Struct voluntary_servitude::atomics::FillOnceAtomicArc
source · pub struct FillOnceAtomicArc<T>(_);
Expand description
Atomic abstraction of a Option<Arc<T>>
that can provide access to a cloned Option<Arc<T>>
and a Option<&T>
Implementations
sourceimpl<T> FillOnceAtomicArc<T>
impl<T> FillOnceAtomicArc<T>
sourcepub fn new<V>(data: V) -> Selfwhere
V: Into<Option<Arc<T>>>,
pub fn new<V>(data: V) -> Selfwhere
V: Into<Option<Arc<T>>>,
Creates new FillOnceAtomicArc
use std::sync::{Arc, atomic::Ordering};
let empty: FillOnceAtomicArc<()> = FillOnceAtomicArc::new(None);
assert_eq!(empty.get_ref(Ordering::SeqCst), None);
let filled = FillOnceAtomicArc::new(Arc::new(10));
assert_eq!(filled.get_ref(Ordering::SeqCst), Some(&10));
sourcepub fn try_store<V>(&self, data: V, order: Ordering) -> Result<(), NotEmpty>where
V: Into<Arc<T>>,
pub fn try_store<V>(&self, data: V, order: Ordering) -> Result<(), NotEmpty>where
V: Into<Arc<T>>,
Stores new Arc<T>
if FillOnceAtomicArc
currently contains a None
This operation is implemented as a single atomic compare_and_swap
.
use std::sync::atomic::Ordering;
let option = FillOnceAtomicArc::default();
let old = option.try_store(5, Ordering::SeqCst);
assert!(old.is_ok());
assert_eq!(option.get_ref(Ordering::SeqCst), Some(&5));
let failed_to_store = option.try_store(10, Ordering::SeqCst);
assert!(failed_to_store.is_err());
assert_eq!(option.get_ref(Ordering::SeqCst), Some(&5));
sourcepub fn load(&self, order: Ordering) -> Option<Arc<T>>
pub fn load(&self, order: Ordering) -> Option<Arc<T>>
Atomically retrieves a cloned Option<Arc<T>>
use std::sync::atomic::Ordering;
let empty: FillOnceAtomicArc<()> = FillOnceAtomicArc::new(None);
assert_eq!(empty.load(Ordering::SeqCst), None);
let filled = FillOnceAtomicArc::from(10);
assert_eq!(filled.load(Ordering::SeqCst).map(|a| *a), Some(10));
sourcepub fn get_ref(&self, order: Ordering) -> Option<&T>
pub fn get_ref(&self, order: Ordering) -> Option<&T>
Atomically extracts a reference to the element stored
use std::sync::atomic::Ordering;
let empty: FillOnceAtomicArc<()> = FillOnceAtomicArc::new(None);
assert_eq!(empty.get_ref(Ordering::SeqCst), None);
let filled = FillOnceAtomicArc::from(10);
assert_eq!(filled.get_ref(Ordering::SeqCst), Some(&10));
sourcepub fn into_inner(self) -> Option<Arc<T>>
pub fn into_inner(self) -> Option<Arc<T>>
Converts itself into a Option<Arc<T>>
let ten = FillOnceAtomicArc::from(10);
assert_eq!(ten.into_inner().map(|a| *a), Some(10));
sourcepub unsafe fn from_raw(ptr: *mut Arc<T>) -> Self
pub unsafe fn from_raw(ptr: *mut Arc<T>) -> Self
Creates new FillOnceAtomicArc
based on a raw pointer
Safety
Unsafe because it uses a raw pointer, so it can’t be sure of its origin (and ownership)
You must own the pointer to call this
use std::{sync::Arc, sync::atomic::Ordering, ptr::null_mut};
let empty = unsafe { FillOnceAtomicArc::<()>::from_raw(null_mut()) };
assert_eq!(empty.get_ref(Ordering::SeqCst), None);
let ptr = Box::into_raw(Box::new(Arc::new(10)));
let filled = unsafe { FillOnceAtomicArc::from_raw(ptr) };
assert_eq!(filled.get_ref(Ordering::SeqCst), Some(&10));
sourcepub fn get_raw(&self, order: Ordering) -> *mut Arc<T>
pub fn get_raw(&self, order: Ordering) -> *mut Arc<T>
Atomically extracts the stored pointer
If pointer returned is not null it’s safe to deref as long as you don’t drop the FillOnceAtomicArc
Safety
To deref it you must ensure that it’s not null
, the FillOnceAtomicArc
wasn’t dropped
Returns null
if FillOnceAtomicArc
is empty (was not initialized or dropped)
use std::{sync::atomic::Ordering, ptr::null_mut, ops::Deref};
let empty: FillOnceAtomicArc<()> = FillOnceAtomicArc::new(None);
assert_eq!(empty.get_raw(Ordering::SeqCst), null_mut());
let filled = FillOnceAtomicArc::from(10);
assert_eq!(unsafe { (&*filled.get_raw(Ordering::SeqCst)).deref().deref() }, &10);
Trait Implementations
sourceimpl<T: Debug> Debug for FillOnceAtomicArc<T>
impl<T: Debug> Debug for FillOnceAtomicArc<T>
sourceimpl<T> Default for FillOnceAtomicArc<T>
impl<T> Default for FillOnceAtomicArc<T>
sourceimpl<T> From<Arc<T>> for FillOnceAtomicArc<T>
impl<T> From<Arc<T>> for FillOnceAtomicArc<T>
sourceimpl<T> From<Option<Arc<T>>> for FillOnceAtomicArc<T>
impl<T> From<Option<Arc<T>>> for FillOnceAtomicArc<T>
sourceimpl<T> From<T> for FillOnceAtomicArc<T>
impl<T> From<T> for FillOnceAtomicArc<T>
Auto Trait Implementations
impl<T> RefUnwindSafe for FillOnceAtomicArc<T>where
T: RefUnwindSafe,
impl<T> Send for FillOnceAtomicArc<T>where
T: Send + Sync,
impl<T> Sync for FillOnceAtomicArc<T>where
T: Send + Sync,
impl<T> Unpin for FillOnceAtomicArc<T>
impl<T> UnwindSafe for FillOnceAtomicArc<T>where
T: RefUnwindSafe,
Blanket Implementations
sourceimpl<T> BorrowMut<T> for Twhere
T: ?Sized,
impl<T> BorrowMut<T> for Twhere
T: ?Sized,
const: unstable · sourcefn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
sourceimpl<T> IntoSql for T
impl<T> IntoSql for T
sourcefn into_sql<T>(self) -> Self::Expressionwhere
Self: AsExpression<T> + Sized,
fn into_sql<T>(self) -> Self::Expressionwhere
Self: AsExpression<T> + Sized,
self
to an expression for Diesel’s query builder. Read moresourcefn as_sql<'a, T>(&'a self) -> <&'a Self as AsExpression<T>>::Expressionwhere
&'a Self: AsExpression<T>,
fn as_sql<'a, T>(&'a self) -> <&'a Self as AsExpression<T>>::Expressionwhere
&'a Self: AsExpression<T>,
&self
to an expression for Diesel’s query builder. Read more