[libvirt] PATCH: 19/28: Reduce return paths for node device driver

Daniel Veillard veillard at redhat.com
Wed Dec 3 10:28:38 UTC 2008

On Mon, Dec 01, 2008 at 12:03:39AM +0000, Daniel P. Berrange wrote:
> This patch reduces the number of return paths in the node device driver
> methods
> In doing this I noticed an annoying problem in the public API contract
> for  virNodeDeviceGetParent. It returns a 'const char *', but the remote
> driver is actually returning an malloc'd string requiring the caller to
> free it, while the node_device driver is returning a const string the
> caller must not free. Ideally we would not have the 'const' annotation
> but changing that now is ABI change, so instead I work around it, by
> making all drivers return a malloc'd string, but then caching this in
> the virNodeDevicePtr object. This mallc'd string is then free'd when
> the object is released. This allows us to work around the public API
> contract problem

  argh, understood !

>  static char *nodeDeviceGetParent(virNodeDevicePtr dev)
>  {
> -    return obj->def->parent;
> +    ret = strdup(obj->def->parent);

   I guess we should report allocation error, even if it probably
doesn't help much at that point.

> +cleanup:
> +    return ret;
>  }

  Okay +1,


Daniel Veillard      | libxml Gnome XML XSLT toolkit  http://xmlsoft.org/
daniel at veillard.com  | Rpmfind RPM search engine http://rpmfind.net/
http://veillard.com/ | virtualization library  http://libvirt.org/

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