1 /* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
2 /* dbus-mainloop.c Main loop utility
3 *
4 * Copyright © 2003, 2004 Red Hat, Inc.
5 * Copyright © 2011 Nokia Corporation
6 *
7 * Licensed under the Academic Free License version 2.1
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
13 *
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
22 *
23 */
24
25 #include <config.h>
26 #include "dbus-mainloop.h"
27
28 #ifndef DOXYGEN_SHOULD_SKIP_THIS
29
30 #include <dbus/dbus-hash.h>
31 #include <dbus/dbus-list.h>
32 #include <dbus/dbus-socket-set.h>
33 #include <dbus/dbus-timeout.h>
34 #include <dbus/dbus-watch.h>
35
36 #define MAINLOOP_SPEW 0
37
38 struct DBusLoop
39 {
40 int refcount;
41 /** DBusPollable => dbus_malloc'd DBusList ** of references to DBusWatch */
42 DBusHashTable *watches;
43 DBusSocketSet *socket_set;
44 DBusList *timeouts;
45 int callback_list_serial;
46 int watch_count;
47 int timeout_count;
48 int depth; /**< number of recursive runs */
49 DBusList *need_dispatch;
50 /** TRUE if we will skip a watch next time because it was OOM; becomes
51 * FALSE between polling, and dealing with the results of the poll */
52 unsigned oom_watch_pending : 1;
53 };
54
55 typedef struct
56 {
57 DBusTimeout *timeout;
58 long last_tv_sec;
59 long last_tv_usec;
60 } TimeoutCallback;
61
62 #define TIMEOUT_CALLBACK(callback) ((TimeoutCallback*)callback)
63
64 static TimeoutCallback*
timeout_callback_new(DBusTimeout * timeout)65 timeout_callback_new (DBusTimeout *timeout)
66 {
67 TimeoutCallback *cb;
68
69 cb = dbus_new (TimeoutCallback, 1);
70 if (cb == NULL)
71 return NULL;
72
73 cb->timeout = timeout;
74 _dbus_get_monotonic_time (&cb->last_tv_sec,
75 &cb->last_tv_usec);
76 return cb;
77 }
78
79 static void
timeout_callback_free(TimeoutCallback * cb)80 timeout_callback_free (TimeoutCallback *cb)
81 {
82 dbus_free (cb);
83 }
84
85 static void
free_watch_table_entry(void * data)86 free_watch_table_entry (void *data)
87 {
88 DBusList **watches = data;
89 DBusWatch *watch;
90
91 /* DBusHashTable sometimes calls free_function(NULL) even if you never
92 * have NULL as a value */
93 if (watches == NULL)
94 return;
95
96 for (watch = _dbus_list_pop_first (watches);
97 watch != NULL;
98 watch = _dbus_list_pop_first (watches))
99 {
100 _dbus_watch_unref (watch);
101 }
102
103 _dbus_assert (*watches == NULL);
104 dbus_free (watches);
105 }
106
107 DBusLoop*
_dbus_loop_new(void)108 _dbus_loop_new (void)
109 {
110 DBusLoop *loop;
111
112 loop = dbus_new0 (DBusLoop, 1);
113 if (loop == NULL)
114 return NULL;
115
116 loop->watches = _dbus_hash_table_new (DBUS_HASH_POLLABLE, NULL,
117 free_watch_table_entry);
118
119 loop->socket_set = _dbus_socket_set_new (0);
120
121 if (loop->watches == NULL || loop->socket_set == NULL)
122 {
123 if (loop->watches != NULL)
124 _dbus_hash_table_unref (loop->watches);
125
126 if (loop->socket_set != NULL)
127 _dbus_socket_set_free (loop->socket_set);
128
129 dbus_free (loop);
130 return NULL;
131 }
132
133 loop->refcount = 1;
134
135 return loop;
136 }
137
138 DBusLoop *
_dbus_loop_ref(DBusLoop * loop)139 _dbus_loop_ref (DBusLoop *loop)
140 {
141 _dbus_assert (loop != NULL);
142 _dbus_assert (loop->refcount > 0);
143
144 loop->refcount += 1;
145
146 return loop;
147 }
148
149 void
_dbus_loop_unref(DBusLoop * loop)150 _dbus_loop_unref (DBusLoop *loop)
151 {
152 _dbus_assert (loop != NULL);
153 _dbus_assert (loop->refcount > 0);
154
155 loop->refcount -= 1;
156 if (loop->refcount == 0)
