D-Bus  1.16.2
dbus-mainloop.c
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  * SPDX-License-Identifier: AFL-2.1 OR GPL-2.0-or-later
8  *
9  * Licensed under the Academic Free License version 2.1
10  *
11  * This program is free software; you can redistribute it and/or modify
12  * it under the terms of the GNU General Public License as published by
13  * the Free Software Foundation; either version 2 of the License, or
14  * (at your option) any later version.
15  *
16  * This program is distributed in the hope that it will be useful,
17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19  * GNU General Public License for more details.
20  *
21  * You should have received a copy of the GNU General Public License
22  * along with this program; if not, write to the Free Software
23  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
24  *
25  */
26 
27 #include <config.h>
28 #include "dbus-mainloop.h"
29 
30 #ifndef DOXYGEN_SHOULD_SKIP_THIS
31 
32 #include <dbus/dbus-hash.h>
33 #include <dbus/dbus-list.h>
34 #include <dbus/dbus-pollable-set.h>
35 #include <dbus/dbus-timeout.h>
36 #include <dbus/dbus-watch.h>
37 
38 #define MAINLOOP_SPEW 0
39 
40 struct DBusLoop
41 {
42  int refcount;
44  DBusHashTable *watches;
45  DBusPollableSet *pollable_set;
46  DBusList *timeouts;
47  int callback_list_serial;
48  int watch_count;
49  int timeout_count;
50  int depth;
51  DBusList *need_dispatch;
54  unsigned oom_watch_pending : 1;
55 };
56 
57 typedef struct
58 {
59  DBusTimeout *timeout;
60  dbus_int64_t last_tv_sec;
61  long last_tv_usec;
62 } TimeoutCallback;
63 
64 #define TIMEOUT_CALLBACK(callback) ((TimeoutCallback*)callback)
65 
66 static TimeoutCallback*
67 timeout_callback_new (DBusTimeout *timeout)
68 {
69  TimeoutCallback *cb;
70 
71  cb = dbus_new (TimeoutCallback, 1);
72  if (cb == NULL)
73  return NULL;
74 
75  cb->timeout = timeout;
76  _dbus_get_monotonic_time (&cb->last_tv_sec,
77  &cb->last_tv_usec);
78  return cb;
79 }
80 
81 static void
82 timeout_callback_free (TimeoutCallback *cb)
83 {
84  dbus_free (cb);
85 }
86 
87 static void
88 free_watch_table_entry (void *data)
89 {
90  DBusList **watches = data;
91  DBusWatch *watch;
92 
93  /* DBusHashTable sometimes calls free_function(NULL) even if you never
94  * have NULL as a value */
95  if (watches == NULL)
96  return;
97 
98  for (watch = _dbus_list_pop_first (watches);
99  watch != NULL;
100  watch = _dbus_list_pop_first (watches))
101  {
102  _dbus_watch_unref (watch);
103  }
104 
105  _dbus_assert (*watches == NULL);
106  dbus_free (watches);
107 }
108 
109 DBusLoop*
110 _dbus_loop_new (void)
111 {
112  DBusLoop *loop;
113 
114  loop = dbus_new0 (DBusLoop, 1);
115  if (loop == NULL)
116  return NULL;
117 
118  loop->watches = _dbus_hash_table_new (DBUS_HASH_POLLABLE, NULL,
119  free_watch_table_entry);
120 
121  loop->pollable_set = _dbus_pollable_set_new (0);
122 
123  if (loop->watches == NULL || loop->pollable_set == NULL)
124  {
125  if (loop->watches != NULL)
126  _dbus_hash_table_unref (loop->watches);
127 
128  if (loop->pollable_set != NULL)
129  _dbus_pollable_set_free (loop->pollable_set);
130 
131  dbus_free (loop);
132  return NULL;
133  }
134 
135  loop->refcount = 1;
136 
137  return loop;
138 }
139 
140 DBusLoop *
141 _dbus_loop_ref (DBusLoop *loop)
142 {
143  _dbus_assert (loop != NULL);
144  _dbus_assert (loop->refcount > 0);
145 
146  loop->refcount += 1;
