Managing GPU memory in OCaml

Question

I am wondering if it is possible to create a finalise method for OCaml records? I am creating a GPU database and I am using OCaml for building the DSL to query and manipulate GPU data, and I need a way to free GPU memory when they are eligible for GC (not referenced anymore).

I have creating a binding to my C-based GPU api to allow to malloc, free and manipulate GPU data but I am looking at solutions to free GPU memory when it is not referenced by variables anymore in the toplevel.

let bids = (**a 1-dim GPU array*) and asks = (**another 1-dim GPU array*) in
let spread = asks - bids 

In this example, I would need to free up the GPU memory for the bids and asks vector residing in GPU memory. I guess I need to write my own language?

Answer 1

What you need is probably custom blocks, since your data is not pure Caml:

http://caml.inria.fr/pub/docs/manual-ocaml-4.00/manual033.html

19.9 Advanced topic: custom blocks

Blocks with tag Custom_tag contain both arbitrary user data and a pointer to a C struct, with type struct custom_operations, that associates user-provided finalization, comparison, hashing, serialization and deserialization functions to this block.

You can attach your C finalization functions to custom blocks. They are called when the block is GCed in OCaml world.