157 {
158 while (loop->need_dispatch)
159 {
160 DBusConnection *connection = _dbus_list_pop_first (&loop->need_dispatch);
161
162 dbus_connection_unref (connection);
163 }
164
165 _dbus_hash_table_unref (loop->watches);
166 _dbus_socket_set_free (loop->socket_set);
167 dbus_free (loop);
168 }
169 }
170
171 static DBusList **
ensure_watch_table_entry(DBusLoop * loop,DBusPollable fd)172 ensure_watch_table_entry (DBusLoop *loop,
173 DBusPollable fd)
174 {
175 DBusList **watches;
176
177 watches = _dbus_hash_table_lookup_pollable (loop->watches, fd);
178
179 if (watches == NULL)
180 {
181 watches = dbus_new0 (DBusList *, 1);
182
183 if (watches == NULL)
184 return watches;
185
186 if (!_dbus_hash_table_insert_pollable (loop->watches, fd, watches))
187 {
188 dbus_free (watches);
189 watches = NULL;
190 }
191 }
192
193 return watches;
194 }
195
196 static void
cull_watches_for_invalid_fd(DBusLoop * loop,DBusPollable fd)197 cull_watches_for_invalid_fd (DBusLoop *loop,
198 DBusPollable fd)
199 {
200 DBusList *link;
201 DBusList **watches;
202
203 _dbus_warn ("invalid request, socket fd %" DBUS_POLLABLE_FORMAT " not open",
204 _dbus_pollable_printable (fd));
205 watches = _dbus_hash_table_lookup_pollable (loop->watches, fd);
206
207 if (watches != NULL)
208 {
209 for (link = _dbus_list_get_first_link (watches);
210 link != NULL;
211 link = _dbus_list_get_next_link (watches, link))
212 _dbus_watch_invalidate (link->data);
213 }
214
215 _dbus_hash_table_remove_pollable (loop->watches, fd);
216 }
217
218 static dbus_bool_t
gc_watch_table_entry(DBusLoop * loop,DBusList ** watches,DBusPollable fd)219 gc_watch_table_entry (DBusLoop *loop,
220 DBusList **watches,
221 DBusPollable fd)
222 {
223 /* If watches is already NULL we have nothing to do */
224 if (watches == NULL)
225 return FALSE;
226
227 /* We can't GC hash table entries if they're non-empty lists */
228 if (*watches != NULL)
229 return FALSE;
230
231 _dbus_hash_table_remove_pollable (loop->watches, fd);
232 return TRUE;
233 }
234
235 static void
refresh_watches_for_fd(DBusLoop * loop,DBusList ** watches,DBusPollable fd)236 refresh_watches_for_fd (DBusLoop *loop,
237 DBusList **watches,
238 DBusPollable fd)
239 {
240 DBusList *link;
241 unsigned int flags = 0;
242 dbus_bool_t interested = FALSE;
243
244 _dbus_assert (_dbus_pollable_is_valid (fd));
245
246 if (watches == NULL)
247 watches = _dbus_hash_table_lookup_pollable (loop->watches, fd);
248
249 /* we allocated this in the first _dbus_loop_add_watch for the fd, and keep
250 * it until there are none left */
251 _dbus_assert (watches != NULL);
252
253 for (link = _dbus_list_get_first_link (watches);
254 link != NULL;
255 link = _dbus_list_get_next_link (watches, link))
256 {
257 if (dbus_watch_get_enabled (link->data) &&
258 !_dbus_watch_get_oom_last_time (link->data))
259 {
260 flags |= dbus_watch_get_flags (link->data);
261 interested = TRUE;
262 }
263 }
264
265 if (interested)
266 _dbus_socket_set_enable (loop->socket_set, fd, flags);
267 else
268 _dbus_socket_set_disable (loop->socket_set, fd);
269 }
270
271 dbus_bool_t
_dbus_loop_add_watch(DBusLoop * loop,DBusWatch * watch)272 _dbus_loop_add_watch (DBusLoop *loop,
273 DBusWatch *watch)
274 {
275 DBusPollable fd;
276 DBusList **watches;
277
278 fd = _dbus_watch_get_pollable (watch);
279 _dbus_assert (_dbus_pollable_is_valid (fd));
280
281 watches = ensure_watch_table_entry (loop, fd);
282
283 if (watches == NULL)
284 return FALSE;
285
