- Require that cv_signal/cv_broadcast be called with the interlock held.

- Provide 'async' versions that don't need the interlock.

share/man/man9/condvar.9

@@ -1,4 +1,4 @@
-.\"	$NetBSD: condvar.9,v 1.5 2007/02/02 07:36:09 wiz Exp $
+.\"	$NetBSD: condvar.9,v 1.6 2007/02/03 16:39:53 ad Exp $
 .\"
 .\" Copyright (c) 2006, 2007 The NetBSD Foundation, Inc.
 .\" All rights reserved.
@@ -34,7 +34,7 @@
 .\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 .\" POSSIBILITY OF SUCH DAMAGE.
 .\"
-.Dd February 2, 2007
+.Dd February 3, 2007
 .Dt CONDVAR 9
 .Os
 .Sh NAME
@@ -47,7 +47,9 @@
 .Nm cv_timedwait ,
 .Nm cv_timedwait_sig ,
 .Nm cv_signal ,
-.Nm cv_broadcast
+.Nm cv_broadcast ,
+.Nm cv_signal_async ,
+.Nm cv_broadcast_async
 .Nd condition variables
 .Sh SYNOPSIS
 .In sys/condvar.h
@@ -67,6 +69,10 @@
 .Fn cv_signal "kcondvar_t *cv"
 .Ft void
 .Fn cv_broadcast "kcondvar_t *cv"
+.Ft void
+.Fn cv_signal_async "kcondvar_t *cv"
+.Ft void
+.Fn cv_broadcast_async "kcondvar_t *cv"
 .Sh DESCRIPTION
 Condition variables (CVs) are used in the kernel to synchronize access
 to resources that are limited (for example, memory) and to wait for
@@ -177,6 +183,10 @@ if the timeout expires.
 .Pp
 Awaken one LWP (potentially among many) that is waiting on the specified
 condition variable.
+The mutex passed to the wait function
+.Po Fa mtx Pc
+must also be held when calling
+.Fn cv_signal .
 .Pp
 (Note that
 .Fn cv_signal
@@ -185,6 +195,20 @@ sense to LWPs waiting on a CV.)
 .It Fn cv_broadcast "cv"
 .Pp
 Awaken all LWPs waiting on the specified condition variable.
+The mutex passed to the wait function
+.Po Fa mtx Pc
+must also be held when calling
+.Fn cv_broadcast .
+.It Fn cv_signal_async "cv" , Fn cv_broadcast_async "cv"
+.Pp
+As per
+.Fn cv_signal
+and
+.Fn cv_broadcast ,
+but the interlock
+.Po Fa mtx Pc
+need not be held.
+Use of these methods is discouraged as they are more costly to execute.
 .El
 .Sh EXAMPLES
 .Bd -literal