Enum rustc_ap_rustc_data_structures::sync::Ordering1.0.0[][src]

#[non_exhaustive]
pub enum Ordering {
    Relaxed,
    Release,
    Acquire,
    AcqRel,
    SeqCst,
}
Expand description

Atomic memory orderings

Memory orderings specify the way atomic operations synchronize memory. In its weakest Ordering::Relaxed, only the memory directly touched by the operation is synchronized. On the other hand, a store-load pair of Ordering::SeqCst operations synchronize other memory while additionally preserving a total order of such operations across all threads.

Rust’s memory orderings are the same as those of C++20.

For more information see the nomicon.

Variants (Non-exhaustive)

This enum is marked as non-exhaustive
Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.
Relaxed

No ordering constraints, only atomic operations.

Corresponds to memory_order_relaxed in C++20.

Release

When coupled with a store, all previous operations become ordered before any load of this value with Acquire (or stronger) ordering. In particular, all previous writes become visible to all threads that perform an Acquire (or stronger) load of this value.

Notice that using this ordering for an operation that combines loads and stores leads to a Relaxed load operation!

This ordering is only applicable for operations that can perform a store.

Corresponds to memory_order_release in C++20.

Acquire

When coupled with a load, if the loaded value was written by a store operation with Release (or stronger) ordering, then all subsequent operations become ordered after that store. In particular, all subsequent loads will see data written before the store.

Notice that using this ordering for an operation that combines loads and stores leads to a Relaxed store operation!

This ordering is only applicable for operations that can perform a load.

Corresponds to memory_order_acquire in C++20.

AcqRel

Has the effects of both Acquire and Release together: For loads it uses Acquire ordering. For stores it uses the Release ordering.

Notice that in the case of compare_and_swap, it is possible that the operation ends up not performing any store and hence it has just Acquire ordering. However, AcqRel will never perform Relaxed accesses.

This ordering is only applicable for operations that combine both loads and stores.

Corresponds to memory_order_acq_rel in C++20.

SeqCst

Like Acquire/Release/AcqRel (for load, store, and load-with-store operations, respectively) with the additional guarantee that all threads see all sequentially consistent operations in the same order.

Corresponds to memory_order_seq_cst in C++20.

Trait Implementations

impl Clone for Ordering[src]

pub fn clone(&self) -> Ordering[src]

Returns a copy of the value. Read more

fn clone_from(&mut self, source: &Self)[src]

Performs copy-assignment from source. Read more

impl Debug for Ordering[src]

pub fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>[src]

Formats the value using the given formatter. Read more

impl Hash for Ordering[src]

pub fn hash<__H>(&self, state: &mut __H) where
    __H: Hasher
[src]

Feeds this value into the given Hasher. Read more

fn hash_slice<H>(data: &[Self], state: &mut H) where
    H: Hasher
1.3.0[src]

Feeds a slice of this type into the given Hasher. Read more

impl PartialEq<Ordering> for Ordering[src]

pub fn eq(&self, other: &Ordering) -> bool[src]

This method tests for self and other values to be equal, and is used by ==. Read more

#[must_use]
fn ne(&self, other: &Rhs) -> bool
[src]

This method tests for !=.

impl Copy for Ordering[src]

impl Eq for Ordering[src]

impl StructuralEq for Ordering[src]

impl StructuralPartialEq for Ordering[src]

Auto Trait Implementations

Blanket Implementations

impl<T> Any for T where
    T: 'static + ?Sized
[src]

pub fn type_id(&self) -> TypeId[src]

Gets the TypeId of self. Read more

impl<T> Borrow<T> for T where
    T: ?Sized
[src]

pub fn borrow(&self) -> &T[src]

Immutably borrows from an owned value. Read more

impl<T> BorrowMut<T> for T where
    T: ?Sized
[src]

pub fn borrow_mut(&mut self) -> &mut T[src]

Mutably borrows from an owned value. Read more

impl<Q, K> Equivalent<K> for Q where
    K: Borrow<Q> + ?Sized,
    Q: Eq + ?Sized
[src]

pub fn equivalent(&self, key: &K) -> bool[src]

Compare self to key and return true if they are equal.

impl<T> From<T> for T[src]

pub fn from(t: T) -> T[src]

Performs the conversion.

impl<T> Instrument for T[src]

fn instrument(self, span: Span) -> Instrumented<Self>[src]

Instruments this type with the provided Span, returning an Instrumented wrapper. Read more

fn in_current_span(self) -> Instrumented<Self>[src]

Instruments this type with the current Span, returning an Instrumented wrapper. Read more

impl<T, U> Into<U> for T where
    U: From<T>, 
[src]

pub fn into(self) -> U[src]

Performs the conversion.

impl<T> ToOwned for T where
    T: Clone
[src]

type Owned = T

The resulting type after obtaining ownership.

pub fn to_owned(&self) -> T[src]

Creates owned data from borrowed data, usually by cloning. Read more

pub fn clone_into(&self, target: &mut T)[src]

🔬 This is a nightly-only experimental API. (toowned_clone_into)

recently added

Uses borrowed data to replace owned data, usually by cloning. Read more

impl<T, U> TryFrom<U> for T where
    U: Into<T>, 
[src]

type Error = Infallible

The type returned in the event of a conversion error.

pub fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>[src]

Performs the conversion.

impl<T, U> TryInto<U> for T where
    U: TryFrom<T>, 
[src]

type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.

pub fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>[src]

Performs the conversion.

impl<V, T> VZip<V> for T where
    V: MultiLane<T>, 

pub fn vzip(self) -> V

impl<'a, T> Captures<'a> for T where
    T: ?Sized
[src]

impl<T> Erased for T[src]