Re: [Xen-devel] new idl helper, append to Array

[Wei Liu <wei.liu2@xxxxxxxxxx>]

On Thu, Feb 04, 2016 at 11:07:58AM +0100, Olaf Hering wrote:
> On Thu, Feb 04, Ian Campbell wrote:
> 
> > I think the append_to variant is probably least gross.
> 
> libxl_device_vscsidev_append_to_vscsictrl() would work too.
> 
> This is what I will use for the time being (modulo introduced runtime bugs):
> 
> void libxl_device_vscsictrl_append_vscsidev(libxl_ctx *ctx,
>                                             libxl_device_vscsictrl *ctrl,
>                                             libxl_device_vscsidev *dev)
> {
>     GC_INIT(ctx);
>     ctrl->vscsidevs = libxl__realloc(NOGC, ctrl->vscsidevs, sizeof(*dev) * 
> (ctrl->num_vscsidevs + 1));
>     libxl_device_vscsidev_init(ctrl->vscsidevs + ctrl->num_vscsidevs);
>     libxl_device_vscsidev_copy(CTX, ctrl->vscsidevs + ctrl->num_vscsidevs, 
> dev);
>     ctrl->num_vscsidevs++;
>     GC_FREE;
> }
> 
> 
> > Wei, is it necessary to init the dst before copy into it?
> 
> It would clear the padding between members, a plain copy will leave them
> uninitialized.
> 

There is that. Yes, _init memset the whole structure to zeros.

Wei.

> Olaf

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