Retire ml_requeue(9) and mq_requeue(9).

As Kenjiro Cho pointed out it is very hard to cancel a dequeue operation
for some queueing disciplines when such it keeps some internal states.

As you can see, APIs can also Live Fast & Die Young.

ok dlg@

3 files changed, 6 insertions, 36 deletions

diff --git a/share/man/man9/Makefile b/share/man/man9/Makefile
index d3039569269..555674da882 100644
--- a/share/man/man9/Makefile
+++ b/share/man/man9/Makefile
@@ -1,4 +1,4 @@
-#	$OpenBSD: Makefile,v 1.258 2015/11/21 00:32:46 dlg Exp $
+#	$OpenBSD: Makefile,v 1.259 2015/11/21 11:46:24 mpi Exp $
 #	$NetBSD: Makefile,v 1.4 1996/01/09 03:23:01 thorpej Exp $
 
 #	Makefile for section 9 (kernel function and variable) manual pages.
@@ -269,7 +269,7 @@ MLINKS+=microtime.9 getmicrotime.9 microtime.9 microuptime.9 \
 	microtime.9 getnanotime.9 microtime.9 nanouptime.9 \
 	microtime.9 getnanouptime.9 microtime.9 bintime.9 \
 	microtime.9 binuptime.9
-MLINKS+=ml_init.9 ml_enqueue.9 ml_init.9 ml_dequeue.9 ml_init.9 ml_requeue.9 \
+MLINKS+=ml_init.9 ml_enqueue.9 ml_init.9 ml_dequeue.9 \
 	ml_init.9 ml_enlist.9 ml_init.9 ml_dechain.9 \
 	ml_init.9 ml_filter.9 ml_init.9 ml_len.9 ml_init.9 ml_empty.9 \
 	ml_init.9 ml_purge.9 \
@@ -280,7 +280,7 @@ MLINKS+=mutex.9 mtx_init.9 mutex.9 mtx_enter.9 mutex.9 mtx_leave.9 \
 	mutex.9 MUTEX_ASSERT_LOCKED.9 mutex.9 MUTEX_ASSERT_UNLOCKED.9 \
 	mutex.9 MUTEX_INITIALIZER.9
 MLINKS+=mutex.9 mtx_enter_try.9
-MLINKS+=mq_init.9 mq_enqueue.9 mq_init.9 mq_dequeue.9 mq_init.9 mq_requeue.9 \
+MLINKS+=mq_init.9 mq_enqueue.9 mq_init.9 mq_dequeue.9 \
 	mq_init.9 mq_enlist.9 mq_init.9 mq_delist.9 \
 	mq_init.9 mq_dechain.9 mq_init.9 mq_filter.9 mq_init.9 mq_purge.9 \
 	mq_init.9 mq_len.9 mq_init.9 mq_empty.9 mq_init.9 mq_drops.9 \
diff --git a/share/man/man9/ml_init.9 b/share/man/man9/ml_init.9
index 6f843aeedd9..626da25450e 100644
--- a/share/man/man9/ml_init.9
+++ b/share/man/man9/ml_init.9
@@ -1,4 +1,4 @@
-.\"     $OpenBSD: ml_init.9,v 1.9 2015/11/21 00:32:46 dlg Exp $
+.\"     $OpenBSD: ml_init.9,v 1.10 2015/11/21 11:46:24 mpi Exp $
 .\"
 .\"  Copyright (c) 2015 David Gwynne <dlg@openbsd.org>
 .\"
@@ -21,7 +21,6 @@
 .Nm ml_init ,
 .Nm ml_enqueue ,
 .Nm ml_dequeue ,
-.Nm ml_requeue ,
 .Nm ml_enlist ,
 .Nm ml_dechain ,
 .Nm ml_len ,
@@ -40,8 +39,6 @@
 .Ft struct mbuf *
 .Fn ml_dequeue "struct mbuf_list *ml"
 .Ft void
-.Fn ml_requeue "struct mbuf_list *ml" "struct mbuf *m"
-.Ft void
 .Fn ml_enlist "struct mbuf_list *ml" "struct mbuf_list *src"
 .Ft struct mbuf *
 .Fn ml_dechain "struct mbuf_list *ml"
@@ -76,10 +73,6 @@ Insertion of a new mbuf at the end of the list.
 .It
 Removal of an mbuf from the head of the list.