147 
148  return loop;
149 }
150 
151 void
152 _dbus_loop_unref (DBusLoop *loop)
153 {
154  _dbus_assert (loop != NULL);
155  _dbus_assert (loop->refcount > 0);
156 
157  loop->refcount -= 1;
158  if (loop->refcount == 0)
159  {
160  while (loop->need_dispatch)
161  {
162  DBusConnection *connection = _dbus_list_pop_first (&loop->need_dispatch);
163 
164  dbus_connection_unref (connection);
165  }
166 
167  _dbus_hash_table_unref (loop->watches);
168  _dbus_pollable_set_free (loop->pollable_set);
169  dbus_free (loop);
170  }
171 }
172 
173 static DBusList **
174 ensure_watch_table_entry (DBusLoop *loop,
175  DBusPollable fd)
176 {
177  DBusList **watches;
178 
179  watches = _dbus_hash_table_lookup_pollable (loop->watches, fd);
180 
181  if (watches == NULL)
182  {
183  watches = dbus_new0 (DBusList *, 1);
184 
185  if (watches == NULL)
186  return watches;
187 
188  if (!_dbus_hash_table_insert_pollable (loop->watches, fd, watches))
189  {
190  dbus_free (watches);
191  watches = NULL;
192  }
193  }
194 
195  return watches;
196 }
197 
198 static void
199 cull_watches_for_invalid_fd (DBusLoop *loop,
200  DBusPollable fd)
201 {
202  DBusList *link;
203  DBusList **watches;
204 
205  _dbus_warn ("invalid request, socket fd %" DBUS_POLLABLE_FORMAT " not open",
206  _dbus_pollable_printable (fd));
207  watches = _dbus_hash_table_lookup_pollable (loop->watches, fd);
208 
209  if (watches != NULL)
210  {
211  for (link = _dbus_list_get_first_link (watches);
212  link != NULL;
213  link = _dbus_list_get_next_link (watches, link))
215  }
216 
217  _dbus_hash_table_remove_pollable (loop->watches, fd);
218 }
219 
220 static dbus_bool_t
221 gc_watch_table_entry (DBusLoop *loop,
222  DBusList **watches,
223  DBusPollable fd)
224 {
225  /* If watches is already NULL we have nothing to do */
226  if (watches == NULL)
227  return FALSE;
228 
229  /* We can't GC hash table entries if they're non-empty lists */
230  if (*watches != NULL)
231  return FALSE;
232 
233  _dbus_hash_table_remove_pollable (loop->watches, fd);
234  return TRUE;
235 }
236 
237 static void
238 refresh_watches_for_fd (DBusLoop *loop,
239  DBusList **watches,
240  DBusPollable fd)
241 {
242  DBusList *link;
243  unsigned int flags = 0;
244  dbus_bool_t interested = FALSE;
245 
246  _dbus_assert (_dbus_pollable_is_valid (fd));
247 
248  if (watches == NULL)
249  watches = _dbus_hash_table_lookup_pollable (loop->watches, fd);
250 
251  /* we allocated this in the first _dbus_loop_add_watch for the fd, and keep
252  * it until there are none left */
253  _dbus_assert (watches != NULL);
254 
255  for (link = _dbus_list_get_first_link (watches);
256  link != NULL;
257  link = _dbus_list_get_next_link (watches, link))
258  {
259  if (dbus_watch_get_enabled (link->data) &&
260  !_dbus_watch_get_oom_last_time (link->data))
261  {
262  flags |= dbus_watch_get_flags (link->data);
263  interested = TRUE;
264  }
265  }
266 
267  if (interested)
268  _dbus_pollable_set_enable (loop->pollable_set, fd, flags);
269  else
270  _dbus_pollable_set_disable (loop->pollable_set, fd);
271 }
272 
274 _dbus_loop_add_watch (DBusLoop *loop,
275  DBusWatch *watch)
276 {
277  DBusPollable fd;
278  DBusList **watches;
279 
280  fd = _dbus_watch_get_pollable (watch);
281  _dbus_assert (_dbus_pollable_is_valid (fd));
282 
283  watches = ensure_watch_table_entry (loop, fd);
284 
285  if (watches == NULL)
286  return FALSE;
287 
288  if (!_dbus_list_append (watches, _dbus_watch_ref (watch)))
289  {
290  _dbus_watch_unref (watch);
291  gc_watch_table_entry (loop, watches, fd);
292 
293  return FALSE;
294  }
295 
296  if (_dbus_list_length_is_one (watches))
297  {
298  if (!_dbus_pollable_set_add (loop->pollable_set, fd,
299  dbus_watch_get_flags (watch),
300  dbus_watch_get_enabled (watch)))
301  {
302  _dbus_hash_table_remove_pollable (loop->watches, fd);
303  return FALSE;
304  }
305  }
306  else
307  {
308  /* we're modifying, not adding, which can't fail with OOM */
309  refresh_watches_for_fd (loop, watches, fd);
310  }
311 
312  loop->callback_list_serial += 1;
313  loop->watch_count += 1;
314  return TRUE;
315 }
316 
317 void
318 _dbus_loop_toggle_watch (DBusLoop *loop,
319  DBusWatch *watch)
320 {
321  refresh_watches_for_fd (loop, NULL, _dbus_watch_get_pollable (watch));
322 }
323 
324 void
325 _dbus_loop_remove_watch (DBusLoop *loop,
326  DBusWatch *watch)
327 {
328  DBusList **watches;
329  DBusList *link;
330  DBusPollable fd;
331 
332  /* This relies on people removing watches before they invalidate them,
333  * which has been safe since fd.o #33336 was fixed. Assert about it
334  * so we don't regress. */
335  fd = _dbus_watch_get_pollable (watch);
336  _dbus_assert (_dbus_pollable_is_valid (fd));
337 
338  watches = _dbus_hash_table_lookup_pollable (loop->watches, fd);
339 
340  if (watches != NULL)
341  {
342  link = _dbus_list_get_first_link (watches);
343  while (link != NULL)
344  {
345  DBusList *next = _dbus_list_get_next_link (watches, link);
346  DBusWatch *this = link->data;
347 
348  if (this == watch)
349  {
350  _dbus_list_remove_link (watches, link);
351  loop->callback_list_serial += 1;
352  loop->watch_count -= 1;
353  _dbus_watch_unref (this);
354 
355  /* if that was the last watch for that fd, drop the hash table
356  * entry, and stop reserving space for it in the socket set */
357  if (gc_watch_table_entry (loop, watches, fd))
358  {
359  _dbus_pollable_set_remove (loop->pollable_set, fd);
360  }
361 
362  return;
363  }
364 
365  link = next;
366  }
367  }
368 
369  _dbus_warn ("could not find watch %p to remove", watch);
370 }
371 
373 _dbus_loop_add_timeout (DBusLoop *loop,
374  DBusTimeout *timeout)
375 {
376  TimeoutCallback *tcb;
377 
378  tcb = timeout_callback_new (timeout);
379  if (tcb == NULL)
380  return FALSE;
381 
382  if (_dbus_list_append (&loop->timeouts, tcb))
383  {
384  loop->callback_list_serial += 1;
385  loop->timeout_count += 1;
386  }
387  else
388  {
389  timeout_callback_free (tcb);
390  return FALSE;
391  }
392 
393  return TRUE;
394 }
395 
396 void
397 _dbus_loop_remove_timeout (DBusLoop *loop,
398  DBusTimeout *timeout)
399 {
400  DBusList *link;
401 
402  link = _dbus_list_get_first_link (&loop->timeouts);
403  while (link != NULL)
404  {
405  DBusList *next = _dbus_list_get_next_link (&loop->timeouts, link);
406  TimeoutCallback *this = link->data;
407 
408  if (this->timeout == timeout)
409  {
410  _dbus_list_remove_link (&loop->timeouts, link);
411  loop->callback_list_serial += 1;
412  loop->timeout_count -= 1;
413  timeout_callback_free (this);
414 
415  return;
416  }
417 
418  link = next;
419  }
420 
421  _dbus_warn ("could not find timeout %p to remove", timeout);
422 }
423 
424 /* Convolutions from GLib, there really must be a better way
425  * to do this.
