Struct AtomicOnce 

pub struct AtomicOnce<T> { /* private fields */ }

Lock-free, single-assignment cell.

Allows multiple threads to race to initialize a value. The winning thread stores its value, while losing threads silently discard their work.

Implementations

impl<T> AtomicOnce<T>

pub const fn new() -> Self

Create a new instance.

pub fn new_initialized(val: Box<T>) -> Self

Creates a new instance already initialized with the given value.

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

Returns a reference to the initialized value, or None if uninitialized.

pub unsafe fn get_unchecked(&self) -> &T

pub fn init(&self, val: Box<T>) -> Result<(), (&T, Box<T>)>

Attempts to initialize the cell with the provided value.

If the cell was already initialized or we lost the CAS race, returns the reference to the initialized value and the owned value val.

pub fn get_or_init<F>(&self, f: F) -> Result<&T, (&T, Box<T>)>

where F: FnOnce() -> Box<T>,

Returns a reference to the value, initializing it with f if necessary. If the cell was already initialized or we lost the CAS race, returns the reference to the initialized value and the owned value that was computed by the f.

Note that f may be executed multiple times concurrently if multiple threads attempt initialization simultaneously. Only one result will be retained.

pub fn into_inner(self) -> Option<T>

Consumes the AtomicOnce, returning the inner value if initialized.

Trait Implementations

impl<T> Drop for AtomicOnce<T>

fn drop(&mut self)

Executes the destructor for this type.

impl<T: Send> Send for AtomicOnce<T>

impl<T: Sync + Send> Sync for AtomicOnce<T>