1 files changed, 54 insertions, 0 deletions
diff --git a/lib/util/circulardoublelinkedlist.h b/lib/util/circulardoublelinkedlist.h
new file mode 100644
index 0000000..3e5c524
--- /dev/null
+++ b/lib/util/circulardoublelinkedlist.h
@@ -0,0 +1,54 @@
+#ifndef __CIRCULARLIST__
+#define __CIRCULARLIST__
+
+/**
+  * ciruclar double linked list implementation
+  *
+  **/
+#include "util.h"
+#include<stdio.h>
+
+struct circular_list {
+	struct circular_list *next;
+	struct circular_list *prev;
+};
+
+#define CIRCULARLIST_INIT(name)	do { (name)->next = (name); (name)->prev = (name); } while(0);
+
+static int inline __circular_list_insert(struct circular_list *prev, struct circular_list *new, struct circular_list *next)
+{
+	prev->next = new;
+	new->prev = prev;
+	new->next = next;
+	next->prev = new;
+}
+
+static int inline circular_list_insert_after(struct circular_list *list, struct circular_list *new_elem)
+{
+	return __circular_list_insert(list, new_elem, list->next);
+}
+
+static int inline circular_list_insert_before(struct circular_list *list, struct circular_list *new_elem)
+{
+	return __circular_list_insert(list->prev, new_elem, list);
+}
+
+static void inline __circular_list_delete(struct circular_list *prev, struct circular_list *elem, struct circular_list *next)
+{
+	prev->next = next;
+	next->prev = prev;
+	elem->next = elem;
+	elem->prev = elem;
+}
+static void inline circular_list_delete(struct circular_list *elem)
+{
+	__circular_list_delete(elem->prev, elem, elem->next);
+}
+
+#define circular_list_get_prev(elem)	(elem)->prev
+#define circular_list_get_next(elem)	(elem)->next
+
+#define CIRCULARLIST_FOR_EACH(pos, head)	for(pos = head->next; pos != head; pos = pos->next)
+#define CONTAINER_OF(ptr, type, member)	((type *)((char *)(ptr) - (unsigned long)(&((type *)0)->member)))
+
+#endif