Re: [Xen-devel] [PATCH 23 of 32 RFC] libxl: use libxl_*_init internally too

[Ian Campbell <Ian.Campbell@xxxxxxxxxx>]

On Mon, 2012-01-16 at 16:16 +0000, Ian Jackson wrote:
> Ian Campbell writes ("Re: [Xen-devel] [PATCH 23 of 32 RFC] libxl: use 
> libxl_*_init internally too"):
> > I think the reason is that sometimes they might allocate memory. Many of
> > them don't (I don't know about vfb in particular) and I don't know
> > whether we prefer consistency in similar functions or avoiding pointless
> > return values (I prefer the former so as to avoid needing to change the
> > public API in the future when we find that we have introduced a way for
> > a function to fail).
> 
> Why might they need to allocate memory ?

e.g. vif->model = strdup("rtl8139").

> > Possibly in the new world order (where init ~= memset and setdefaults
> > does thework) this will no longer be the case, but then the same will
> > become true of the setdefaults function.
> 
> Yes.  I think it's OK for setdefaults to be able to fail.
> 
> Having infallible init functions is a real boon because it makes the
> caller's memory management much easier, because they can always safely
> dispose.

I think my series has made more *_init functions have no possibility of
failure but I don't think it is all of them.

Ian.



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