Crate atomic_once_cell
source ·Expand description
atomic_once_cell
provides two new types, AtomicOnceCell
and
AtomicLazy
, which are thread-safe and mostly lock-free drop-in
replacements of [core::lazy::OnceCell
] and [core::lazy::Lazy
]
suitable for use in #[no_std]
environments.
Blocking
Because dereferencing AtomicLazy
can’t fail, it can’t be
lock-free (if you know a way, please tell me).
Both types can be used in a non-blocking way, but there are some
blocking calls that should not be used from interrupt handlers or
other contexts where blocking will lead to a deadlock. Blocking is
based on
crossbeam::utils::Backoff
,
and will be reduced to a spinlock in #[no_std]
environments.
Examples
AtomicOnceCell
use atomic_once_cell::AtomicOnceCell;
static CELL: AtomicOnceCell<String> = AtomicOnceCell::new();
fn main() {
CELL.set("Hello, World!".to_owned()).unwrap();
assert_eq!(*CELL.get().unwrap(), "Hello, World!");
}
AtomicLazy
use atomic_once_cell::AtomicLazy;
static LAZY: AtomicLazy<String> = AtomicLazy::new(|| "Hello, World!".to_owned());
fn main() {
assert_eq!(*LAZY, "Hello, World!");
}
Structs
- A thread-safe value which is initialized on the first access.
- A thread-safe cell which can be written to only once.