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use std::{sync::mpsc, thread, time::Duration};
use tracing::{
metadata::Metadata,
span,
subscriber::{self, Interest, Subscriber},
Event,
};
#[test]
fn register_callsite_doesnt_deadlock() {
pub struct EvilSubscriber;
impl Subscriber for EvilSubscriber {
fn register_callsite(&self, meta: &'static Metadata<'static>) -> Interest {
tracing::info!(?meta, "registered a callsite");
Interest::always()
}
fn enabled(&self, _: &Metadata<'_>) -> bool {
true
}
fn new_span(&self, _: &span::Attributes<'_>) -> span::Id {
span::Id::from_u64(1)
}
fn record(&self, _: &span::Id, _: &span::Record<'_>) {}
fn record_follows_from(&self, _: &span::Id, _: &span::Id) {}
fn event(&self, _: &Event<'_>) {}
fn enter(&self, _: &span::Id) {}
fn exit(&self, _: &span::Id) {}
}
subscriber::set_global_default(EvilSubscriber).unwrap();
// spawn a thread, and assert it doesn't hang...
let (tx, didnt_hang) = mpsc::channel();
let th = thread::spawn(move || {
tracing::info!("hello world!");
tx.send(()).unwrap();
});
didnt_hang
// Note: 60 seconds is *way* more than enough, but let's be generous in
// case of e.g. slow CI machines.
.recv_timeout(Duration::from_secs(60))
.expect("the thread must not have hung!");
th.join().expect("thread should join successfully");
}