Struct CancellationToken 

pub struct CancellationToken { /* private fields */ }

Cooperative cancellation handle. Cheap to clone (one Arc bump); safe to share across threads / tasks.

Every clone shares one flag: cancelling any clone is observed by all of them, and a cancelled token never resets. Cancellation is a request, not preemption — the work only stops where it polls Self::is_cancelled.

Examples

use lattice_protocol::CancellationToken;

let token = CancellationToken::new();
let worker_copy = token.clone(); // handed to the evaluator

let mut steps = 0;
for i in 0..1_000 {
    if worker_copy.is_cancelled() {
        break; // bail with the domain's "cancelled" error
    }
    steps += 1;
    if i == 9 {
        token.cancel(); // e.g. the user pressed Esc
    }
}
assert_eq!(steps, 10);
assert!(worker_copy.is_cancelled());

Implementations

impl CancellationToken

pub fn new() -> CancellationToken

Build a fresh, un-cancelled token.

pub fn never() -> CancellationToken

Build a token that can never be cancelled. Useful as a default for callers that don’t drive cancellation.

pub fn cancel(&self)

Flip the token. Subsequent is_cancelled calls (on this clone or any other) will observe the cancellation.

pub fn is_cancelled(&self) -> bool

Cheap (one atomic load) check. Returns true iff the token has been cancelled by some clone.

Trait Implementations

impl CheckCancelled for CancellationToken

fn check(&self) -> Result<(), CommandError>

Ok(()) while the token is live; [CommandError::Cancelled] once it has been cancelled. Cheap (one atomic load) – call it every inner-loop iteration.

impl Clone for CancellationToken

fn clone(&self) -> CancellationToken

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for CancellationToken

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

Formats the value using the given formatter.

impl Default for CancellationToken

fn default() -> CancellationToken

Returns the “default value” for a type.