rust/tests/ui/threads-sendsync/task-comm-14.rs
Alex Crichton 75fa9f6dec compiletest: Add a //@ needs-threads directive
This commit is extracted from #122036 and adds a new directive to the
`compiletest` test runner, `//@ needs-threads`. This is intended to
capture the need that a target must implement threading to execute a
specific test, typically one that uses `std::thread`. This is primarily
done for WebAssembly targets which currently do not have threads by
default. This enables transitioning a lot of `//@ ignore-wasm*`-style
ignores into a more self-documenting `//@ needs-threads` directive.
Additionally the `wasm32-wasi-preview1-threads` target, for example,
does actually have threads, but isn't tested in CI at this time. This
change enables running these tests for that target, but not other wasm
targets.
2024-03-06 12:35:07 -08:00

36 lines
764 B
Rust

//@ run-pass
#![allow(unused_parens)]
//@ needs-threads
use std::sync::mpsc::{channel, Sender};
use std::thread;
pub fn main() {
let (tx, rx) = channel();
// Spawn 10 threads each sending us back one isize.
let mut i = 10;
while (i > 0) {
println!("{}", i);
let tx = tx.clone();
thread::spawn({let i = i; move|| { child(i, &tx) }});
i = i - 1;
}
// Spawned threads are likely killed before they get a chance to send
// anything back, so we deadlock here.
i = 10;
while (i > 0) {
println!("{}", i);
rx.recv().unwrap();
i = i - 1;
}
println!("main thread exiting");
}
fn child(x: isize, tx: &Sender<isize>) {
println!("{}", x);
tx.send(x).unwrap();
}