286 if (!_dbus_list_append (watches, _dbus_watch_ref (watch)))
287 {
288 _dbus_watch_unref (watch);
289 gc_watch_table_entry (loop, watches, fd);
290
291 return FALSE;
292 }
293
294 if (_dbus_list_length_is_one (watches))
295 {
296 if (!_dbus_socket_set_add (loop->socket_set, fd,
297 dbus_watch_get_flags (watch),
298 dbus_watch_get_enabled (watch)))
299 {
300 _dbus_hash_table_remove_pollable (loop->watches, fd);
301 return FALSE;
302 }
303 }
304 else
305 {
306 /* we're modifying, not adding, which can't fail with OOM */
307 refresh_watches_for_fd (loop, watches, fd);
308 }
309
310 loop->callback_list_serial += 1;
311 loop->watch_count += 1;
312 return TRUE;
313 }
314
315 void
_dbus_loop_toggle_watch(DBusLoop * loop,DBusWatch * watch)316 _dbus_loop_toggle_watch (DBusLoop *loop,
317 DBusWatch *watch)
318 {
319 refresh_watches_for_fd (loop, NULL, _dbus_watch_get_pollable (watch));
320 }
321
322 void
_dbus_loop_remove_watch(DBusLoop * loop,DBusWatch * watch)323 _dbus_loop_remove_watch (DBusLoop *loop,
324 DBusWatch *watch)
325 {
326 DBusList **watches;
327 DBusList *link;
328 DBusPollable fd;
329
330 /* This relies on people removing watches before they invalidate them,
331 * which has been safe since fd.o #33336 was fixed. Assert about it
332 * so we don't regress. */
333 fd = _dbus_watch_get_pollable (watch);
334 _dbus_assert (_dbus_pollable_is_valid (fd));
335
336 watches = _dbus_hash_table_lookup_pollable (loop->watches, fd);
337
338 if (watches != NULL)
339 {
340 link = _dbus_list_get_first_link (watches);
341 while (link != NULL)
342 {
343 DBusList *next = _dbus_list_get_next_link (watches, link);
344 DBusWatch *this = link->data;
345
346 if (this == watch)
347 {
348 _dbus_list_remove_link (watches, link);
349 loop->callback_list_serial += 1;
350 loop->watch_count -= 1;
351 _dbus_watch_unref (this);
352
353 /* if that was the last watch for that fd, drop the hash table
354 * entry, and stop reserving space for it in the socket set */
355 if (gc_watch_table_entry (loop, watches, fd))
356 {
357 _dbus_socket_set_remove (loop->socket_set, fd);
358 }
359
360 return;
361 }
362
363 link = next;
364 }
365 }
366
367 _dbus_warn ("could not find watch %p to remove", watch);
368 }
369
370 dbus_bool_t
_dbus_loop_add_timeout(DBusLoop * loop,DBusTimeout * timeout)371 _dbus_loop_add_timeout (DBusLoop *loop,
372 DBusTimeout *timeout)
373 {
374 TimeoutCallback *tcb;
375
376 tcb = timeout_callback_new (timeout);
377 if (tcb == NULL)
378 return FALSE;
379
380 if (_dbus_list_append (&loop->timeouts, tcb))
381 {
382 loop->callback_list_serial += 1;
383 loop->timeout_count += 1;
384 }
385 else
386 {
387 timeout_callback_free (tcb);
388 return FALSE;
389 }
390
391 return TRUE;
392 }
393
394 void
_dbus_loop_remove_timeout(DBusLoop * loop,DBusTimeout * timeout)395 _dbus_loop_remove_timeout (DBusLoop *loop,
396 DBusTimeout *timeout)
397 {
398 DBusList *link;
399
400 link = _dbus_list_get_first_link (&loop->timeouts);
401 while (link != NULL)
402 {
403 DBusList *next = _dbus_list_get_next_link (&loop->timeouts, link);
404 TimeoutCallback *this = link->data;
405
406 if (this->timeout == timeout)
407 {
408 _dbus_list_remove_link (&loop->timeouts, link);
409 loop->callback_list_serial += 1;
410 loop->timeout_count -= 1;
411 timeout_callback_free (this);
412
413 return;
414 }
415
416 link = next;
417 }
418
419 _dbus_warn ("could not find timeout %p to remove", timeout);
420 }
421
422 /* Convolutions from GLib, there really must be a better way
423 * to do this.
