D-Bus  1.6.12
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  * 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-watch.h>
34 
35 #define MAINLOOP_SPEW 0
36 
37 #if MAINLOOP_SPEW
38 #ifdef DBUS_ENABLE_VERBOSE_MODE
39 static const char*
40 watch_flags_to_string (int flags)
41 {
42  const char *watch_type;
43 
44  if ((flags & DBUS_WATCH_READABLE) &&
45  (flags & DBUS_WATCH_WRITABLE))
46  watch_type = "readwrite";
47  else if (flags & DBUS_WATCH_READABLE)
48  watch_type = "read";
49  else if (flags & DBUS_WATCH_WRITABLE)
50  watch_type = "write";
51  else
52  watch_type = "not read or write";
53  return watch_type;
54 }
55 #endif /* DBUS_ENABLE_VERBOSE_MODE */
56 #endif /* MAINLOOP_SPEW */
57 
58 struct DBusLoop
59 {
60  int refcount;
62  DBusHashTable *watches;
63  DBusSocketSet *socket_set;
64  DBusList *timeouts;
65  int callback_list_serial;
66  int watch_count;
67  int timeout_count;
68  int depth;
69  DBusList *need_dispatch;
72  unsigned oom_watch_pending : 1;
73 };
74 
75 typedef struct
76 {
77  DBusTimeout *timeout;
78  unsigned long last_tv_sec;
79  unsigned long last_tv_usec;
80 } TimeoutCallback;
81 
82 #define TIMEOUT_CALLBACK(callback) ((TimeoutCallback*)callback)
83 
84 static TimeoutCallback*
85 timeout_callback_new (DBusTimeout *timeout)
86 {
87  TimeoutCallback *cb;
88 
89  cb = dbus_new (TimeoutCallback, 1);
90  if (cb == NULL)
91  return NULL;
92 
93  cb->timeout = timeout;
94  _dbus_get_monotonic_time (&cb->last_tv_sec,
95  &cb->last_tv_usec);
96  return cb;
97 }
98 
99 static void
100 timeout_callback_free (TimeoutCallback *cb)
101 {
102  dbus_free (cb);
103 }
104 
105 static void
106 free_watch_table_entry (void *data)
107 {
108  DBusList **watches = data;
109  DBusWatch *watch;
110 
111  /* DBusHashTable sometimes calls free_function(NULL) even if you never
112  * have NULL as a value */
113  if (watches == NULL)
114  return;
115 
116  for (watch = _dbus_list_pop_first (watches);
117  watch != NULL;
118  watch = _dbus_list_pop_first (watches))
119  {
120  _dbus_watch_unref (watch);
121  }
122 
123  _dbus_assert (*watches == NULL);
124  dbus_free (watches);
125 }
126 
127 DBusLoop*
128 _dbus_loop_new (void)
129 {
130  DBusLoop *loop;
131 
132  loop = dbus_new0 (DBusLoop, 1);
133  if (loop == NULL)
134  return NULL;
135 
136  loop->watches = _dbus_hash_table_new (DBUS_HASH_INT, NULL,
137  free_watch_table_entry);
138 
139  loop->socket_set = _dbus_socket_set_new (0);
140 
141  if (loop->watches == NULL || loop->socket_set == NULL)
142  {
143  if (loop->watches != NULL)
144  _dbus_hash_table_unref (loop->watches);
145 
146  if (loop->socket_set != NULL)
147  _dbus_socket_set_free (loop->socket_set);
148 
149  dbus_free (loop);
150  return NULL;
151  }
152 
153  loop->refcount = 1;
154 
155  return loop;
156 }
157 
158 DBusLoop *
159 _dbus_loop_ref (DBusLoop *loop)
160 {
161  _dbus_assert (loop != NULL);
162  _dbus_assert (loop->refcount > 0);
163 
164  loop->refcount += 1;
165 
166  return loop;
167 }
168 
169 void
170 _dbus_loop_unref (DBusLoop *loop)
171 {
172  _dbus_assert (loop != NULL);
173  _dbus_assert (loop->refcount > 0);
174 
175  loop->refcount -= 1;
176  if (loop->refcount == 0)
