4 * Copyright 2003, 2004 Develer S.r.l. (http://www.develer.com/)
5 * Copyright 2001 Bernardo Innocenti <bernie@develer.com>
6 * This file is part of DevLib - See README.devlib for information.
11 * \author Bernardo Innocenti <bernie@develer.com>
13 * \brief General pourpose double-linked lists
18 *#* Revision 1.16 2006/01/23 23:10:38 bernie
19 *#* REVERSE_FOREACH_NODE(): New macro; FOREACHNODE(): Rename to FOREACH_NODE.
21 *#* Revision 1.15 2005/11/04 16:20:02 bernie
22 *#* Fix reference to README.devlib in header.
24 *#* Revision 1.14 2005/07/19 07:25:18 bernie
25 *#* Refactor to remove type aliasing problems.
27 *#* Revision 1.13 2005/04/11 19:10:28 bernie
28 *#* Include top-level headers from cfg/ subdir.
30 *#* Revision 1.12 2005/01/22 04:21:32 bernie
31 *#* Add integrity checks.
33 *#* Revision 1.11 2004/12/31 16:44:11 bernie
34 *#* list_remHead(), list_remTail(): Name like normal functions.
36 *#* Revision 1.10 2004/11/28 23:21:05 bernie
37 *#* Remove obsolete INITLIST macro.
39 *#* Revision 1.9 2004/10/21 09:37:55 bernie
40 *#* Revamp documentation.
42 *#* Revision 1.8 2004/10/19 08:46:34 bernie
45 *#* Revision 1.7 2004/08/25 14:12:09 rasky
46 *#* Aggiornato il comment block dei log RCS
48 *#* Revision 1.6 2004/07/30 14:34:10 rasky
49 *#* Vari fix per documentazione e commenti
50 *#* Aggiunte PP_CATn e STATIC_ASSERT
52 *#* Revision 1.5 2004/07/20 23:45:01 bernie
53 *#* Finally remove redundant protos.
55 *#* Revision 1.4 2004/07/18 22:12:53 bernie
56 *#* Fix warnings with GCC 3.3.2.
58 *#* Revision 1.3 2004/07/18 22:01:43 bernie
59 *#* REMHEAD(), REMTAIL(): Move to list.h as inline functions.
61 *#* Revision 1.2 2004/06/03 11:27:09 bernie
62 *#* Add dual-license information.
64 *#* Revision 1.1 2004/05/23 15:43:16 bernie
65 *#* Import mware modules.
71 #include <cfg/compiler.h> /* INLINE */
72 #include <cfg/debug.h> /* ASSERT() */
75 * This structure represents a node for bidirectional lists.
77 * Data is usually appended to nodes by making them the first
78 * field of another struture, as a poor-man's form of inheritance.
87 * Head of a doubly-linked list of \c Node structs.
89 * Lists must be initialized with LIST_INIT() prior to use.
91 * Nodes can be added and removed from either end of the list
92 * with O(1) performance. Iterating over these lists can be
93 * tricky: use the FOREACH_NODE() macro instead.
103 * Template for a naked node in a list of \a T structures.
105 * To be used as data member in other structures:
110 * DECLARE_NODE_ANON(struct Foo)
115 * DECLARE_LIST_TYPE(Foo);
119 * static LIST_TYPE(Foo) foo_list;
120 * static Foo foo1, foo2;
123 * LIST_INIT(&foo_list);
124 * ADDHEAD(&foo_list, &foo1);
125 * INSERTBEFORE(&foo_list, &foo2);
126 * FOREACH_NODE(fp, &foo_list)
132 #define DECLARE_NODE_ANON(T) \
135 /*! Declare a typesafe node for structures of type \a T. */
136 #define DECLARE_NODE_TYPE(T) \
137 typedef struct T##Node { T *succ; T *pred; } T##Node
139 /*! Template for a list of \a T structures. */
140 #define DECLARE_LIST_TYPE(T) \
141 DECLARE_NODE_TYPE(T); \
142 typedef struct T##List { \
147 #define NODE_TYPE(T) T##Node
148 #define LIST_TYPE(T) T##List
151 * Get a pointer to the first node in a list.
153 * If \a l is empty, result points to l->tail.
155 #define LIST_HEAD(l) ((l)->head.succ)
158 * Get a pointer to the last node in a list.