424 */
425 static dbus_bool_t
check_timeout(long tv_sec,long tv_usec,TimeoutCallback * tcb,int * timeout)426 check_timeout (long tv_sec,
427 long tv_usec,
428 TimeoutCallback *tcb,
429 int *timeout)
430 {
431 long sec_remaining;
432 long msec_remaining;
433 long expiration_tv_sec;
434 long expiration_tv_usec;
435 long interval_seconds;
436 long interval_milliseconds;
437 int interval;
438
439 /* I'm pretty sure this function could suck (a lot) less */
440
441 interval = dbus_timeout_get_interval (tcb->timeout);
442
443 interval_seconds = interval / 1000L;
444 interval_milliseconds = interval % 1000L;
445
446 expiration_tv_sec = tcb->last_tv_sec + interval_seconds;
447 expiration_tv_usec = tcb->last_tv_usec + interval_milliseconds * 1000;
448 if (expiration_tv_usec >= 1000000)
449 {
450 expiration_tv_usec -= 1000000;
451 expiration_tv_sec += 1;
452 }
453
454 sec_remaining = expiration_tv_sec - tv_sec;
455 msec_remaining = (expiration_tv_usec - tv_usec) / 1000L;
456
457 #if MAINLOOP_SPEW
458 _dbus_verbose ("Interval is %ld seconds %ld msecs\n",
459 interval_seconds,
460 interval_milliseconds);
461 _dbus_verbose ("Now is %lu seconds %lu usecs\n",
462 tv_sec, tv_usec);
463 _dbus_verbose ("Last is %lu seconds %lu usecs\n",
464 tcb->last_tv_sec, tcb->last_tv_usec);
465 _dbus_verbose ("Exp is %lu seconds %lu usecs\n",
466 expiration_tv_sec, expiration_tv_usec);
467 _dbus_verbose ("Pre-correction, sec_remaining %ld msec_remaining %ld\n",
468 sec_remaining, msec_remaining);
469 #endif
470
471 /* We do the following in a rather convoluted fashion to deal with
472 * the fact that we don't have an integral type big enough to hold
473 * the difference of two timevals in milliseconds.
474 */
475 if (sec_remaining < 0 || (sec_remaining == 0 && msec_remaining < 0))
476 {
477 *timeout = 0;
478 }
479 else
480 {
481 if (msec_remaining < 0)
482 {
483 msec_remaining += 1000;
484 sec_remaining -= 1;
485 }
486
487 if (sec_remaining > (_DBUS_INT_MAX / 1000) ||
488 msec_remaining > _DBUS_INT_MAX)
489 *timeout = _DBUS_INT_MAX;
490 else
491 *timeout = sec_remaining * 1000 + msec_remaining;
492 }
493
494 if (*timeout > interval)
495 {
496 /* This indicates that the system clock probably moved backward */
497 _dbus_verbose ("System clock set backward! Resetting timeout.\n");
498
499 tcb->last_tv_sec = tv_sec;
500 tcb->last_tv_usec = tv_usec;
501
502 *timeout = interval;
503 }
504
505 #if MAINLOOP_SPEW
506 _dbus_verbose (" timeout expires in %d milliseconds\n", *timeout);
507 #endif
508
509 return *timeout == 0;
510 }
511
512 dbus_bool_t
_dbus_loop_dispatch(DBusLoop * loop)513 _dbus_loop_dispatch (DBusLoop *loop)
514 {
515
516 #if MAINLOOP_SPEW
517 _dbus_verbose (" %d connections to dispatch\n", _dbus_list_get_length (&loop->need_dispatch));
518 #endif
519
520 if (loop->need_dispatch == NULL)
521 return FALSE;
522
523 next:
524 while (loop->need_dispatch != NULL)
525 {
526 DBusConnection *connection = _dbus_list_pop_first (&loop->need_dispatch);
527
528 while (TRUE)
529 {
530 DBusDispatchStatus status;
