Re: [PATCH v8 4/7] rust: time: Add wrapper for fsleep function
From: Miguel Ojeda
Date: Fri Jan 17 2025 - 13:59:38 EST
On Thu, Jan 16, 2025 at 5:42 AM FUJITA Tomonori
<fujita.tomonori@xxxxxxxxx> wrote:
>
> +/// `delta` must be 0 or greater and no more than `u32::MAX / 2` microseconds.
> +/// If a value outside the range is given, the function will sleep
> +/// for `u32::MAX / 2` microseconds (= ~2147 seconds or ~36 minutes) at least.
I would emphasize with something like:
`delta` must be within [0, `u32::MAX / 2`] microseconds;
otherwise, it is erroneous behavior. That is, it is considered a bug
to call this function with an out-of-range value, in which case the
function will sleep for at least the maximum value in the range and
may warn in the future.
In addition, I would add a new paragraph how the behavior differs
w.r.t. the C `fsleep()`, i.e. IIRC from the past discussions,
`fsleep()` would do an infinite sleep instead. So I think it is
important to highlight that.
> + // The argument of fsleep is an unsigned long, 32-bit on 32-bit architectures.
> + // Considering that fsleep rounds up the duration to the nearest millisecond,
> + // set the maximum value to u32::MAX / 2 microseconds.
Nit: please use Markdown code spans in normal comments (no need for
intra-doc links there).
> + let duration = if delta > MAX_DURATION || delta.is_negative() {
> + // TODO: add WARN_ONCE() when it's supported.
Ditto (also "Add").
By the way, can this be written differently maybe? e.g. using a range
since it is `const`?
You can probably reuse `delta` as the new bindings name, since we
don't need the old one after this step.
Thanks!
Cheers,
Miguel