
495 | int error_mask; | |
c2c6d25f | 496 | #endif |
b5a0ac70 | 497 | |
b5a0ac70 | 498 | { |
b5a0ac70 SS |
499 | { |
500 | /* With poll, the ready_mask could have any of three events | |
371d5dec MS |
501 | set to 1: POLLHUP, POLLERR, POLLNVAL. These events |
502 | cannot be used in the requested event mask (events), but | |
503 | they can be returned in the return mask (revents). We | |
504 | need to check for those event too, and add them to the | |
505 | mask which will be passed to the handler. */ | |
b5a0ac70 SS |
506 | |
507 | /* See if the desired events (mask) match the received | |
371d5dec | 508 | events (ready_mask). */ |
b5a0ac70 | 509 | |
44f45770 | 510 | if (use_poll) |
c2c6d25f | 511 | { |
44f45770 | 512 | #ifdef HAVE_POLL |
652c71b4 AS |
513 | /* POLLHUP means EOF, but can be combined with POLLIN to |
514 | signal more data to read. */ | |
44f45770 | 515 | error_mask = POLLHUP | POLLERR | POLLNVAL; |
70b66289 | 516 | mask = ready_mask & (file_ptr->mask | error_mask); |
44f45770 | 517 | |
652c71b4 | 518 | if ((mask & (POLLERR | POLLNVAL)) != 0) |
44f45770 | 519 | { |
371d5dec MS |
520 | /* Work in progress. We may need to tell somebody |
521 | what kind of error we had. */ | |
652c71b4 | 522 | if (mask & POLLERR) |
29f2bf4f | 523 | warning (_("Error detected on fd %d"), file_ptr->fd); |
652c71b4 | 524 | if (mask & POLLNVAL) |
29f2bf4f TT |
525 | warning (_("Invalid or non-`poll'able fd %d"), |
526 | file_ptr->fd); | |
44f45770 EZ |
527 | file_ptr->error = 1; |
528 | } | |
529 | else | |
530 | file_ptr->error = 0; | |
531 | #else | |
8e65ff28 | 532 | internal_error (__FILE__, __LINE__, |
e2e0b3e5 | 533 | _("use_poll without HAVE_POLL")); |
44f45770 | 534 | #endif /* HAVE_POLL */ |
6426a772 JM |
535 | } |
536 | else | |
c2c6d25f | 537 | { |
70b66289 | 538 | if (ready_mask & GDB_EXCEPTION) |
44f45770 | 539 | { |
29f2bf4f TT |
540 | warning (_("Exception condition detected on fd %d"), |
541 | file_ptr->fd); | |
44f45770 EZ |
542 | file_ptr->error = 1; |
543 | } | |
544 | else | |
545 | file_ptr->error = 0; | |
70b66289 | 546 | mask = ready_mask & file_ptr->mask; |
c2c6d25f | 547 | } |
b5a0ac70 | 548 | |
371d5dec | 549 | /* If there was a match, then call the handler. */ |
b5a0ac70 | 550 | if (mask != 0) |
2acceee2 | 551 | (*file_ptr->proc) (file_ptr->error, file_ptr->client_data); |
b5a0ac70 SS |
552 | } |
553 | } | |
554 | } | |
555 | ||
70b66289 PA |
556 | /* Wait for new events on the monitored file descriptors. Run the |
557 | event handler if the first descriptor that is detected by the poll. | |
558 | If BLOCK and if there are no events, this function will block in | |
559 | the call to poll. Return 1 if an event was handled. Return -1 if | |
560 | there are no file descriptors to monitor. Return 1 if an event was | |
561 | handled, otherwise returns 0. */ | |
562 | ||
b5a0ac70 | 563 | static int |
50d01748 | 564 | gdb_wait_for_event (int block) |
b5a0ac70 SS |
565 | { |
566 | file_handler *file_ptr; | |