531
532 status = dbus_connection_dispatch (connection);
533
534 if (status == DBUS_DISPATCH_COMPLETE)
535 {
536 dbus_connection_unref (connection);
537 goto next;
538 }
539 else
540 {
541 if (status == DBUS_DISPATCH_NEED_MEMORY)
542 _dbus_wait_for_memory ();
543 }
544 }
545 }
546
547 return TRUE;
548 }
549
550 dbus_bool_t
_dbus_loop_queue_dispatch(DBusLoop * loop,DBusConnection * connection)551 _dbus_loop_queue_dispatch (DBusLoop *loop,
552 DBusConnection *connection)
553 {
554 if (_dbus_list_append (&loop->need_dispatch, connection))
555 {
556 dbus_connection_ref (connection);
557 return TRUE;
558 }
559 else
560 return FALSE;
561 }
562
563 /* Returns TRUE if we invoked any timeouts or have ready file
564 * descriptors, which is just used in test code as a debug hack
565 */
566
567 dbus_bool_t
_dbus_loop_iterate(DBusLoop * loop,dbus_bool_t block)568 _dbus_loop_iterate (DBusLoop *loop,
569 dbus_bool_t block)
570 {
571 #define N_STACK_DESCRIPTORS 64
572 dbus_bool_t retval;
573 DBusSocketEvent ready_fds[N_STACK_DESCRIPTORS];
574 int i;
575 DBusList *link;
576 int n_ready;
577 int initial_serial;
578 long timeout;
579 int orig_depth;
580
581 retval = FALSE;
582
583 orig_depth = loop->depth;
584
585 #if MAINLOOP_SPEW
586 _dbus_verbose ("Iteration block=%d depth=%d timeout_count=%d watch_count=%d\n",
587 block, loop->depth, loop->timeout_count, loop->watch_count);
588 #endif
589
590 if (_dbus_hash_table_get_n_entries (loop->watches) == 0 &&
591 loop->timeouts == NULL)
592 goto next_iteration;
593
594 timeout = -1;
595 if (loop->timeout_count > 0)
596 {
597 long tv_sec;
598 long tv_usec;
599
600 _dbus_get_monotonic_time (&tv_sec, &tv_usec);
601
602 link = _dbus_list_get_first_link (&loop->timeouts);
603 while (link != NULL)
604 {
605 DBusList *next = _dbus_list_get_next_link (&loop->timeouts, link);
606 TimeoutCallback *tcb = link->data;
607
608 if (dbus_timeout_get_enabled (tcb->timeout))
609 {
610 int msecs_remaining;
611
612 if (_dbus_timeout_needs_restart (tcb->timeout))
613 {
614 tcb->last_tv_sec = tv_sec;
615 tcb->last_tv_usec = tv_usec;
616 _dbus_timeout_restarted (tcb->timeout);
617 }
618
619 check_timeout (tv_sec, tv_usec, tcb, &msecs_remaining);
620
621 if (timeout < 0)
622 timeout = msecs_remaining;
623 else
624 timeout = MIN (msecs_remaining, timeout);
625
626 #if MAINLOOP_SPEW
627 _dbus_verbose (" timeout added, %d remaining, aggregate timeout %ld\n",
628 msecs_remaining, timeout);
629 #endif
630
631 _dbus_assert (timeout >= 0);
632 }
633 #if MAINLOOP_SPEW
634 else
635 {
636 _dbus_verbose (" skipping disabled timeout\n");
637 }
638 #endif
639
640 link = next;
641 }
642 }
643
644 /* Never block if we have stuff to dispatch */
645 if (!block || loop->need_dispatch != NULL)
646 {
647 timeout = 0;
648 #if MAINLOOP_SPEW
649 _dbus_verbose (" timeout is 0 as we aren't blocking\n");
650 #endif
651 }
652
653 /* if a watch was OOM last time, don't wait longer than the OOM
654 * wait to re-enable it
655 */
656 if (loop->oom_watch_pending)
657 timeout = MIN (timeout, _dbus_get_oom_wait ());
