[][src]Struct tokio::sync::Barrier

pub struct Barrier { /* fields omitted */ }

A barrier enables multiple threads to synchronize the beginning of some computation.

use tokio::sync::Barrier;

use futures::future::join_all;
use std::sync::Arc;

let mut handles = Vec::with_capacity(10);
let barrier = Arc::new(Barrier::new(10));
for _ in 0..10 {
    let c = barrier.clone();
    // The same messages will be printed together.
    // You will NOT see any interleaving.
    handles.push(async move {
        println!("before wait");
        let wr = c.wait().await;
        println!("after wait");
// Will not resolve until all "before wait" messages have been printed
let wrs = join_all(handles).await;
// Exactly one barrier will resolve as the "leader"
assert_eq!(wrs.into_iter().filter(|wr| wr.is_leader()).count(), 1);


impl Barrier[src]

pub fn new(n: usize) -> Barrier[src]

Creates a new barrier that can block a given number of threads.

A barrier will block n-1 threads which call [Barrier::wait] and then wake up all threads at once when the nth thread calls wait.

pub async fn wait<'_>(&'_ self) -> BarrierWaitResult[src]

Does not resolve until all tasks have rendezvoused here.

Barriers are re-usable after all threads have rendezvoused once, and can be used continuously.

A single (arbitrary) future will receive a [BarrierWaitResult] that returns true from [BarrierWaitResult::is_leader] when returning from this function, and all other threads will receive a result that will return false from is_leader.

Trait Implementations

impl Debug for Barrier[src]

Auto Trait Implementations

impl !RefUnwindSafe for Barrier

impl Send for Barrier

impl Sync for Barrier

impl Unpin for Barrier

impl !UnwindSafe for Barrier

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<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.