0f71a2f6 | 567 | int num_found = 0; |
b5a0ac70 | 568 | |
371d5dec | 569 | /* Make sure all output is done before getting another event. */ |
c1cd3163 | 570 | flush_streams (); |
7be570e7 | 571 | |
b5a0ac70 SS |
572 | if (gdb_notifier.num_fds == 0) |
573 | return -1; | |
574 | ||
70b66289 PA |
575 | if (block) |
576 | update_wait_timeout (); | |
577 | ||
44f45770 EZ |
578 | if (use_poll) |
579 | { | |
b5a0ac70 | 580 | #ifdef HAVE_POLL |
50d01748 PA |
581 | int timeout; |
582 | ||
583 | if (block) | |
584 | timeout = gdb_notifier.timeout_valid ? gdb_notifier.poll_timeout : -1; | |
585 | else | |
586 | timeout = 0; | |
587 | ||
588 | num_found = poll (gdb_notifier.poll_fds, | |
589 | (unsigned long) gdb_notifier.num_fds, timeout); | |
44f45770 EZ |
590 | |
591 | /* Don't print anything if we get out of poll because of a | |
50d01748 | 592 | signal. */ |
44f45770 | 593 | if (num_found == -1 && errno != EINTR) |
e2e0b3e5 | 594 | perror_with_name (("poll")); |
44f45770 | 595 | #else |
8e65ff28 | 596 | internal_error (__FILE__, __LINE__, |
e2e0b3e5 | 597 | _("use_poll without HAVE_POLL")); |
44f45770 EZ |
598 | #endif /* HAVE_POLL */ |
599 | } | |
600 | else | |
c2c6d25f | 601 | { |
50d01748 | 602 | struct timeval select_timeout; |
50d01748 | 603 | struct timeval *timeout_p; |
d7f9d729 | 604 | |
50d01748 PA |
605 | if (block) |
606 | timeout_p = gdb_notifier.timeout_valid | |
607 | ? &gdb_notifier.select_timeout : NULL; | |
608 | else | |
609 | { | |
610 | memset (&select_timeout, 0, sizeof (select_timeout)); | |
611 | timeout_p = &select_timeout; | |
612 | } | |
613 | ||
44f45770 EZ |
614 | gdb_notifier.ready_masks[0] = gdb_notifier.check_masks[0]; |
615 | gdb_notifier.ready_masks[1] = gdb_notifier.check_masks[1]; | |
616 | gdb_notifier.ready_masks[2] = gdb_notifier.check_masks[2]; | |
011825f0 MM |
617 | num_found = gdb_select (gdb_notifier.num_fds, |
618 | &gdb_notifier.ready_masks[0], | |
619 | &gdb_notifier.ready_masks[1], | |
620 | &gdb_notifier.ready_masks[2], | |
50d01748 | 621 | timeout_p); |
44f45770 | 622 | |
371d5dec | 623 | /* Clear the masks after an error from select. */ |
44f45770 EZ |
624 | if (num_found == -1) |
625 | { | |
626 | FD_ZERO (&gdb_notifier.ready_masks[0]); | |
627 | FD_ZERO (&gdb_notifier.ready_masks[1]); | |
628 | FD_ZERO (&gdb_notifier.ready_masks[2]); | |
50d01748 PA |
629 | |
630 | /* Dont print anything if we got a signal, let gdb handle | |
631 | it. */ | |
44f45770 | 632 | if (errno != EINTR) |
e2e0b3e5 | 633 | perror_with_name (("select")); |
44f45770 | 634 | } |
c2c6d25f | 635 | } |
b5a0ac70 | 636 | |
4e63d0ac PA |
637 | /* Avoid looking at poll_fds[i]->revents if no event fired. */ |
638 | if (num_found <= 0) | |
639 | return 0; | |
640 | ||
70b66289 PA |
641 | /* Run event handlers. We always run just one handler and go back |
642 | to polling, in case a handler changes the notifier list. Since | |
643 | events for sources we haven't consumed yet wake poll/select | |
644 | immediately, no event is lost. */ | |
