util/list: Add list splicing functions

This adds functions for splicing one list into another.  These have
more-or-less the same API as the kernel list splicing functions.  The
implementation, however, was stolen from the Wayland list implementation.

Reviewed-by: Mark Janes <mark.a.janes@intel.com>
Reviewed-by: Rob Clark <robclark@freedesktop.org>

diff --git a/src/util/list.h b/src/util/list.h
index 066f9b8dfe50bb5852e9b31d781e602cb6b55ce4..f0dec5da60874c7cf9e6028589e9d1f03697816b 100644 (file)
--- a/src/util/list.h
+++ b/src/util/list.h
@@ -116,6 +116,28 @@ static inline unsigned list_length(struct list_head *list)
    return length;
 }
 
+static inline void list_splice(struct list_head *src, struct list_head *dst)
+{
+   if (list_empty(src))
+      return;
+
+   src->next->prev = dst;
+   src->prev->next = dst->next;
+   dst->next->prev = src->prev;
+   dst->next = src->next;
+}
+
+static inline void list_splicetail(struct list_head *src, struct list_head *dst)
+{
+   if (list_empty(src))
+      return;
+
+   src->prev->next = dst;
+   src->next->prev = dst->prev;
+   dst->prev->next = src->next;
+   dst->prev = src->prev;
+}
+
 static inline void list_validate(struct list_head *list)
 {
    struct list_head *node;