Struct SpinLock 

pub struct SpinLock<T, const SPIN: usize = 5, const YIELD: usize = 10, const SLEEP: u64 = 100> { /* private fields */ }

Available on crate feature unsafe_sync only.

🧵 A spinlock providing mutual exclusion without blocking.

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^{📍 work/sync}

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Uses an atomic flag for synchronization, with a configurable backoff strategy.

Examples

let lock = SpinLock::<i32, 5, 10, 100>::new(42);

let mut guard = lock.lock(); // Acquire the lock
*guard += 1; // Modify the locked value

if let Some(mut guard) = lock.try_lock() {
    *guard *= 2; // Modify only if lock was acquired
}
// Lock is automatically released when `guard` goes out of scope

Implementations

impl<T, const SPIN: usize, const YIELD: usize, const SLEEP: u64> SpinLock<T, SPIN, YIELD, SLEEP>

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

Creates a new spinlock with the given value.

pub fn lock(&self) -> SpinLockGuard<'_, T, SPIN, YIELD, SLEEP>

Acquires the lock, spinning until it is available.

This method employs an adaptive backoff strategy to minimize CPU contention:

• Spins (spin_loop()) for SPIN iterations to avoid unnecessary thread switching.
• Yields (ThreadExt::yield_now()) for the next YIELD - SPIN iterations, allowing other threads to progress.
• Sleeps (ThreadExt::sleep_ns(SLEEP)) if SLEEP > 0, reducing CPU load under high contention.

Environment

• In std environments, the full backoff strategy is used.
• In no_std environments, only spin_loop() is available.

Compile-Time Optimization

Unnecessary branches are removed at compile time if their respective constant is set to 0.

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

Attempts to acquire the lock without blocking.

Returns Some(SpinLockGuard<T>) if successful, otherwise None.

pub fn is_locked(&self) -> bool

Checks if the lock is currently held.

pub fn into_inner(self) -> T

Consumes the lock and returns the inner value.

pub fn try_into_inner(&self) -> Option<T>

Tries to consume the lock and return the inner value.

If the lock is currently unlocked, this method returns Some(T). Otherwise, it returns None without blocking or modifying the lock.

pub unsafe fn debug_force_unlock(&self)

Available on debug-assertions enabled only.

Forces the lock to be released without dropping the guard.

Safety

• This is a manual unlocking mechanism. If used incorrectly, it may allow multiple threads to access T simultaneously.

Trait Implementations

impl<T, const SPIN: usize, const YIELD: usize, const SLEEP: u64> Debug for SpinLock<T, SPIN, YIELD, SLEEP>

fn fmt(&self, f: &mut Formatter<'_>) -> FmtResult<()>

Formats the value using the given formatter.

impl<T: Default, const SPIN: usize, const YIELD: usize, const SLEEP: u64> Default for SpinLock<T, SPIN, YIELD, SLEEP>

fn default() -> SpinLock<T, SPIN, YIELD, SLEEP>

Returns the “default value” for a type.

impl<T> Send for SpinLock<T>

where T: Send,

impl<T> Sync for SpinLock<T>

where T: Send,