Add SPLASSERT.9 man page. SPLASSERT() commit to follow immediately.

Approved by: jkh

share/man/man9/SPLASSERT.9

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+.\" -*- nroff -*-
+.\"
+.\" Copyright (c) 1996 Joanthan M Bresler
+.\"
+.\" All rights reserved.
+.\"
+.\" This program is free software.
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\"    notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\"    notice, this list of conditions and the following disclaimer in the
+.\"    documentation and/or other materials provided with the distribution.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY EXPRESS OR
+.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+.\" IN NO EVENT SHALL THE DEVELOPERS BE LIABLE FOR ANY DIRECT, INDIRECT,
+.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+.\"
+.\" $FreeBSD$
+.\"
+.Dd January 14, 2000
+.Os
+.Dt SPLASSERT 9
+.Sh NAME
+.Nm SPLASSERT
+.Nd kernel spl level verification macro
+.Sh SYNOPSIS
+.Fd options INVARIANTS
+.Fd options INVARIANT_SUPPORT
+.Fn SPLASSERT "char *level, char *msg"
+.Sh DESCRIPTION
+In a kernel compiled with both "options INVARIANTS"
+and "options INVARIANT_SUPPORT",
+the 
+.Fn SPLASSERT
+macro compares the current spl level of the kernel with the spl
+.Ar level
+specified in the macro
+.Fn SPLASSERT
+If the specified
+.Ar level
+is not active
+.Fn SPLASSERT
+calls the 
+.Fn KASSERT
+macro with the
+.Ar msg,
+terminating the running system.
+.Pp
+In a kernel that does not have both "options INVARIANTS"
+and "options INVARIANT_SUPPORT",
+the 
+.Fn SPLASSERT
+macro is defined to be no-op.  
+.Sh EXAMPLE
+The kernel function
+.Fn rtredirect
+must be called at
+.Fn splnet
+.Bd -literal -offset indent
+void
+rtalloc(ro)
+	register struct route *ro;
+{
+	SPLASSERT(net, "rtalloc()");
+	rtalloc_ign(ro, 0UL);
+}
+.Ed
+.Pp
+.Sh SEE ALSO
+.Xr config 8 ,
+.Xr KASSERT 9 ,
+.Xr panic 9 
+.Sh AUTHORS
+This man page was written by
+.An Jonathan M Bresler .