linux/rust/kernel/sync.rs

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// 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()
}
}
/// 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)
};
}