Re: [Qemu-devel] [PATCH 1/2] char: io_channel_send: don't lose written bytes

[Anthony Liguori <aliguori@us.ibm.com>]

Laszlo Ersek <lersek@redhat.com> writes:

> On 07/16/13 20:57, Anthony Liguori wrote:
>> Laszlo Ersek <lersek@redhat.com> writes:
>> 
>>> The g_io_channel_write_chars() documentation states,
>>>
>>>   bytes_written: The number of bytes written. This can be nonzero even if
>>>                  the return value is not G_IO_STATUS_NORMAL. [...]
>>>
>>> io_channel_send() could lose such bytes before.
>>>
>>> Furthermore, the (status == G_IO_STATUS_EOF) condition used to evaluate to
>>> constant false whenever it was reached. When that condition actually held,
>>> it always led to -1 / EINVAL. This patch (almost) distinguishes
>>> G_IO_STATUS_EOF only when no bytes have been written, and then treats it
>>> as an error.
>> 
>> Just for my own benefit, I always assume G_IO_STATUS_EOF cannot happen
>> if bytes_written > 0.  I see what you mean by the comment but do you
>> have any reason to believe this happens in practice?
>
> In my opinion, G_IO_STATUS_EOF doesn't make any sense whatsoever for a
> write operation (for count>0) if glib kept any resemblance to write(),
> and should never happen in practice.

Okay, thanks!

I'll give other folks a chance to look at this series and then apply in
a day or so.

Regards,

Anthony Liguori

>
> The awkward commit message only captures the fact that I didn't forget
> about G_IO_STATUS_EOF, I considered it explicitly.
>
>> Reviewed-by: Anthony Liguori <aliguori@us.ibm.com>
>
> Thanks!
>
> Laszlo