177  {
178  while (loop->need_dispatch)
179  {
180  DBusConnection *connection = _dbus_list_pop_first (&loop->need_dispatch);
181 
182  dbus_connection_unref (connection);
183  }
184 
185  _dbus_hash_table_unref (loop->watches);
186  _dbus_socket_set_free (loop->socket_set);
187  dbus_free (loop);
188  }
189 }
190 
191 static DBusList **
192 ensure_watch_table_entry (DBusLoop *loop,
193  int fd)
194 {
195  DBusList **watches;
196 
197  watches = _dbus_hash_table_lookup_int (loop->watches, fd);
198 
199  if (watches == NULL)
200  {
201  watches = dbus_new0 (DBusList *, 1);
202 
203  if (watches == NULL)
204  return watches;
205 
206  if (!_dbus_hash_table_insert_int (loop->watches, fd, watches))
207  {
208  dbus_free (watches);
209  watches = NULL;
210  }
211  }
212 
213  return watches;
214 }
215 
216 static void
217 cull_watches_for_invalid_fd (DBusLoop *loop,
218  int fd)
219 {
220  DBusList *link;
221  DBusList **watches;
222 
223  _dbus_warn ("invalid request, socket fd %d not open\n", fd);
224  watches = _dbus_hash_table_lookup_int (loop->watches, fd);
225 
226  if (watches != NULL)
227  {
228  for (link = _dbus_list_get_first_link (watches);
229  link != NULL;
230  link = _dbus_list_get_next_link (watches, link))
232  }
233 
234  _dbus_hash_table_remove_int (loop->watches, fd);
235 }
236 
237 static dbus_bool_t
238 gc_watch_table_entry (DBusLoop *loop,
239  DBusList **watches,
240  int fd)
241 {
242  /* If watches is already NULL we have nothing to do */
243  if (watches == NULL)
244  return FALSE;
245 
246  /* We can't GC hash table entries if they're non-empty lists */
247  if (*watches != NULL)
248  return FALSE;
249 
250  _dbus_hash_table_remove_int (loop->watches, fd);
251  return TRUE;
252 }
253 
254 static void
255 refresh_watches_for_fd (DBusLoop *loop,
256  DBusList **watches,
257  int fd)
258 {
259  DBusList *link;
260  unsigned int flags = 0;
261  dbus_bool_t interested = FALSE;
262 
263  _dbus_assert (fd != -1);
264 
265  if (watches == NULL)
266  watches = _dbus_hash_table_lookup_int (loop->watches, fd);
267 
268  /* we allocated this in the first _dbus_loop_add_watch for the fd, and keep
269  * it until there are none left */
270  _dbus_assert (watches != NULL);
271 
272  for (link = _dbus_list_get_first_link (watches);
273  link != NULL;
274  link = _dbus_list_get_next_link (watches, link))
275  {
276  if (dbus_watch_get_enabled (link->data) &&
277  !_dbus_watch_get_oom_last_time (link->data))
278  {
279  flags |= dbus_watch_get_flags (link->data);
280  interested = TRUE;
281  }
282  }
283 
284  if (interested)
285  _dbus_socket_set_enable (loop->socket_set, fd, flags);
286  else
287  _dbus_socket_set_disable (loop->socket_set, fd);
288 }
289 
291 _dbus_loop_add_watch (DBusLoop *loop,
292  DBusWatch *watch)
293 {
294  int fd;
295  DBusList **watches;
296 
297  fd = dbus_watch_get_socket (watch);
298  _dbus_assert (fd != -1);
299 
300  watches = ensure_watch_table_entry (loop, fd);
301 
302  if (watches == NULL)
303  return FALSE;
304 
305  if (!_dbus_list_append (watches, _dbus_watch_ref (watch)))
306  {
307  _dbus_watch_unref (watch);
308  gc_watch_table_entry (loop, watches, fd);
