linux/rust/kernel/sync.rs
Miguel Ojeda 7c81aa85ee rust: sync: implement Default for LockClassKey
In the upcoming Rust 1.78.0, Clippy suggests to implement `Default` even
when `new()` is `const`, since `Default::default()` may call `const`
functions even if it is not `const` itself [1]:

    error: you should consider adding a `Default` implementation for `LockClassKey`
      --> rust/kernel/sync.rs:31:5
       |
    31 | /     pub const fn new() -> Self {
    32 | |         Self(Opaque::uninit())
    33 | |     }
       | |_____^

Thus implement it.

Link: https://github.com/rust-lang/rust-clippy/pull/10903 [1]
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Link: https://lore.kernel.org/r/20240401212303.537355-2-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-05-05 19:22:25 +02:00

68 lines
1.7 KiB
Rust

// SPDX-License-Identifier: GPL-2.0
//! Synchronisation primitives.
//!
//! This module contains the kernel APIs related to synchronisation that have been ported or
//! wrapped for usage by Rust code in the kernel.
use crate::types::Opaque;
mod arc;
mod condvar;
pub mod lock;
mod locked_by;
pub use arc::{Arc, ArcBorrow, UniqueArc};
pub use condvar::{new_condvar, CondVar, CondVarTimeoutResult};
pub use lock::mutex::{new_mutex, Mutex};
pub use lock::spinlock::{new_spinlock, SpinLock};
pub use locked_by::LockedBy;
/// Represents a lockdep class. It's a wrapper around C's `lock_class_key`.
#[repr(transparent)]
pub struct LockClassKey(Opaque<bindings::lock_class_key>);
// SAFETY: `bindings::lock_class_key` is designed to be used concurrently from multiple threads and
// provides its own synchronization.
unsafe impl Sync for LockClassKey {}
impl LockClassKey {
/// Creates a new lock class key.
pub const fn new() -> Self {
Self(Opaque::uninit())
}
pub(crate) fn as_ptr(&self) -> *mut bindings::lock_class_key {
self.0.get()
}
}
impl Default for LockClassKey {
fn default() -> Self {
Self::new()
}
}
/// Defines a new static lock class and returns a pointer to it.
#[doc(hidden)]
#[macro_export]
macro_rules! static_lock_class {
() => {{
static CLASS: $crate::sync::LockClassKey = $crate::sync::LockClassKey::new();
&CLASS
}};
}
/// Returns the given string, if one is provided, otherwise generates one based on the source code
/// location.
#[doc(hidden)]
#[macro_export]
macro_rules! optional_name {
() => {
$crate::c_str!(::core::concat!(::core::file!(), ":", ::core::line!()))
};
($name:literal) => {
$crate::c_str!($name)
};
}