Re: [Xen-devel] Error reporting capabilities for libxc

["Daniel P. Berrange" <berrange@xxxxxxxxxx>]

On Tue, Sep 26, 2006 at 01:58:11PM +0100, Ian Pratt wrote:
> > On 26/9/06 12:45, "Stephen C. Tweedie" <sct@xxxxxxxxxx> wrote:
> > 
> > >> So, I've prototyped a simple error reporting mechanism for 
> > libxc. The 
> > >> idea is we first define an enum for the broad classes of 
> > errors which can occur.
> > > ...
> > > 
> > >> Any way, the upshot of all this work:
> > >>   # xm create error
> > >>   Using config file "error".
> > >>   Error: [2, 'Kernel ELF architecture 3 does not match Xen 
> > >> architecture 62']
> > > 
> > > IMHO this is sorely needed.  Any comments from XenSource people?
> > 
> > I'd agree something like this is necessary in the 3.0.4 
> > timeframe. I'll let one of the guys more acquainted with xend 
> > comment in detail. There's also the question of how this will 
> > integrate with the proposed 'XenAPI'.
> 
> Yep, definitely needs to happen. However, I think we should at least
> discuss alternative potentially less clunky implementation methods.
> Perhaps we should use a thread local errno and error string variables?

Attached is an update to the original patch which annotates the static
variables with __thread so that they are setup per-thread. It also adds
more informative error reporting for bad kernels.

The only issue is that __thread is a GCC specific extension, so I'm not
sure this will work for the Solaris folks ?

  http://gcc.gnu.org/onlinedocs/gcc/Thread_002dLocal.html

The other option is to use the POSIX APIs  pthread_getspecific & 
pthread_setspecific. It'll make the code alot more cumbersome, but
would certainly be portable. I'm certainly willing to do this though
if need be...

  Signed-off-by: Daniel P. Berrange <berrange@xxxxxxxxxx>

Regards,
Dan.
-- 
|=- Red Hat, Engineering, Emerging Technologies, Boston.  +1 978 392 2496 -=|
|=-           Perl modules: http://search.cpan.org/~danberr/              -=|
|=-               Projects: http://freshmeat.net/~danielpb/               -=|
|=-  GnuPG: 7D3B9505   F3C9 553F A1DA 4AC2 5648 23C1 B3DF F742 7D3B 9505  -=|

Attachment: xen-libxc-errors9.patch
Description: Text document

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