426  */
427 static dbus_bool_t
428 check_timeout (dbus_int64_t tv_sec,
429  long tv_usec,
430  TimeoutCallback *tcb,
431  int *timeout)
432 {
433  dbus_int64_t sec_remaining;
434  long msec_remaining;
435  dbus_int64_t expiration_tv_sec;
436  long expiration_tv_usec;
437  dbus_int64_t interval_seconds;
438  long interval_milliseconds;
439  int interval;
440 
441  /* I'm pretty sure this function could suck (a lot) less */
442 
443  interval = dbus_timeout_get_interval (tcb->timeout);
444 
445  interval_seconds = interval / 1000L;
446  interval_milliseconds = interval % 1000L;
447 
448  expiration_tv_sec = tcb->last_tv_sec + interval_seconds;
449  expiration_tv_usec = tcb->last_tv_usec + interval_milliseconds * 1000;
450  if (expiration_tv_usec >= 1000000)
451  {
452  expiration_tv_usec -= 1000000;
453  expiration_tv_sec += 1;
454  }
455 
456  sec_remaining = expiration_tv_sec - tv_sec;
457  msec_remaining = (expiration_tv_usec - tv_usec) / 1000L;
458 
459 #if MAINLOOP_SPEW
460  _dbus_verbose ("Interval is %ld seconds %ld msecs\n",
461  interval_seconds,
462  interval_milliseconds);
463  _dbus_verbose ("Now is %lu seconds %lu usecs\n",
464  tv_sec, tv_usec);
465  _dbus_verbose ("Last is %lu seconds %lu usecs\n",
466  tcb->last_tv_sec, tcb->last_tv_usec);
467  _dbus_verbose ("Exp is %lu seconds %lu usecs\n",
468  expiration_tv_sec, expiration_tv_usec);
469  _dbus_verbose ("Pre-correction, sec_remaining %ld msec_remaining %ld\n",
470  sec_remaining, msec_remaining);
471 #endif
472 
473  /* We do the following in a rather convoluted fashion to deal with
474  * the fact that we don't have an integral type big enough to hold
475  * the difference of two timevals in milliseconds.
476  */
477  if (sec_remaining < 0 || (sec_remaining == 0 && msec_remaining < 0))
478  {
479  *timeout = 0;
480  }
481  else
482  {
483  if (msec_remaining < 0)
484  {
485  msec_remaining += 1000;
486  sec_remaining -= 1;
487  }
488 
489  if (sec_remaining > (_DBUS_INT_MAX / 1000) ||
490  msec_remaining > _DBUS_INT_MAX)
491  *timeout = _DBUS_INT_MAX;
492  else
493  *timeout = sec_remaining * 1000 + msec_remaining;
494  }
495 
496  if (*timeout > interval)
497  {
498  /* This indicates that the system clock probably moved backward */
499  _dbus_verbose ("System clock set backward! Resetting timeout.\n");
500 
501  tcb->last_tv_sec = tv_sec;
502  tcb->last_tv_usec = tv_usec;
503 
504  *timeout = interval;
505  }
506 
507 #if MAINLOOP_SPEW
508  _dbus_verbose (" timeout expires in %d milliseconds\n", *timeout);
509 #endif
510 
511  return *timeout == 0;
512 }
513 
515 _dbus_loop_dispatch (DBusLoop *loop)
516 {
517 
518 #if MAINLOOP_SPEW
519  _dbus_verbose (" %d connections to dispatch\n", _dbus_list_get_length (&loop->need_dispatch));
520 #endif
521 
522  if (loop->need_dispatch == NULL)
523  return FALSE;
524 
525  next:
526  while (loop->need_dispatch != NULL)
527  {
528  DBusConnection *connection = _dbus_list_pop_first (&loop->need_dispatch);
529 
530  while (TRUE)
531  {
532  DBusDispatchStatus status;
533 
534  status = dbus_connection_dispatch (connection);
535 
536  if (status == DBUS_DISPATCH_COMPLETE)
537  {
538  dbus_connection_unref (connection);
539  goto next;
540  }
541  else
542  {
543  if (status == DBUS_DISPATCH_NEED_MEMORY)
544  _dbus_wait_for_memory ();
545  }
546  }
547  }
548 
549  return TRUE;
550 }
551 
553 _dbus_loop_queue_dispatch (DBusLoop *loop,
554  DBusConnection *connection)
555 {
556  if (_dbus_list_append (&loop->need_dispatch, connection))
557  {
558  dbus_connection_ref (connection);
559  return TRUE;
560  }
561  else
562  return FALSE;
563 }
564 
565 /* Returns the smaller non-negative number of the two, or the larger negative
566  * number if both numbers are negative. Poll interprets negative timeout as
567  * infinity, which makes it longer than any actual timeout.
