Re: n_tty: Check the other end of pty pair before returning EAGAIN on a read()

[Marc Aurele La France <tsi@tuyoix.net>]

On Fri, 11 Dec 2015, Peter Hurley wrote:
> On 12/11/2015 05:37 AM, Marc Aurele La France wrote:

>> I am not asking to read data before it has been produced.  I am puzzled
>> that despite knowing that the data exists, I can now be lied to when I
>> try to retrieve it, when I wasn't before.  We are talking about what is
>> essentially a two-way pipe, not some network or serial connection with
>> transmission delays userland has long experience in dealing with.

>> These previously internal additional delays, that are now exposed to
>> userland, are simply an implementation detail that userland did not,
>> and should not, need to worry about.
>
> Your mental model is that pseudo-terminals are a synchronous pipe, which
> is not true.
>
> But this argument is pointless because the regression needs to be fixed
> regardless of the merits.

Fair enough.

Anything new on this?

Thanks.

Marc.