Re: [Xen-devel] [PATCH][libxen] Fix 'contents' field of set structures in libxen iinterface

[Ewan Mellor <ewan@xxxxxxxxxxxxx>]

On Fri, Nov 03, 2006 at 05:41:31PM -0700, Jim Fehlig wrote:

> Many of the set structures in the libxen interface contain a 'contents' 
> field with too many dimensions, particularly when 'contents' stores 
> references.  References are defined in the various xen_*_decl.h headers 
> as 'void *'.  Sets of the various classes are defined for example as
> 
>  typedef void *xen_vm;
> 
>  typedef struct xen_vm_set
>  {
>     size_t size;
>     xen_vm *contents[];
>  } xen_vm_set;
> 
> The additional dimension on 'contents' for sets of references is not 
> required.
> 

I meant to discuss this with you when you sent this privately a few weeks
ago -- sorry I forgot.

I can see what you're trying to do here.  The problem is that populating this
set becomes difficult.  The sets are read off the wire using the generic
code in xen_common.c, guided by the abstract_type that's passed in.  The thing
is, we have only one indicator for sets (SET) but with your patch we'll need
to introduce a second indicator, to distinguish between sets where the value
is put in place (like handles) and sets where the value placed is a pointer
(like sets of records).  This will have to be part of a larger patch,
unfortunately.  I'll have a hack now and see what I can do.

Cheers,

Ewan.

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel