xref: /freebsd/contrib/ntp/libntp/lib/isc/include/isc/list.h (revision a466cc55373fc3cf86837f09da729535b57e69a1)
1 /*
2  * Copyright (C) 2004, 2006, 2007, 2011, 2012  Internet Systems Consortium, Inc. ("ISC")
3  * Copyright (C) 1997-2002  Internet Software Consortium.
4  *
5  * Permission to use, copy, modify, and/or distribute this software for any
6  * purpose with or without fee is hereby granted, provided that the above
7  * copyright notice and this permission notice appear in all copies.
8  *
9  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
10  * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
11  * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
12  * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
13  * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
14  * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
15  * PERFORMANCE OF THIS SOFTWARE.
16  */
17 
18 /* $Id$ */
19 
20 #ifndef ISC_LIST_H
21 #define ISC_LIST_H 1
22 #include <isc/boolean.h>
23 #include <isc/assertions.h>
24 
25 #ifdef ISC_LIST_CHECKINIT
26 #define ISC_LINK_INSIST(x) ISC_INSIST(x)
27 #else
28 #define ISC_LINK_INSIST(x)
29 #endif
30 
31 #define ISC_LIST(type) struct { type *head, *tail; }
32 #define ISC_LIST_INIT(list) \
33 	do { (list).head = NULL; (list).tail = NULL; } while (0)
34 
35 #define ISC_LINK(type) struct { type *prev, *next; }
36 #define ISC_LINK_INIT_TYPE(elt, link, type) \
37 	do { \
38 		(elt)->link.prev = (type *)(-1); \
39 		(elt)->link.next = (type *)(-1); \
40 	} while (0)
41 #define ISC_LINK_INIT(elt, link) \
42 	ISC_LINK_INIT_TYPE(elt, link, void)
43 #define ISC_LINK_LINKED(elt, link) ((void *)((elt)->link.prev) != (void *)(-1))
44 
45 #define ISC_LIST_HEAD(list) ((list).head)
46 #define ISC_LIST_TAIL(list) ((list).tail)
47 #define ISC_LIST_EMPTY(list) ISC_TF((list).head == NULL)
48 
49 #define __ISC_LIST_PREPENDUNSAFE(list, elt, link) \
50 	do { \
51 		if ((list).head != NULL) \
52 			(list).head->link.prev = (elt); \
53 		else \
54 			(list).tail = (elt); \
55 		(elt)->link.prev = NULL; \
56 		(elt)->link.next = (list).head; \
57 		(list).head = (elt); \
58 	} while (0)
59 
60 #define ISC_LIST_PREPEND(list, elt, link) \
61 	do { \
62 		ISC_LINK_INSIST(!ISC_LINK_LINKED(elt, link)); \
63 		__ISC_LIST_PREPENDUNSAFE(list, elt, link); \
64 	} while (0)
65 
66 #define ISC_LIST_INITANDPREPEND(list, elt, link) \
67 		__ISC_LIST_PREPENDUNSAFE(list, elt, link)
68 
69 #define __ISC_LIST_APPENDUNSAFE(list, elt, link) \
70 	do { \
71 		if ((list).tail != NULL) \
72 			(list).tail->link.next = (elt); \
73 		else \
74 			(list).head = (elt); \
75 		(elt)->link.prev = (list).tail; \
76 		(elt)->link.next = NULL; \
77 		(list).tail = (elt); \
78 	} while (0)
79 
80 #define ISC_LIST_APPEND(list, elt, link) \
81 	do { \
82 		ISC_LINK_INSIST(!ISC_LINK_LINKED(elt, link)); \
83 		__ISC_LIST_APPENDUNSAFE(list, elt, link); \
84 	} while (0)
85 
86 #define ISC_LIST_INITANDAPPEND(list, elt, link) \
87 		__ISC_LIST_APPENDUNSAFE(list, elt, link)
88 
89 #define __ISC_LIST_UNLINKUNSAFE_TYPE(list, elt, link, type) \
90 	do { \
91 		if ((elt)->link.next != NULL) \
92 			(elt)->link.next->link.prev = (elt)->link.prev; \
93 		else { \
94 			ISC_INSIST((list).tail == (elt)); \
95 			(list).tail = (elt)->link.prev; \
96 		} \
97 		if ((elt)->link.prev != NULL) \
98 			(elt)->link.prev->link.next = (elt)->link.next; \
99 		else { \
100 			ISC_INSIST((list).head == (elt)); \
