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