160 * If \a l is empty, result points to l->head.
162 #define LIST_TAIL(l) ((l)->tail.pred)
165 * Iterate over all nodes in a list.
167 * This macro generates a "for" statement using the following parameters:
168 * \param n Node pointer to be used in each iteration.
169 * \param l Pointer to list.
171 #define FOREACH_NODE(n, l) \
173 (n) = (typeof(n))LIST_HEAD(l); \
174 ((Node *)(n))->succ; \
175 (n) = (typeof(n))(((Node *)(n))->succ) \
178 #define FOREACHNODE FOREACH_NODE /* OBSOLETE */
181 * Iterate backwards over all nodes in a list.
183 * This macro generates a "for" statement using the following parameters:
184 * \param n Node pointer to be used in each iteration.
185 * \param l Pointer to list.
187 #define REVERSE_FOREACH_NODE(n, l) \
189 (n) = (typeof(n))LIST_TAIL(l); \
190 ((Node *)(n))->pred; \
191 (n) = (typeof(n))(((Node *)(n))->pred) \
194 /*! Initialize a list. */
195 #define LIST_INIT(l) \
197 (l)->head.succ = (typeof((l)->head.succ)) &(l)->tail; \
198 (l)->head.pred = NULL; \
199 (l)->tail.succ = NULL; \
200 (l)->tail.pred = (typeof((l)->tail.pred)) &(l)->head; \
204 /*! Make sure that a list is valid (it was initialized and is not corrupted). */
205 #define LIST_ASSERT_VALID(l) \
208 ASSERT((l)->head.succ != NULL); \
209 ASSERT((l)->head.pred == NULL); \
210 ASSERT((l)->tail.succ == NULL); \
211 ASSERT((l)->tail.pred != NULL); \
215 ASSERT(n->pred == pred); \
218 ASSERT(n == &(l)->tail); \
221 #define INVALIDATE_NODE(n) ((n)->succ = (n)->pred = NULL)
223 #define LIST_ASSERT_VALID(l) do {} while (0)
224 #define INVALIDATE_NODE(n) do {} while (0)
227 /*! Add node to list head. */
228 #define ADDHEAD(l,n) \
232 (n)->succ = (l)->head.succ; \
233 (n)->pred = (l)->head.succ->pred; \
234 (n)->succ->pred = (n); \
235 (n)->pred->succ = (n); \
238 /*! Add node to list tail. */
239 #define ADDTAIL(l,n) \
243 (n)->succ = &(l)->tail; \
244 (n)->pred = (l)->tail.pred; \
245 (n)->pred->succ = (n); \
246 (l)->tail.pred = (n); \
250 * Insert node \a n before node \a ln.
252 * \note You can't pass in a list header as \a ln, but
253 * it is safe to pass list-\>head of an empty list.
255 #define INSERT_BEFORE(n,ln) \
258 (n)->pred = (ln)->pred; \
259 (ln)->pred->succ = (n); \
264 * Remove \a n from whatever list it is in.
266 * \note Removing a node that has not previously been
267 * inserted into a list invokes undefined behavior.
271 (n)->pred->succ = (n)->succ; \
272 (n)->succ->pred = (n)->pred; \
273 INVALIDATE_NODE(n); \
276 /*! Tell whether a list is empty. */
277 #define LIST_EMPTY(l) ( (void *)((l)->head.succ) == (void *)(&(l)->tail) )
280 * Unlink a node from the head of the list \a l.
282 * \return Pointer to node, or NULL if the list was empty.
284 INLINE Node *list_remHead(List *l)
291 n = l->head.succ; /* Get first node. */
292 l->head.succ = n->succ; /* Link list head to second node. */
293 n->succ->pred = &l->head; /* Link second node to list head. */
300 * Unlink a node from the tail of the list \a l.
302 * \return Pointer to node, or NULL if the list was empty.
304 INLINE Node *list_remTail(List *l)
311 n = l->tail.pred; /* Get last node. */
312 l->tail.pred = n->pred; /* Link list tail to second last node. */
313 n->pred->succ = &l->tail; /* Link second last node to list tail. */
320 #define REMHEAD list_remHead
321 #define REMTAIL list_remTail
322 #define INSERTBEFORE INSERT_BEFORE
323 #define ISLISTEMPTY LIST_EMPTY
326 #endif /* MWARE_LIST_H */