D-Bus  1.13.7
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,
92  void *data,
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;
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 
255  _dbus_list_clear_full (&watch_list->watches,
257 
258  dbus_free (watch_list);
259 }
260 
261 #ifdef DBUS_ENABLE_VERBOSE_MODE
262 static const char*
263 watch_flags_to_string (int flags)
264 {
265  const char *watch_type;
266 
267  if ((flags & DBUS_WATCH_READABLE) &&
268  (flags & DBUS_WATCH_WRITABLE))
269  watch_type = "readwrite";
270  else if (flags & DBUS_WATCH_READABLE)
271  watch_type = "read";
272  else if (flags & DBUS_WATCH_WRITABLE)
273  watch_type = "write";
274  else
275  watch_type = "not read or write";
276  return watch_type;
277 }
278 #endif /* DBUS_ENABLE_VERBOSE_MODE */
279 
296  DBusAddWatchFunction add_function,
297  DBusRemoveWatchFunction remove_function,
298  DBusWatchToggledFunction toggled_function,
299  void *data,
301 {
302  /* Add watches with the new watch function, failing on OOM */
303  if (add_function != NULL)
304  {
305  DBusList *link;
306 
307  link = _dbus_list_get_first_link (&watch_list->watches);
308  while (link != NULL)
309  {
310  DBusList *next = _dbus_list_get_next_link (&watch_list->watches,
311  link);
312 #ifdef DBUS_ENABLE_VERBOSE_MODE
313  DBusWatch *watch = link->data;
314 
315  _dbus_verbose ("Adding a %s watch on fd %" DBUS_POLLABLE_FORMAT " using newly-set add watch function\n",
316  watch_flags_to_string (dbus_watch_get_flags (link->data)),
317  _dbus_pollable_printable (watch->fd));
318 #endif
319 
320  if (!(* add_function) (link->data, data))
321  {
322  /* remove it all again and return FALSE */
323  DBusList *link2;
324 
325  link2 = _dbus_list_get_first_link (&watch_list->watches);
326  while (link2 != link)
327  {
328  DBusList *next2 = _dbus_list_get_next_link (&watch_list->watches,
329  link2);
330 #ifdef DBUS_ENABLE_VERBOSE_MODE
331  DBusWatch *watch2 = link2->data;
332 
333  _dbus_verbose ("Removing watch on fd %" DBUS_POLLABLE_FORMAT " using newly-set remove function because initial add failed\n",
334  _dbus_pollable_printable (watch2->fd));
335 #endif
336 
337  (* remove_function) (link2->data, data);
338 
339  link2 = next2;
340  }
341 
342  return FALSE;
343  }
344 
345  link = next;
346  }
347  }
348 
349  /* Remove all current watches from previous watch handlers */
350 
351  if (watch_list->remove_watch_function != NULL)
352  {
353  _dbus_verbose ("Removing all pre-existing watches\n");
354 
355  _dbus_list_foreach (&watch_list->watches,
357  watch_list->watch_data);
358  }
359 
360  if (watch_list->watch_free_data_function != NULL)
361  (* watch_list->watch_free_data_function) (watch_list->watch_data);
362 
363  watch_list->add_watch_function = add_function;
364  watch_list->remove_watch_function = remove_function;
365  watch_list->watch_toggled_function = toggled_function;
366  watch_list->watch_data = data;
368 
369  return TRUE;
370 }
371 
382  DBusWatch *watch)
383 {
384  if (!_dbus_list_append (&watch_list->watches, watch))
385  return FALSE;
386 
387  _dbus_watch_ref (watch);
388 
389  if (watch_list->add_watch_function != NULL)
390  {
391  _dbus_verbose ("Adding watch on fd %" DBUS_POLLABLE_FORMAT "\n",
392  _dbus_pollable_printable (watch->fd));
393 
394  if (!(* watch_list->add_watch_function) (watch,
395  watch_list->watch_data))
396  {
397  _dbus_list_remove_last (&watch_list->watches, watch);
398  _dbus_watch_unref (watch);
399  return FALSE;
400  }
401  }
402 
403  return TRUE;
404 }
405 
413 void
415  DBusWatch *watch)
416 {
417  if (!_dbus_list_remove (&watch_list->watches, watch))
418  _dbus_assert_not_reached ("Nonexistent watch was removed");
419 
420  if (watch_list->remove_watch_function != NULL)
421  {
422  _dbus_verbose ("Removing watch on fd %" DBUS_POLLABLE_FORMAT "\n",
423  _dbus_pollable_printable (watch->fd));
424 
425  (* watch_list->remove_watch_function) (watch,
426  watch_list->watch_data);
427  }
428 