b5a0ac70 | 645 | |
4e63d0ac PA |
646 | /* To level the fairness across event descriptors, we handle them in |
647 | a round-robin-like fashion. The number and order of descriptors | |
648 | may change between invocations, but this is good enough. */ | |
44f45770 EZ |
649 | if (use_poll) |
650 | { | |
b5a0ac70 | 651 | #ifdef HAVE_POLL |
4e63d0ac PA |
652 | int i; |
653 | int mask; | |
b5a0ac70 | 654 | |
4e63d0ac PA |
655 | while (1) |
656 | { | |
657 | if (gdb_notifier.next_poll_fds_index >= gdb_notifier.num_fds) | |
658 | gdb_notifier.next_poll_fds_index = 0; | |
659 | i = gdb_notifier.next_poll_fds_index++; | |
44f45770 | 660 | |
4e63d0ac PA |
661 | gdb_assert (i < gdb_notifier.num_fds); |
662 | if ((gdb_notifier.poll_fds + i)->revents) | |
663 | break; | |
664 | } | |
70b66289 | 665 | |
4e63d0ac PA |
666 | for (file_ptr = gdb_notifier.first_file_handler; |
667 | file_ptr != NULL; | |
668 | file_ptr = file_ptr->next_file) | |
669 | { | |
670 | if (file_ptr->fd == (gdb_notifier.poll_fds + i)->fd) | |
671 | break; | |
44f45770 | 672 | } |
4e63d0ac PA |
673 | gdb_assert (file_ptr != NULL); |
674 | ||
675 | mask = (gdb_notifier.poll_fds + i)->revents; | |
676 | handle_file_event (file_ptr, mask); | |
677 | return 1; | |
44f45770 | 678 | #else |
8e65ff28 | 679 | internal_error (__FILE__, __LINE__, |
e2e0b3e5 | 680 | _("use_poll without HAVE_POLL")); |
44f45770 EZ |
681 | #endif /* HAVE_POLL */ |
682 | } | |
683 | else | |
684 | { | |
4e63d0ac PA |
685 | /* See comment about even source fairness above. */ |
686 | int mask = 0; | |
687 | ||
688 | do | |
b5a0ac70 | 689 | { |
4e63d0ac | 690 | file_ptr = get_next_file_handler_to_handle_and_advance (); |
44f45770 EZ |
691 | |
692 | if (FD_ISSET (file_ptr->fd, &gdb_notifier.ready_masks[0])) | |
693 | mask |= GDB_READABLE; | |
694 | if (FD_ISSET (file_ptr->fd, &gdb_notifier.ready_masks[1])) | |
695 | mask |= GDB_WRITABLE; | |
696 | if (FD_ISSET (file_ptr->fd, &gdb_notifier.ready_masks[2])) | |
697 | mask |= GDB_EXCEPTION; | |
b5a0ac70 | 698 | } |
4e63d0ac PA |
699 | while (mask == 0); |
700 | ||
701 | handle_file_event (file_ptr, mask); | |
702 | return 1; | |
b5a0ac70 | 703 | } |
b5a0ac70 SS |
704 | return 0; |
705 | } | |
706 | \f | |
dcb07cfa PA |
707 | /* Create a timer that will expire in MS milliseconds from now. When |
708 | the timer is ready, PROC will be executed. At creation, the timer | |
709 | is added to the timers queue. This queue is kept sorted in order | |
710 | of increasing timers. Return a handle to the timer struct. */ | |
711 | ||
c2c6d25f | 712 | int |
dcb07cfa | 713 | create_timer (int ms, timer_handler_func *proc, |
371d5dec | 714 | gdb_client_data client_data) |
c2c6d25f | 715 | { |
dcb07cfa | 716 | using namespace std::chrono; |
c2c6d25f | 717 | struct gdb_timer *timer_ptr, *timer_index, *prev_timer; |
6426a772 | 718 | |
dcb07cfa | 719 | steady_clock::time_point time_now = steady_clock::now (); |
c2c6d25f | 720 | |
dcb07cfa PA |
