minitrace does not work on monoio

[jon-chuang]

minitrace = 0.4.0 monoio = 0.0.4

collector.collect().await does not return

[jon-chuang]

Some notes: GlobalCollector receives and processes the command, but the callback via futures::channel::oneshot::channel fails. Investigating why now.

Edit:

1. tested that this does not work by substituting tokio::sync::oneshot::channel
2. works with std::sync::mpsc::channel (unbounded)

[zhongzc]

Can you provide a minimal reproducible example?

[jon-chuang]

Yes

let mut rt_ = monoio::RuntimeBuilder::new().build().unwrap();

rt_.block_on(async move {
    let (root, collector) = Span::root("hi!");
    let spans = collector.collect().await;
    println!("spans: {:?}", spans);
});

If you instrument, commit_collect, you will see that rx.await never gets polled successfully.

[zhongzc]

For this example, I'm afraid it's a misuse of minitrace.

The root span should be dropped before collect, or the collection will be never performed.

You can try:

let mut rt_ = monoio::RuntimeBuilder::new().build().unwrap();

rt_.block_on(async move {
    let (root, collector) = Span::root("hi!");
    drop(root);
    let spans = collector.collect().await;
    println!("spans: {:?}", spans);
});

[jon-chuang]

my apologies, it fails with drop(root) and

fn().in_span(root).await;

too.

Note that for these cases, it works when I swap out oneshot::channel with std::sync::mpsc::channel. I have not tried tokio and futures unbounded/bounded channels.

[zhongzc]

my apologies, it fails with drop(root) and

fn().in_span(root).await;

too.

Note that for these cases, it works when I swap out oneshot::channel with std::sync::mpsc::channel. I have not tried tokio and futures unbounded/bounded channels.

Got. Seems an issue from monoio. We can discuss this further over here.