Re: [PATCH v3 1/3] QIOChannel: Add io_async_writev & io_async_flush callbacks

[Leonardo Bras Soares Passos]

Hello Peter, thanks for reviewing!

On Tue, Sep 28, 2021 at 6:52 PM Peter Xu <peterx@redhat.com> wrote:
>
> On Fri, Sep 24, 2021 at 06:16:04PM +0100, Daniel P. Berrangé wrote:
> > > +ssize_t qio_channel_async_writev(QIOChannel *ioc,
> > > +                                 const struct iovec *iov,
> > > +                                 size_t niov,
> > > +                                 int *fds,
> > > +                                 size_t nfds,
> > > +                                 Error **errp);
> >
> > This is missing any flags. We need something like
> >
> >    QIO_CHANNEL_WRITE_FLAG_ZEROCOPY
> >
> > passed in an 'unsigned int flags' parameter. This in
> > turn makes me question whether we should have the
> > common helpers at all, as the api is going to be
> > different for sync vs async.
> >
> > The QIOChannelFeature enum probably ought to be
> > extended with QIO_CHANNEL_FEATURE_WRITE_ZEROCOPY with
> > support for probing whether that's supported or not.
>
> I'm also wondering whether we could just drop the fds/nfds as per my knowledge
> SCM_RIGHT is the only user, at the meantime I don't see why an async interface
> would pass in any fd anyways..  Thanks,

FWIW, I think it's a great idea.
Daniel, what do you think?

>
> --
> Peter Xu
>

Best regards,
Leonardo