Re: partial writes in bse-jack?

[Tim Janik <timj gtk org>]

On Wed, 7 Jun 2006, Stefan Westerfeld wrote:

> On Sun, Jun 04, 2006 at 02:46:38AM +0200, Tim Janik wrote:

> > so in theory, if your check_io() function was correctly implemented,
> > i'd expect partial writes to never occour. (that being said, it might
> > still make sense to guard against them via a Cond or similar, in case
> > more poll funcitons are being added in the future.)
>
> I debugged it now, and its simply that the the timeout value computed by
> my bse jack driver can become 0 (for instance if there are just 32
> samples which miss for writing a whole engine block size to the output
> ringbuffer).

ok.

> When I stop using the timeout, but instead rely on a newly introduced
> public bse_engine_mastere_wakeup() function (right now its private), the
> code works as expected. Of course setting timeout to  MAX (1,
> computedtimeout) also works, but thats not what I want to do, since
> timeout based stuff is less reliable when jitter is present than pipe
> based signalling.

well, timeout based handling is what the engine and drivers are currently
designed for. i repeatedly told you about that. if you think the current
model can be switched to polling and be as reliable, i need at least 2
things from you:
1) a bse-jack driver that *does* work with timeouts;
2) a patch that switches *all* drivers to notify + polling.

then we have a basis for discussing, testing, benchmarking and working on
timeout vs. poll() handling.
that can and should be done seperately though, independent of jack or
other driver development.

>   Cu... Stefan

---
ciaoTJ