W3C home > Mailing lists > Public > public-audio@w3.org > July to September 2013

Re: New proposal for fixing race conditions

From: Olivier Thereaux <Olivier.Thereaux@bbc.co.uk>
Date: Wed, 24 Jul 2013 11:02:31 +0000
To: WG <public-audio@w3.org>
Message-ID: <CE156B89.83F1%olivier.thereaux@bbc.co.uk>
Hi all,

On 23/07/2013 17:11, "Chris Wilson" <cwilso@google.com> wrote:
>This seems like an awfully big deal to me, so I have to question - what's
>the benefit?  It is
> not to my knowledge required to avoid crashes or other potential
>security issues; the only downside is if an author modifies a playing
>audio buffer, they could get differing playback results depending on
>precise timing.  That doesn't seem any different, to
> me, than what happens with small timing differences in event delivery
>today, or setting audio times that are too close to "now" - if you want
>the full power of the audio system, you have to learn how to work closely
>with the system and adapt to environments.
>  As Chris pointed out, there is some experience working with the API as
>it is today, and I haven't heard of (or personally experienced) any
>problems traced to this issue.
>[…]
>I feel designing the API around prevent race conditions everywhere is 1)
>ultimately not going to be successful anyway, and 2) is like wrapping
>everything with bubble wrap.  It will prevent some minor bruises, but it
>will also make it quite a bit more costly
> (in memory and time) to get the tasks needed done.

I'll take my co-chair hat off for a minute - just to note that the way
Chris just presented his point resonates with me. Having worked in
security (a long time ago) I do struggle a bit with the idea of fixing a
problem on principle, rather than after weighing the severity, probability
of the problem and the cost of fixing it.

To be honest, the possibility of setting a precedent or being the only API
in the whole web platform with a race condition does not worry me as much
as a discussion about fixing a risk where the group can't remotely agree
on:

* the probability (ROC's examples versus ChrisR's point that in 2 years of
early adopter usage there has been no recorded instance of the problem) of
the problem,
* the severity (opinions seem to range from "it's not a bug it's a
feature" to "serious interoperability risk") of the problem,
* the cost of fixing the problem later rather than now (hardly discussed
at all), or
* the cost of the proposed solutions (e.g "I doubt that memcpy will do
much harm" versus "quite a heavy weight on interacting with audio buffer
data").

[co-chair hat somewhat back on] Obviously, I am not saying that proponents
or opponents of any solution have been relying solely on abstract
principles in their argumentation. I do however invite everyone to
consider the criteria above rather than principles of purity if/when we
move to a vote (more on this soon).


>Olivier, to answer your question, I believe this would currently be an
>Objection.

[co-chair hat firmly back on] Noted, thanks.

Olivier



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Received on Wednesday, 24 July 2013 11:03:01 UTC

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