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 devlib/README for information.
11 * \author Bernardo Innocenti <bernie@develer.com>
13 * \brief General pourpose double-linked lists
18 *#* Revision 1.14 2005/07/19 07:25:18 bernie
19 *#* Refactor to remove type aliasing problems.
21 *#* Revision 1.13 2005/04/11 19:10:28 bernie
22 *#* Include top-level headers from cfg/ subdir.
24 *#* Revision 1.12 2005/01/22 04:21:32 bernie
25 *#* Add integrity checks.
27 *#* Revision 1.11 2004/12/31 16:44:11 bernie
28 *#* list_remHead(), list_remTail(): Name like normal functions.
30 *#* Revision 1.10 2004/11/28 23:21:05 bernie
31 *#* Remove obsolete INITLIST macro.
33 *#* Revision 1.9 2004/10/21 09:37:55 bernie
34 *#* Revamp documentation.
36 *#* Revision 1.8 2004/10/19 08:46:34 bernie
39 *#* Revision 1.7 2004/08/25 14:12:09 rasky
40 *#* Aggiornato il comment block dei log RCS
42 *#* Revision 1.6 2004/07/30 14:34:10 rasky
43 *#* Vari fix per documentazione e commenti
44 *#* Aggiunte PP_CATn e STATIC_ASSERT
46 *#* Revision 1.5 2004/07/20 23:45:01 bernie
47 *#* Finally remove redundant protos.
49 *#* Revision 1.4 2004/07/18 22:12:53 bernie
50 *#* Fix warnings with GCC 3.3.2.
52 *#* Revision 1.3 2004/07/18 22:01:43 bernie
53 *#* REMHEAD(), REMTAIL(): Move to list.h as inline functions.
55 *#* Revision 1.2 2004/06/03 11:27:09 bernie
56 *#* Add dual-license information.
58 *#* Revision 1.1 2004/05/23 15:43:16 bernie
59 *#* Import mware modules.
65 #include <cfg/compiler.h> /* INLINE */
66 #include <cfg/debug.h> /* ASSERT() */
69 * This structure represents a node for bidirectional lists.
71 * Data is usually appended to nodes by making them the first
72 * field of another struture, as a poor-man's form of inheritance.
81 * Head of a doubly-linked list of \c Node structs.
83 * Lists must be initialized with LIST_INIT() prior to use.
85 * Nodes can be added and removed from either end of the list
86 * with O(1) performance. Iterating over these lists can be
87 * tricky: use the FOREACHNODE() macro instead.
97 * Template for a naked node in a list of \a T structures.
99 * To be used as data member in other structures:
104 * DECLARE_NODE_ANON(struct Foo)
109 * DECLARE_LIST_TYPE(Foo);
113 * static LIST_TYPE(Foo) foo_list;
114 * static Foo foo1, foo2;
117 * LIST_INIT(&foo_list);
118 * LIST_ADDHEAD(&foo_list, &foo1);
119 * INSERTBEFORE(&foo_list, &foo2);
120 * FOREACHNODE(fp, &foo_list)
126 #define DECLARE_NODE_ANON(T) \
129 /*! Declare a typesafe node for structures of type \a T. */
130 #define DECLARE_NODE_TYPE(T) \
131 typedef struct T##Node { T *succ; T *pred; } T##Node
133 /*! Template for a list of \a T structures. */
134 #define DECLARE_LIST_TYPE(T) \
135 DECLARE_NODE_TYPE(T); \
136 typedef struct T##List { \
141 #define NODE_TYPE(T) T##Node
142 #define LIST_TYPE(T) T##List
145 * Get a pointer to the first node in a list.
147 * If \a l is empty, result points to l->tail.
149 #define LIST_HEAD(l) ((l)->head.succ)
152 * Get a pointer to the last node in a list.
154 * If \a l is empty, result points to l->head.
156 #define LIST_TAIL(l) ((l)->tail.pred)
159 * Iterate over all nodes in a list.
161 * This macro generates a "for" statement using the following parameters:
162 * \param n Node pointer to be used in each iteration.
163 * \param l Pointer to list.
165 #define FOREACHNODE(n, l) \
167 (n) = (typeof(n))LIST_HEAD(l); \
168 ((Node *)(n))->succ; \
169 (n) = (typeof(n))(((Node *)(n))->succ) \
172 /*! Initialize a list. */
173 #define LIST_INIT(l) \
175 (l)->head.succ = (typeof((l)->head.succ)) &(l)->tail; \
176 (l)->head.pred = NULL; \
177 (l)->tail.succ = NULL; \
178 (l)->tail.pred = (typeof((l)->tail.pred)) &(l)->head; \
182 /*! Make sure that a list is valid (it was initialized and is not corrupted). */
183 #define LIST_ASSERT_VALID(l) \
186 ASSERT((l)->head.succ != NULL); \
187 ASSERT((l)->head.pred == NULL); \
188 ASSERT((l)->tail.succ == NULL); \
189 ASSERT((l)->tail.pred != NULL); \
193 ASSERT(n->pred == pred); \
196 ASSERT(n == &(l)->tail); \
199 #define INVALIDATE_NODE(n) ((n)->succ = (n)->pred = NULL)
201 #define LIST_ASSERT_VALID(l) do {} while (0)
202 #define INVALIDATE_NODE(n) do {} while (0)
205 /*! Add node to list head. */
206 #define ADDHEAD(l,n) \
210 (n)->succ = (l)->head.succ; \
211 (n)->pred = (l)->head.succ->pred; \
212 (n)->succ->pred = (n); \
213 (n)->pred->succ = (n); \
216 /*! Add node to list tail. */
217 #define ADDTAIL(l,n) \
221 (n)->succ = &(l)->tail; \
222 (n)->pred = (l)->tail.pred; \
223 (n)->pred->succ = (n); \
224 (l)->tail.pred = (n); \
228 * Insert node \a n before node \a ln.
230 * \note You can't pass in a list header as \a ln, but
231 * it is safe to pass list-\>head of an empty list.
233 #define INSERT_BEFORE(n,ln) \
236 (n)->pred = (ln)->pred; \
237 (ln)->pred->succ = (n); \
242 * Remove \a n from whatever list it is in.
244 * \note Removing a node that has not previously been
245 * inserted into a list invokes undefined behavior.
249 (n)->pred->succ = (n)->succ; \
250 (n)->succ->pred = (n)->pred; \
251 INVALIDATE_NODE(n); \
254 /*! Tell whether a list is empty. */
255 #define LIST_EMPTY(l) ( (void *)((l)->head.succ) == (void *)(&(l)->tail) )
258 * Unlink a node from the head of the list \a l.
260 * \return Pointer to node, or NULL if the list was empty.
262 INLINE Node *list_remHead(List *l)
269 n = l->head.succ; /* Get first node. */
270 l->head.succ = n->succ; /* Link list head to second node. */
271 n->succ->pred = &l->head; /* Link second node to list head. */
278 * Unlink a node from the tail of the list \a l.
280 * \return Pointer to node, or NULL if the list was empty.
282 INLINE Node *list_remTail(List *l)
289 n = l->tail.pred; /* Get last node. */
290 l->tail.pred = n->pred; /* Link list tail to second last node. */
291 n->pred->succ = &l->tail; /* Link second last node to list tail. */
298 #define REMHEAD list_remHead
299 #define REMTAIL list_remTail
300 #define INSERTBEFORE INSERT_BEFORE
301 #define ISLISTEMPTY LIST_EMPTY
304 #endif /* MWARE_LIST_H */