1 files changed, 44 insertions, 0 deletions
diff --git a/libqueue/queue/dl.h b/libqueue/queue/dl.h
new file mode 100644
index 0000000..e53843f
--- /dev/null
+++ b/libqueue/queue/dl.h
@@ -0,0 +1,44 @@
+/* vim: set ts=4 sw=4 ai:
+ * dl.h -- doubly linked list implementation derived from NetBSD's queue.h
+ */
+
+#ifndef DL_H
+#define DL_H
+
+struct dle {
+	void *data;
+	struct dle *next;
+	struct dle **pprev;
+};
+
+struct dlh {
+	struct dle *first;
+};
+
+#define dl_first(hd) ((hd)->first)
+#define dl_next(e) ((e)->next)
+#define dl_empty(hd) (((hd)->first) == NULL)
+#define dl_init(hd) ((hd)->first = NULL)
+
+#define dl_foreach(var,head) \
+	for ((var) = ((head)->first); \
+		(var) != NULL; \
+		(var) = ((var)->next))
+
+#define dl_foreach_safe(var,head,vnext) \
+	for ((var) = ((head)->first); \
+		(var) != NULL && ((vnext) = dl_next((var)), 1); \
+		(var) = (vnext))
+
+struct dlh *dl_new(void);
+struct dle *dl_elem_new(void *);
+void dl_insert_after(struct dle *, struct dle *);
+void dl_insert_before(struct dle *, struct dle *);
+void dl_insert_head(struct dlh *, struct dle *);
+void dl_remove(struct dlh *, struct dle *);
+void dl_replace(struct dle *, struct dle *);
+void dl_move(struct dlh *, struct dlh *);
+void dl_cleanup(struct dlh *, void (*)(void *));
+struct dle *dl_find_from_data(struct dlh *, const void *, int (*)(const void *, const void *));
+
+#endif/*!DL_H*/