[PATCH v4 3/4] alist: Add support for an allocated pointer list

[Simon Glass]

Hi Tom,

On Fri, 26 Jul 2024 at 08:33, Tom Rini <trini at konsulko.com> wrote:
>
> On Fri, Jul 26, 2024 at 08:00:37AM -0600, Simon Glass wrote:
> > In various places it is useful to have an array of structures, but allow
> > it to grow. In some cases we work around it by setting maximum number of
> > entries, using a Kconfig option. In other places we use a linked list,
> > which does not provide for random access and can complicate the code.
> >
> > Introduce a new data structure, which is a variable-sized list of structs
> > each of the same, pre-set size. It provides O(1) access and is reasonably
> > efficient at expanding linearly, since it doubles in size when it runs out
> > of space.
> >
> > Signed-off-by: Simon Glass <sjg at chromium.org>
> > ---
> >
> > Changes in v4:
> > - Avoid using realloc() unless specifically enabled by Kconfig
>
> Is this really so performance critical that we can't always just use
> malloc/free here?

I would have to write some sort of test suite to get a better feel for
that. The realloc() can be instant if there is space above the current
item, whereas the malloc() approach always does a copy.

It is certainly odd to use malloc()/free() when realloc() is there, so
I think it makes sense to provide the option.

Regards,
SImon