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atomic_u32.rs
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atomic_u32.rs
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use std::cell::UnsafeCell;
use std::fmt;
use std::ops::Deref;
/// `AtomicU32` providing an additional `load_unsync` function.
pub(crate) struct AtomicU32 {
inner: UnsafeCell<std::sync::atomic::AtomicU32>,
}
unsafe impl Send for AtomicU32 {}
unsafe impl Sync for AtomicU32 {}
impl AtomicU32 {
pub(crate) const fn new(val: u32) -> AtomicU32 {
let inner = UnsafeCell::new(std::sync::atomic::AtomicU32::new(val));
AtomicU32 { inner }
}
/// Performs an unsynchronized load.
///
/// # Safety
///
/// All mutations must have happened before the unsynchronized load.
/// Additionally, there must be no concurrent mutations.
pub(crate) unsafe fn unsync_load(&self) -> u32 {
*(*self.inner.get()).get_mut()
}
}
impl Deref for AtomicU32 {
type Target = std::sync::atomic::AtomicU32;
fn deref(&self) -> &Self::Target {
// safety: it is always safe to access `&self` fns on the inner value as
// we never perform unsafe mutations.
unsafe { &*self.inner.get() }
}
}
impl fmt::Debug for AtomicU32 {
fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
self.deref().fmt(fmt)
}
}