1 // SPDX-License-Identifier: GPL-2.0 2 3 //! Synchronisation primitives. 4 //! 5 //! This module contains the kernel APIs related to synchronisation that have been ported or 6 //! wrapped for usage by Rust code in the kernel. 7 8 use crate::types::Opaque; 9 10 mod arc; 11 pub mod lock; 12 13 pub use arc::{Arc, ArcBorrow, UniqueArc}; 14 15 /// Represents a lockdep class. It's a wrapper around C's `lock_class_key`. 16 #[repr(transparent)] 17 pub struct LockClassKey(Opaque<bindings::lock_class_key>); 18 19 // SAFETY: `bindings::lock_class_key` is designed to be used concurrently from multiple threads and 20 // provides its own synchronization. 21 unsafe impl Sync for LockClassKey {} 22 23 impl LockClassKey { 24 /// Creates a new lock class key. 25 pub const fn new() -> Self { 26 Self(Opaque::uninit()) 27 } 28 29 pub(crate) fn as_ptr(&self) -> *mut bindings::lock_class_key { 30 self.0.get() 31 } 32 } 33 34 /// Defines a new static lock class and returns a pointer to it. 35 #[doc(hidden)] 36 #[macro_export] 37 macro_rules! static_lock_class { 38 () => {{ 39 static CLASS: $crate::sync::LockClassKey = $crate::sync::LockClassKey::new(); 40 &CLASS 41 }}; 42 } 43 44 /// Returns the given string, if one is provided, otherwise generates one based on the source code 45 /// location. 46 #[doc(hidden)] 47 #[macro_export] 48 macro_rules! optional_name { 49 () => { 50 $crate::c_str!(::core::concat!(::core::file!(), ":", ::core::line!())) 51 }; 52 ($name:literal) => { 53 $crate::c_str!($name) 54 }; 55 } 56