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 pub mod poll; 15 16 pub use arc::{Arc, ArcBorrow, UniqueArc}; 17 pub use condvar::{new_condvar, CondVar, CondVarTimeoutResult}; 18 pub use lock::global::{global_lock, GlobalGuard, GlobalLock, GlobalLockBackend, GlobalLockedBy}; 19 pub use lock::mutex::{new_mutex, Mutex}; 20 pub use lock::spinlock::{new_spinlock, SpinLock}; 21 pub use locked_by::LockedBy; 22 23 /// Represents a lockdep class. It's a wrapper around C's `lock_class_key`. 24 #[repr(transparent)] 25 pub struct LockClassKey(Opaque<bindings::lock_class_key>); 26 27 // SAFETY: `bindings::lock_class_key` is designed to be used concurrently from multiple threads and 28 // provides its own synchronization. 29 unsafe impl Sync for LockClassKey {} 30 31 impl LockClassKey { 32 /// Creates a new lock class key. 33 pub const fn new() -> Self { 34 Self(Opaque::uninit()) 35 } 36 37 pub(crate) fn as_ptr(&self) -> *mut bindings::lock_class_key { 38 self.0.get() 39 } 40 } 41 42 impl Default for LockClassKey { 43 fn default() -> Self { 44 Self::new() 45 } 46 } 47 48 /// Defines a new static lock class and returns a pointer to it. 49 #[doc(hidden)] 50 #[macro_export] 51 macro_rules! static_lock_class { 52 () => {{ 53 static CLASS: $crate::sync::LockClassKey = $crate::sync::LockClassKey::new(); 54 &CLASS 55 }}; 56 } 57 58 /// Returns the given string, if one is provided, otherwise generates one based on the source code 59 /// location. 60 #[doc(hidden)] 61 #[macro_export] 62 macro_rules! optional_name { 63 () => { 64 $crate::c_str!(::core::concat!(::core::file!(), ":", ::core::line!())) 65 }; 66 ($name:literal) => { 67 $crate::c_str!($name) 68 }; 69 } 70