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

A barrier will block all threads which call wait() until the nth thread calls wait(), and then wake up all threads at once.

§Examples

use std::sync::Barrier;

let barrier = Barrier::new(10);

Blocks the current thread until all threads have rendezvoused here.

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

A single (arbitrary) thread 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 BarrierWaitResult::is_leader().

§Examples

use std::sync::Barrier;
use std::thread;

let n = 10;
let barrier = Barrier::new(n);
thread::scope(|s| {
    for _ in 0..n {
        // The same messages will be printed together.
        // You will NOT see any interleaving.
        s.spawn(|| {
            println!("before wait");
            barrier.wait();
            println!("after wait");
        });
    }
});