309 
310  return FALSE;
311  }
312 
313  if (_dbus_list_length_is_one (watches))
314  {
315  if (!_dbus_socket_set_add (loop->socket_set, fd,
316  dbus_watch_get_flags (watch),
317  dbus_watch_get_enabled (watch)))
318  {
319  _dbus_hash_table_remove_int (loop->watches, fd);
320  return FALSE;
321  }
322  }
323  else
324  {
325  /* we're modifying, not adding, which can't fail with OOM */
326  refresh_watches_for_fd (loop, watches, fd);
327  }
328 
329  loop->callback_list_serial += 1;
330  loop->watch_count += 1;
331  return TRUE;
332 }
333 
334 void
335 _dbus_loop_toggle_watch (DBusLoop *loop,
336  DBusWatch *watch)
337 {
338  refresh_watches_for_fd (loop, NULL, dbus_watch_get_socket (watch));
339 }
340 
341 void
342 _dbus_loop_remove_watch (DBusLoop *loop,
343  DBusWatch *watch)
344 {
345  DBusList **watches;
346  DBusList *link;
347  int fd;
348 
349  /* This relies on people removing watches before they invalidate them,
350  * which has been safe since fd.o #33336 was fixed. Assert about it
351  * so we don't regress. */
352  fd = dbus_watch_get_socket (watch);
353  _dbus_assert (fd != -1);
354 
355  watches = _dbus_hash_table_lookup_int (loop->watches, fd);
356 
357  if (watches != NULL)
358  {
359  link = _dbus_list_get_first_link (watches);
360  while (link != NULL)
361  {
362  DBusList *next = _dbus_list_get_next_link (watches, link);
363  DBusWatch *this = link->data;
364 
365  if (this == watch)
366  {
367  _dbus_list_remove_link (watches, link);
368  loop->callback_list_serial += 1;
369  loop->watch_count -= 1;
370  _dbus_watch_unref (this);
371 
372  /* if that was the last watch for that fd, drop the hash table
373  * entry, and stop reserving space for it in the socket set */
374  if (gc_watch_table_entry (loop, watches, fd))
375  {
376  _dbus_socket_set_remove (loop->socket_set, fd);
377  }
378 
379  return;
380  }
381 
382  link = next;
383  }
384  }
385 
386  _dbus_warn ("could not find watch %p to remove\n", watch);
387 }
388 
390 _dbus_loop_add_timeout (DBusLoop *loop,
391  DBusTimeout *timeout)
392 {
393  TimeoutCallback *tcb;
394 
395  tcb = timeout_callback_new (timeout);
396  if (tcb == NULL)
397  return FALSE;
398 
399  if (_dbus_list_append (&loop->timeouts, tcb))
400  {
401  loop->callback_list_serial += 1;
402  loop->timeout_count += 1;
403  }
404  else
405  {
406  timeout_callback_free (tcb);
407  return FALSE;
408  }
409 
410  return TRUE;
411 }
412 
413 void
414 _dbus_loop_remove_timeout (DBusLoop *loop,
415  DBusTimeout *timeout)
416 {
417  DBusList *link;
418 
419  link = _dbus_list_get_first_link (&loop->timeouts);
420  while (link != NULL)
421  {
422  DBusList *next = _dbus_list_get_next_link (&loop->timeouts, link);
423  TimeoutCallback *this = link->data;
424 
425  if (this->timeout == timeout)
426  {
427  _dbus_list_remove_link (&loop->timeouts, link);
428  loop->callback_list_serial += 1;
429  loop->timeout_count -= 1;
430  timeout_callback_free (this);
431 
432  return;
433  }
434 
435  link = next;
436  }
437 
438  _dbus_warn ("could not find timeout %p to remove\n", timeout);
439 }
440 
441 /* Convolutions from GLib, there really must be a better way
442  * to do this.
