sync code with last improvements from OpenBSD

lib/libdrm/util_double_list.h

@@ -0,0 +1,143 @@
+/*
+ *
+ * Copyright 2006 Tungsten Graphics, Inc., Bismarck, ND. USA.
+ * All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sub license, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
+ * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
+ * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+ * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
+ * USE OR OTHER DEALINGS IN THE SOFTWARE.
+ *
+ * The above copyright notice and this permission notice (including the
+ * next paragraph) shall be included in all copies or substantial portions
+ * of the Software.
+ *
+ */
+
+/**
+ * \file
+ * List macros heavily inspired by the Linux kernel
+ * list handling. No list looping yet.
+ *
+ * Is not threadsafe, so common operations need to
+ * be protected using an external mutex.
+ */
+#ifndef _U_DOUBLE_LIST_H_
+#define _U_DOUBLE_LIST_H_
+
+#include <stddef.h>
+
+struct list_head
+{
+    struct list_head *prev;
+    struct list_head *next;
+};
+
+static inline void list_inithead(struct list_head *item)
+{
+    item->prev = item;
+    item->next = item;
+}
+
+static inline void list_add(struct list_head *item, struct list_head *list)
+{
+    item->prev = list;
+    item->next = list->next;
+    list->next->prev = item;
+    list->next = item;
+}
+
+static inline void list_addtail(struct list_head *item, struct list_head *list)
+{
+    item->next = list;
+    item->prev = list->prev;
+    list->prev->next = item;
+    list->prev = item;
+}
+
+static inline void list_replace(struct list_head *from, struct list_head *to)
+{
+    to->prev = from->prev;
+    to->next = from->next;
+    from->next->prev = to;
+    from->prev->next = to;
+}
+
+static inline void list_del(struct list_head *item)
+{
+    item->prev->next = item->next;
+    item->next->prev = item->prev;
+}
+
+static inline void list_delinit(struct list_head *item)
+{
+    item->prev->next = item->next;
+    item->next->prev = item->prev;
+    item->next = item;
+    item->prev = item;
+}
+
+#define LIST_INITHEAD(__item) list_inithead(__item)
+#define LIST_ADD(__item, __list) list_add(__item, __list)
+#define LIST_ADDTAIL(__item, __list) list_addtail(__item, __list)
+#define LIST_REPLACE(__from, __to) list_replace(__from, __to)
+#define LIST_DEL(__item) list_del(__item)
+#define LIST_DELINIT(__item) list_delinit(__item)
+
+#define LIST_ENTRY(__type, __item, __field)   \
+    ((__type *)(((char *)(__item)) - offsetof(__type, __field)))
+
+#define LIST_FIRST_ENTRY(__ptr, __type, __field)   \
+    LIST_ENTRY(__type, (__ptr)->next, __field)
+
+#define LIST_LAST_ENTRY(__ptr, __type, __field)   \
+    LIST_ENTRY(__type, (__ptr)->prev, __field)
+
+#define LIST_IS_EMPTY(__list)                   \
+    ((__list)->next == (__list))
+
+#ifndef container_of
+#define container_of(ptr, sample, member)				\
+    (void *)((char *)(ptr)						\
+	     - ((char *)&((__typeof__(sample))0)->member))
+#endif
+
+#define LIST_FOR_EACH_ENTRY(pos, head, member)				\
+   for (pos = container_of((head)->next, pos, member);			\
+	&pos->member != (head);						\
+	pos = container_of(pos->member.next, pos, member))
+
+#define LIST_FOR_EACH_ENTRY_SAFE(pos, storage, head, member)	\
+   for (pos = container_of((head)->next, pos, member),			\
+	storage = container_of(pos->member.next, pos, member);	\
+	&pos->member != (head);						\
+	pos = storage, storage = container_of(storage->member.next, storage, member))
+
+#define LIST_FOR_EACH_ENTRY_SAFE_REV(pos, storage, head, member)	\
+   for (pos = container_of((head)->prev, pos, member),			\
+	storage = container_of(pos->member.prev, pos, member);		\
+	&pos->member != (head);						\
+	pos = storage, storage = container_of(storage->member.prev, storage, member))
+
+#define LIST_FOR_EACH_ENTRY_FROM(pos, start, head, member)		\
+   for (pos = container_of((start), pos, member);			\
+	&pos->member != (head);						\
+	pos = container_of(pos->member.next, pos, member))
+
+#define LIST_FOR_EACH_ENTRY_FROM_REV(pos, start, head, member)		\
+   for (pos = container_of((start), pos, member);			\
+	&pos->member != (head);						\
+	pos = container_of(pos->member.prev, pos, member))
+
+#endif /*_U_DOUBLE_LIST_H_*/