658
659 #if MAINLOOP_SPEW
660 _dbus_verbose (" polling on %d descriptors timeout %ld\n", _DBUS_N_ELEMENTS (ready_fds), timeout);
661 #endif
662
663 n_ready = _dbus_socket_set_poll (loop->socket_set, ready_fds,
664 _DBUS_N_ELEMENTS (ready_fds), timeout);
665
666 /* re-enable any watches we skipped this time */
667 if (loop->oom_watch_pending)
668 {
669 DBusHashIter hash_iter;
670
671 loop->oom_watch_pending = FALSE;
672
673 _dbus_hash_iter_init (loop->watches, &hash_iter);
674
675 while (_dbus_hash_iter_next (&hash_iter))
676 {
677 DBusList **watches;
678 DBusPollable fd;
679 dbus_bool_t changed;
680
681 changed = FALSE;
682 fd = _dbus_hash_iter_get_pollable_key (&hash_iter);
683 watches = _dbus_hash_iter_get_value (&hash_iter);
684
685 for (link = _dbus_list_get_first_link (watches);
686 link != NULL;
687 link = _dbus_list_get_next_link (watches, link))
688 {
689 DBusWatch *watch = link->data;
690
691 if (_dbus_watch_get_oom_last_time (watch))
692 {
693 _dbus_watch_set_oom_last_time (watch, FALSE);
694 changed = TRUE;
695 }
696 }
697
698 if (changed)
699 refresh_watches_for_fd (loop, watches, fd);
700 }
701
702 retval = TRUE; /* return TRUE here to keep the loop going,
703 * since we don't know the watch was inactive */
704 }
705
706 initial_serial = loop->callback_list_serial;
707
708 if (loop->timeout_count > 0)
709 {
710 long tv_sec;
711 long tv_usec;
712
713 _dbus_get_monotonic_time (&tv_sec, &tv_usec);
714
715 /* It'd be nice to avoid this O(n) thingy here */
716 link = _dbus_list_get_first_link (&loop->timeouts);
717 while (link != NULL)
718 {
719 DBusList *next = _dbus_list_get_next_link (&loop->timeouts, link);
720 TimeoutCallback *tcb = link->data;
721
722 if (initial_serial != loop->callback_list_serial)
723 goto next_iteration;
724
725 if (loop->depth != orig_depth)
726 goto next_iteration;
727
728 if (dbus_timeout_get_enabled (tcb->timeout))
729 {
730 int msecs_remaining;
731
732 if (check_timeout (tv_sec, tv_usec,
733 tcb, &msecs_remaining))
734 {
735 /* Save last callback time and fire this timeout */
736 tcb->last_tv_sec = tv_sec;
737 tcb->last_tv_usec = tv_usec;
738
739 #if MAINLOOP_SPEW
740 _dbus_verbose (" invoking timeout\n");
741 #endif
742
743 /* can theoretically return FALSE on OOM, but we just
744 * let it fire again later - in practice that's what
745 * every wrapper callback in dbus-daemon used to do */
746 dbus_timeout_handle (tcb->timeout);
747
748 retval = TRUE;
749 }
750 else
751 {
752 #if MAINLOOP_SPEW
753 _dbus_verbose (" timeout has not expired\n");
754 #endif
755 }
756 }
757 #if MAINLOOP_SPEW
758 else
759 {
760 _dbus_verbose (" skipping invocation of disabled timeout\n");
761 }
762 #endif
763
764 link = next;
765 }
766 }
767
768 if (n_ready > 0)
769 {
770 for (i = 0; i < n_ready; i++)
771 {
772 DBusList **watches;
773 DBusList *next;
774 unsigned int condition;
775 dbus_bool_t any_oom;
776
777 /* FIXME I think this "restart if we change the watches"
778 * approach could result in starving watches
779 * toward the end of the list.