443  */
444 static dbus_bool_t
445 check_timeout (unsigned long tv_sec,
446  unsigned long tv_usec,
447  TimeoutCallback *tcb,
448  int *timeout)
449 {
450  long sec_remaining;
451  long msec_remaining;
452  unsigned long expiration_tv_sec;
453  unsigned long expiration_tv_usec;
454  long interval_seconds;
455  long interval_milliseconds;
456  int interval;
457 
458  /* I'm pretty sure this function could suck (a lot) less */
459 
460  interval = dbus_timeout_get_interval (tcb->timeout);
461 
462  interval_seconds = interval / 1000L;
463  interval_milliseconds = interval % 1000L;
464 
465  expiration_tv_sec = tcb->last_tv_sec + interval_seconds;
466  expiration_tv_usec = tcb->last_tv_usec + interval_milliseconds * 1000;
467  if (expiration_tv_usec >= 1000000)
468  {
469  expiration_tv_usec -= 1000000;
470  expiration_tv_sec += 1;
471  }
472 
473  sec_remaining = expiration_tv_sec - tv_sec;
474  /* need to force this to be signed, as it is intended to sometimes
475  * produce a negative result
476  */
477  msec_remaining = ((long) expiration_tv_usec - (long) tv_usec) / 1000L;
478 
479 #if MAINLOOP_SPEW
480  _dbus_verbose ("Interval is %ld seconds %ld msecs\n",
481  interval_seconds,
482  interval_milliseconds);
483  _dbus_verbose ("Now is %lu seconds %lu usecs\n",
484  tv_sec, tv_usec);
485  _dbus_verbose ("Last is %lu seconds %lu usecs\n",
486  tcb->last_tv_sec, tcb->last_tv_usec);
487  _dbus_verbose ("Exp is %lu seconds %lu usecs\n",
488  expiration_tv_sec, expiration_tv_usec);
489  _dbus_verbose ("Pre-correction, sec_remaining %ld msec_remaining %ld\n",
490  sec_remaining, msec_remaining);
491 #endif
492 
493  /* We do the following in a rather convoluted fashion to deal with
494  * the fact that we don't have an integral type big enough to hold
495  * the difference of two timevals in milliseconds.
496  */
497  if (sec_remaining < 0 || (sec_remaining == 0 && msec_remaining < 0))
498  {
499  *timeout = 0;
500  }
501  else
502  {
503  if (msec_remaining < 0)
504  {
505  msec_remaining += 1000;
506  sec_remaining -= 1;
507  }
508 
509  if (sec_remaining > (_DBUS_INT_MAX / 1000) ||
510  msec_remaining > _DBUS_INT_MAX)
511  *timeout = _DBUS_INT_MAX;
512  else
513  *timeout = sec_remaining * 1000 + msec_remaining;
514  }
515 
516  if (*timeout > interval)
517  {
518  /* This indicates that the system clock probably moved backward */
519  _dbus_verbose ("System clock set backward! Resetting timeout.\n");
520 
521  tcb->last_tv_sec = tv_sec;
522  tcb->last_tv_usec = tv_usec;
523 
524  *timeout = interval;
525  }
526 
527 #if MAINLOOP_SPEW
528  _dbus_verbose (" timeout expires in %d milliseconds\n", *timeout);
529 #endif
530 
531  return *timeout == 0;
532 }
533 
535 _dbus_loop_dispatch (DBusLoop *loop)
536 {
537 
538 #if MAINLOOP_SPEW
539  _dbus_verbose (" %d connections to dispatch\n", _dbus_list_get_length (&loop->need_dispatch));
540 #endif
541 
542  if (loop->need_dispatch == NULL)
543  return FALSE;
544 
545  next:
546  while (loop->need_dispatch != NULL)
547  {
548  DBusConnection *connection = _dbus_list_pop_first (&loop->need_dispatch);
