Re: [Pyode-user] bug: read from free'd memory when joint in jointgroup

[Chris B. <chr...@gm...>]

On 17/08/06, Chris Bainbridge <chr...@gm...> wrote:
> The attached patch to current cvs fixes my memory problems. The
> ode.World needs to keep track of all Joint, Body, Geom objects, since
> dWorldDestroy removes the underlying objects (in the case of Geom the
> body it links to is removed rather than the Geom itself, but Geom then
> tries to unlink itself from the Body).

Ok, it doesn't fix everything... to deal with non-deterministic
destructor order pyode would have to know about every pointer between
ode objects, and some are hidden and can't be easily changed through
the API without knowing if both underlying objects are still valid
(body->geom for example). So we would need to ensure that the
underlying ODE objects are deconstructed in the right order, and
deconstruction is delayed when we know that another python object that
is still valid has an ode internal pointer to the to-be-destroyed
object. Argh. It's probably easier to have an explicit cleanup
function to be called at the end of a simulation that detaches all
geoms, joints, and bodies, and then actually destroy the underlying
objects in the usual pyrex destructor.