1//! Atomic types.
2//!
3//! * [`AtomicCell`], a thread-safe mutable memory location.
4//! * [`AtomicConsume`], for reading from primitive atomic types with "consume" ordering.
5
6#[cfg(target_has_atomic = "ptr")]
7#[cfg(not(crossbeam_loom))]
8// Use "wide" sequence lock if the pointer width <= 32 for preventing its counter against wrap
9// around.
10//
11// In narrow architectures (pointer width <= 16), the counter is still <= 32-bit and may be
12// vulnerable to wrap around. But it's mostly okay, since in such a primitive hardware, the
13// counter will not be increased that fast.
14// Note that Rust (and C99) pointers must be at least 16-bit (i.e., 8-bit targets are impossible): https://github.com/rust-lang/rust/pull/49305
15#[cfg_attr(
16 any(target_pointer_width = "16", target_pointer_width = "32"),
17 path = "seq_lock_wide.rs"
18)]
19mod seq_lock;
20
21#[cfg(target_has_atomic = "ptr")]
22// We cannot provide AtomicCell under cfg(crossbeam_loom) because loom's atomic
23// types have a different in-memory representation than the underlying type.
24// TODO: The latest loom supports fences, so fallback using seqlock may be available.
25#[cfg(not(crossbeam_loom))]
26mod atomic_cell;
27#[cfg(target_has_atomic = "ptr")]
28#[cfg(not(crossbeam_loom))]
29pub use atomic_cell::AtomicCell;
30
31mod consume;
32pub use consume::AtomicConsume;
33