549 
550  while (TRUE)
551  {
552  DBusDispatchStatus status;
553 
554  status = dbus_connection_dispatch (connection);
555 
556  if (status == DBUS_DISPATCH_COMPLETE)
557  {
558  dbus_connection_unref (connection);
559  goto next;
560  }
561  else
562  {
563  if (status == DBUS_DISPATCH_NEED_MEMORY)
564  _dbus_wait_for_memory ();
565  }
566  }
567  }
568 
569  return TRUE;
570 }
571 
573 _dbus_loop_queue_dispatch (DBusLoop *loop,
574  DBusConnection *connection)
575 {
576  if (_dbus_list_append (&loop->need_dispatch, connection))
577  {
578  dbus_connection_ref (connection);
579  return TRUE;
580  }
581  else
582  return FALSE;
583 }
584 
585 /* Returns TRUE if we invoked any timeouts or have ready file
586  * descriptors, which is just used in test code as a debug hack
587  */
588 
590 _dbus_loop_iterate (DBusLoop *loop,
591  dbus_bool_t block)
592 {
593 #define N_STACK_DESCRIPTORS 64
594  dbus_bool_t retval;
595  DBusSocketEvent ready_fds[N_STACK_DESCRIPTORS];
596  int i;
597  DBusList *link;
598  int n_ready;
599  int initial_serial;
600  long timeout;
601  int orig_depth;
602 
603  retval = FALSE;
604 
605  orig_depth = loop->depth;
606 
607 #if MAINLOOP_SPEW
608  _dbus_verbose ("Iteration block=%d depth=%d timeout_count=%d watch_count=%d\n",
609  block, loop->depth, loop->timeout_count, loop->watch_count);
610 #endif
611 
612  if (_dbus_hash_table_get_n_entries (loop->watches) == 0 &&
613  loop->timeouts == NULL)
614  goto next_iteration;
615 
616  timeout = -1;
617  if (loop->timeout_count > 0)
618  {
619  unsigned long tv_sec;
620  unsigned long tv_usec;
621 
622  _dbus_get_monotonic_time (&tv_sec, &tv_usec);
623 
624  link = _dbus_list_get_first_link (&loop->timeouts);
625  while (link != NULL)
626  {
627  DBusList *next = _dbus_list_get_next_link (&loop->timeouts, link);
628  TimeoutCallback *tcb = link->data;
629 
630  if (dbus_timeout_get_enabled (tcb->timeout))
631  {
632  int msecs_remaining;
633 
634  check_timeout (tv_sec, tv_usec, tcb, &msecs_remaining);
635 
636  if (timeout < 0)
637  timeout = msecs_remaining;
638  else
639  timeout = MIN (msecs_remaining, timeout);
640 
641 #if MAINLOOP_SPEW
642  _dbus_verbose (" timeout added, %d remaining, aggregate timeout %ld\n",
643  msecs_remaining, timeout);
644 #endif
645 
646  _dbus_assert (timeout >= 0);
647 
648  if (timeout == 0)
649  break; /* it's not going to get shorter... */
650  }
651 #if MAINLOOP_SPEW
652  else
653  {
654  _dbus_verbose (" skipping disabled timeout\n");
655  }
656 #endif
657 
658  link = next;
659  }
660  }
661 
662  /* Never block if we have stuff to dispatch */
663  if (!block || loop->need_dispatch != NULL)
664  {
665  timeout = 0;
666 #if MAINLOOP_SPEW
667  _dbus_verbose (" timeout is 0 as we aren't blocking\n");
668 #endif
669  }
670 
671  /* if a watch was OOM last time, don't wait longer than the OOM
672  * wait to re-enable it
673  */
674  if (loop->oom_watch_pending)
675  timeout = MIN (timeout, _dbus_get_oom_wait ());
676 
677 #if MAINLOOP_SPEW
