From: Benno Lossin <benno.lossin@proton.me>
To: Boqun Feng <boqun.feng@gmail.com>
Cc: rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org,
"Thomas Gleixner" <tglx@linutronix.de>,
"Alice Ryhl" <aliceryhl@google.com>,
"Miguel Ojeda" <ojeda@kernel.org>,
"Alex Gaynor" <alex.gaynor@gmail.com>,
"Wedson Almeida Filho" <wedsonaf@gmail.com>,
"Gary Guo" <gary@garyguo.net>,
"Björn Roy Baron" <bjorn3_gh@protonmail.com>,
"Andreas Hindborg" <a.hindborg@samsung.com>,
"John Stultz" <jstultz@google.com>,
"Stephen Boyd" <sboyd@kernel.org>,
"Valentin Obst" <kernel@valentinobst.de>
Subject: Re: [PATCH 2/5] rust: time: Introduce Duration type
Date: Wed, 27 Mar 2024 11:18:28 +0000 [thread overview]
Message-ID: <e93d124b-e2db-4a7d-848c-6d4fb389d780@proton.me> (raw)
In-Reply-To: <ZgMDGYMj7V50PZbP@boqun-archlinux>
On 26.03.24 18:17, Boqun Feng wrote:
> On Tue, Mar 26, 2024 at 10:11:07AM -0700, Boqun Feng wrote:
> [...]
>>>> +impl Duration {
>>>> + /// Creates a new duration of `ns` nanoseconds.
>>>> + pub const fn new(ns: i64) -> Self {
>>>> + Self { inner: ns }
>>>> + }
>>>> +
>>>> + /// Divides the number of nanoseconds by a compile-time constant.
>>>> + #[inline]
>>>> + fn divns_constant<const DIV: i64>(self) -> i64 {
>>>> + self.to_ns() / DIV
>>>> + }
>>>
>>> I am a bit confused, why is this better than writing
>>> `self.to_ns() / DIV` at the callsite?
>>>
>>
>> Hmm.. you're right, there should be no difference I think. If there is
>> nothing I'm missing from Alice, I will drop this function in the next
>> version.
>>
>
> On a second thought, I think this prevents accidentally divide a
> non-const value, in other words, if you use this function, you're
> guaranteed the divisor is a constant, and you have the compiler checking
> that for you. So in that sense, I think it makes sense to remain it
> here. Thoughts?
I don't see the value in that. It does not prevent me from just doing
`self.to_ns() / DIV` now. I imagine that 99% of the time users will want
to get milliseconds or microseconds and we should have methods for that
(when we have users). But for the last 1% I don't think we need this
method.
--
Cheers,
Benno
next prev parent reply other threads:[~2024-03-27 11:18 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-03-24 22:33 [PATCH 0/5] rust: time: Add clock read support Boqun Feng
2024-03-24 22:33 ` [PATCH 1/5] rust: time: doc: Add missing C header link to jiffies Boqun Feng
2024-03-26 16:44 ` Benno Lossin
2024-03-24 22:33 ` [PATCH 2/5] rust: time: Introduce Duration type Boqun Feng
2024-03-26 16:50 ` Benno Lossin
2024-03-26 17:11 ` Boqun Feng
2024-03-26 17:17 ` Boqun Feng
2024-03-27 11:18 ` Benno Lossin [this message]
2024-03-24 22:33 ` [PATCH 3/5] rust: time: Introduce clock reading framework Boqun Feng
2024-03-26 17:00 ` Benno Lossin
2024-03-26 19:19 ` Boqun Feng
2024-03-27 12:50 ` Benno Lossin
2024-03-27 17:49 ` Boqun Feng
2024-03-24 22:33 ` [PATCH 4/5] rust: time: Support reading CLOCK_MONOTONIC Boqun Feng
2024-03-26 17:03 ` Benno Lossin
2024-03-26 19:21 ` Boqun Feng
2024-03-24 22:33 ` [PATCH 5/5] rust: time: Add Instant::elapsed() for monotonic clocks Boqun Feng
2024-03-26 17:13 ` Benno Lossin
2024-03-26 18:00 ` Boqun Feng
2024-03-26 18:04 ` Boqun Feng
2024-03-27 1:09 ` Boqun Feng
2024-03-27 11:31 ` Benno Lossin
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