721 | timer_ptr = new gdb_timer (); |
722 | timer_ptr->when = time_now + milliseconds (ms); | |
c2c6d25f JM |
723 | timer_ptr->proc = proc; |
724 | timer_ptr->client_data = client_data; | |
6426a772 | 725 | timer_list.num_timers++; |
c2c6d25f JM |
726 | timer_ptr->timer_id = timer_list.num_timers; |
727 | ||
728 | /* Now add the timer to the timer queue, making sure it is sorted in | |
371d5dec | 729 | increasing order of expiration. */ |
c2c6d25f | 730 | |
6426a772 JM |
731 | for (timer_index = timer_list.first_timer; |
732 | timer_index != NULL; | |
c2c6d25f JM |
733 | timer_index = timer_index->next) |
734 | { | |
dcb07cfa | 735 | if (timer_index->when > timer_ptr->when) |
c2c6d25f JM |
736 | break; |
737 | } | |
6426a772 | 738 | |
c2c6d25f JM |
739 | if (timer_index == timer_list.first_timer) |
740 | { | |
741 | timer_ptr->next = timer_list.first_timer; | |
742 | timer_list.first_timer = timer_ptr; | |
743 | ||
744 | } | |
745 | else | |
746 | { | |
6426a772 JM |
747 | for (prev_timer = timer_list.first_timer; |
748 | prev_timer->next != timer_index; | |
c2c6d25f JM |
749 | prev_timer = prev_timer->next) |
750 | ; | |
6426a772 | 751 | |
c2c6d25f JM |
752 | prev_timer->next = timer_ptr; |
753 | timer_ptr->next = timer_index; | |
754 | } | |
755 | ||
756 | gdb_notifier.timeout_valid = 0; | |
757 | return timer_ptr->timer_id; | |
758 | } | |
759 | ||
760 | /* There is a chance that the creator of the timer wants to get rid of | |
371d5dec | 761 | it before it expires. */ |
c2c6d25f JM |
762 | void |
763 | delete_timer (int id) | |
764 | { | |
765 | struct gdb_timer *timer_ptr, *prev_timer = NULL; | |
766 | ||
371d5dec | 767 | /* Find the entry for the given timer. */ |
c2c6d25f JM |
768 | |
769 | for (timer_ptr = timer_list.first_timer; timer_ptr != NULL; | |
770 | timer_ptr = timer_ptr->next) | |
771 | { | |
772 | if (timer_ptr->timer_id == id) | |
773 | break; | |
774 | } | |
775 | ||
776 | if (timer_ptr == NULL) | |
777 | return; | |
371d5dec | 778 | /* Get rid of the timer in the timer list. */ |
c2c6d25f JM |
779 | if (timer_ptr == timer_list.first_timer) |
780 | timer_list.first_timer = timer_ptr->next; | |
781 | else | |
782 | { | |
783 | for (prev_timer = timer_list.first_timer; | |
784 | prev_timer->next != timer_ptr; | |
785 | prev_timer = prev_timer->next) | |
786 | ; | |
787 | prev_timer->next = timer_ptr->next; | |
788 | } | |
dcb07cfa | 789 | delete timer_ptr; |
c2c6d25f JM |
790 | |
791 | gdb_notifier.timeout_valid = 0; | |
792 | } | |
793 | ||
dcb07cfa PA |
794 | /* Convert a std::chrono duration to a struct timeval. */ |
795 | ||
796 | template<typename Duration> | |
797 | static struct timeval | |
798 | duration_cast_timeval (const Duration &d) | |
799 | { | |
800 | using namespace std::chrono; | |
801 | seconds sec = duration_cast<seconds> (d); | |
802 | microseconds msec = duration_cast<microseconds> (d - sec); | |
803 | ||
804 | struct timeval tv; | |
805 | tv.tv_sec = sec.count (); | |
806 | tv.tv_usec = msec.count (); | |