678  _dbus_verbose (" polling on %d descriptors timeout %ld\n", n_fds, timeout);
679 #endif
680 
681  n_ready = _dbus_socket_set_poll (loop->socket_set, ready_fds,
682  _DBUS_N_ELEMENTS (ready_fds), timeout);
683 
684  /* re-enable any watches we skipped this time */
685  if (loop->oom_watch_pending)
686  {
687  DBusHashIter hash_iter;
688 
689  loop->oom_watch_pending = FALSE;
690 
691  _dbus_hash_iter_init (loop->watches, &hash_iter);
692 
693  while (_dbus_hash_iter_next (&hash_iter))
694  {
695  DBusList **watches;
696  int fd;
697  dbus_bool_t changed;
698 
699  changed = FALSE;
700  fd = _dbus_hash_iter_get_int_key (&hash_iter);
701  watches = _dbus_hash_iter_get_value (&hash_iter);
702 
703  for (link = _dbus_list_get_first_link (watches);
704  link != NULL;
705  link = _dbus_list_get_next_link (watches, link))
706  {
707  DBusWatch *watch = link->data;
708 
709  if (_dbus_watch_get_oom_last_time (watch))
710  {
711  _dbus_watch_set_oom_last_time (watch, FALSE);
712  changed = TRUE;
713  }
714  }
715 
716  if (changed)
717  refresh_watches_for_fd (loop, watches, fd);
718  }
719 
720  retval = TRUE; /* return TRUE here to keep the loop going,
721  * since we don't know the watch was inactive */
722  }
723 
724  initial_serial = loop->callback_list_serial;
725 
726  if (loop->timeout_count > 0)
727  {
728  unsigned long tv_sec;
729  unsigned long tv_usec;
730 
731  _dbus_get_monotonic_time (&tv_sec, &tv_usec);
732 
733  /* It'd be nice to avoid this O(n) thingy here */
734  link = _dbus_list_get_first_link (&loop->timeouts);
735  while (link != NULL)
736  {
737  DBusList *next = _dbus_list_get_next_link (&loop->timeouts, link);
738  TimeoutCallback *tcb = link->data;
739 
740  if (initial_serial != loop->callback_list_serial)
741  goto next_iteration;
742 
743  if (loop->depth != orig_depth)
744  goto next_iteration;
745 
746  if (dbus_timeout_get_enabled (tcb->timeout))
747  {
748  int msecs_remaining;
749 
750  if (check_timeout (tv_sec, tv_usec,
751  tcb, &msecs_remaining))
752  {
753  /* Save last callback time and fire this timeout */
754  tcb->last_tv_sec = tv_sec;
755  tcb->last_tv_usec = tv_usec;
756 
757 #if MAINLOOP_SPEW
758  _dbus_verbose (" invoking timeout\n");
759 #endif
760 
761  /* can theoretically return FALSE on OOM, but we just
762  * let it fire again later - in practice that's what
763  * every wrapper callback in dbus-daemon used to do */
764  dbus_timeout_handle (tcb->timeout);
765 
766  retval = TRUE;
767  }
768  else
769  {
770 #if MAINLOOP_SPEW
771  _dbus_verbose (" timeout has not expired\n");
772 #endif
773  }
774  }
775 #if MAINLOOP_SPEW
776  else
777  {
778  _dbus_verbose (" skipping invocation of disabled timeout\n");
779  }
780 #endif
781 
782  link = next;
783  }
784  }
785 
786  if (n_ready > 0)
787  {
788  for (i = 0; i < n_ready; i++)
789  {
790  DBusList **watches;
791  DBusList *next;
792  unsigned int condition;
793  dbus_bool_t any_oom;
794 
795  /* FIXME I think this "restart if we change the watches"
796  * approach could result in starving watches
797  * toward the end of the list.