429  _dbus_watch_unref (watch);
430 }
431 
440 void
442  DBusWatch *watch,
444 {
445  enabled = !!enabled;
446 
447  if (enabled == watch->enabled)
448  return;
449 
450  watch->enabled = enabled;
451 
452  if (watch_list->watch_toggled_function != NULL)
453  {
454  _dbus_verbose ("Toggling watch %p on fd %" DBUS_POLLABLE_FORMAT " to %d\n",
455  watch,
456  _dbus_pollable_printable (watch->fd),
457  watch->enabled);
458 
459  (* watch_list->watch_toggled_function) (watch,
460  watch_list->watch_data);
461  }
462 }
463 
471 void
474 {
475  DBusList *link;
476 
477  for (link = _dbus_list_get_first_link (&watch_list->watches);
478  link != NULL;
479  link = _dbus_list_get_next_link (&watch_list->watches, link))
480  {
481  _dbus_watch_list_toggle_watch (watch_list, link->data, enabled);
482  }
483 }
484 
497 void
500  void *data,
502 {
503  if (watch->free_handler_data_function)
504  (* watch->free_handler_data_function) (watch->handler_data);
505 
506  watch->handler = handler;
507  watch->handler_data = data;
509 }
510 
542 int
544 {
545  _dbus_return_val_if_fail (watch != NULL, -1);
546 
547  return dbus_watch_get_unix_fd(watch);
548 }
549 
563 int
565 {
566  _dbus_return_val_if_fail (watch != NULL, -1);
567 
568  /* FIXME remove #ifdef and do this on a lower level
569  * (watch should have set_socket and set_unix_fd and track
570  * which it has, and the transport should provide the
571  * appropriate watch type)
572  */
573 #ifdef DBUS_UNIX
574  return watch->fd;
575 #else
576  return dbus_watch_get_socket( watch );
577 #endif
578 }
579 
592 int
594 {
595  _dbus_return_val_if_fail (watch != NULL, -1);
596 
597 #ifdef DBUS_UNIX
598  return watch->fd;
599 #else
600  return _dbus_socket_get_int (watch->fd);
601 #endif
602 }
603 
605 _dbus_watch_get_socket (DBusWatch *watch)
606 {
607  DBusSocket s;
608 
609  _dbus_assert (watch != NULL);
610 
611 #ifdef DBUS_UNIX
612  s.fd = watch->fd;
613 #else
614  s = watch->fd;
615 #endif
616 
617  return s;
618 }
619 
620 DBusPollable
621 _dbus_watch_get_pollable (DBusWatch *watch)
622 {
623  _dbus_assert (watch != NULL);
624 
625  return watch->fd;
626 }
627 
641 unsigned int
643 {
644  _dbus_return_val_if_fail (watch != NULL, 0);
645  _dbus_assert ((watch->flags & VALID_WATCH_FLAGS) == watch->flags);
646 
647  return watch->flags;
648 }
649 
657 void*
659 {
660  _dbus_return_val_if_fail (watch != NULL, NULL);
661 
662  return watch->data;
663 }
664 
676 void
678  void *data,
680 {
681  _dbus_return_if_fail (watch != NULL);
682 
683  _dbus_verbose ("Setting watch fd %" DBUS_POLLABLE_FORMAT " data to data = %p function = %p from data = %p function = %p\n",
684  _dbus_pollable_printable (watch->fd),
685  data, free_data_function, watch->data, watch->free_data_function);
686 
687  if (watch->free_data_function != NULL)
688  (* watch->free_data_function) (watch->data);
689 
690  watch->data = data;
692 }
693 
703 {
704  _dbus_return_val_if_fail (watch != NULL, FALSE);
705 
706  return watch->enabled;
707 }
708 
709 
734  unsigned int flags)
735 {
736  _dbus_return_val_if_fail (watch != NULL, FALSE);
737 
738 #ifndef DBUS_DISABLE_CHECKS
739  if (!_dbus_pollable_is_valid (watch->fd) || watch->flags == 0)
740  {
741  _dbus_warn_check_failed ("Watch is invalid, it should have been removed");
742  return TRUE;
743  }
744 #endif
745 
746  _dbus_return_val_if_fail (_dbus_pollable_is_valid (watch->fd) /* fails if watch was removed */, TRUE);
747 
748  _dbus_watch_sanitize_condition (watch, &flags);
749 
750  if (flags == 0)
751  {
752  _dbus_verbose ("After sanitization, watch flags on fd %" DBUS_POLLABLE_FORMAT " were 0\n",
753  _dbus_pollable_printable (watch->fd));
754  return TRUE;
755  }
756  else
757  return (* watch->handler) (watch, flags,
758  watch->handler_data);
759 }
760 
761 
DBusWatch * _dbus_watch_new(DBusPollable fd, unsigned int flags, dbus_bool_t enabled, DBusWatchHandler handler, void *data, DBusFreeFunction free_data_function)
Creates a new DBusWatch.
