[0.7] panick when loading a blocking resource #2995

winteler · 2024-09-19T10:15:28Z

Hello,

I believe I found an race condition with blocking resources. When loading a blocking resource in a <Suspense/>, I'm sometimes getting:

thread 'tokio-runtime-worker' panicked at reactive_graph-0.1.0-beta5/src/computed/async_derived/future_impls.rs:83:29:
At reproduce-leptos-0-7-beta5/src/app.rs:70:33, you tried to access a reactive value which was defined at src/app.rs:61:20, but it has already been disposed.

From my short tests, it looks like this is more likely to happen when the resource takes some time to load (hence the sleep in the reproduction below).

Leptos Dependencies

leptos = { version = "0.7.0-beta5", features = ["nightly"] }
leptos_axum = { version = "0.7.0-beta5", optional = true }
leptos_meta = { version = "0.7.0-beta5" }
leptos_router = { version = "0.7.0-beta5", features = ["nightly"] }

To Reproduce

use leptos::either::Either;
use leptos::prelude::*;
use leptos_meta::{provide_meta_context, MetaTags, Stylesheet, Title};
use leptos_router::{
    components::{Route, Router, Routes},
    StaticSegment,
};

pub fn shell(options: LeptosOptions) -> impl IntoView {
    view! {
        <!DOCTYPE html>
        <html lang="en">
            <head>
                <meta charset="utf-8"/>
                <meta name="viewport" content="width=device-width, initial-scale=1"/>
                <AutoReload options=options.clone() />
                <HydrationScripts options/>
                <MetaTags/>
            </head>
            <body>
                <App/>
            </body>
        </html>
    }
}

#[server]
pub async fn data() -> Result<String, ServerFnError> {
    tokio::time::sleep(tokio::time::Duration::from_millis(1000)).await;
    log!("Get data.");
    Ok(String::from("hello world"))
}

#[component]
pub fn App() -> impl IntoView {
    // Provides context that manages stylesheets, titles, meta tags, etc.
    provide_meta_context();

    view! {
        // injects a stylesheet into the document <head>
        // id=leptos means cargo-leptos will hot-reload this stylesheet
        <Stylesheet id="leptos" href="/pkg/reproduce-leptos-0-7-beta5.css"/>

        // sets the document title
        <Title text="Welcome to Leptos"/>

        // content for this welcome page
        <Router>
            <main>
                <Routes fallback=|| "Page not found.".into_view()>
                    <Route path=StaticSegment("") view=HomePage/>
                </Routes>
            </main>
        </Router>
    }
}

/// Renders the home page of your application.
#[component]
fn HomePage() -> impl IntoView {
    let resource = Resource::new_blocking(
        move || (),
        move |_| data()
    );
    view! {
        <h1>"Welcome to Leptos!"</h1>
        <Suspense>
        {
            move || Suspend::new(async move {
                match &resource.await {
                    Ok(value) => Either::Left(view! { <div>{value.clone()}</div> }),
                    Err(_e) => Either::Right(view! { <div>"Error test"</div> }),
                }
            })
        }
        </Suspense>
    }
}

As mentioned before, the error doesn't systematically appear, so maybe you'll need to try a few times or play with the tokio::time::sleep to reproduce it. Please tell me if there is any way I can help :)

The text was updated successfully, but these errors were encountered:

gbj added the bug Something isn't working label Sep 19, 2024

gbj mentioned this issue Sep 19, 2024

At … you tried to access a reactive value which was defined at …, but it has already been disposed. #2842

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[0.7] panick when loading a blocking resource #2995

[0.7] panick when loading a blocking resource #2995

winteler commented Sep 19, 2024 •

edited

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[0.7] panick when loading a blocking resource #2995

[0.7] panick when loading a blocking resource #2995

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winteler commented Sep 19, 2024 • edited Loading

winteler commented Sep 19, 2024 •

edited

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