svn commit: r296947 - head/share/man/man9

[Konstantin Belousov]

On Wed, Mar 16, 2016 at 06:39:48PM +0000, Bryan Drewery wrote:
> Author: bdrewery
> Date: Wed Mar 16 18:39:48 2016
> New Revision: 296947
> URL: https://svnweb.freebsd.org/changeset/base/296947
> 
> Log:
>   Remove incorrect BUGS entry about asserting lock not held.
>   
>   For non-WITNESS< assertion support for SA_UNLOCKED was added in r125421 and
>   made to panic in r126316.
>   
>   MFC after:	1 week
> 
> Modified:
>   head/share/man/man9/sx.9
> 
> Modified: head/share/man/man9/sx.9
> ==============================================================================
> --- head/share/man/man9/sx.9	Wed Mar 16 17:35:55 2016	(r296946)
> +++ head/share/man/man9/sx.9	Wed Mar 16 18:39:48 2016	(r296947)
> @@ -26,7 +26,7 @@
>  .\"
>  .\" $FreeBSD$
>  .\"
> -.Dd March 13, 2016
> +.Dd March 16, 2016
>  .Dt SX 9
>  .Os
>  .Sh NAME
> @@ -320,11 +320,6 @@ end up sleeping while holding a mutex, w
>  .Xr rwlock 9 ,
>  .Xr sema 9
>  .Sh BUGS
> -Currently there is no way to assert that a lock is not held.
> -This is not possible in the
> -.No non- Ns Dv WITNESS
> -case for asserting that this thread
> -does not hold a shared lock.
>  In the
>  .No non- Ns Dv WITNESS
>  case, the
The removed text was not quite correct, but its removal is not quite correct
either.  sx (and rw) locks do not track shared owners, so in non-witness
case only exclusive ownership by curthread triggers panic for SA_UNLOCKED
case.  Shared ownership is silently ignored by the assert.