Struct tokio::task::JoinError

pub struct JoinError { /* private fields */ }

Available on crate feature rt only.

Task failed to execute to completion.

Implementations

impl 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);
    }
}

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)>

Returns 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.

Layout

Note: Most layout information is completely unstable and may even differ between compilations. The only exception is types with certain repr(...) attributes. Please see the Rust Reference's “Type Layout” chapter for details on type layout guarantees.

Size: 24 bytes