D-Bus: dbus-list.c Source File

D-Bus 1.16.2

dbus-list.c
1/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
2/* dbus-list.c Generic linked list utility (internal to D-Bus implementation)
3 *
4 * Copyright (C) 2002 Red Hat, Inc.
5 *
6 * SPDX-License-Identifier: AFL-2.1 OR GPL-2.0-or-later
7 *
8 * Licensed under the Academic Free License version 2.1
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
14 *
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
23 *
24 */
25
26#include <config.h>
27#include "dbus-internals.h"
28#include "dbus-list.h"
29#include "dbus-mempool.h"
30#include "dbus-threads-internal.h"
31#include <dbus/dbus-test-tap.h>
32
41/* Protected by _DBUS_LOCK (list) */
42static DBusMemPool *list_pool;
43
54/* the mem pool is probably a speed hit, with the thread
55 * lock, though it does still save memory - unknown.
56 */
57static DBusList*
58alloc_link (void *data)
59{
60 DBusList *link;
61
62 if (!_DBUS_LOCK (list))
63 return FALSE;
64
65 if (list_pool == NULL)
66 {
67 list_pool = _dbus_mem_pool_new (sizeof (DBusList), TRUE);
68
69 if (list_pool == NULL)
70 {
71 _DBUS_UNLOCK (list);
72 return NULL;
73 }
74
75 link = _dbus_mem_pool_alloc (list_pool);
76 if (link == NULL)
77 {
78 _dbus_mem_pool_free (list_pool);
79 list_pool = NULL;
80 _DBUS_UNLOCK (list);
81 return NULL;
82 }
83 }
84 else
85 {
86 link = _dbus_mem_pool_alloc (list_pool);
87 }
88
89 if (link)
90 link->data = data;
91
92 _DBUS_UNLOCK (list);
93
94 return link;
95}
96
97static void
98free_link (DBusList *link)
99{
100 if (!_DBUS_LOCK (list))
101 _dbus_assert_not_reached ("we should have initialized global locks "
102 "before we allocated a linked-list link");
103
104 if (_dbus_mem_pool_dealloc (list_pool, link))
105 {
106 _dbus_mem_pool_free (list_pool);
107 list_pool = NULL;
108 }
109
110 _DBUS_UNLOCK (list);
111}
112
113static void
114link_before (DBusList **list,
115 DBusList *before_this_link,
116 DBusList *link)
117{
118 if (*list == NULL)
119 {
120 link->prev = link;
121 link->next = link;
122 *list = link;
123 }
124 else
125 {
126 link->next = before_this_link;
127 link->prev = before_this_link->prev;
128 before_this_link->prev = link;
129 link->prev->next = link;
130
131 if (before_this_link == *list)
132 *list = link;
133 }
134}
135
136static void
137link_after (DBusList **list,
138 DBusList *after_this_link,
139 DBusList *link)
140{
141 if (*list == NULL)
142 {
143 link->prev = link;
144 link->next = link;
145 *list = link;
146 }
147 else
148 {
149 link->prev = after_this_link;
150 link->next = after_this_link->next;
151 after_this_link->next = link;
152 link->next->prev = link;
153 }
154}
155
156#ifdef DBUS_ENABLE_STATS
157void
158_dbus_list_get_stats (dbus_uint32_t *in_use_p,
159 dbus_uint32_t *in_free_list_p,
160 dbus_uint32_t *allocated_p)
161{
162 if (!_DBUS_LOCK (list))
163 {
164 *in_use_p = 0;
165 *in_free_list_p = 0;
166 *allocated_p = 0;
167 return;
168 }
169
170 _dbus_mem_pool_get_stats (list_pool, in_use_p, in_free_list_p, allocated_p);
171 _DBUS_UNLOCK (list);
172}
173#endif
174
244 DBusList*
245_dbus_list_alloc_link (void *data)
246{
247 return alloc_link (data);
248}
249
256void
257_dbus_list_free_link (DBusList *link)
258{
259 free_link (link);
260}
261
262
272 dbus_bool_t
273_dbus_list_append (DBusList **list,
274 void *data)
275{
276 if (!_dbus_list_prepend (list, data))
277 return FALSE;
278
279 /* Now cycle the list forward one so the prepended node is the tail */
280 *list = (*list)->next;
281
282 return TRUE;
283}
284
294 dbus_bool_t
295_dbus_list_prepend (DBusList **list,
296 void *data)
297{
298 DBusList *link;
299
300 link = alloc_link (data);
301 if (link == NULL)
302 return FALSE;
303
304 link_before (list, *list, link);
305
306 return TRUE;
307}
308
317void
318_dbus_list_append_link (DBusList **list,
319 DBusList *link)
320{
321 _dbus_list_prepend_link (list, link);
322
323 /* Now cycle the list forward one so the prepended node is the tail */
324 *list = (*list)->next;
