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+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+#pragma once
+
+/***
+ This file is part of systemd.
+
+ Copyright 2010 Lennart Poettering
+
+ systemd is free software; you can redistribute it and/or modify it
+ under the terms of the GNU Lesser General Public License as published by
+ the Free Software Foundation; either version 2.1 of the License, or
+ (at your option) any later version.
+
+ systemd is distributed in the hope that it will be useful, but
+ WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public License
+ along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+/* The head of the linked list. Use this in the structure that shall
+ * contain the head of the linked list */
+#define LIST_HEAD(t,name) \
+ t *name
+
+/* The pointers in the linked list's items. Use this in the item structure */
+#define LIST_FIELDS(t,name) \
+ t *name##_next, *name##_prev
+
+/* Initialize the list's head */
+#define LIST_HEAD_INIT(t,head) \
+ do { \
+ (head) = NULL; } \
+ while(false)
+
+/* Initialize a list item */
+#define LIST_INIT(t,name,item) \
+ do { \
+ t *_item = (item); \
+ assert(_item); \
+ _item->name##_prev = _item->name##_next = NULL; \
+ } while(false)
+
+/* Prepend an item to the list */
+#define LIST_PREPEND(t,name,head,item) \
+ do { \
+ t **_head = &(head), *_item = (item); \
+ assert(_item); \
+ if ((_item->name##_next = *_head)) \
+ _item->name##_next->name##_prev = _item; \
+ _item->name##_prev = NULL; \
+ *_head = _item; \
+ } while(false)
+
+/* Remove an item from the list */
+#define LIST_REMOVE(t,name,head,item) \
+ do { \
+ t **_head = &(head), *_item = (item); \
+ assert(_item); \
+ if (_item->name##_next) \
+ _item->name##_next->name##_prev = _item->name##_prev; \
+ if (_item->name##_prev) \
+ _item->name##_prev->name##_next = _item->name##_next; \
+ else { \
+ assert(*_head == _item); \
+ *_head = _item->name##_next; \
+ } \
+ _item->name##_next = _item->name##_prev = NULL; \
+ } while(false)
+
+/* Find the head of the list */
+#define LIST_FIND_HEAD(t,name,item,head) \
+ do { \
+ t *_item = (item); \
+ assert(_item); \
+ while (_item->name##_prev) \
+ _item = _item->name##_prev; \
+ (head) = _item; \
+ } while (false)
+
+/* Find the head of the list */
+#define LIST_FIND_TAIL(t,name,item,tail) \
+ do { \
+ t *_item = (item); \
+ assert(_item); \
+ while (_item->name##_next) \
+ _item = _item->name##_next; \
+ (tail) = _item; \
+ } while (false)
+
+/* Insert an item after another one (a = where, b = what) */
+#define LIST_INSERT_AFTER(t,name,head,a,b) \
+ do { \
+ t **_head = &(head), *_a = (a), *_b = (b); \
+ assert(_b); \
+ if (!_a) { \
+ if ((_b->name##_next = *_head)) \
+ _b->name##_next->name##_prev = _b; \
+ _b->name##_prev = NULL; \
+ *_head = _b; \
+ } else { \
+ if ((_b->name##_next = _a->name##_next)) \
+ _b->name##_next->name##_prev = _b; \
+ _b->name##_prev = _a; \
+ _a->name##_next = _b; \
+ } \
+ } while(false)
+
+#define LIST_JUST_US(name,item) \
+ (!(item)->name##_prev && !(item)->name##_next) \
+
+#define LIST_FOREACH(name,i,head) \
+ for ((i) = (head); (i); (i) = (i)->name##_next)
+
+#define LIST_FOREACH_SAFE(name,i,n,head) \
+ for ((i) = (head); (i) && (((n) = (i)->name##_next), 1); (i) = (n))
+
+#define LIST_FOREACH_BEFORE(name,i,p) \
+ for ((i) = (p)->name##_prev; (i); (i) = (i)->name##_prev)
+
+#define LIST_FOREACH_AFTER(name,i,p) \
+ for ((i) = (p)->name##_next; (i); (i) = (i)->name##_next)