Re: [Caml-list] Exceptions and Gc.

[Dmitry Bely <dmitry.bely@gmail.com>]

It has nothing to do with exceptions. The problem is that OCaml
runtime does not execute the garbage collector on program exit. But
you can write

let _ = at_exit Gc.full_major

if you need to force GC.

On Mon, Mar 20, 2017 at 10:22 PM, Romain Beauxis
<romain.beauxis@gmail.com> wrote:
> Hi guys,
>
> Apologies if I'm beating a dead horse but I think I've never wondered about
> this: What are the assumptions related to the garbage collector when an
> exception is raised?
>
> I sort-of always assumed it would be run but it doesn't seem that this is
> the case. This code:
> let () =
>   let g () =
>     let f _ =
>       Printf.printf "Collecting x\n%!"
>     in
>     let x = Bytes.create 1024 in
>     Gc.finalise f x;
>     ()
>   in
>   g ();
>   Gc.full_major();
>   raise Not_found
>
> Shows that the finalization function is never call if I remove the call to
> full_major. Any reason for that?
>
> The reason I'm asking if that I know I've been writing C bindings where some
> cleanup operations are wrapped up in the finalization code with the
> expectation that, except for a hard crash, it would always be executed at
> some point in the future..
>
> Thanks for y'all comments!
> Romain

- Dmitry Bely