798  */
799  if (initial_serial != loop->callback_list_serial)
800  goto next_iteration;
801 
802  if (loop->depth != orig_depth)
803  goto next_iteration;
804 
805  _dbus_assert (ready_fds[i].flags != 0);
806 
807  if (_DBUS_UNLIKELY (ready_fds[i].flags & _DBUS_WATCH_NVAL))
808  {
809  cull_watches_for_invalid_fd (loop, ready_fds[i].fd);
810  goto next_iteration;
811  }
812 
813  condition = ready_fds[i].flags;
814  _dbus_assert ((condition & _DBUS_WATCH_NVAL) == 0);
815 
816  /* condition may still be 0 if we got some
817  * weird POLLFOO thing like POLLWRBAND
818  */
819  if (condition == 0)
820  continue;
821 
822  watches = _dbus_hash_table_lookup_int (loop->watches,
823  ready_fds[i].fd);
824 
825  if (watches == NULL)
826  continue;
827 
828  any_oom = FALSE;
829 
830  for (link = _dbus_list_get_first_link (watches);
831  link != NULL;
832  link = next)
833  {
834  DBusWatch *watch = link->data;
835 
836  next = _dbus_list_get_next_link (watches, link);
837 
838  if (dbus_watch_get_enabled (watch))
839  {
840  dbus_bool_t oom;
841 
842  oom = !dbus_watch_handle (watch, condition);
843 
844  if (oom)
845  {
846  _dbus_watch_set_oom_last_time (watch, TRUE);
847  loop->oom_watch_pending = TRUE;
848  any_oom = TRUE;
849  }
850 
851 #if MAINLOOP_SPEW
852  _dbus_verbose (" Invoked watch, oom = %d\n", oom);
853 #endif
854  retval = TRUE;
855 
856  /* We re-check this every time, in case the callback
857  * added/removed watches, which might make our position in
858  * the linked list invalid. See the FIXME above. */
859  if (initial_serial != loop->callback_list_serial ||
860  loop->depth != orig_depth)
861  {
862  if (any_oom)
863  refresh_watches_for_fd (loop, NULL, ready_fds[i].fd);
864 
865  goto next_iteration;
866  }
867  }
868  }
869 
870  if (any_oom)
871  refresh_watches_for_fd (loop, watches, ready_fds[i].fd);
872  }
873  }
874 
875  next_iteration:
876 #if MAINLOOP_SPEW
877  _dbus_verbose (" moving to next iteration\n");
878 #endif
879 
880  if (_dbus_loop_dispatch (loop))
881  retval = TRUE;
882 
883 #if MAINLOOP_SPEW
884  _dbus_verbose ("Returning %d\n", retval);
885 #endif
886 
887  return retval;
888 }
889 
890 void
891 _dbus_loop_run (DBusLoop *loop)
892 {
893  int our_exit_depth;
894 
895  _dbus_assert (loop->depth >= 0);
896 
897  _dbus_loop_ref (loop);
898 
899  our_exit_depth = loop->depth;
900  loop->depth += 1;
901 
902  _dbus_verbose ("Running main loop, depth %d -> %d\n",
903  loop->depth - 1, loop->depth);
904 
905  while (loop->depth != our_exit_depth)
906  _dbus_loop_iterate (loop, TRUE);
907 
908  _dbus_loop_unref (loop);
909 }
910 
911 void
912 _dbus_loop_quit (DBusLoop *loop)
913 {
914  _dbus_assert (loop->depth > 0);
915 
916  loop->depth -= 1;
917 
918  _dbus_verbose ("Quit main loop, depth %d -> %d\n",
919  loop->depth + 1, loop->depth);
920 }
921 
922 int
923 _dbus_get_oom_wait (void)
924 {
925 #ifdef DBUS_BUILD_TESTS
926  /* make tests go fast */
927  return 0;
928 #else
929  return 500;
930 #endif
931 }
932 
933 void
934 _dbus_wait_for_memory (void)
935 {
936  _dbus_verbose ("Waiting for more memory\n");
937  _dbus_sleep_milliseconds (_dbus_get_oom_wait ());
938 }
939 
940 #endif /* !DOXYGEN_SHOULD_SKIP_THIS */
Internals of DBusTimeout.
Definition: dbus-timeout.c:40
int _dbus_hash_table_get_n_entries(DBusHashTable *table)
Gets the number of hash entries in a hash table.
Definition: dbus-hash.c:1397
DBusDispatchStatus
Indicates the status of incoming data on a DBusConnection.
Implementation of DBusWatch.
Definition: dbus-watch.c:40
#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:700
dbus_bool_t _dbus_list_length_is_one(DBusList **list)
Check whether length is exactly one.
Definition: dbus-list.c:772
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:169
#define dbus_new(type, count)
Safe macro for using dbus_malloc().
Definition: dbus-memory.h:58
DBUS_EXPORT dbus_bool_t dbus_watch_get_enabled(DBusWatch *watch)
Returns whether a watch is enabled or not.
