[PD] pd_free vs canvas_vis

[Mathieu Bouchard]

Le 2011-11-19 à 11:39:00, Ivica Ico Bukvic a écrit :

> Jonathan and I have been working on trying to have patch close itself 
> through the script. However, even in the newest Pd the problem persists 
> in that if one invokes menuclose via patch it crashes pd. I suspect this 
> is because the closure happens while Pd is still traversing the tree and 
> then trips up on newly deallocated memory pool invoked by the pd_free.

I don't think that you can actually get out of this problem without 
something like reference-counting. Or else it's going to be quite hackish.

I think that Pd should get reference-counting on a large scale. This is 
not a new idea, but I think that I'm the only one to have considered it 
realistic. This would solve several problems (freeing symbols, etc) and 
not just this one. But it would require a somewhat different API and ABI 
than what we have now, which is the big hurdle.

The new API would require only adding function calls to the source, to 
mark which pointers are still potentially in use. The new API could 
compile to either the new ABI or the old ABI using header tricks.

A C++-based header could make the new API feel more like the old one, by 
impliciting nearly all of the new calls (by redefining t_atom::operator=).

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| Mathieu BOUCHARD ----- téléphone : +1.514.383.3801 ----- Montréal, QC