Struct atomic_option::AtomicOption
[−]
[src]
pub struct AtomicOption<T> { /* fields omitted */ }
An atomic version of Option<Box<T>>
, useful for moving owned objects
between threads in a wait-free manner.
Methods
impl<T> AtomicOption<T>
[src]
fn new(data: Box<T>) -> AtomicOption<T>
Create a new AtomicOption storing the specified data.
let opt = AtomicOption::new(Box::new(7)); let value = opt.take(Ordering::SeqCst).unwrap(); assert_eq!(value, Box::new(7));
unsafe fn from_raw(ptr: *mut T) -> AtomicOption<T>
Create a new AtomicOption from a raw pointer.
fn empty() -> AtomicOption<T>
Create a new AtomicOption storing None.
let opt: AtomicOption<()> = AtomicOption::empty(); let value = opt.take(Ordering::SeqCst); assert!(value.is_none());
fn take(&self, ordering: Ordering) -> Option<Box<T>>
Take the value out of the AtomicOption, if there is one.
let opt = AtomicOption::new(Box::new(178)); let first_take = opt.take(Ordering::SeqCst); let second_take = opt.take(Ordering::SeqCst); assert_eq!(first_take, Some(Box::new(178))); assert!(second_take.is_none());
fn swap(&self, new: Box<T>, ordering: Ordering) -> Option<Box<T>>
Swap the value in the AtomicOption with a new one, returning the old value if there was one.
let opt = AtomicOption::new(Box::new(1236)); let old = opt.swap(Box::new(542), Ordering::SeqCst).unwrap(); assert_eq!(old, Box::new(1236)); let new = opt.take(Ordering::SeqCst).unwrap(); assert_eq!(new, Box::new(542));
fn replace(&self, new: Option<Box<T>>, ordering: Ordering) -> Option<Box<T>>
Replace the Option in the AtomicOption with a new one, returning the old option.
let opt = AtomicOption::empty(); let old = opt.replace(Some(Box::new("hello")), Ordering::SeqCst); assert!(old.is_none()); let new = opt.take(Ordering::SeqCst).unwrap(); assert_eq!(new, Box::new("hello"));
fn try_store(&self, new: Box<T>, ordering: Ordering) -> Option<Box<T>>
Store the new value in the AtomicOption iff it currently contains a None.
None is returned if the store succeeded, or Some is returned with the rejected data if the store fails.
This operation is implemented as a single atomic compare_and_swap
.
let opt = AtomicOption::empty(); let stored = opt.try_store(Box::new("some data"), Ordering::SeqCst); assert!(stored.is_none()); let stored2 = opt.try_store(Box::new("some more data"), Ordering::SeqCst); assert_eq!(stored2, Some(Box::new("some more data"))); let value = opt.take(Ordering::SeqCst).unwrap(); assert_eq!(value, Box::new("some data"));
fn spinlock(&self, ordering: Ordering) -> Box<T>
Execute a compare_and_swap
loop until there is a value in the AtomicOption,
then return it.
// We'll use an AtomicOption as a lightweight channel transferring data via a spinlock. let tx = Arc::new(AtomicOption::empty()); let rx = tx.clone(); thread::spawn(move || { assert_eq!(*rx.spinlock(Ordering::Acquire), 7); }); tx.swap(Box::new(7), Ordering::Release);
fn load_raw(&self, ordering: Ordering) -> *const T
Get the raw value stored in the AtomicOption.
Safety
It is almost never safe to read from this pointer.
Trait Implementations
impl<T> Sync for AtomicOption<T>
[src]
impl<T> From<Option<Box<T>>> for AtomicOption<T>
[src]
fn from(opt: Option<Box<T>>) -> AtomicOption<T>
Performs the conversion.