D-Bus  1.12.16
dbus-watch.c
1 /* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
2 /* dbus-watch.c DBusWatch implementation
3  *
4  * Copyright (C) 2002, 2003 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-internals.h"
26 #include "dbus-watch.h"
27 #include "dbus-list.h"
28 
40 struct DBusWatch
41 {
42  int refcount;
43  DBusPollable fd;
44  unsigned int flags;
47  void *handler_data;
50  void *data;
52  unsigned int enabled : 1;
53  unsigned int oom_last_time : 1;
54 };
55 
57 _dbus_watch_get_enabled (DBusWatch *watch)
58 {
59  return watch->enabled;
60 }
61 
63 _dbus_watch_get_oom_last_time (DBusWatch *watch)
64 {
65  return watch->oom_last_time;
66 }
67 
68 void
69 _dbus_watch_set_oom_last_time (DBusWatch *watch,
70  dbus_bool_t oom)
71 {
72  watch->oom_last_time = oom;
73 }
74 
87 DBusWatch*
88 _dbus_watch_new (DBusPollable fd,
89  unsigned int flags,
90  dbus_bool_t enabled,
91  DBusWatchHandler handler,
92  void *data,
93  DBusFreeFunction free_data_function)
94 {
95  DBusWatch *watch;
96 
97 #define VALID_WATCH_FLAGS (DBUS_WATCH_WRITABLE | DBUS_WATCH_READABLE)
98 
99  _dbus_assert ((flags & VALID_WATCH_FLAGS) == flags);
100 
101  watch = dbus_new0 (DBusWatch, 1);
102  if (watch == NULL)
103  return NULL;
104 
105  watch->refcount = 1;
106  watch->fd = fd;
107  watch->flags = flags;
108  watch->enabled = enabled;
109 
110  watch->handler = handler;
111  watch->handler_data = data;
112  watch->free_handler_data_function = free_data_function;
113 
114  return watch;
115 }
116 
123 DBusWatch *
125 {
126  watch->refcount += 1;
127 
128  return watch;
129 }
130 
137 void
139 {
140  _dbus_assert (watch != NULL);
141  _dbus_assert (watch->refcount > 0);
142 
143  watch->refcount -= 1;
144  if (watch->refcount == 0)
145  {
146  if (_dbus_pollable_is_valid (watch->fd))
147  _dbus_warn ("this watch should have been invalidated");
148 
149  dbus_watch_set_data (watch, NULL, NULL); /* call free_data_function */
150 
151  if (watch->free_handler_data_function)
152  (* watch->free_handler_data_function) (watch->handler_data);
153 
154  dbus_free (watch);
155  }
156 }
157 
168 void
170 {
171  _dbus_pollable_invalidate (&watch->fd);
172  watch->flags = 0;
173 }
174 
184 void
186  unsigned int *condition)
187 {
188  if (!(watch->flags & DBUS_WATCH_READABLE))
189  *condition &= ~DBUS_WATCH_READABLE;
190  if (!(watch->flags & DBUS_WATCH_WRITABLE))
191  *condition &= ~DBUS_WATCH_WRITABLE;
192 }
193 
194 
215 {
221  void *watch_data;
223 };
224 
233 {
234  DBusWatchList *watch_list;
235 
236  watch_list = dbus_new0 (DBusWatchList, 1);
237  if (watch_list == NULL)
238  return NULL;
239 
240  return watch_list;
241 }
242 
248 void
250 {
251  /* free watch_data and removes watches as a side effect */
252  _dbus_watch_list_set_functions (watch_list,
253  NULL, NULL, NULL, NULL, NULL);
254  _dbus_list_foreach (&watch_list->watches,
256  NULL);
257  _dbus_list_clear (&watch_list->watches);
258 
259  dbus_free (watch_list);
260 }
261 
262 #ifdef DBUS_ENABLE_VERBOSE_MODE
263 static const char*
264 watch_flags_to_string (int flags)
265 {
266  const char *watch_type;
267 
268  if ((flags & DBUS_WATCH_READABLE) &&
269  (flags & DBUS_WATCH_WRITABLE))
270  watch_type = "readwrite";
271  else if (flags & DBUS_WATCH_READABLE)
272  watch_type = "read";
273  else if (flags & DBUS_WATCH_WRITABLE)
274  watch_type = "write";
275  else
276  watch_type = "not read or write";
277  return watch_type;
278 }
279 #endif /* DBUS_ENABLE_VERBOSE_MODE */
280 
297  DBusAddWatchFunction add_function,
298  DBusRemoveWatchFunction remove_function,
299  DBusWatchToggledFunction toggled_function,