568  */
569 static int
570 min_poll_timeout (int a,
571  int b)
572 {
573  if (a < b)
574  return a < 0 ? b : a;
575  else
576  return b < 0 ? a : b;
577 }
578 
579 /* Returns TRUE if we invoked any timeouts or have ready file
580  * descriptors, which is just used in test code as a debug hack
581  */
582 
584 _dbus_loop_iterate (DBusLoop *loop,
585  dbus_bool_t block)
586 {
587 #define N_STACK_DESCRIPTORS 64
588  dbus_bool_t retval;
589  DBusPollableEvent ready_fds[N_STACK_DESCRIPTORS];
590  int i;
591  DBusList *link;
592  int n_ready;
593  int initial_serial;
594  int timeout;
595  int orig_depth;
596 
597  retval = FALSE;
598 
599  orig_depth = loop->depth;
600 
601 #if MAINLOOP_SPEW
602  _dbus_verbose ("Iteration block=%d depth=%d timeout_count=%d watch_count=%d\n",
603  block, loop->depth, loop->timeout_count, loop->watch_count);
604 #endif
605 
606  if (_dbus_hash_table_get_n_entries (loop->watches) == 0 &&
607  loop->timeouts == NULL)
608  goto next_iteration;
609 
610  timeout = -1;
611  if (loop->timeout_count > 0)
612  {
613  dbus_int64_t tv_sec;
614  long tv_usec;
615 
616  _dbus_get_monotonic_time (&tv_sec, &tv_usec);
617 
618  link = _dbus_list_get_first_link (&loop->timeouts);
619  while (link != NULL)
620  {
621  DBusList *next = _dbus_list_get_next_link (&loop->timeouts, link);
622  TimeoutCallback *tcb = link->data;
623 
624  if (dbus_timeout_get_enabled (tcb->timeout))
625  {
626  int msecs_remaining;
627 
628  if (_dbus_timeout_needs_restart (tcb->timeout))
629  {
630  tcb->last_tv_sec = tv_sec;
631  tcb->last_tv_usec = tv_usec;
632  _dbus_timeout_restarted (tcb->timeout);
633  }
634 
635  check_timeout (tv_sec, tv_usec, tcb, &msecs_remaining);
636 
637  timeout = min_poll_timeout (msecs_remaining, timeout);
638 
639 #if MAINLOOP_SPEW
640  _dbus_verbose (" timeout added, %d remaining, aggregate timeout %ld\n",
641  msecs_remaining, timeout);
642 #endif
643 
644  _dbus_assert (timeout >= 0);
645  }
646 #if MAINLOOP_SPEW
647  else
648  {
649  _dbus_verbose (" skipping disabled timeout\n");
650  }
651 #endif
652 
653  link = next;
654  }
655  }
656 
657  /* Never block if we have stuff to dispatch */
658  if (!block || loop->need_dispatch != NULL)
659  {
660  timeout = 0;
661 #if MAINLOOP_SPEW
662  _dbus_verbose (" timeout is 0 as we aren't blocking\n");
663 #endif
664  }
665 
666  /* if a watch was OOM last time, don't wait longer than the OOM
667  * wait to re-enable it
668  */
669  if (loop->oom_watch_pending)
670  timeout = min_poll_timeout (timeout, _dbus_get_oom_wait ());
671 
672 #if MAINLOOP_SPEW
673  _dbus_verbose (" polling on %d descriptors timeout %ld\n", _DBUS_N_ELEMENTS (ready_fds), timeout);
674 #endif
675 
676  n_ready = _dbus_pollable_set_poll (loop->pollable_set, ready_fds,
677  _DBUS_N_ELEMENTS (ready_fds), timeout);
678 
679  /* re-enable any watches we skipped this time */
680  if (loop->oom_watch_pending)
681  {
682  DBusHashIter hash_iter;
683 
684  loop->oom_watch_pending = FALSE;
685 
686  _dbus_hash_iter_init (loop->watches, &hash_iter);
687 
688  while (_dbus_hash_iter_next (&hash_iter))
689  {
690  DBusList **watches;
691  DBusPollable fd;
692  dbus_bool_t changed;
693 
694  changed = FALSE;
695  fd = _dbus_hash_iter_get_pollable_key (&hash_iter);
696  watches = _dbus_hash_iter_get_value (&hash_iter);
697 
698  for (link = _dbus_list_get_first_link (watches);
699  link != NULL;
700  link = _dbus_list_get_next_link (watches, link))
701  {
702  DBusWatch *watch = link->data;
703 
704  if (_dbus_watch_get_oom_last_time (watch))
705  {
