Enum OnceState 

pub enum OnceState {
    New,
    Poisoned,
    InProgress,
    Done,
}

Current state of a Once.

Variants

New

A closure has not been executed yet.

Poisoned

A closure was executed but panicked.

InProgress

A thread is currently executing a closure.

Done

A closure has completed successfully.

Implementations

impl OnceState

pub const fn is_poisoned(self) -> bool

Returns true if this is the Poisoned state. When a state is passed to Once::call_once_force, this indicates that the Once was poisoned before the closure was invoked.

Examples

A poisoned Once:

use parking_lot::Once;
use std::thread;

static INIT: Once = Once::new();

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 parking_lot::Once;

static INIT: Once = Once::new();

INIT.call_once_force(|state| {
    assert!(!state.is_poisoned());
});

pub const fn poisoned(self) -> bool

Alias for is_poisoned.

pub const fn is_completed(self) -> bool

Returns true if this is the Done state.

pub const fn done(self) -> bool

Alias for is_completed.

Trait Implementations

impl Clone for OnceState

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for OnceState

impl Debug for OnceState

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Eq for OnceState

impl PartialEq for OnceState

fn eq(&self, other: &Self) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for OnceState