Re: [PATCH v8 1/5] QIOChannel: Add flags on io_writev and introduce io_flush callback

[Leonardo Bras Soares Passos]

Thanks for reviewing, Juan!

On Fri, Feb 18, 2022 at 1:36 PM Juan Quintela <quintela@redhat.com> wrote:
>
> Leonardo Bras <leobras@redhat.com> wrote:
> > Add flags to io_writev and introduce io_flush as optional callback to
> > QIOChannelClass, allowing the implementation of zero copy writes by
> > subclasses.
> >
> > How to use them:
> > - Write data using 
> > qio_channel_writev*(...,QIO_CHANNEL_WRITE_FLAG_ZERO_COPY),
> > - Wait write completion with qio_channel_flush().
> >
> > Notes:
> > As some zero copy write implementations work asynchronously, it's
> > recommended to keep the write buffer untouched until the return of
> > qio_channel_flush(), to avoid the risk of sending an updated buffer
> > instead of the buffer state during write.
> >
> > As io_flush callback is optional, if a subclass does not implement it, then:
> > - io_flush will return 0 without changing anything.
> >
> > Also, some functions like qio_channel_writev_full_all() were adapted to
> > receive a flag parameter. That allows shared code between zero copy and
> > non-zero copy writev, and also an easier implementation on new flags.
> >
> > Signed-off-by: Leonardo Bras <leobras@redhat.com>
>
> Reviewed-by: Juan Quintela <quintela@redhat.com>
>
> As everybody pointed out about the missing assertion...
>