#[non_exhaustive]
pub enum Ordering {
Relaxed,
Release,
Acquire,
AcqRel,
SeqCst,
}
Atomic memory orderings
Memory orderings specify the way atomic operations synchronize memory.
In its weakest Relaxed
, only the memory directly touched by the
operation is synchronized. On the other hand, a store-load pair of 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
LLVM's.
For more information see the nomicon.
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.
No ordering constraints, only atomic operations.
Corresponds to LLVM's Monotonic
ordering.
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 LLVM's Release
ordering.
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 LLVM's Acquire
ordering.
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 LLVM's AcquireRelease
ordering.
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 LLVM's SequentiallyConsistent
ordering.
Performs copy-assignment from source
. Read more
This method tests for self
and other
values to be equal, and is used by ==
. Read more
This method tests for !=
.
Feeds this value into the given [Hasher
]. Read more
Feeds a slice of this type into the given [Hasher
]. Read more
Formats the value using the given formatter. Read more
The ordering of the operation when it succeeds.
The ordering of the operation when it fails. Read more
Creates owned data from borrowed data, usually by cloning. Read more
🔬 This is a nightly-only experimental API. (toowned_clone_into
)
recently added
Uses borrowed data to replace owned data, usually by cloning. Read more
🔬 This is a nightly-only experimental API. (try_from
)
The type returned in the event of a conversion error.
🔬 This is a nightly-only experimental API. (try_from
)
Immutably borrows from an owned value. Read more
🔬 This is a nightly-only experimental API. (get_type_id
)
this method will likely be replaced by an associated static
Mutably borrows from an owned value. Read more
type Error = <U as TryFrom<T>>::Error
🔬 This is a nightly-only experimental API. (try_from
)
The type returned in the event of a conversion error.
🔬 This is a nightly-only experimental API. (try_from
)
Create an error for a missing method specialization. Defaults to panicking with type, trait & method names. S
is the encoder/decoder state type, T
is the type being encoded/decoded, and the arguments are the names of the trait and method that should've been overridden. Read more