[Caml-list] Bigarray

[Caml-list] Bigarray

[Fady Nassif]

Hello,

When we create a BigArray from C is it created in the C heap or in the 
Caml Heap? And if we create it in Caml what happen?.
Since there is no data copying at all, I have some confusion about that.

Thanks

Fady

Re: [Caml-list] Bigarray

[Michael Ekstrand]

On 04/14/2011 03:21 AM, Fady Nassif wrote:
> When we create a BigArray from C is it created in the C heap or in the
> Caml Heap? And if we create it in Caml what happen?.
> Since there is no data copying at all, I have some confusion about that.

The bigarray's contents are created in the C heap in both cases. If you
create a new bigarray from OCaml, the bigarray module uses malloc() to
allocate the array's storage.

When you create one from C, you allocate the memory yourself (typically
using malloc()) and then wrap in in a bigarray object. If you used
malloc() to allocate the memory and want OCaml to take responsibility
for freeing it when the bigarray object is garbage collected, you can
specify BIGARRAY_MANAGED in the flags parameter to alloc_bigarray_dims.
This (undocumented) flag is used by the internal bigarray code when it
creates a new bigarray with malloc. Otherwise, you are responsible for
somehow freeing the bigarray storage at the appropriate time.

- Michael