 .It
-Reinsertion of an mbuf at the head of the list.
-.It
-Removal of the entire chain of mbufs on the list.
-.El
 .Bl -tag -width Ds
 .It Fn ml_init "struct mbuf_list *ml"
 Initialise the
@@ -97,12 +90,6 @@ mbuf list.
 Dequeue an mbuf from the front of the
 .Fa ml
 mbuf list.
-.It Fn ml_requeue "struct mbuf_list *ml" "struct mbuf *m"
-Enqueue mbuf
-.Fa m
-at the head of the
-.Fa ml
-mbuf list.
 .It Fn ml_enlist "struct mbuf_list *ml" "struct mbuf_list *src"
 Enqueue all the mbufs on the
 .Fa src
@@ -164,7 +151,6 @@ Note that it is unsafe to modify the list while iterating over it.
 .Fn ml_init ,
 .Fn ml_enqueue ,
 .Fn ml_dequeue ,
-.Fn ml_requeue ,
 .Fn ml_enlist ,
 .Fn ml_dechain ,
 .Fn ml_len ,
diff --git a/share/man/man9/mq_init.9 b/share/man/man9/mq_init.9
index ed960f889e6..e9edba9bd13 100644
--- a/share/man/man9/mq_init.9
+++ b/share/man/man9/mq_init.9
@@ -1,4 +1,4 @@
-.\"     $OpenBSD: mq_init.9,v 1.5 2015/11/02 09:21:48 dlg Exp $
+.\"     $OpenBSD: mq_init.9,v 1.6 2015/11/21 11:46:24 mpi Exp $
 .\"
 .\"  Copyright (c) 2015 David Gwynne <dlg@openbsd.org>
 .\"
@@ -14,14 +14,13 @@
 .\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 .\"
-.Dd $Mdocdate: November 2 2015 $
+.Dd $Mdocdate: November 21 2015 $
 .Dt MQ_INIT 9
 .Os
 .Sh NAME
 .Nm mq_init ,
 .Nm mq_enqueue ,
 .Nm mq_dequeue ,
-.Nm mq_requeue ,
 .Nm mq_enlist ,
 .Nm mq_delist ,
 .Nm mq_dechain ,
@@ -41,8 +40,6 @@
 .Ft struct mbuf *
 .Fn mq_dequeue "struct mbuf_queue *mq"
 .Ft int
-.Fn mq_requeue "struct mbuf_queue *mq" "struct mbuf *m"
-.Ft int
 .Fn mq_enlist "struct mbuf_queue *mq" "struct mbuf_list *ml"
 .Ft void
 .Fn mq_delist "struct mbuf_queue *mq" "struct mbuf_list *ml"
@@ -119,14 +116,6 @@ mbuf queue.
 Dequeue an mbuf from the front of the
 .Fa mq
 mbuf queue.
-.It Fn mq_requeue "struct mbuf_queue *mq" "struct mbuf *m"
-Enqueue mbuf
-.Fa m
-at the head of the
-.Fa mq
-mbuf queue.
-Note, this operation will succeed even if it will cause the queue to exceed its
-maximum length.
 .It Fn mq_enlist "struct mbuf_queue *mq" "struct mbuf_list *ml"
 Enqueue all the mbufs on the
 .Fa ml
@@ -194,7 +183,6 @@ already exist on the queue.
 .Fn mq_init ,
 .Fn mq_enqueue ,
 .Fn mq_dequeue ,
-.Fn mq_requeue ,
 .Fn mq_enlist ,
 .Fn mq_delist ,
 .Fn mq_dechain ,
@@ -238,10 +226,6 @@ returns 0 if the mbuf was successfully queued, or non-zero if the
 mbuf was freed because it would cause the queue to exceed its maximum
 length.
 .Pp
-.Fn mq_requeue
-returns non-zero if the mbuf queue is now full, otherwise 0.
-length.
-.Pp
 .Fn mq_enlist
 returns the number of mbufs that were dropped from the list if the
 length of the queue exceeded its maximum length.