807 | return tv; | |
808 | } | |
809 | ||
70b66289 PA |
810 | /* Update the timeout for the select() or poll(). Returns true if the |
811 | timer has already expired, false otherwise. */ | |
6426a772 | 812 | |
70b66289 PA |
813 | static int |
814 | update_wait_timeout (void) | |
c2c6d25f | 815 | { |
2acceee2 | 816 | if (timer_list.first_timer != NULL) |
c2c6d25f | 817 | { |
dcb07cfa PA |
818 | using namespace std::chrono; |
819 | steady_clock::time_point time_now = steady_clock::now (); | |
820 | struct timeval timeout; | |
6426a772 | 821 | |
dcb07cfa | 822 | if (timer_list.first_timer->when < time_now) |
c2c6d25f | 823 | { |
70b66289 | 824 | /* It expired already. */ |
dcb07cfa PA |
825 | timeout.tv_sec = 0; |
826 | timeout.tv_usec = 0; | |
827 | } | |
828 | else | |
829 | { | |
830 | steady_clock::duration d = timer_list.first_timer->when - time_now; | |
831 | timeout = duration_cast_timeval (d); | |
c2c6d25f JM |
832 | } |
833 | ||
70b66289 | 834 | /* Update the timeout for select/ poll. */ |
44f45770 EZ |
835 | if (use_poll) |
836 | { | |
c2c6d25f | 837 | #ifdef HAVE_POLL |
dcb07cfa | 838 | gdb_notifier.poll_timeout = timeout.tv_sec * 1000; |
c2c6d25f | 839 | #else |
8e65ff28 | 840 | internal_error (__FILE__, __LINE__, |
e2e0b3e5 | 841 | _("use_poll without HAVE_POLL")); |
44f45770 EZ |
842 | #endif /* HAVE_POLL */ |
843 | } | |
844 | else | |
845 | { | |
dcb07cfa PA |
846 | gdb_notifier.select_timeout.tv_sec = timeout.tv_sec; |
847 | gdb_notifier.select_timeout.tv_usec = timeout.tv_usec; | |
44f45770 | 848 | } |
c2c6d25f | 849 | gdb_notifier.timeout_valid = 1; |
70b66289 | 850 | |
dcb07cfa | 851 | if (timer_list.first_timer->when < time_now) |
70b66289 | 852 | return 1; |
c2c6d25f | 853 | } |
6426a772 | 854 | else |
c2c6d25f | 855 | gdb_notifier.timeout_valid = 0; |
70b66289 PA |
856 | |
857 | return 0; | |
858 | } | |
859 | ||
860 | /* Check whether a timer in the timers queue is ready. If a timer is | |
861 | ready, call its handler and return. Update the timeout for the | |
862 | select() or poll() as well. Return 1 if an event was handled, | |
863 | otherwise returns 0.*/ | |
864 | ||
865 | static int | |
866 | poll_timers (void) | |
867 | { | |
868 | if (update_wait_timeout ()) | |
869 | { | |
870 | struct gdb_timer *timer_ptr = timer_list.first_timer; | |
871 | timer_handler_func *proc = timer_ptr->proc; | |
872 | gdb_client_data client_data = timer_ptr->client_data; | |
873 | ||
874 | /* Get rid of the timer from the beginning of the list. */ | |
875 | timer_list.first_timer = timer_ptr->next; | |
876 | ||
877 | /* Delete the timer before calling the callback, not after, in | |
878 | case the callback itself decides to try deleting the timer | |
879 | too. */ | |
0e05cf3a | 880 | delete timer_ptr; |
70b66289 PA |
881 | |
882 | /* Call the procedure associated with that timer. */ | |
883 | (proc) (client_data); | |
884 | ||
885 | return 1; | |
886 | } | |
887 | ||
888 | return 0; | |
c2c6d25f | 889 | } |