Add _NEW flag to mtx(9), sx(9), rmlock(9) and rwlock(9).

A _NEW flag passed to _init_flags() to avoid check for double-init.

Differential Revision:	https://reviews.freebsd.org/D1208
Reviewed by:	jhb, wblock
MFC after:	1 Month

1 files changed, 10 insertions, 1 deletions

diff --git a/share/man/man9/sx.9 b/share/man/man9/sx.9
index b9987497ba40..01fffaae7e1e 100644
--- a/share/man/man9/sx.9
+++ b/share/man/man9/sx.9
@@ -26,7 +26,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd November 16, 2011
+.Dd December 13, 2014
 .Dt SX 9
 .Os
 .Sh NAME
@@ -144,6 +144,15 @@ Allow threads to recursively acquire exclusive locks for
 .It Dv SX_QUIET
 Do not log any operations for this lock via
 .Xr ktr 4 .
+.It Dv SX_NEW
+If the kernel has been compiled with
+.Cd "options INVARIANTS" ,
+.Fn sx_init
+will assert that the
+.Fa sx
+has not been initialized multiple times without intervening calls to
+.Fn sx_destroy
+unless this option is specified.
 .El
 .Pp
 Shared/exclusive locks are destroyed with