From: Edwin Van leeuwen <edder@...>
Date: 2007-11-06T05:08:17+09:00
Subject: Re: Pulseaudio c extension callback function

Paul Brannan wrote:
> klass is a temporary variable; you probably don't want to take its
> address.  Instead you can cast klass to a pointer:
> 
>     pa_context_set_state_callback( DATA_PTR( klass ), callback, (void 
> *)klass );
> 
> then in your callback function, write:
> 
>     VALUE obj = (VALUE *) klass;
> 

Thanks, it worked when I changed it to:

VALUE obj = (VALUE) klass;

Otherwise I got a compile error. I really should refresh my c, because 
clearly my approach of changing the code until it stops segvaulting is 
not the best :) Although it seems to give me decent progress :)

> If I understand your question, when the context object is destroyed, you
> need to unregister the callback.  That will ensure that the library
> doesn't keep a reference to the freed object.  You can do this by
> passing a `free' function to Data_Wrap_Struct.

Yes, I am already using the unref function for the context itself. I am 
not sure if that also unregisters the callback. I guess I should be 
testing that later.

Edwin
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