Definition: dbus-watch.c:88
Implementation of DBusWatch.
Definition: dbus-watch.c:40
#define NULL
A null pointer, defined appropriately for C or C++.
void(* DBusFreeFunction)(void *memory)
The type of a function which frees a block of memory.
Definition: dbus-memory.h:63
void dbus_free(void *memory)
Frees a block of memory previously allocated by dbus_malloc() or dbus_malloc0().
Definition: dbus-memory.c:703
DBusFreeFunction watch_free_data_function
Free function for watch callback data.
Definition: dbus-watch.c:222
void * handler_data
Watch handler data.
Definition: dbus-watch.c:47
void(* DBusWatchToggledFunction)(DBusWatch *watch, void *data)
Called when dbus_watch_get_enabled() may return a different value than it did before.
DBUS_EXPORT dbus_bool_t dbus_watch_get_enabled(DBusWatch *watch)
Returns whether a watch is enabled or not.
Definition: dbus-watch.c:702
#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
void _dbus_warn_check_failed(const char *format,...)
Prints a "critical" warning to stderr when an assertion fails; differs from _dbus_warn primarily in t...
dbus_bool_t(* DBusWatchHandler)(DBusWatch *watch, unsigned int flags, void *data)
function to run when the watch is handled
Definition: dbus-watch.h:43
void _dbus_watch_list_toggle_watch(DBusWatchList *watch_list, DBusWatch *watch, dbus_bool_t enabled)
Sets a watch to the given enabled state, invoking the application&#39;s DBusWatchToggledFunction if appro...
Definition: dbus-watch.c:441
DBusAddWatchFunction add_watch_function
Callback for adding a watch.
Definition: dbus-watch.c:218
DBusFreeFunction free_data_function
Free the application data.
Definition: dbus-watch.c:51
void _dbus_watch_list_free(DBusWatchList *watch_list)
Frees a DBusWatchList.
Definition: dbus-watch.c:249
void _dbus_list_clear_full(DBusList **list, DBusFreeFunction function)
Free every link and every element in the list.
Definition: dbus-list.c:568
DBusWatchToggledFunction watch_toggled_function
Callback on toggling enablement.
Definition: dbus-watch.c:220
DBusWatchList * _dbus_watch_list_new(void)
Creates a new watch list.
Definition: dbus-watch.c:232
void * watch_data
Data for watch callbacks.
Definition: dbus-watch.c:221
dbus_bool_t _dbus_list_remove(DBusList **list, void *data)
Removes a value from the list.
Definition: dbus-list.c:416
unsigned int flags
Conditions to watch.
Definition: dbus-watch.c:44
#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:119
dbus_bool_t _dbus_watch_list_set_functions(DBusWatchList *watch_list, DBusAddWatchFunction add_function, DBusRemoveWatchFunction remove_function, DBusWatchToggledFunction toggled_function, void *data, DBusFreeFunction free_data_function)
Sets the watch functions.
Definition: dbus-watch.c:295
Socket interface.
Definition: dbus-sysdeps.h:178
dbus_bool_t _dbus_list_remove_last(DBusList **list, void *data)
Removes a value from the list.
