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

[Daniel Veillard]

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

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