src/gallium/auxiliary/util/u_double_list.h

   1 /**************************************************************************
   2  *
   3  * Copyright 2006 Tungsten Graphics, Inc., Bismarck, ND. USA.
   4  * All Rights Reserved.
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a
   7  * copy of this software and associated documentation files (the
   8  * "Software"), to deal in the Software without restriction, including
   9  * without limitation the rights to use, copy, modify, merge, publish,
  10  * distribute, sub license, and/or sell copies of the Software, and to
  11  * permit persons to whom the Software is furnished to do so, subject to
  12  * the following conditions:
  13  *
  14  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  15  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
  17  * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
  18  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
  19  * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
  20  * USE OR OTHER DEALINGS IN THE SOFTWARE.
  21  *
  22  * The above copyright notice and this permission notice (including the
  23  * next paragraph) shall be included in all copies or substantial portions
  24  * of the Software.
  25  *
  26  **************************************************************************/
  27
  28 /**
  29  * \file
  30  * List macros heavily inspired by the Linux kernel
  31  * list handling. No list looping yet.
  32  *
  33  * Is not threadsafe, so common operations need to
  34  * be protected using an external mutex.
  35  */
  36
  37 #ifndef _U_DOUBLE_LIST_H_
  38 #define _U_DOUBLE_LIST_H_
  39
  40
  41 #include <stddef.h>
  42
  43
  44 struct list_head
  45 {
  46     struct list_head *prev;
  47     struct list_head *next;
  48 };
  49
  50
  51 #define LIST_INITHEAD(__item)                   \
  52   do {                                          \
  53     (__item)->prev = (__item);                  \
  54     (__item)->next = (__item);                  \
  55   } while (0)
  56
  57 #define LIST_ADD(__item, __list)                \
  58   do {                                          \
  59     (__item)->prev = (__list);                  \
  60     (__item)->next = (__list)->next;            \
  61     (__list)->next->prev = (__item);            \
  62     (__list)->next = (__item);                  \
  63   } while (0)
  64
  65 #define LIST_ADDTAIL(__item, __list)            \
  66   do {                                          \
  67     (__item)->next = (__list);                  \
  68     (__item)->prev = (__list)->prev;            \
  69     (__list)->prev->next = (__item);            \
  70     (__list)->prev = (__item);                  \
  71   } while(0)
  72
  73 #define LIST_REPLACE(__from, __to)              \
  74   do {                                          \
  75     (__to)->prev = (__from)->prev;              \
  76     (__to)->next = (__from)->next;              \
  77     (__from)->next->prev = (__to);              \
  78     (__from)->prev->next = (__to);              \
  79   } while (0)
  80
  81 #define LIST_DEL(__item)                        \
  82   do {                                          \
  83     (__item)->prev->next = (__item)->next;      \
  84     (__item)->next->prev = (__item)->prev;      \
  85   } while(0)
  86
  87 #define LIST_DELINIT(__item)                    \
  88   do {                                          \
  89     (__item)->prev->next = (__item)->next;      \
  90     (__item)->next->prev = (__item)->prev;      \
  91     (__item)->next = (__item);                  \
  92     (__item)->prev = (__item);                  \
  93   } while(0)
  94
  95 #define LIST_ENTRY(__type, __item, __field)   \
  96     ((__type *)(((char *)(__item)) - offsetof(__type, __field)))
  97
  98 #define LIST_IS_EMPTY(__list)                   \
  99     ((__list)->next == (__list))
 100
 101
 102 #endif /*_U_DOUBLE_LIST_H_*/