Function drop_suspended_async_hook

tests/all/call_hook.rs:703–810

()

#[tokio::test]
async fn drop_suspended_async_hook() -> Result<(), Error> {
    struct Handler;

    #[async_trait::async_trait]
    impl CallHookHandler<u32> for Handler {
        async fn handle_call_event(
            &self,
            mut ctx: StoreContextMut<'_, u32>,
            _ch: CallHook,
        ) -> Result<()> {
            let state = ctx.data_mut();
            assert_eq!(*state, 0);
            *state += 1;
            let _dec = Decrement(state);

            // Simulate some sort of event which takes a number of yields
            for _ in 0..500 {
                tokio::task::yield_now().await;
            }
            Ok(())
        }
    }

    let engine = Engine::default();
    let mut store = Store::new(&engine, 0);
    store.call_hook_async(Handler);

    let mut linker = Linker::new(&engine);

    // Simulate a host function that has lots of yields with an infinite loop.
    linker.func_wrap_async("host", "f", |mut cx, _: ()| {
        Box::new(async move {
            let state = cx.data_mut();
            assert_eq!(*state, 0);
            *state += 1;
            let _dec = Decrement(state);
            for _ in 0.. {
                tokio::task::yield_now().await;
            }
        })
    })?;

    let wat = r#"
        (module
            (import "host" "f" (func $f))
            (func (export "") call $f)
        )
    "#;
    let module = Module::new(&engine, wat)?;

    let inst = linker.instantiate_async(&mut store, &module).await?;
    assert_eq!(*store.data(), 0);
    let export = inst
        .get_typed_func::<(), ()>(&mut store, "")
        .expect("export is func");

    // First test that if we drop in the middle of an async hook that everything
    // is alright.