325}
326
335void
336_dbus_list_prepend_link (DBusList **list,
337 DBusList *link)
338{
339 link_before (list, *list, link);
340}
341
350 dbus_bool_t
351_dbus_list_insert_after (DBusList **list,
352 DBusList *after_this_link,
353 void *data)
354{
355 DBusList *link;
356
357 if (after_this_link == NULL)
358 return _dbus_list_prepend (list, data);
359 else
360 {
361 link = alloc_link (data);
362 if (link == NULL)
363 return FALSE;
364
365 link_after (list, after_this_link, link);
366 }
367
368 return TRUE;
369}
370
378void
379_dbus_list_insert_before_link (DBusList **list,
380 DBusList *before_this_link,
381 DBusList *link)
382{
383 if (before_this_link == NULL)
384 _dbus_list_append_link (list, link);
385 else
386 link_before (list, before_this_link, link);
387}
388
396void
397_dbus_list_insert_after_link (DBusList **list,
398 DBusList *after_this_link,
399 DBusList *link)
400{
401 if (after_this_link == NULL)
402 _dbus_list_prepend_link (list, link);
403 else
404 link_after (list, after_this_link, link);
405}
406
417 dbus_bool_t
418_dbus_list_remove (DBusList **list,
419 void *data)
420{
421 DBusList *link;
422
423 link = *list;
424 while (link != NULL)
425 {
426 if (link->data == data)
427 {
428 _dbus_list_remove_link (list, link);
429 return TRUE;
430 }
431
432 link = _dbus_list_get_next_link (list, link);
433 }
434
435 return FALSE;
436}
437
448 dbus_bool_t
449_dbus_list_remove_last (DBusList **list,
450 void *data)
451{
452 DBusList *link;
453
454 link = _dbus_list_find_last (list, data);
455 if (link)
456 {
457 _dbus_list_remove_link (list, link);
458 return TRUE;
459 }
460 else
461 return FALSE;
462}
463
474 DBusList*
475_dbus_list_find_last (DBusList **list,
476 void *data)
477{
478 DBusList *link;
479
480 link = _dbus_list_get_last_link (list);
481
482 while (link != NULL)
483 {
484 if (link->data == data)
485 return link;
486
487 link = _dbus_list_get_prev_link (list, link);
488 }
489
490 return NULL;
491}
492
501void
502_dbus_list_unlink (DBusList **list,
503 DBusList *link)
504{
505 if (link->next == link)
506 {
507 /* one-element list */
508 *list = NULL;
509 }
510 else
511 {
512 link->prev->next = link->next;
513 link->next->prev = link->prev;
514
515 if (*list == link)
516 *list = link->next;
517 }
518
519 link->next = NULL;
520 link->prev = NULL;
521}
522
529void
530_dbus_list_remove_link (DBusList **list,
531 DBusList *link)
532{
533 _dbus_list_unlink (list, link);
534 free_link (link);
535}
536
544void
545_dbus_list_clear (DBusList **list)
546{
547 DBusList *link;
548
549 link = *list;
550 while (link != NULL)
551 {
552 DBusList *next = _dbus_list_get_next_link (list, link);
553
554 free_link (link);
555
556 link = next;
557 }
558
559 *list = NULL;
560}
561
569void
570_dbus_list_clear_full (DBusList **list,
571 DBusFreeFunction function)
572{
573 DBusList *link;
574
575 link = *list;
576 while (link != NULL)
577 {
578 DBusList *next = _dbus_list_get_next_link (list, link);
579
580 function (link->data);
581 free_link (link);
582
583 link = next;
584 }
585
586 *list = NULL;
587}
588
596 DBusList*
597_dbus_list_get_first_link (DBusList **list)
598{
599 return *list;
600}
601
609 DBusList*
610_dbus_list_get_last_link (DBusList **list)
611{
612 if (*list == NULL)
613 return NULL;
614 else
615 return (*list)->prev;
616}
617
625void*
626_dbus_list_get_last (DBusList **list)
627{
628 if (*list == NULL)
629 return NULL;
630 else
631 return (*list)->prev->data;
632}
633
641void*
642_dbus_list_get_first (DBusList **list)
643{
644 if (*list == NULL)
645 return NULL;
646 else
647 return (*list)->data;
648}
649
657 DBusList*
658_dbus_list_pop_first_link (DBusList **list)
659{
660 DBusList *link;
661
662 link = _dbus_list_get_first_link (list);
663 if (link == NULL)
664 return NULL;
665
666 _dbus_list_unlink (list, link);
667
668 return link;
669}
670
678void*
679_dbus_list_pop_first (DBusList **list)
680{
681 DBusList *link;
682 void *data;
683
684 link = _dbus_list_get_first_link (list);