706  _dbus_watch_set_oom_last_time (watch, FALSE);
707  changed = TRUE;
708  }
709  }
710 
711  if (changed)
712  refresh_watches_for_fd (loop, watches, fd);
713  }
714 
715  retval = TRUE; /* return TRUE here to keep the loop going,
716  * since we don't know the watch was inactive */
717  }
718 
719  initial_serial = loop->callback_list_serial;
720 
721  if (loop->timeout_count > 0)
722  {
723  dbus_int64_t tv_sec;
724  long tv_usec;
725 
726  _dbus_get_monotonic_time (&tv_sec, &tv_usec);
727 
728  /* It'd be nice to avoid this O(n) thingy here */
729  link = _dbus_list_get_first_link (&loop->timeouts);
730  while (link != NULL)
731  {
732  DBusList *next = _dbus_list_get_next_link (&loop->timeouts, link);
733  TimeoutCallback *tcb = link->data;
734 
735  if (initial_serial != loop->callback_list_serial)
736  goto next_iteration;
737 
738  if (loop->depth != orig_depth)
739  goto next_iteration;
740 
741  if (dbus_timeout_get_enabled (tcb->timeout))
742  {
743  int msecs_remaining;
744 
745  if (check_timeout (tv_sec, tv_usec,
746  tcb, &msecs_remaining))
747  {
748  /* Save last callback time and fire this timeout */
749  tcb->last_tv_sec = tv_sec;
750  tcb->last_tv_usec = tv_usec;
751 
752 #if MAINLOOP_SPEW
753  _dbus_verbose (" invoking timeout\n");
754 #endif
755 
756  /* can theoretically return FALSE on OOM, but we just
757  * let it fire again later - in practice that's what
758  * every wrapper callback in dbus-daemon used to do */
759  dbus_timeout_handle (tcb->timeout);
760 
761  retval = TRUE;
762  }
763  else
764  {
765 #if MAINLOOP_SPEW
766  _dbus_verbose (" timeout has not expired\n");
767 #endif
768  }
769  }
770 #if MAINLOOP_SPEW
771  else
772  {
773  _dbus_verbose (" skipping invocation of disabled timeout\n");
774  }
775 #endif
776 
777  link = next;
778  }
779  }
780 
781  if (n_ready > 0)
782  {
783  for (i = 0; i < n_ready; i++)
784  {
785  DBusList **watches;
786  DBusList *next;
787  unsigned int condition;
788  dbus_bool_t any_oom;
789 
790  /* FIXME I think this "restart if we change the watches"
791  * approach could result in starving watches
792  * toward the end of the list.
793  */
794  if (initial_serial != loop->callback_list_serial)
795  goto next_iteration;
796 
797  if (loop->depth != orig_depth)
798  goto next_iteration;
799 
800  _dbus_assert (ready_fds[i].flags != 0);
801 
802  if (_DBUS_UNLIKELY (ready_fds[i].flags & _DBUS_WATCH_NVAL))
803  {
804  cull_watches_for_invalid_fd (loop, ready_fds[i].fd);
805  goto next_iteration;
806  }
807 
808  condition = ready_fds[i].flags;
809  _dbus_assert ((condition & _DBUS_WATCH_NVAL) == 0);
810 
811  /* condition may still be 0 if we got some
812  * weird POLLFOO thing like POLLWRBAND
813  */
814  if (condition == 0)
815  continue;
816 
817  watches = _dbus_hash_table_lookup_pollable (loop->watches,
818  ready_fds[i].fd);
819 
820  if (watches == NULL)
821  continue;
822 
823  any_oom = FALSE;
824 
825  for (link = _dbus_list_get_first_link (watches);
826  link != NULL;
827  link = next)
828  {
829  DBusWatch *watch = link->data;
830 
831  next = _dbus_list_get_next_link (watches, link);
832 
833  if (dbus_watch_get_enabled (watch))
834  {
835  dbus_bool_t oom;
836 
837  oom = !dbus_watch_handle (watch, condition);
838 
839  if (oom)
840  {
841  _dbus_watch_set_oom_last_time (watch, TRUE);
842  loop->oom_watch_pending = TRUE;
843  any_oom = TRUE;
844  }
845 
846 #if MAINLOOP_SPEW
847  _dbus_verbose (" Invoked watch, oom = %d\n", oom);
848 #endif
849  retval = TRUE;
850 
851  /* We re-check this every time, in case the callback
