On Fri, Jul 27, 2012 at 09:16:48AM +0000, Gleb Smirnoff wrote: > Author: glebius > Date: Fri Jul 27 09:16:48 2012 > New Revision: 238828 > URL: http://svn.freebsd.org/changeset/base/238828 > > Log: > Add assertion for refcount overflow. > > Submitted by: Andrey Zonov <andrey zonov.org> > Reviewed by: kib It was discussed rather then reviewed.
I suggest that the assert may be expressed as a check after the increment,
which verifies that counter is != 0. This allows to avoid namespace
pollution due to limits.h.
>
> Modified:
> head/sys/sys/refcount.h
>
> Modified: head/sys/sys/refcount.h
> ==============================================================================
> --- head/sys/sys/refcount.h Fri Jul 27 08:28:44 2012 (r238827)
> +++ head/sys/sys/refcount.h Fri Jul 27 09:16:48 2012 (r238828)
> @@ -32,6 +32,7 @@
> #ifndef __SYS_REFCOUNT_H__
> #define __SYS_REFCOUNT_H__
>
> +#include <sys/limits.h>
> #include <machine/atomic.h>
>
> #ifdef _KERNEL
> @@ -51,6 +52,7 @@ static __inline void
> refcount_acquire(volatile u_int *count)
> {
>
> + KASSERT(*count < UINT_MAX, ("refcount %p overflowed", count));
> atomic_add_acq_int(count, 1);
> }
>
pgpJxVKV88a0I.pgp
Description: PGP signature