685 if (link == NULL)
686 return NULL;
687
688 data = link->data;
689 _dbus_list_remove_link (list, link);
690
691 return data;
692}
693
701void*
702_dbus_list_pop_last (DBusList **list)
703{
704 DBusList *link;
705 void *data;
706
707 link = _dbus_list_get_last_link (list);
708 if (link == NULL)
709 return NULL;
710
711 data = link->data;
712 _dbus_list_remove_link (list, link);
713
714 return data;
715}
716
726 dbus_bool_t
727_dbus_list_copy (DBusList **list,
728 DBusList **dest)
729{
730 DBusList *link;
731
732 _dbus_assert (list != dest);
733
734 *dest = NULL;
735
736 link = *list;
737 while (link != NULL)
738 {
739 if (!_dbus_list_append (dest, link->data))
740 {
741 /* free what we have so far */
742 _dbus_list_clear (dest);
743 return FALSE;
744 }
745
746 link = _dbus_list_get_next_link (list, link);
747 }
748
749 return TRUE;
750}
751
759int
760_dbus_list_get_length (DBusList **list)
761{
762 DBusList *link;
763 int length;
764
765 length = 0;
766
767 link = *list;
768 while (link != NULL)
769 {
770 ++length;
771
772 link = _dbus_list_get_next_link (list, link);
773 }
774
775 return length;
776}
777
788void
789_dbus_list_foreach (DBusList **list,
790 DBusForeachFunction function,
791 void *data)
792{
793 DBusList *link;
794
795 link = *list;
796 while (link != NULL)
797 {
798 DBusList *next = _dbus_list_get_next_link (list, link);
799
800 (* function) (link->data, data);
801
802 link = next;
803 }
804}
805
812 dbus_bool_t
813_dbus_list_length_is_one (DBusList **list)
814{
815 return (*list != NULL &&
816 (*list)->next == *list);
817}
818
_dbus_assert_not_reached
#define _dbus_assert_not_reached(explanation)
Aborts with an error message if called.
Definition dbus-internals.h:164
_dbus_assert
#define _dbus_assert(condition)
Aborts with an error message if the condition is false.
Definition dbus-internals.h:153
_DBUS_UNLOCK
#define _DBUS_UNLOCK(name)
Unlocks a global lock.
Definition dbus-internals.h:438
DBusForeachFunction
void(* DBusForeachFunction)(void *element, void *data)
Used to iterate over each item in a collection, such as a DBusList.
Definition dbus-internals.h:347
_DBUS_LOCK
#define _DBUS_LOCK(name)
Locks a global lock, initializing it first if necessary.
Definition dbus-internals.h:437
_dbus_list_get_first_link
DBusList * _dbus_list_get_first_link(DBusList **list)
Gets the first link in the list.
Definition dbus-list.c:597
_dbus_list_insert_before_link
void _dbus_list_insert_before_link(DBusList **list, DBusList *before_this_link, DBusList *link)
Inserts a link into the list before the given existing link.
Definition dbus-list.c:379
_dbus_list_copy
dbus_bool_t _dbus_list_copy(DBusList **list, DBusList **dest)
Copies a list.
Definition dbus-list.c:727
_dbus_list_pop_first_link
DBusList * _dbus_list_pop_first_link(DBusList **list)
Removes the first link in the list and returns it.
Definition dbus-list.c:658
_dbus_list_length_is_one
dbus_bool_t _dbus_list_length_is_one(DBusList **list)
Check whether length is exactly one.
Definition dbus-list.c:813
_dbus_list_get_last
void * _dbus_list_get_last(DBusList **list)
Gets the last data in the list.
Definition dbus-list.c:626
_dbus_list_remove
dbus_bool_t _dbus_list_remove(DBusList **list, void *data)
Removes a value from the list.
Definition dbus-list.c:418
_dbus_list_append_link
void _dbus_list_append_link(DBusList **list, DBusList *link)
Appends a link to the list.
Definition dbus-list.c:318
_dbus_list_insert_after_link
void _dbus_list_insert_after_link(DBusList **list, DBusList *after_this_link, DBusList *link)
Inserts a link into the list after the given existing link.
Definition dbus-list.c:397
_dbus_list_clear_full
void _dbus_list_clear_full(DBusList **list, DBusFreeFunction function)
Free every link and every element in the list.
Definition dbus-list.c:570
_dbus_list_insert_after
dbus_bool_t _dbus_list_insert_after(DBusList **list, DBusList *after_this_link, void *data)
Inserts data into the list after the given existing link.
