rust/tests/pass/concurrency/spin_loop.rs
2022-07-08 16:08:32 +00:00

44 lines
1.2 KiB
Rust

//@ignore-windows: Concurrency on Windows is not supported yet.
use std::sync::atomic::{AtomicUsize, Ordering};
use std::thread;
static FLAG: AtomicUsize = AtomicUsize::new(0);
fn spin() {
let j = thread::spawn(|| {
while FLAG.load(Ordering::Acquire) == 0 {
// We do *not* yield, and yet this should terminate eventually.
}
});
thread::yield_now(); // schedule the other thread
FLAG.store(1, Ordering::Release);
j.join().unwrap();
}
fn two_player_ping_pong() {
static FLAG: AtomicUsize = AtomicUsize::new(0);
let waiter1 = thread::spawn(|| {
while FLAG.load(Ordering::Acquire) == 0 {
// We do *not* yield, and yet this should terminate eventually.
}
});
let waiter2 = thread::spawn(|| {
while FLAG.load(Ordering::Acquire) == 0 {
// We do *not* yield, and yet this should terminate eventually.
}
});
let progress = thread::spawn(|| {
FLAG.store(1, Ordering::Release);
});
// The first `join` blocks the main thread and thus takes it out of the equation.
waiter1.join().unwrap();
waiter2.join().unwrap();
progress.join().unwrap();
}
fn main() {
spin();
two_player_ping_pong();
}