# Enum std::sync::atomic::Ordering [−] [src]

    pub enum Ordering {
        Relaxed,
        Release,
        Acquire,
        AcqRel,
        SeqCst,
    }

Atomic memory orderings

Memory orderings limit the ways that both the compiler and CPU may reorder instructions around atomic operations. At its most restrictive, "sequentially consistent" atomics allow neither reads nor writes to be moved either before or after the atomic operation; on the other end "relaxed" atomics allow all reorderings.

Rust's memory orderings are the same as LLVM's.

## Variants

`Relaxed` | No ordering constraints, only atomic operations. Corresponds to LLVM's `Monotonic` ordering.
`Release` | When coupled with a store, all previous writes become visible to another thread that performs a load with `Acquire` ordering on the same value.
`Acquire` | When coupled with a load, all subsequent loads will see data written before a store with `Release` ordering on the same value in another thread.
`AcqRel` | When coupled with a load, uses `Acquire` ordering, and with a store `Release` ordering.
`SeqCst` | Like `AcqRel` with the additional guarantee that all threads see all sequentially consistent operations in the same order.

## Trait Implementations

### Derived Implementations

### `impl Clone for Ordering`

#### `fn clone(&self) -> Ordering`

#### `fn clone_from(&mut self, source: &Self)`

### `impl Copy for Ordering`

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