[][src]Struct tokio::task::JoinHandle

pub struct JoinHandle<T> { /* fields omitted */ }
This is supported on feature="rt-core" only.

An owned permission to join on a task (await its termination).

This can be thought of as the equivalent of std::thread::JoinHandle for a task rather than a thread.

A JoinHandle detaches the associated task when it is dropped, which means that there is no longer any handle to the task, and no way to join on it.

This struct is created by the task::spawn and task::spawn_blocking functions.


Creation from task::spawn:

use tokio::task;

let join_handle: task::JoinHandle<_> = task::spawn(async {
    // some work here

Creation from task::spawn_blocking:

use tokio::task;

let join_handle: task::JoinHandle<_> = task::spawn_blocking(|| {
    // some blocking work here

Child being detached and outliving its parent:

use tokio::task;
use tokio::time;
use std::time::Duration;

let original_task = task::spawn(async {
    let _detached_task = task::spawn(async {
        // Here we sleep to make sure that the first task returns before.
        // This will be called, even though the JoinHandle is dropped.
        println!("♫ Still alive ♫");

original_task.await.expect("The task being joined has panicked");
println!("Original task is joined.");

// We make sure that the new task has time to run, before the main
// task returns.


Trait Implementations

impl<T> Debug for JoinHandle<T> where
    T: Debug

impl<T> Drop for JoinHandle<T>[src]

impl<T> Future for JoinHandle<T>[src]

type Output = Result<T, JoinError>

The type of value produced on completion.

impl<T: Send> Send for JoinHandle<T>[src]

impl<T: Send> Sync for JoinHandle<T>[src]

impl<T> Unpin for JoinHandle<T>[src]

Auto Trait Implementations

impl<T> !RefUnwindSafe for JoinHandle<T>

impl<T> !UnwindSafe for JoinHandle<T>

Blanket Implementations

impl<T> Any for T where
    T: 'static + ?Sized

impl<T> Borrow<T> for T where
    T: ?Sized

impl<T> BorrowMut<T> for T where
    T: ?Sized

impl<T> From<T> for T[src]

impl<T, U> Into<U> for T where
    U: From<T>, 

impl<T, U> TryFrom<U> for T where
    U: Into<T>, 

type Error = Infallible

The type returned in the event of a conversion error.

impl<F, T, E> TryFuture for F where
    F: Future<Output = Result<T, E>> + ?Sized

type Ok = T

The type of successful values yielded by this future

type Error = E

The type of failures yielded by this future

impl<T, U> TryInto<U> for T where
    U: TryFrom<T>, 

type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.