include/list.h

   1 /*
   2  * Copyright (c) 2002-2004 MontaVista Software, Inc.
   3  *
   4  * All rights reserved.
   5  *
   6  * Author: Steven Dake (sdake@mvista.com)
   7  *
   8  * This software licensed under BSD license, the text of which follows:
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions are met:
  12  *
  13  * - Redistributions of source code must retain the above copyright notice,
  14  *   this list of conditions and the following disclaimer.
  15  * - Redistributions in binary form must reproduce the above copyright notice,
  16  *   this list of conditions and the following disclaimer in the documentation
  17  *   and/or other materials provided with the distribution.
  18  * - Neither the name of the MontaVista Software, Inc. nor the names of its
  19  *   contributors may be used to endorse or promote products derived from this
  20  *   software without specific prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  23  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  25  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
  26  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  27  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  28  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  29  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  30  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  31  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
  32  * THE POSSIBILITY OF SUCH DAMAGE.
  33  */
  34 /*
  35  * This implementation uses the same API as the linux kernel to
  36  * help us kernel developers easily use the list primatives
  37  */
  38 #ifndef LIST_H_DEFINED
  39 #define LIST_H_DEFINED
  40
  41 struct list_head {
  42         struct list_head *next;
  43         struct list_head *prev;
  44 };
  45
  46 #define DECLARE_LIST_INIT(name) \
  47     struct list_head name = { &(name), &(name) }
  48
  49 static void inline list_init (struct list_head *head)
  50 {
  51         head->next = head;
  52         head->prev = head;
  53 }
  54
  55 static void inline list_add (struct list_head *element, struct list_head *head)
  56 {
  57         head->next->prev = element;
  58         element->next = head->next;
  59         element->prev = head;
  60         head->next = element;
  61 }
  62 static void inline list_add_tail (struct list_head *element, struct list_head *head)
  63 {
  64         head->prev->next = element;
  65         element->next = head;
  66         element->prev = head->prev;
  67         head->prev = element;
  68 }
  69 static void inline list_del (struct list_head *remove)
  70 {
  71         remove->next->prev = remove->prev;
  72         remove->prev->next = remove->next;
  73 #ifdef DEBUG
  74         remove->next = (struct list_head *)0xdeadb33f;
  75         remove->prev = (struct list_head *)0xdeadb33f;
  76 #endif
  77 }
  78
  79 #define list_entry(ptr,type,member)\
  80         ((type *)((char *)(ptr)-(unsigned long)(&((type *)0)->member)))
  81
  82 static inline int list_empty(struct list_head *l)
  83 {
  84         return l->next == l;
  85 }
  86
  87 static inline void list_splice (struct list_head *list, struct list_head *head)
  88 {
  89         struct list_head *first;
  90         struct list_head *last;
  91         struct list_head *current;
  92
  93         first = list->next;
  94         last = list->prev;
  95         current = head->next;
  96
  97         first->prev = head;
  98         head->next = first;
  99         last->next = current;
 100         current->prev = last;
 101 }
 102
 103 #endif /* LIST_H_DEFINED */