Re: [Qemu-devel] [RFC PATCH 2/4] qmp/hmp: Add getfd_file monitor command

[Luiz Capitulino <lcapitulino@redhat.com>]

On Tue, 22 May 2012 18:34:19 -0400
Corey Bryant <coreyb@linux.vnet.ibm.com> wrote:

> On 05/22/2012 04:26 PM, Luiz Capitulino wrote:
> > On Tue, 22 May 2012 16:02:19 -0400
> > Corey Bryant<coreyb@linux.vnet.ibm.com>  wrote:
> >
> >>> But there's a small problem. Today getfd commands are closely tied to the
> >>> Monitor. In Anthony's development tree, the getfd commands are tied to the
> >>> new QMP server's session support.
> >>>
> >>> Asking you to integrate the new QMP server only to have the getfd command
> >>> returning a simple integer would be too much, but at the same time I think
> >>> you'll have to at least to break it from the monitor. This means moving its
> >>> data structure away from the Monitor object and probably reworking the
> >>> internal API used to get fds (ie. monitor_get_fd()).
> >>>
> >>> Shouldn't be hard, but you should be careful not to break external users.
> >>>
> >>
> >> Just to verify, are you talking about moving the "fds" off the Monitor
> >> struct?  -->  QLIST_HEAD(,mon_fd_t) fds;
> >
> > Yes.
> >
> >> Was this already moved away from the Monitor struct in Anthony's
> >> development tree?  If not do you have a recommendation on where to move it?
> >
> > Yes, iirc it moved inside the new QMP server session support in Anthony's tree.
> >
> >> I think this would make more sense to me if I took a look at the getfd
> >> code in Anthony's development tree.  Is this the correct tree?  I had
> >> some issues cloning it.  https://github.com/aliguori/qemu-next.git
> >
> > The 'development' tree I'm referring to is the old glib branch in
> > git://repo.or.cz/qemu/aliguori.git.
> >
> 
> Hmm, it looks like fds is still on the Monitor struct in that branch. 

Oh, you're right. That code is unfinished. It seems that I kept the finished
version in my mind.

Well, I don't think that moving the fd array to another object will buy us
much, so you can keep it this way. Note that you still have to convert do_getfd()
to the QAPI as pointed out by Stefan and that the monitor object (*mon pointer)
won't be passed to it. You'll have to use cur_mon in qmp_getfd() (as Anthony's
version does).