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 mod condvar; 12 pub mod lock; 13 mod locked_by; 14 15 pub use arc::{Arc, ArcBorrow, UniqueArc}; 16 pub use condvar::CondVar; 17 pub use lock::{mutex::Mutex, spinlock::SpinLock}; 18 pub use locked_by::LockedBy; 19 20 /// Represents a lockdep class. It's a wrapper around C's `lock_class_key`. 21 #[repr(transparent)] 22 pub struct LockClassKey(Opaque<bindings::lock_class_key>); 23 24 // SAFETY: `bindings::lock_class_key` is designed to be used concurrently from multiple threads and 25 // provides its own synchronization. 26 unsafe impl Sync for LockClassKey {} 27 28 impl LockClassKey { 29 /// Creates a new lock class key. 30 pub const fn new() -> Self { 31 Self(Opaque::uninit()) 32 } 33 34 pub(crate) fn as_ptr(&self) -> *mut bindings::lock_class_key { 35 self.0.get() 36 } 37 } 38 39 /// Defines a new static lock class and returns a pointer to it. 40 #[doc(hidden)] 41 #[macro_export] 42 macro_rules! static_lock_class { 43 () => {{ 44 static CLASS: $crate::sync::LockClassKey = $crate::sync::LockClassKey::new(); 45 &CLASS 46 }}; 47 } 48 49 /// Returns the given string, if one is provided, otherwise generates one based on the source code 50 /// location. 51 #[doc(hidden)] 52 #[macro_export] 53 macro_rules! optional_name { 54 () => { 55 $crate::c_str!(::core::concat!(::core::file!(), ":", ::core::line!())) 56 }; 57 ($name:literal) => { 58 $crate::c_str!($name) 59 }; 60 } 61