Struct Token

pub struct Token { /* private fields */ }

A cancellation token. It tracks the state and holds an optional deadline for the operation. To share Token across threads, wrap it in a std::sync::Arc.

Implementations

impl Token

pub fn new() -> Self

Create a new Token with no deadline. The token will be marked as canceled only once Token::cancel has been called.

pub fn with_duration(duration: Duration) -> Self

Create a new Token with a deadline set to the current clock plus the specified duration. The token will be marked as canceled either when Token::cancel is called, or when the operation calls either Token::is_canceled or Token::check_cancel and the current clock exceeds the computed deadline.

pub fn with_deadline(deadline: Instant) -> Self

Create a new Token with a deadline set to the specified instant. The token will be marked as canceled either when Token::cancel is called, or when the operation calls either Token::is_canceled or Token::check_cancel and the current clock exceeds the specified deadline.

pub fn cancel(&self)

Explicitly mark the token as being canceled. This method is async signal safe.

pub fn was_canceled(&self) -> bool

Check whether the token was canceled. This method is intended to be called by code that initiated (rather than performed) an operation to test whether that operation was successful. If you want to test for cancellation in the body of your processing code you should use either Token::is_canceled or Token::check_cancel. Using Token::check_cancel to propagate a Result value is often a cleaner design than using Token::was_canceled.

pub fn is_canceled(&self) -> bool

Test whether an ongoing operation should cease due to cancellation. If a deadline has been set, the current clock will be evaluated and compared against the deadline, setting the state to canceled if appropriate. Returns true if the operation has been canceled.

pub fn check_cancel(&self) -> Result<(), Canceled>

Test whether an ongoing operation should cease due to cancellation, propagating a Canceled error value if the operation has been canceled. If a deadline has been set, the current clock will be evaluated and compared against the deadline, setting the state to canceled if appropriate.

Trait Implementations

impl Debug for Token

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

Formats the value using the given formatter.

impl Default for Token

fn default() -> Token

Returns the “default value” for a type.