Re: [PATCH] rust: xarray: Add an abstraction for XArray

From: Asahi Lina
Date: Fri Feb 24 2023 - 07:32:27 EST


On 24/02/2023 20.44, Asahi Lina wrote:
> The XArray is an abstract data type which behaves like a very large
> array of pointers. Add a Rust abstraction for this data type.
>
> The initial implementation uses explicit locking on get operations and
> returns a guard which blocks mutation, ensuring that the referenced
> object remains alive. To avoid excessive serialization, users are
> expected to use an inner type that can be efficiently cloned (such as
> Arc<T>), and eagerly clone and drop the guard to unblock other users
> after a lookup.
>
> Future variants may support using RCU instead to avoid mutex locking.
>
> This abstraction also introduces a reservation mechanism, which can be
> used by alloc-capable XArrays to reserve a free slot without immediately
> filling it, and then do so at a later time. If the reservation is
> dropped without being filled, the slot is freed again for other users,
> which eliminates the need for explicit cleanup code.
>
> Signed-off-by: Asahi Lina <lina@xxxxxxxxxxxxx>
> ---

I forgot to mention this depends on the Error series [1]. Sorry about that!

[1]
https://lore.kernel.org/rust-for-linux/20230224-rust-error-v1-0-f8f9a9a87303@xxxxxxxxxxxxx/T/#t

~~ Lina