include/urcu/hlist.h

   1 #ifndef _KCOMPAT_HLIST_H
   2 #define _KCOMPAT_HLIST_H
   3
   4 /*
   5  * Kernel sourcecode compatible lightweight single pointer list head useful
   6  * for implementing hash tables
   7  *
   8  * Copyright (C) 2009 Novell Inc.
   9  *
  10  * Author: Jan Blunck <jblunck@suse.de>
  11  *
  12  * Copyright (C) 2010-2013 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
  13  *
  14  * This program is free software; you can redistribute it and/or modify it
  15  * under the terms of the GNU Lesser General Public License version 2.1 as
  16  * published by the Free  Software Foundation.
  17  */
  18
  19 #include <stddef.h>
  20 #include <urcu/compiler.h>
  21
  22 struct cds_hlist_head {
  23         struct cds_hlist_node *next;
  24 };
  25
  26 struct cds_hlist_node {
  27         struct cds_hlist_node *next, *prev;
  28 };
  29
  30 /* Initialize a new list head. */
  31 static inline
  32 void CDS_INIT_HLIST_HEAD(struct cds_hlist_head *ptr)
  33 {
  34         ptr->next = NULL;
  35 }
  36
  37 #define CDS_HLIST_HEAD(name) \
  38         struct cds_hlist_head name = { NULL }
  39
  40 #define CDS_HLIST_HEAD_INIT(name) \
  41         { .next = NULL }
  42
  43 /* Get typed element from list at a given position. */
  44 #define cds_hlist_entry(ptr, type, member)      caa_container_of(ptr, type, member)
  45
  46 /* Get typed element from list at a given position, keeping NULL pointers. */
  47 #define cds_hlist_entry_safe(ptr, type, member)                                 \
  48         ({                                                                      \
  49                 __typeof__(ptr) ____ret = ptr;                                  \
  50                 ____ret ? cds_hlist_entry(____ret, type, member) : NULL;        \
  51         })
  52
  53 /* Add new element at the head of the list. */
  54 static inline
  55 void cds_hlist_add_head(struct cds_hlist_node *newp,
  56                 struct cds_hlist_head *head)
  57 {
  58         if (head->next)
  59                 head->next->prev = newp;
  60         newp->next = head->next;
  61         newp->prev = (struct cds_hlist_node *) head;
  62         head->next = newp;
  63 }
  64
  65 /* Remove element from list. */
  66 static inline
  67 void cds_hlist_del(struct cds_hlist_node *elem)
  68 {
  69         if (elem->next)
  70                 elem->next->prev = elem->prev;
  71         elem->prev->next = elem->next;
  72 }
  73
  74 #define cds_hlist_for_each(pos, head) \
  75         for (pos = (head)->next; pos != NULL; pos = pos->next)
  76
  77 #define cds_hlist_for_each_safe(pos, p, head) \
  78         for (pos = (head)->next; \
  79                 (pos != NULL) && (p = pos->next, 1); \
  80                 pos = p)
  81
  82 /*
  83  * cds_hlist_for_each_entry and cds_hlist_for_each_entry_safe take
  84  * respectively 4 and 5 arguments, while the Linux kernel APIs take 3,
  85  * and 4. We implement cds_hlist_for_each_entry_2() and
  86  * cds_hlist_for_each_entry_safe_2() to follow the Linux kernel APIs.
  87  */
  88 #define cds_hlist_for_each_entry(entry, pos, head, member) \
  89         for (pos = (head)->next, \
  90                         entry = cds_hlist_entry(pos, __typeof__(*entry), member); \
  91                 pos != NULL; \
  92                 pos = pos->next, \
  93                         entry = cds_hlist_entry(pos, __typeof__(*entry), member))
  94
  95 #define cds_hlist_for_each_entry_safe(entry, pos, p, head, member) \
  96         for (pos = (head)->next, \
  97                         entry = cds_hlist_entry(pos, __typeof__(*entry), member); \
  98                 (pos != NULL) && (p = pos->next, 1); \
  99                 pos = p, \
 100                         entry = cds_hlist_entry(pos, __typeof__(*entry), member))
 101
 102 #define cds_hlist_for_each_entry_2(entry, head, member) \
 103         for (entry = cds_hlist_entry_safe((head)->next, __typeof__(*entry), member); \
 104                 entry != NULL; \
 105                 entry = cds_hlist_entry_safe(entry->member.next, __typeof__(*entry), member))
 106
 107 #define cds_hlist_for_each_entry_safe_2(entry, e, head, member) \
 108         for (entry = cds_hlist_entry_safe((head)->next, __typeof__(*entry), member); \
 109                 (entry != NULL) && (e = (cds_hlist_entry_safe(entry->member.next, \
 110                                                 __typeof__(*entry), member)), 1); \
 111                 entry = e)
 112
 113 #endif  /* _KCOMPAT_HLIST_H */