101 			(list).head = (elt)->link.next; \
102 		} \
103 		(elt)->link.prev = (type *)(-1); \
104 		(elt)->link.next = (type *)(-1); \
105 	} while (0)
106 
107 #define __ISC_LIST_UNLINKUNSAFE(list, elt, link) \
108 	__ISC_LIST_UNLINKUNSAFE_TYPE(list, elt, link, void)
109 
110 #define ISC_LIST_UNLINK_TYPE(list, elt, link, type) \
111 	do { \
112 		ISC_LINK_INSIST(ISC_LINK_LINKED(elt, link)); \
113 		__ISC_LIST_UNLINKUNSAFE_TYPE(list, elt, link, type); \
114 	} while (0)
115 #define ISC_LIST_UNLINK(list, elt, link) \
116 	ISC_LIST_UNLINK_TYPE(list, elt, link, void)
117 
118 #define ISC_LIST_PREV(elt, link) ((elt)->link.prev)
119 #define ISC_LIST_NEXT(elt, link) ((elt)->link.next)
120 
121 #define __ISC_LIST_INSERTBEFOREUNSAFE(list, before, elt, link) \
122 	do { \
123 		if ((before)->link.prev == NULL) \
124 			ISC_LIST_PREPEND(list, elt, link); \
125 		else { \
126 			(elt)->link.prev = (before)->link.prev; \
127 			(before)->link.prev = (elt); \
128 			(elt)->link.prev->link.next = (elt); \
129 			(elt)->link.next = (before); \
130 		} \
131 	} while (0)
132 
133 #define ISC_LIST_INSERTBEFORE(list, before, elt, link) \
134 	do { \
135 		ISC_LINK_INSIST(ISC_LINK_LINKED(before, link)); \
136 		ISC_LINK_INSIST(!ISC_LINK_LINKED(elt, link)); \
137 		__ISC_LIST_INSERTBEFOREUNSAFE(list, before, elt, link); \
138 	} while (0)
139 
140 #define __ISC_LIST_INSERTAFTERUNSAFE(list, after, elt, link) \
141 	do { \
142 		if ((after)->link.next == NULL) \
143 			ISC_LIST_APPEND(list, elt, link); \
144 		else { \
145 			(elt)->link.next = (after)->link.next; \
146 			(after)->link.next = (elt); \
147 			(elt)->link.next->link.prev = (elt); \
148 			(elt)->link.prev = (after); \
149 		} \
150 	} while (0)
151 
152 #define ISC_LIST_INSERTAFTER(list, after, elt, link) \
153 	do { \
154 		ISC_LINK_INSIST(ISC_LINK_LINKED(after, link)); \
155 		ISC_LINK_INSIST(!ISC_LINK_LINKED(elt, link)); \
156 		__ISC_LIST_INSERTAFTERUNSAFE(list, after, elt, link); \
157 	} while (0)
158 
159 #define ISC_LIST_APPENDLIST(list1, list2, link) \
160 	do { \
161 		if (ISC_LIST_EMPTY(list1)) \
162 			(list1) = (list2); \
163 		else if (!ISC_LIST_EMPTY(list2)) { \
164 			(list1).tail->link.next = (list2).head; \
165 			(list2).head->link.prev = (list1).tail; \
166 			(list1).tail = (list2).tail; \
167 		} \
168 		(list2).head = NULL; \
169 		(list2).tail = NULL; \
170 	} while (0)
171 
172 #define ISC_LIST_PREPENDLIST(list1, list2, link) \
173 	do { \
174 		if (ISC_LIST_EMPTY(list1)) \
175 			(list1) = (list2); \
176 		else if (!ISC_LIST_EMPTY(list2)) { \
177 			(list2).tail->link.next = (list1).head; \
178 			(list1).head->link.prev = (list2).tail; \
179 			(list1).head = (list2).head; \
180 		} \
181 		(list2).head = NULL; \
182 		(list2).tail = NULL; \
183 	} while (0)
184 
185 #define ISC_LIST_ENQUEUE(list, elt, link) ISC_LIST_APPEND(list, elt, link)
186 #define __ISC_LIST_ENQUEUEUNSAFE(list, elt, link) \
187 	__ISC_LIST_APPENDUNSAFE(list, elt, link)
188 #define ISC_LIST_DEQUEUE(list, elt, link) \
189 	 ISC_LIST_UNLINK_TYPE(list, elt, link, void)
190 #define ISC_LIST_DEQUEUE_TYPE(list, elt, link, type) \
191 	 ISC_LIST_UNLINK_TYPE(list, elt, link, type)
192 #define __ISC_LIST_DEQUEUEUNSAFE(list, elt, link) \
193 	__ISC_LIST_UNLINKUNSAFE_TYPE(list, elt, link, void)
194 #define __ISC_LIST_DEQUEUEUNSAFE_TYPE(list, elt, link, type) \
195 	__ISC_LIST_UNLINKUNSAFE_TYPE(list, elt, link, type)
196 
197 #endif /* ISC_LIST_H */
198