.\" Copyright (c) 2000 Jeroen Ruigrok van der Werven,
.\"                    Jonathan M. Bresler
.\"
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.\"
.\" This program is free software.
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.\" $FreeBSD$
.\"
.Dd March 19 2000
.Os
.Dt CONDSPLASSERT 9
.Sh NAME
.Nm CONDSPLASSERT
.Nd conditional kernel spl level verification macro
.Sh SYNOPSIS
.Cd options INVARIANTS
.Cd options INVARIANT_SUPPORT
.Fn CONDSPLASSERT condition level "const char *msg"
.Sh DESCRIPTION
In a kernel compiled with both "options INVARIANTS"
and "options INVARIANT_SUPPORT",
the
.Fn CONDSPLASSERT
macro compares the current spl level of the kernel with the spl
.Ar level
specified in the macro
.Fn CONDSPLASSERT
if the specified condition is met.
If the specified
.Ar level
is not active
.Fn CONDSPLASSERT
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 CONDSPLASSERT
macro is defined to be a no-op.
.Pp
The behaviour of
.Fn CONDSPLASSERT
is tunable by means of the
.Xr sysctl 8
knob kern.splassertmode.
When set to 0 the
.Fn CONDSPLASSERT
macro is defined to be a no-op.
When set to 1 the
.Fn CONDSPLASSERT
macro is defined to log information to the console.
When set to 2 the
.Fn CONDSPLASSERT
macro is defined to
.Xr panic 9 .
.Sh EXAMPLES
The kernel function
.Fn swp_pager_meta_build
must be called
.Fn splvm
and has to match a certain object type:
.Bd -literal -offset indent
CONDSPLASSERT(object->type == OBJT_SWAP, vm,
              "swp_pager_meta_build");
if (object->type != OBJT_SWAP) {
        object->type = OBJT_SWAP;
        object->un_pager.swp.swp_bcount = 0;
.Ed
.Pp
.Sh SEE ALSO
.Xr config 8 ,
.Xr KASSERT 9 ,
.Xr panic 9 ,
.Xr SPLASSERT 9
.Sh AUTHORS
This manual page was written by
.An Jeroen Ruigrok van der Werven
.Aq asmodai@FreeBSD.org ,
based on the
.Xr SPLASSERT 9
manpage by
.An Jonathan M. Bresler
.Aq jmb@FreeBSD.org .