[pulseaudio-discuss] [PATCH] sink-input, source-output: add a couple of assertions

[Tanu Kaskinen]

On Mon, 2017-10-30 at 17:43 +0530, Arun Raghavan wrote:
> On Mon, 30 Oct 2017, at 12:45 AM, Tanu Kaskinen wrote:
> > Coverity complained about data->sink being possibly NULL when it's
> > dereferenced later. It was difficult for me to figure out whether that
> > was a false positive or not. Hopefully the comments make it a bit
> > easier to reason about the code in the future.
> > 
> > It might be a good idea to set data->req_formats early, so that it's
> > always set when setting the sink for a stream. Currently, if the
> > application doesn't use the new format negotiation API, req_formats is
> > set according to the sample spec at a very late stage. That means that
> > sometimes data->sink gets set after data->req_formats, and sometimes
> > data->req_formats gets set after data->sink, which makes it difficult to
> > follow the code.
> 
> It's hard to deterministically set it earlier than pa_sink_input_new(),
> unless we make it a contract that it is set before that call for all
> callers. Or did you mean we should set it early just for the
> protocol-native case?

I think we could have a rule saying that if
pa_sink_input_new_data_set_sink() is called, that must happen after
calling pa_sink_input_new_data_set_formats() or
pa_sink_input_new_data_set_sample_spec() (set_sample_spec() could
internally call set_formats()).

It's already mandatory to set the requested formats or the sample spec
before calling pa_sink_input_new(), so it can't happen that the sink
input implementor would only set the sink and not the formats. The
implementor just has to order the calls the right way.

I applied this patch now without the second paragraph in the commit
message.

-- 
Tanu

https://www.patreon.com/tanuk