[pulseaudio-discuss] [PATCH 2/6] Turn device ports into reference counted objects

[Colin Guthrie]

'Twas brillig, and David Henningsson at 08/11/11 20:17 did gyre and gimble:
>> In my opinion assertions are proper error handling when the error in
>> question is a programming error in our own code.
> 
> Eh, I'd say proper error handling is to fix our own code's programming
> error! :-)

I suspect what was meant was that when we accidentally call one of our
own functions incorrectly, then it should be good enough to hit an
assert to tell us we've hit the "error between the chair and the
keyboard" case. IMO, this is a valid use of asserts() to find and
eradicate this class of problem. Obviously it goes without saying that
the correct way to address this is to fix the calling code, but the
assert has done it's job well, so it's use is justified.

> I'm not saying we should never use asserts, but I think we over-use
> them. (And a lot of this goes back to Lennart's code as well.) Instead
> of going the extra mile and thinking "hmm, what if this could actually
> happen, what should we do in that case?", I suspect that sometimes we
> just put in an assert instead, just out of laziness, and see if anyone
> ever complains about it. True or not?


I think it's a fine line at times, but I think asserts() work well. What
I mean is that the laziness argument goes both ways and you can take the
opposite extreme that if you handle error cases more gracefully all you
get is a line in a log file for something that you really do want to
complain and or get upstream. Now an assert *is* brutal here, but if the
thing doesn't crash out on the user, we'll likely never know about the
issue and the underlying problem itself may go unnoticed.

So while it's arguably not user friendly at all times, I think it's a
good mechanism to ensure we have robust code over time. Yes, this means
we rely on downstreams cooperating and pushing bug reports (and
hopefully, as is often the case with your good self, bug fixes too) up
to us.

That's my opinion, but I can appreciate the frustration of "unnecessary"
bug reports downstream that have to be dealt with - but even if the fix
is to drop the assert, hopefully something useful is learned about that
particular bit of code as a result.

Col


-- 

Colin Guthrie
gmane(at)colin.guthr.ie
http://colin.guthr.ie/

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