Struct SpinLock 

pub struct SpinLock<T: ?Sized, G: Guardian = IrqDisabled> {
    locked: AtomicBool,
    owner_cpu: AtomicUsize,
    _guardian: PhantomData<G>,
    data: UnsafeCell<T>,
}

A spinlock parameterised by a Guardian.

The default guardian is IrqDisabled, preserving existing call-site semantics with no source changes required.

Supports T: ?Sized for SpinLock<dyn Trait> and other DST types. The data field is last so that the struct can hold dynamically sized types.

Fields

locked: AtomicBool

owner_cpu: AtomicUsize

CPU index of the current lock holder (usize::MAX when unlocked). Used for deadlock diagnostics only.

_guardian: PhantomData<G>

data: UnsafeCell<T>

Must be the last field: when T: ?Sized, this is a DST and Rust requires the dynamically sized field to be last in the struct.

Implementations

impl<T, G: Guardian> SpinLock<T, G>

pub const fn new(data: T) -> Self

Create a new, unlocked spinlock.

T must be Sized here because we construct a new value.

impl<T: ?Sized, G: Guardian> SpinLock<T, G>

pub fn lock(&self) -> SpinLockGuard<'_, T, G>

Acquire the lock, spinning until available.

The guardian’s enter() hook runs before the spin loop so that the CPU is already in the protected mode while we wait. This closes the window where an IRQ or preempt-switch could occur between protect and acquire.

pub fn try_lock(&self) -> Option<SpinLockGuard<'_, T, G>>

Try to acquire the lock without spinning.

pub fn owner_cpu(&self) -> usize

Returns the owner CPU index (usize::MAX if unlocked).

pub fn get_mut(&mut self) -> &mut T

Returns a mutable reference to the underlying data.

By holding &mut self, the compiler guarantees exclusive access to the lock; no other reference exists, so the inner data can be accessed without acquiring the lock.

impl<T: ?Sized> SpinLock<T, IrqDisabled>

pub fn try_lock_no_irqsave(&self) -> Option<SpinLockGuard<'_, T, IrqDisabled>>

Try to acquire without touching RFLAGS.

Returns None if IRQs are currently enabled (no IrqDisabledToken can be produced) or the lock is already held. The caller must ensure that IRQs remain disabled for the entire lifetime of the returned guard.

Trait Implementations

impl<T: ?Sized + Send, G: Guardian> Send for SpinLock<T, G>

impl<T: ?Sized + Send, G: Guardian> Sync for SpinLock<T, G>