780 */
781 if (initial_serial != loop->callback_list_serial)
782 goto next_iteration;
783
784 if (loop->depth != orig_depth)
785 goto next_iteration;
786
787 _dbus_assert (ready_fds[i].flags != 0);
788
789 if (_DBUS_UNLIKELY (ready_fds[i].flags & _DBUS_WATCH_NVAL))
790 {
791 cull_watches_for_invalid_fd (loop, ready_fds[i].fd);
792 goto next_iteration;
793 }
794
795 condition = ready_fds[i].flags;
796 _dbus_assert ((condition & _DBUS_WATCH_NVAL) == 0);
797
798 /* condition may still be 0 if we got some
799 * weird POLLFOO thing like POLLWRBAND
800 */
801 if (condition == 0)
802 continue;
803
804 watches = _dbus_hash_table_lookup_pollable (loop->watches,
805 ready_fds[i].fd);
806
807 if (watches == NULL)
808 continue;
809
810 any_oom = FALSE;
811
812 for (link = _dbus_list_get_first_link (watches);
813 link != NULL;
814 link = next)
815 {
816 DBusWatch *watch = link->data;
817
818 next = _dbus_list_get_next_link (watches, link);
819
820 if (dbus_watch_get_enabled (watch))
821 {
822 dbus_bool_t oom;
823
824 oom = !dbus_watch_handle (watch, condition);
825
826 if (oom)
827 {
828 _dbus_watch_set_oom_last_time (watch, TRUE);
829 loop->oom_watch_pending = TRUE;
830 any_oom = TRUE;
831 }
832
833 #if MAINLOOP_SPEW
834 _dbus_verbose (" Invoked watch, oom = %d\n", oom);
835 #endif
836 retval = TRUE;
837
838 /* We re-check this every time, in case the callback
839 * added/removed watches, which might make our position in
840 * the linked list invalid. See the FIXME above. */
841 if (initial_serial != loop->callback_list_serial ||
842 loop->depth != orig_depth)
843 {
844 if (any_oom)
845 refresh_watches_for_fd (loop, NULL, ready_fds[i].fd);
846
847 goto next_iteration;
848 }
849 }
850 }
851
852 if (any_oom)
853 refresh_watches_for_fd (loop, watches, ready_fds[i].fd);
854 }
855 }
856
857 next_iteration:
858 #if MAINLOOP_SPEW
859 _dbus_verbose (" moving to next iteration\n");
860 #endif
861
862 if (_dbus_loop_dispatch (loop))
863 retval = TRUE;
864
865 #if MAINLOOP_SPEW
866 _dbus_verbose ("Returning %d\n", retval);
867 #endif
868
869 return retval;
870 }
871
872 void
_dbus_loop_run(DBusLoop * loop)873 _dbus_loop_run (DBusLoop *loop)
874 {
875 int our_exit_depth;
876
877 _dbus_assert (loop->depth >= 0);
878
879 _dbus_loop_ref (loop);
880
881 our_exit_depth = loop->depth;
882 loop->depth += 1;
883
884 _dbus_verbose ("Running main loop, depth %d -> %d\n",
885 loop->depth - 1, loop->depth);
886
887 while (loop->depth != our_exit_depth)
888 _dbus_loop_iterate (loop, TRUE);
889
890 _dbus_loop_unref (loop);
891 }
892
893 void
_dbus_loop_quit(DBusLoop * loop)894 _dbus_loop_quit (DBusLoop *loop)
895 {
896 _dbus_assert (loop->depth > 0);
897
898 loop->depth -= 1;
899
900 _dbus_verbose ("Quit main loop, depth %d -> %d\n",
901 loop->depth + 1, loop->depth);
902 }
903
904 int
_dbus_get_oom_wait(void)905 _dbus_get_oom_wait (void)
906 {
907 #ifdef DBUS_ENABLE_EMBEDDED_TESTS
908 /* make tests go fast */
909 return 0;
910 #else
911 return 500;
912 #endif
913 }
914
915 void
_dbus_wait_for_memory(void)916 _dbus_wait_for_memory (void)
917 {
918 _dbus_verbose ("Waiting for more memory\n");
919 _dbus_sleep_milliseconds (_dbus_get_oom_wait ());
920 }
921
922 #endif /* !DOXYGEN_SHOULD_SKIP_THIS */
923