Hi,
Indeed. We could malloc and set-finalizer! and that should work and be safe. However, as far as I understand, this approach has some disadvantages:
- malloc is relatively slow compared to chicken's internal allocation (eg make-string) that uses the stack
- there is a practical limit on finalizers that Chicken can handle
- large number of set-finalizer!s will slow things down
I forgot to mention that I don't want to go for this approach in this case because it will impact us heavily, since we allocate oid objects a lot. I believe that is why Evan went for the alternative make-primitive method. So I think we really _want_ to involve the Chicken GC, but we need to give it some more info than just a #<c-pointer>.
I've used this make-blob approach that is in the attached patches before, with success. Unfortunately, it doesn't integrate well with the foreigners egg, but I hope it is still a good candidate here for the oid, buf and revspec structures.
K.
Kristian Lein-Mathisen <kristianlein@gmail.com> writes:
> From what I gather, there is no way to allocate memory and return a pointer
> to it, safely, in CHICKEN.
> Won't the garbage collector potentially overwrite whatever region was
> allocated since it has no way of knowing it?
There's allocate from chicken.memory that does just that. It allocates
using 'malloc', and chicken GC will have no knowledge or way of
interfering with the memory. Free the memory using 'free' from the same
module.