300  void *data,
301  DBusFreeFunction free_data_function)
302 {
303  /* Add watches with the new watch function, failing on OOM */
304  if (add_function != NULL)
305  {
306  DBusList *link;
307 
308  link = _dbus_list_get_first_link (&watch_list->watches);
309  while (link != NULL)
310  {
311  DBusList *next = _dbus_list_get_next_link (&watch_list->watches,
312  link);
313 #ifdef DBUS_ENABLE_VERBOSE_MODE
314  DBusWatch *watch = link->data;
315 
316  _dbus_verbose ("Adding a %s watch on fd %" DBUS_POLLABLE_FORMAT " using newly-set add watch function\n",
317  watch_flags_to_string (dbus_watch_get_flags (link->data)),
318  _dbus_pollable_printable (watch->fd));
319 #endif
320 
321  if (!(* add_function) (link->data, data))
322  {
323  /* remove it all again and return FALSE */
324  DBusList *link2;
325 
326  link2 = _dbus_list_get_first_link (&watch_list->watches);
327  while (link2 != link)
328  {
329  DBusList *next2 = _dbus_list_get_next_link (&watch_list->watches,
330  link2);
331 #ifdef DBUS_ENABLE_VERBOSE_MODE
332  DBusWatch *watch2 = link2->data;
333 
334  _dbus_verbose ("Removing watch on fd %" DBUS_POLLABLE_FORMAT " using newly-set remove function because initial add failed\n",
335  _dbus_pollable_printable (watch2->fd));
336 #endif
337 
338  (* remove_function) (link2->data, data);
339 
340  link2 = next2;
341  }
342 
343  return FALSE;
344  }
345 
346  link = next;
347  }
348  }
349 
350  /* Remove all current watches from previous watch handlers */
351 
352  if (watch_list->remove_watch_function != NULL)
353  {
354  _dbus_verbose ("Removing all pre-existing watches\n");
355 
356  _dbus_list_foreach (&watch_list->watches,
358  watch_list->watch_data);
359  }
360 
361  if (watch_list->watch_free_data_function != NULL)
362  (* watch_list->watch_free_data_function) (watch_list->watch_data);
363 
364  watch_list->add_watch_function = add_function;
365  watch_list->remove_watch_function = remove_function;
366  watch_list->watch_toggled_function = toggled_function;
367  watch_list->watch_data = data;
368  watch_list->watch_free_data_function = free_data_function;
369 
370  return TRUE;
371 }
372 
383  DBusWatch *watch)
384 {
385  if (!_dbus_list_append (&watch_list->watches, watch))
386  return FALSE;
387 
388  _dbus_watch_ref (watch);
389 
390  if (watch_list->add_watch_function != NULL)
391  {
392  _dbus_verbose ("Adding watch on fd %" DBUS_POLLABLE_FORMAT "\n",
393  _dbus_pollable_printable (watch->fd));
394 
395  if (!(* watch_list->add_watch_function) (watch,
396  watch_list->watch_data))
397  {
398  _dbus_list_remove_last (&watch_list->watches, watch);
399  _dbus_watch_unref (watch);
400  return FALSE;
401  }
402  }
403 
404  return TRUE;
405 }
406 
414 void
416  DBusWatch *watch)
417 {
418  if (!_dbus_list_remove (&watch_list->watches, watch))
419  _dbus_assert_not_reached ("Nonexistent watch was removed");
420 
421  if (watch_list->remove_watch_function != NULL)
422  {
423  _dbus_verbose ("Removing watch on fd %" DBUS_POLLABLE_FORMAT "\n",
424  _dbus_pollable_printable (watch->fd));
425 
426  (* watch_list->remove_watch_function) (watch,
427  watch_list->watch_data);
428  }
429 
430  _dbus_watch_unref (watch);
431 }
432 
441 void
443  DBusWatch *watch,
444  dbus_bool_t enabled)
445 {
446  enabled = !!enabled;
447 
448  if (enabled == watch->enabled)
449  return;
450 
451  watch->enabled = enabled;
452 
453  if (watch_list->watch_toggled_function != NULL)
454  {
455  _dbus_verbose ("Toggling watch %p on fd %" DBUS_POLLABLE_FORMAT " to %d\n",
456  watch,
457  _dbus_pollable_printable (watch->fd),
458  watch->enabled);
459 