Definition: dbus-watch.c:645
void _dbus_list_remove_link(DBusList **list, DBusList *link)
Removes a link from the list.
Definition: dbus-list.c:516
DBusConnection * dbus_connection_ref(DBusConnection *connection)
Increments the reference count of a DBusConnection.
#define _dbus_assert(condition)
Aborts with an error message if the condition is false.
void * data
Data stored at this element.
Definition: dbus-list.h:38
Implementation details of DBusConnection.
dbus_bool_t _dbus_hash_table_remove_int(DBusHashTable *table, int key)
Removes the hash entry for the given key.
Definition: dbus-hash.c:1151
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:361
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:90
#define _DBUS_INT_MAX
Maximum value of type &quot;int&quot;.
void * _dbus_hash_table_lookup_int(DBusHashTable *table, int key)
Looks up the value for a given integer in a hash table of type DBUS_HASH_INT.
Definition: dbus-hash.c:1074
void _dbus_get_monotonic_time(long *tv_sec, long *tv_usec)
Get current time, as in gettimeofday().
DBUS_EXPORT dbus_bool_t dbus_timeout_get_enabled(DBusTimeout *timeout)
Returns whether a timeout is enabled or not.
Definition: dbus-timeout.c:486
int _dbus_hash_iter_get_int_key(DBusHashIter *iter)
Gets the key for the current entry.
Definition: dbus-hash.c:659
Hash keys are integers.
Definition: dbus-hash.h:70
#define dbus_new0(type, count)
Safe macro for using dbus_malloc0().
Definition: dbus-memory.h:59
As in POLLOUT.
DBusHashTable * _dbus_hash_table_new(DBusHashType type, DBusFreeFunction key_free_function, DBusFreeFunction value_free_function)
Constructs a new hash table.
Definition: dbus-hash.c:285
dbus_uint32_t dbus_bool_t
A boolean, valid values are TRUE and FALSE.
Definition: dbus-types.h:35
DBUS_EXPORT int dbus_watch_get_socket(DBusWatch *watch)
Returns a socket to be watched, on UNIX this will return -1 if our transport is not socket-based so d...
Definition: dbus-watch.c:564
DBUS_EXPORT dbus_bool_t dbus_timeout_handle(DBusTimeout *timeout)
Calls the timeout handler for this timeout.
Definition: dbus-timeout.c:472
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:259
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:543
void * _dbus_list_pop_first(DBusList **list)
Removes the first value in the list and returns it.
Definition: dbus-list.c:638
#define _DBUS_N_ELEMENTS(array)
Computes the number of elements in a fixed-size array using sizeof().
dbus_bool_t _dbus_hash_table_insert_int(DBusHashTable *table, int key, void *value)
Creates a hash entry with the given key and value.
Definition: dbus-hash.c:1248
#define TRUE
Expands to &quot;1&quot;.
DBusWatch * _dbus_watch_ref(DBusWatch *watch)
Increments the reference count of a DBusWatch object.
Definition: dbus-watch.c:124
A node in a linked list.
Definition: dbus-list.h:34
int _dbus_list_get_length(DBusList **list)
Gets the length of a list.
Definition: dbus-list.c:719
void _dbus_hash_iter_init(DBusHashTable *table, DBusHashIter *iter)
Initializes a hash table iterator.
Definition: dbus-hash.c:517
void * _dbus_hash_iter_get_value(DBusHashIter *iter)
Gets the value of the current entry.
Definition: dbus-hash.c:613
DBusList * _dbus_list_get_first_link(DBusList **list)
Gets the first link in the list.
Definition: dbus-list.c:556
#define FALSE
Expands to &quot;0&quot;.
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:676
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:138
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:585
As in POLLIN.
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:168
void _dbus_sleep_milliseconds(int milliseconds)
Sleeps the given number of milliseconds.
DBUS_EXPORT int dbus_timeout_get_interval(DBusTimeout *timeout)
Gets the timeout interval.
Definition: dbus-timeout.c:416