1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 *
21 * Copyright (c) 2002-2006 Neterion, Inc.
22 */
23
24 #ifndef XGE_LIST_H
25 #define XGE_LIST_H
26
27 #include "xge-debug.h"
28
29 __EXTERN_BEGIN_DECLS
30
31 /**
32 * struct xge_list_t - List item.
33 * @prev: Previous list item.
34 * @next: Next list item.
35 *
36 * Item of a bi-directional linked list.
37 */
38 typedef struct xge_list_t {
39 struct xge_list_t* prev;
40 struct xge_list_t* next;
41 } xge_list_t;
42
43 /**
44 * xge_list_init - Initialize linked list.
45 * header: first element of the list (head)
46 *
47 * Initialize linked list.
48 * See also: xge_list_t{}.
49 */
xge_list_init(xge_list_t * header)50 static inline void xge_list_init (xge_list_t *header)
51 {
52 header->next = header;
53 header->prev = header;
54 }
55
56 /**
57 * xge_list_is_empty - Is the list empty?
58 * header: first element of the list (head)
59 *
60 * Determine whether the bi-directional list is empty. Return '1' in
61 * case of 'empty'.
62 * See also: xge_list_t{}.
63 */
xge_list_is_empty(xge_list_t * header)64 static inline int xge_list_is_empty(xge_list_t *header)
65 {
66 xge_assert(header != NULL);
67
68 return header->next == header;
69 }
70
71 /**
72 * xge_list_first_get - Return the first item from the linked list.
73 * header: first element of the list (head)
74 *
75 * Returns the next item from the header.
76 * Returns NULL if the next item is header itself
77 * See also: xge_list_remove(), xge_list_insert(), xge_list_t{}.
78 */
xge_list_first_get(xge_list_t * header)79 static inline xge_list_t *xge_list_first_get(xge_list_t *header)
80 {
81 xge_assert(header != NULL);
82 xge_assert(header->next != NULL);
83 xge_assert(header->prev != NULL);
84
85 if(header->next == header)
86 return NULL;
87 else
88 return header->next;
89 }
90
91 /**
92 * xge_list_remove - Remove the specified item from the linked list.
93 * item: element of the list
94 *
95 * Remove item from a list.
96 * See also: xge_list_insert(), xge_list_t{}.
97 */
xge_list_remove(xge_list_t * item)98 static inline void xge_list_remove(xge_list_t *item)
99 {
100 xge_assert(item != NULL);
101 xge_assert(item->next != NULL);
102 xge_assert(item->prev != NULL);
103
104 item->next->prev = item->prev;
105 item->prev->next = item->next;
106 #ifdef XGE_DEBUG_ASSERT
107 item->next = item->prev = NULL;
108 #endif
109 }
110
111 /**
112 * xge_list_insert - Insert a new item after the specified item.
113 * new_item: new element of the list
114 * prev_item: element of the list after which the new element is
115 * inserted
116 *
117 * Insert new item (new_item) after given item (prev_item).
118 * See also: xge_list_remove(), xge_list_insert_before(), xge_list_t{}.
119 */
xge_list_insert(xge_list_t * new_item,xge_list_t * prev_item)120 static inline void xge_list_insert (xge_list_t *new_item,
121 xge_list_t *prev_item)
122 {
123 xge_assert(new_item != NULL);
124 xge_assert(prev_item != NULL);
125 xge_assert(prev_item->next != NULL);
126
127 new_item->next = prev_item->next;
128 new_item->prev = prev_item;
129 prev_item->next->prev = new_item;
130 prev_item->next = new_item;
131 }
132
133 /**
134 * xge_list_insert_before - Insert a new item before the specified item.
135 * new_item: new element of the list
136 * next_item: element of the list after which the new element is inserted
137 *
138 * Insert new item (new_item) before given item (next_item).
139 */
xge_list_insert_before(xge_list_t * new_item,xge_list_t * next_item)140 static inline void xge_list_insert_before (xge_list_t *new_item,
141 xge_list_t *next_item)
142 {
143 xge_assert(new_item != NULL);
144 xge_assert(next_item != NULL);
145 xge_assert(next_item->next != NULL);
146
147 new_item->next = next_item;
148 new_item->prev = next_item->prev;
149 next_item->prev->next = new_item;
150 next_item->prev = new_item;
151 }
152
153 #define xge_list_for_each(_p, _h) \
154 for (_p = (_h)->next, xge_os_prefetch(_p->next); _p != (_h); \
155 _p = _p->next, xge_os_prefetch(_p->next))
156
157 #define xge_list_for_each_safe(_p, _n, _h) \
158 for (_p = (_h)->next, _n = _p->next; _p != (_h); \
159 _p = _n, _n = _p->next)
160
161 #ifdef __GNUC__
162 /**
163 * xge_container_of - Given a member, return the containing structure.
164 * @ptr: the pointer to the member.
165 * @type: the type of the container struct this is embedded in.
166 * @member: the name of the member within the struct.
167 *
168 * Cast a member of a structure out to the containing structure.
169 */
170 #define xge_container_of(ptr, type, member) ({ \
171 __typeof( ((type *)0)->member ) *__mptr = (ptr); \
172 (type *)(void *)( (char *)__mptr - ((size_t) &((type *)0)->member) );})
173 #else
174 /* type unsafe version */
175 #define xge_container_of(ptr, type, member) \
176 ((type*)(void*)((char*)(ptr) - ((size_t) &((type *)0)->member)))
177 #endif
178
179 /**
180 * xge_offsetof - Offset of the member in the containing structure.
181 * @t: struct name.
182 * @m: the name of the member within the struct.
183 *
184 * Return the offset of the member @m in the structure @t.
185 */
186 #define xge_offsetof(t, m) ((size_t) (&((t *)0)->m))
187
188 __EXTERN_END_DECLS
189
190 #endif /* XGE_LIST_H */
191