Re: [PATCH v6 02/14] rust: hrtimer: introduce hrtimer support

[Alice Ryhl]

On Fri, Jan 10, 2025 at 9:17 PM Andreas Hindborg <a.hindborg@xxxxxxxxxx> wrote:
>
> This patch adds support for intrusive use of the hrtimer system. For now,
> only one timer can be embedded in a Rust struct.
>
> The hrtimer Rust API is based on the intrusive style pattern introduced by
> the Rust workqueue API.
>
> Signed-off-by: Andreas Hindborg <a.hindborg@xxxxxxxxxx>
> +/// A timer backed by a C `struct hrtimer`.
> +///
> +/// # Invariants
> +///
> +/// * `self.timer` is initialized by `bindings::hrtimer_setup`.
> +#[pin_data]
> +#[repr(C)]
> +pub struct HrTimer<U> {

nit: We usually use repr(transparent) instead.

> +    #[pin]
> +    timer: Opaque<bindings::hrtimer>,
> +    _t: PhantomData<U>,
> +}
> +
> +// SAFETY: A `HrTimer` can be moved to other threads and used/dropped from there.
> +unsafe impl<U> Send for HrTimer<U> {}
> +
> +// SAFETY: Timer operations are locked on C side, so it is safe to operate on a
> +// timer from multiple threads
> +unsafe impl<U> Sync for HrTimer<U> {}
> +
> +impl<T> HrTimer<T> {

You are inconsistent with whether the generic parameter is called T or U.

Alice