[pulseaudio-discuss] Memory oddities in module-dbus-protocol

[Tanu Kaskinen]

On Thu, 2012-01-26 at 12:35 +0100, David Henningsson wrote:
> I'm trying to trace down a memory error in module-dbus-protocol, but I 
> am confused.
> 
> Either you use synchronous hooks, and then you can reference the 
> original core objects, or you use asynchronous subscription events, in 
> which case the pointers can become dangling at any time, so you can't 
> point into the core and have to make memory copies of *everything*. Right?

Make copies, or check if the objects are still in the core before
referencing them. I tried to make those checks where needed, but
apparently I failed at that.

> The card is handled by subscription events, and I get memory errors on 
> quit [1] due to it referencing the profile's name as a hash key (!). But 
> while investigating I also saw pa_dbusiface_card_profile objects having 
> a pointer to the profile, which is disturbing.
> 
> If this is the only place where things are broken, I can fix it. But if 
> the same logic faults apply to all over the dbus protocol module, that 
> makes me quite uneasy with shipping it in a stable distribution, 
> especially as I don't know any consumer that makes use of this information.

Now that you've pointed out this issue, I don't trust the code at all
anymore. The only sane way forward is to convert all code in the dbus
module to use hooks instead of the subscription system.

I volunteer to do that work.

-- 
Tanu