Definition dbus-list.c:351
_dbus_list_remove_link
void _dbus_list_remove_link(DBusList **list, DBusList *link)
Removes a link from the list.
Definition dbus-list.c:530
_dbus_list_get_first
void * _dbus_list_get_first(DBusList **list)
Gets the first data in the list.
Definition dbus-list.c:642
_dbus_list_get_last_link
DBusList * _dbus_list_get_last_link(DBusList **list)
Gets the last link in the list.
Definition dbus-list.c:610
_dbus_list_unlink
void _dbus_list_unlink(DBusList **list, DBusList *link)
Removes the given link from the list, but doesn't free it.
Definition dbus-list.c:502
_dbus_list_find_last
DBusList * _dbus_list_find_last(DBusList **list, void *data)
Finds a value in the list.
Definition dbus-list.c:475
_dbus_list_pop_last
void * _dbus_list_pop_last(DBusList **list)
Removes the last value in the list and returns it.
Definition dbus-list.c:702
_dbus_list_get_prev_link
#define _dbus_list_get_prev_link(list, link)
Gets the previous link in the list, or NULL if there are no more links.
Definition dbus-list.h:122
_dbus_list_free_link
void _dbus_list_free_link(DBusList *link)
Frees a linked list node allocated with _dbus_list_alloc_link.
Definition dbus-list.c:257
_dbus_list_pop_first
void * _dbus_list_pop_first(DBusList **list)
Removes the first value in the list and returns it.
Definition dbus-list.c:679
_dbus_list_foreach
void _dbus_list_foreach(DBusList **list, DBusForeachFunction function, void *data)
Calls the given function for each element in the list.
Definition dbus-list.c:789
_dbus_list_get_length
int _dbus_list_get_length(DBusList **list)
Gets the length of a list.
Definition dbus-list.c:760
_dbus_list_clear
void _dbus_list_clear(DBusList **list)
Frees all links in the list and sets the list head to NULL.
Definition dbus-list.c:545
_dbus_list_prepend_link
void _dbus_list_prepend_link(DBusList **list, DBusList *link)
Prepends a link to the list.
Definition dbus-list.c:336
_dbus_list_prepend
dbus_bool_t _dbus_list_prepend(DBusList **list, void *data)
Prepends a value to the list.
Definition dbus-list.c:295
_dbus_list_alloc_link
DBusList * _dbus_list_alloc_link(void *data)
Allocates a linked list node.
Definition dbus-list.c:245
_dbus_list_remove_last
dbus_bool_t _dbus_list_remove_last(DBusList **list, void *data)
Removes a value from the list.
Definition dbus-list.c:449
_dbus_list_append
dbus_bool_t _dbus_list_append(DBusList **list, void *data)
Appends a value to the list.
Definition dbus-list.c:273
_dbus_list_get_next_link
#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
NULL
#define NULL
A null pointer, defined appropriately for C or C++.
Definition dbus-macros.h:51
TRUE
#define TRUE
Expands to "1".
Definition dbus-macros.h:41
FALSE
#define FALSE
Expands to "0".
Definition dbus-macros.h:44
_dbus_mem_pool_alloc
void * _dbus_mem_pool_alloc(DBusMemPool *pool)
Allocates an object from the memory pool.
Definition dbus-mempool.c:227
_dbus_mem_pool_dealloc
dbus_bool_t _dbus_mem_pool_dealloc(DBusMemPool *pool, void *element)
Deallocates an object previously created with _dbus_mem_pool_alloc().
Definition dbus-mempool.c:366
_dbus_mem_pool_free
void _dbus_mem_pool_free(DBusMemPool *pool)
Frees a memory pool (and all elements allocated from it).
Definition dbus-mempool.c:200
_dbus_mem_pool_new
DBusMemPool * _dbus_mem_pool_new(int element_size, dbus_bool_t zero_elements)
Creates a new memory pool, or returns NULL on failure.
Definition dbus-mempool.c:148
DBusFreeFunction
void(* DBusFreeFunction)(void *memory)
The type of a function which frees a block of memory.
Definition dbus-memory.h:65
dbus_uint32_t
unsigned int dbus_uint32_t
A 32-bit unsigned integer on all platforms.
Definition dbus-arch-deps.h:45
dbus_bool_t
dbus_uint32_t dbus_bool_t
A boolean, valid values are TRUE and FALSE.
Definition dbus-types.h:37
DBusList
A node in a linked list.
Definition dbus-list.h:37
DBusList::data
void * data
Data stored at this element.
Definition dbus-list.h:40
DBusList::next
DBusList * next
Next list node.
Definition dbus-list.h:39
DBusList::prev
DBusList * prev
Previous list node.
Definition dbus-list.h:38
DBusMemPool
Internals fields of DBusMemPool.
Definition dbus-mempool.c:109