460  (* watch_list->watch_toggled_function) (watch,
461  watch_list->watch_data);
462  }
463 }
464 
472 void
474  dbus_bool_t enabled)
475 {
476  DBusList *link;
477 
478  for (link = _dbus_list_get_first_link (&watch_list->watches);
479  link != NULL;
480  link = _dbus_list_get_next_link (&watch_list->watches, link))
481  {
482  _dbus_watch_list_toggle_watch (watch_list, link->data, enabled);
483  }
484 }
485 
498 void
500  DBusWatchHandler handler,
501  void *data,
502  DBusFreeFunction free_data_function)
503 {
504  if (watch->free_handler_data_function)
505  (* watch->free_handler_data_function) (watch->handler_data);
506 
507  watch->handler = handler;
508  watch->handler_data = data;
509  watch->free_handler_data_function = free_data_function;
510 }
511 
543 int
545 {
546  _dbus_return_val_if_fail (watch != NULL, -1);
547 
548  return dbus_watch_get_unix_fd(watch);
549 }
550 
564 int
566 {
567  _dbus_return_val_if_fail (watch != NULL, -1);
568 
569  /* FIXME remove #ifdef and do this on a lower level
570  * (watch should have set_socket and set_unix_fd and track
571  * which it has, and the transport should provide the
572  * appropriate watch type)
573  */
574 #ifdef DBUS_UNIX
575  return watch->fd;
576 #else
577  return dbus_watch_get_socket( watch );
578 #endif
579 }
580 
593 int
595 {
596  _dbus_return_val_if_fail (watch != NULL, -1);
597 
598 #ifdef DBUS_UNIX
599  return watch->fd;
600 #else
601  return _dbus_socket_get_int (watch->fd);
602 #endif
603 }
604 
606 _dbus_watch_get_socket (DBusWatch *watch)
607 {
608  DBusSocket s;
609 
610  _dbus_assert (watch != NULL);
611 
612 #ifdef DBUS_UNIX
613  s.fd = watch->fd;
614 #else
615  s = watch->fd;
616 #endif
617 
618  return s;
619 }
620 
621 DBusPollable
622 _dbus_watch_get_pollable (DBusWatch *watch)
623 {
624  _dbus_assert (watch != NULL);
625 
626  return watch->fd;
627 }
628 
642 unsigned int
644 {
645  _dbus_return_val_if_fail (watch != NULL, 0);
646  _dbus_assert ((watch->flags & VALID_WATCH_FLAGS) == watch->flags);
647 
648  return watch->flags;
649 }
650 
658 void*
660 {
661  _dbus_return_val_if_fail (watch != NULL, NULL);
662 
663  return watch->data;
664 }
665 
677 void
679  void *data,
680  DBusFreeFunction free_data_function)
681 {
682  _dbus_return_if_fail (watch != NULL);
683 
684  _dbus_verbose ("Setting watch fd %" DBUS_POLLABLE_FORMAT " data to data = %p function = %p from data = %p function = %p\n",
685  _dbus_pollable_printable (watch->fd),
686  data, free_data_function, watch->data, watch->free_data_function);
687 
688  if (watch->free_data_function != NULL)
689  (* watch->free_data_function) (watch->data);
690 
691  watch->data = data;
692  watch->free_data_function = free_data_function;
693 }
694 
704 {
705  _dbus_return_val_if_fail (watch != NULL, FALSE);
706 
707  return watch->enabled;
708 }
709 
710 
735  unsigned int flags)
736 {
737  _dbus_return_val_if_fail (watch != NULL, FALSE);
738 
739 #ifndef DBUS_DISABLE_CHECKS
740  if (!_dbus_pollable_is_valid (watch->fd) || watch->flags == 0)
741  {
742  _dbus_warn_check_failed ("Watch is invalid, it should have been removed");
743  return TRUE;
744  }
745 #endif
746 
747  _dbus_return_val_if_fail (_dbus_pollable_is_valid (watch->fd) /* fails if watch was removed */, TRUE);
748 
749  _dbus_watch_sanitize_condition (watch, &flags);
750 
751  if (flags == 0)
752  {
753  _dbus_verbose ("After sanitization, watch flags on fd %" DBUS_POLLABLE_FORMAT " were 0\n",
754  _dbus_pollable_printable (watch->fd));
755  return TRUE;
756  }
757  else
758  return (* watch->handler) (watch, flags,
759  watch->handler_data);
760 }
761 
762