852  * added/removed watches, which might make our position in
853  * the linked list invalid. See the FIXME above. */
854  if (initial_serial != loop->callback_list_serial ||
855  loop->depth != orig_depth)
856  {
857  if (any_oom)
858  refresh_watches_for_fd (loop, NULL, ready_fds[i].fd);
859 
860  goto next_iteration;
861  }
862  }
863  }
864 
865  if (any_oom)
866  refresh_watches_for_fd (loop, watches, ready_fds[i].fd);
867  }
868  }
869 
870  next_iteration:
871 #if MAINLOOP_SPEW
872  _dbus_verbose (" moving to next iteration\n");
873 #endif
874 
875  if (_dbus_loop_dispatch (loop))
876  retval = TRUE;
877 
878 #if MAINLOOP_SPEW
879  _dbus_verbose ("Returning %d\n", retval);
880 #endif
881 
882  return retval;
883 }
884 
885 void
886 _dbus_loop_run (DBusLoop *loop)
887 {
888  int our_exit_depth;
889 
890  _dbus_assert (loop->depth >= 0);
891 
892  _dbus_loop_ref (loop);
893 
894  our_exit_depth = loop->depth;
895  loop->depth += 1;
896 
897  _dbus_verbose ("Running main loop, depth %d -> %d\n",
898  loop->depth - 1, loop->depth);
899 
900  while (loop->depth != our_exit_depth)
901  _dbus_loop_iterate (loop, TRUE);
902 
903  _dbus_loop_unref (loop);
904 }
905 
906 void
907 _dbus_loop_quit (DBusLoop *loop)
908 {
909  _dbus_assert (loop->depth > 0);
910 
911  loop->depth -= 1;
912 
913  _dbus_verbose ("Quit main loop, depth %d -> %d\n",
914  loop->depth + 1, loop->depth);
915 }
916 
917 int
918 _dbus_get_oom_wait (void)
919 {
920 #ifdef DBUS_ENABLE_EMBEDDED_TESTS
921  /* make tests go fast */
922  return 0;
923 #else
924  return 500;
925 #endif
926 }
927 
928 void
929 _dbus_wait_for_memory (void)
930 {
931  _dbus_verbose ("Waiting for more memory\n");
932  _dbus_sleep_milliseconds (_dbus_get_oom_wait ());
933 }
934 
935 #endif /* !DOXYGEN_SHOULD_SKIP_THIS */
Internals of DBusTimeout.
Definition: dbus-timeout.c:42
DBusDispatchStatus
Indicates the status of incoming data on a DBusConnection.
Implementation of DBusWatch.
Definition: dbus-watch.c:42
#define NULL
A null pointer, defined appropriately for C or C++.
More memory is needed to continue.
void dbus_free(void *memory)
Frees a block of memory previously allocated by dbus_malloc() or dbus_malloc0().
Definition: dbus-memory.c:710
dbus_bool_t _dbus_timeout_needs_restart(DBusTimeout *timeout)
Returns whether a timeout needs restart time counting in the event loop.
Definition: dbus-timeout.c:389
dbus_bool_t _dbus_list_length_is_one(DBusList **list)
Check whether length is exactly one.
Definition: dbus-list.c:813
#define dbus_new(type, count)
Safe macro for using dbus_malloc().
Definition: dbus-memory.h:59
DBUS_EXPORT dbus_bool_t dbus_watch_get_enabled(DBusWatch *watch)
Returns whether a watch is enabled or not.
Definition: dbus-watch.c:704
void _dbus_list_remove_link(DBusList **list, DBusList *link)
Removes a link from the list.
Definition: dbus-list.c:530
DBusConnection * dbus_connection_ref(DBusConnection *connection)
Increments the reference count of a DBusConnection.
void * data
Data stored at this element.
Definition: dbus-list.h:40
void _dbus_hash_table_unref(DBusHashTable *table)
Decrements the reference count for a hash table, freeing the hash table if the count reaches zero...
Definition: dbus-hash.c:368
Implementation details of DBusConnection.
dbus_bool_t _dbus_hash_iter_next(DBusHashIter *iter)
Move the hash iterator forward one step, to the next hash entry.
Definition: dbus-hash.c:550
Hash iterator object.
Definition: dbus-hash.h:49
#define _dbus_list_get_next_link(list, link)
Gets the next link in the list, or NULL if there are no more links.
