// 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 mod poll;pub mod rcu; pub use arc::{Arc, ArcBorrow, UniqueArc};pub use condvar::{new_condvar, CondVar, CondVarTimeoutResult};pub use lock::global::{global_lock, GlobalGuard, GlobalLock, GlobalLockBackend, GlobalLockedBy};pub use lock::mutex::{new_mutex, Mutex, MutexGuard};pub use lock::spinlock::{new_spinlock, SpinLock, SpinLockGuard};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 {    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 =            // SAFETY: lockdep expects uninitialized memory when it's handed a statically allocated            // lock_class_key            unsafe { ::core::mem::MaybeUninit::uninit().assume_init() };        &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)    };}