Struct tokio::task::JoinError

pub struct JoinError {
    repr: Repr,
    id: Id,
}

Task failed to execute to completion.

Fields

repr: Repr

id: Id

Implementations

impl JoinError

pub(crate) fn cancelled(id: Id) -> JoinError

pub(crate) fn panic(id: Id, err: Box<dyn Any + Send + 'static>) -> JoinError

pub fn is_cancelled(&self) -> bool

Returns true if the error was caused by the task being cancelled.

See the module level docs for more information on cancellation.

pub fn is_panic(&self) -> bool

Returns true if the error was caused by the task panicking.

Examples

use std::panic;

#[tokio::main]
async fn main() {
    let err = tokio::spawn(async {
        panic!("boom");
    }).await.unwrap_err();

    assert!(err.is_panic());
}

pub fn into_panic(self) -> Box<dyn Any + Send + 'static>

Consumes the join error, returning the object with which the task panicked.

Panics

into_panic() panics if the Error does not represent the underlying task terminating with a panic. Use is_panic to check the error reason or try_into_panic for a variant that does not panic.

Examples

use std::panic;

#[tokio::main]
async fn main() {
    let err = tokio::spawn(async {
        panic!("boom");
    }).await.unwrap_err();

    if err.is_panic() {
        // Resume the panic on the main task
        panic::resume_unwind(err.into_panic());
    }
}

pub fn try_into_panic(self) -> Result<Box<dyn Any + Send + 'static>, JoinError>

Consumes the join error, returning the object with which the task panicked if the task terminated due to a panic. Otherwise, self is returned.

Examples

use std::panic;

#[tokio::main]
async fn main() {
    let err = tokio::spawn(async {
        panic!("boom");
    }).await.unwrap_err();

    if let Ok(reason) = err.try_into_panic() {
        // Resume the panic on the main task
        panic::resume_unwind(reason);
    }
}

pub fn id(&self) -> Id

Returns a task ID that identifies the task which errored relative to other currently spawned tasks.

Trait Implementations

impl Debug for JoinError

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

Formats the value using the given formatter.

impl Display for JoinError

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

Formats the value using the given formatter.

impl Error for JoinError

fn source(&self) -> Option<&(dyn Error + 'static)>

The lower-level source of this error, if any.

fn description(&self) -> &str

👎Deprecated since 1.42.0: use the Display impl or to_string()

fn cause(&self) -> Option<&dyn Error>

👎Deprecated since 1.33.0: replaced by Error::source, which can support downcasting

fn provide<'a>(&'a self, request: &mut Request<'a>)

🔬This is a nightly-only experimental API. (error_generic_member_access)

Provides type based access to context intended for error reports.

impl From<JoinError> for Error

fn from(src: JoinError) -> Error

Converts to this type from the input type.