Re: [Qemu-devel] [PATCH 2/2] char: use a fixed idx for child muxed chr

[Marc-André Lureau]

Hi

On Tue, Oct 11, 2016 at 8:44 PM Daniel P. Berrange <address@hidden>
wrote:

>
> Not sure if this is immediately helpful to your scneario or
> not, but I'd like to see the qemu_chr_add_handlers method
> removed long term, and everything converted to use the
> qemu_chr_fe_add_watch function instead. This reverses the data
> flow pattern - with chr_add_handlers the chardev code pushes
> data from the backend into the frontends, but with fe_add_watch
> the frontend pulls data from the backend.
>

Very interesting, that would help, but I think that wouldn't be enough,
since we would still have the "event" handlers to properly register/track.
Furthermore, that upside-down change is not easy. I think I will simply go
with a new fe handler tag.


>
> To properly fix the non-blocking writes from the frontend to
> the backend[1] will likely require use of qemu_chr_fe_add_watch,
> and so having that function used for everything will make the
> code clearer overall IMHO.
>
> Regards,
> Daniel
>
> [1] eg the long term solution to replace this hack:
>
> commit 90f998f5f4267a0c22e983f533d19b9de1849283
> Author: Daniel P. Berrange <address@hidden>
> Date:   Tue Sep 6 14:56:05 2016 +0100
>
>     char: convert qemu_chr_fe_write to qemu_chr_fe_write_all
>
>
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-- 
Marc-André Lureau