Introduce REMOVE_NEXT() macro's for SLIST and STAILQ.

Even though single linked lists allow items to be removed at constant time
(when the previous element is known), the queue macro's don't allow this.
Implement new REMOVE_NEXT() macro's. Because the REMOVE() macro's also
contain the same code, make it call REMOVE_NEXT().

The OpenBSD version of SLIST_REMOVE_NEXT() needs a reference to the list
head, even though it is unused. We'd better mimic this. The STAILQ version
also needs a reference to the list. This means the prototypes of both
macro's are the same.

Approved by:	philip (mentor)
PR:		kern/121117

1 files changed, 20 insertions, 0 deletions

diff --git a/share/man/man3/queue.3 b/share/man/man3/queue.3
index b4556e5..372c4ad 100644
--- a/share/man/man3/queue.3
+++ b/share/man/man3/queue.3
@@ -48,6 +48,7 @@
 .Nm SLIST_INSERT_HEAD ,
 .Nm SLIST_NEXT ,
 .Nm SLIST_REMOVE_HEAD ,
+.Nm SLIST_REMOVE_NEXT ,
 .Nm SLIST_REMOVE ,
 .Nm STAILQ_CONCAT ,
 .Nm STAILQ_EMPTY ,
@@ -64,6 +65,7 @@
 .Nm STAILQ_LAST ,
 .Nm STAILQ_NEXT ,
 .Nm STAILQ_REMOVE_HEAD ,
+.Nm STAILQ_REMOVE_NEXT ,
 .Nm STAILQ_REMOVE ,
 .Nm LIST_EMPTY ,
 .Nm LIST_ENTRY ,
@@ -114,6 +116,7 @@ lists and tail queues
 .Fn SLIST_INSERT_HEAD "SLIST_HEAD *head" "TYPE *elm" "SLIST_ENTRY NAME"
 .Fn SLIST_NEXT "TYPE *elm" "SLIST_ENTRY NAME"
 .Fn SLIST_REMOVE_HEAD "SLIST_HEAD *head" "SLIST_ENTRY NAME"
+.Fn SLIST_REMOVE_NEXT "SLIST_HEAD *head" "TYPE *elm" "SLIST_ENTRY NAME"
 .Fn SLIST_REMOVE "SLIST_HEAD *head" "TYPE *elm" "TYPE" "SLIST_ENTRY NAME"
 .\"
 .Fn STAILQ_CONCAT "STAILQ_HEAD *head1" "STAILQ_HEAD *head2"
@@ -131,6 +134,7 @@ lists and tail queues
 .Fn STAILQ_LAST "STAILQ_HEAD *head" "TYPE" "STAILQ_ENTRY NAME"
 .Fn STAILQ_NEXT "TYPE *elm" "STAILQ_ENTRY NAME"
 .Fn STAILQ_REMOVE_HEAD "STAILQ_HEAD *head" "STAILQ_ENTRY NAME"
+.Fn STAILQ_REMOVE_NEXT "STAILQ_HEAD *head" "TYPE *elm" "STAILQ_ENTRY NAME"
 .Fn STAILQ_REMOVE "STAILQ_HEAD *head" "TYPE *elm" "TYPE" "STAILQ_ENTRY NAME"
 .\"
 .Fn LIST_EMPTY "LIST_HEAD *head"
@@ -387,6 +391,14 @@ this macro instead of the generic
 macro.
 .Pp
 The macro
+.Nm SLIST_REMOVE_NEXT
+removes the element after
+.Fa elm
+from the list. Unlike
+.Fa SLIST_REMOVE ,
+this macro does not traverse the entire list.
+.Pp
+The macro
 .Nm SLIST_REMOVE
 removes the element
 .Fa elm
@@ -561,6 +573,14 @@ use this macro explicitly rather than the generic
 macro.
 .Pp
 The macro
+.Nm STAILQ_REMOVE_NEXT
+removes the element after
+.Fa elm
+from the tail queue. Unlike
+.Fa STAILQ_REMOVE ,
+this macro does not traverse the entire tail queue.
+.Pp
+The macro
 .Nm STAILQ_REMOVE
 removes the element
 .Fa elm