On Tue, Aug 2, 2011 at 3:00 AM, Nat Goodspeed <n...@lindenlab.com> wrote:
>
>
> http://docs.python.org/library/weakref.html#module-weakref
>
>
Unfortunately, I can't use `weakref` I already tried that, but the problem
is that the weak references get deleted (and their value set to `None`)
before `__del__` is called. So when `removeEventHandler` is called, it won't
be able to find the weakref it's supposed to remove (because its value has
been changed to `None`).
To fix, this would require some special handling of Python function objects
in the `EventManager` — I don't want that, I wish to keep the manager
agnostic to Python since I'm going to be pushing events into it from both
C++ and Python. I'd like to solve this problem exclusively through the
`EventManager` wrapper class I wrote.
On Tue, Aug 2, 2011 at 3:24 AM, Jim Bosch-2 [via Boost] <
ml-node+3711102-1593261807-256...@n4.nabble.com> wrote:
>
> Are these cycles actually a problem in practice? Python does do garbage
> collection, so it might be that it knows about all these dependencies
> and just hasn't bothered to try to delete them because it doesn't need
> the memory yet.
>
>
Yes, they are problematic. When the object gets removed it should not
receive any more events or it will very likely result in some odd behavior
on the screen. These objects are entity states in a game. A state dictates
how an entity reacts to game events and when the entity changes its state,
the old one should stop giving the entity instructions, or they will
conflict with the instructions given by the new state.
--
View this message in context:
http://boost.2283326.n4.nabble.com/Boost-Python-Callbacks-to-class-functions-tp3709880p3711324.html
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