Definition: dbus-list.h:121
#define _DBUS_INT_MAX
Maximum value of type "int".
DBUS_EXPORT dbus_bool_t dbus_timeout_get_enabled(DBusTimeout *timeout)
Returns whether a timeout is enabled or not.
Definition: dbus-timeout.c:514
#define dbus_new0(type, count)
Safe macro for using dbus_malloc0().
Definition: dbus-memory.h:60
int _dbus_hash_table_get_n_entries(DBusHashTable *table)
Gets the number of hash entries in a hash table.
Definition: dbus-hash.c:1461
void * _dbus_hash_iter_get_value(DBusHashIter *iter)
Gets the value of the current entry.
Definition: dbus-hash.c:620
dbus_uint32_t dbus_bool_t
A boolean, valid values are TRUE and FALSE.
Definition: dbus-types.h:37
DBUS_EXPORT dbus_bool_t dbus_timeout_handle(DBusTimeout *timeout)
Calls the timeout handler for this timeout.
Definition: dbus-timeout.c:500
DBusDispatchStatus dbus_connection_dispatch(DBusConnection *connection)
Processes any incoming data.
All currently available data has been processed.
void _dbus_warn(const char *format,...)
Prints a warning message to stderr.
dbus_bool_t _dbus_list_append(DBusList **list, void *data)
Appends a value to the list.
Definition: dbus-list.c:273
void _dbus_watch_invalidate(DBusWatch *watch)
Clears the file descriptor from a now-invalid watch object so that no one tries to use it...
Definition: dbus-watch.c:171
_DBUS_GNUC_EXTENSION typedef long dbus_int64_t
A 64-bit signed integer.
void * _dbus_list_pop_first(DBusList **list)
Removes the first value in the list and returns it.
Definition: dbus-list.c:679
#define _DBUS_N_ELEMENTS(array)
Computes the number of elements in a fixed-size array using sizeof().
#define TRUE
Expands to "1".
#define _dbus_assert(condition)
Aborts with an error message if the condition is false.
void _dbus_get_monotonic_time(dbus_int64_t *tv_sec, long *tv_usec)
Get current time, as in gettimeofday().
A node in a linked list.
Definition: dbus-list.h:36
void _dbus_hash_iter_init(DBusHashTable *table, DBusHashIter *iter)
Initializes a hash table iterator.
Definition: dbus-hash.c:524
void _dbus_watch_unref(DBusWatch *watch)
Decrements the reference count of a DBusWatch object and finalizes the object if the count reaches ze...
Definition: dbus-watch.c:140
int _dbus_list_get_length(DBusList **list)
Gets the length of a list.
Definition: dbus-list.c:760
DBusList * _dbus_list_get_first_link(DBusList **list)
Gets the first link in the list.
Definition: dbus-list.c:597
#define FALSE
Expands to "0".
DBUS_EXPORT dbus_bool_t dbus_watch_handle(DBusWatch *watch, unsigned int flags)
Called to notify the D-Bus library when a previously-added watch is ready for reading or writing...
Definition: dbus-watch.c:735
DBusWatch * _dbus_watch_ref(DBusWatch *watch)
Increments the reference count of a DBusWatch object.
Definition: dbus-watch.c:126
DBUS_EXPORT unsigned int dbus_watch_get_flags(DBusWatch *watch)
Gets flags from DBusWatchFlags indicating what conditions should be monitored on the file descriptor...
Definition: dbus-watch.c:644
void dbus_connection_unref(DBusConnection *connection)
Decrements the reference count of a DBusConnection, and finalizes it if the count reaches zero...
Internals of DBusHashTable.
Definition: dbus-hash.c:175
void _dbus_sleep_milliseconds(int milliseconds)
Sleeps the given number of milliseconds.
DBusHashTable * _dbus_hash_table_new(DBusHashType type, DBusFreeFunction key_free_function, DBusFreeFunction value_free_function)
Constructs a new hash table.
Definition: dbus-hash.c:292
void _dbus_timeout_restarted(DBusTimeout *timeout)
Mark timeout as restarted (setting timestamps is responsibility of the event loop).
Definition: dbus-timeout.c:401
DBUS_EXPORT int dbus_timeout_get_interval(DBusTimeout *timeout)
Gets the timeout interval.
Definition: dbus-timeout.c:444