pub struct OnceState { /* private fields */ }
Expand description
State yielded to Once::call_once_force()
’s closure parameter. The state
can be used to query the poison status of the Once
.
Implementations§
source§impl OnceState
impl OnceState
sourcepub fn is_poisoned(&self) -> bool
pub fn is_poisoned(&self) -> bool
Returns true
if the associated Once
was poisoned prior to the
invocation of the closure passed to Once::call_once_force()
.
Examples
A poisoned Once
:
use std::sync::Once;
use std::thread;
static INIT: Once = Once::new();
// poison the once
let handle = thread::spawn(|| {
INIT.call_once(|| panic!());
});
assert!(handle.join().is_err());
INIT.call_once_force(|state| {
assert!(state.is_poisoned());
});
An unpoisoned Once
:
use std::sync::Once;
static INIT: Once = Once::new();
INIT.call_once_force(|state| {
assert!(!state.is_poisoned());
});
Trait Implementations§
Auto Trait Implementations§
impl !RefUnwindSafe for OnceState
impl Send for OnceState
impl !Sync for OnceState
impl Unpin for OnceState
impl UnwindSafe for OnceState
Blanket Implementations§
source§impl<T> ArchivePointee for T
impl<T> ArchivePointee for T
§type ArchivedMetadata = ()
type ArchivedMetadata = ()
The archived version of the pointer metadata for this type.
source§fn pointer_metadata(
_: &<T as ArchivePointee>::ArchivedMetadata
) -> <T as Pointee>::Metadata
fn pointer_metadata( _: &<T as ArchivePointee>::ArchivedMetadata ) -> <T as Pointee>::Metadata
Converts some archived metadata to the pointer metadata for itself.
source§impl<T> BorrowMut<T> for Twhere
T: ?Sized,
impl<T> BorrowMut<T> for Twhere T: ?Sized,
source§fn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
Mutably borrows from an owned value. Read more
source§impl<F, W, T, D> Deserialize<With<T, W>, D> for Fwhere
W: DeserializeWith<F, T, D>,
D: Fallible + ?Sized,
F: ?Sized,
impl<F, W, T, D> Deserialize<With<T, W>, D> for Fwhere W: DeserializeWith<F, T, D>, D: Fallible + ?Sized, F: ?Sized,
source§impl<T> LayoutRaw for T
impl<T> LayoutRaw for T
source§fn layout_raw(_: <T as Pointee>::Metadata) -> Result<Layout, LayoutError>
fn layout_raw(_: <T as Pointee>::Metadata) -> Result<Layout, LayoutError>
Gets the layout of the type.