Definition: dbus-list.c:447
#define dbus_new0(type, count)
Safe macro for using dbus_malloc0().
Definition: dbus-memory.h:58
As in POLLOUT.
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:593
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:271
void _dbus_watch_sanitize_condition(DBusWatch *watch, unsigned int *condition)
Sanitizes the given condition so that it only contains flags that the DBusWatch requested.
Definition: dbus-watch.c:185
void _dbus_list_foreach(DBusList **list, DBusForeachFunction function, void *data)
Calls the given function for each element in the list.
Definition: dbus-list.c:787
void _dbus_watch_list_toggle_all_watches(DBusWatchList *watch_list, dbus_bool_t enabled)
Sets all watches to the given enabled state, invoking the application&#39;s DBusWatchToggledFunction if a...
Definition: dbus-watch.c:472
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
unsigned int oom_last_time
Whether it was OOM last time.
Definition: dbus-watch.c:53
void * data
Application data.
Definition: dbus-watch.c:50
DBUS_EXPORT int dbus_watch_get_unix_fd(DBusWatch *watch)
Returns a UNIX file descriptor to be watched, which may be a pipe, socket, or other type of descripto...
Definition: dbus-watch.c:564
int refcount
Reference count.
Definition: dbus-watch.c:42
#define TRUE
Expands to "1".
#define _dbus_assert_not_reached(explanation)
Aborts with an error message if called.
dbus_bool_t _dbus_watch_list_add_watch(DBusWatchList *watch_list, DBusWatch *watch)
Adds a new watch to the watch list, invoking the application DBusAddWatchFunction if appropriate...
Definition: dbus-watch.c:381
DBUS_EXPORT DBUS_DEPRECATED int dbus_watch_get_fd(DBusWatch *watch)
Deprecated former name of dbus_watch_get_unix_fd().
Definition: dbus-watch.c:543
dbus_bool_t(* DBusAddWatchFunction)(DBusWatch *watch, void *data)
Called when libdbus needs a new watch to be monitored by the main loop.
DBUS_EXPORT void dbus_watch_set_data(DBusWatch *watch, void *data, DBusFreeFunction free_data_function)
Sets data which can be retrieved with dbus_watch_get_data().
Definition: dbus-watch.c:677
void(* DBusRemoveWatchFunction)(DBusWatch *watch, void *data)
Called when libdbus no longer needs a watch to be monitored by the main loop.
DBusWatchList implementation details.
Definition: dbus-watch.c:214
unsigned int enabled
Whether it&#39;s enabled.
Definition: dbus-watch.c:52
DBUS_EXPORT void * dbus_watch_get_data(DBusWatch *watch)
Gets data previously set with dbus_watch_set_data() or NULL if none.
Definition: dbus-watch.c:658
void _dbus_watch_list_remove_watch(DBusWatchList *watch_list, DBusWatch *watch)
Removes a watch from the watch list, invoking the application&#39;s DBusRemoveWatchFunction if appropriat...
Definition: dbus-watch.c:414
A node in a linked list.
Definition: dbus-list.h:34
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
void(* DBusForeachFunction)(void *element, void *data)
Used to iterate over each item in a collection, such as a DBusList.
DBusList * _dbus_list_get_first_link(DBusList **list)
Gets the first link in the list.
Definition: dbus-list.c:595
#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:733
DBusWatch * _dbus_watch_ref(DBusWatch *watch)
Increments the reference count of a DBusWatch object.
Definition: dbus-watch.c:124
DBusPollable fd
File descriptor.
Definition: dbus-watch.c:43
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:642
As in POLLIN.
DBusFreeFunction free_handler_data_function
Free the watch handler data.
Definition: dbus-watch.c:48
void _dbus_watch_set_handler(DBusWatch *watch, DBusWatchHandler handler, void *data, DBusFreeFunction free_data_function)
Sets the handler for the watch.
Definition: dbus-watch.c:498
DBusRemoveWatchFunction remove_watch_function
Callback for removing a watch.
Definition: dbus-watch.c:219
DBusWatchHandler handler
Watch handler.
Definition: dbus-watch.c:46
DBusList * watches
Watch objects.
Definition: dbus-watch.c:216