`glue::task::spawn` shouldn't panic when the entire wasm program is running on a WebWorker

[Officeyutong]

Recently I'm writing a wasm program using tokio_with_wasm that runs in a standalone WebWorker (meaning that I called init functions from wasm-bindgen in the worker). This program runs entirely in the worker, it only communicates with the main thread through onmessage/postMessage.

The program will just panic when calling spawn, at

tokio-with-wasm/package/src/glue/task/mod.rs

Line 181 in b4171d7

panic!();

From #27 (comment) I can see that tokio_with_wasm doesn't allow spawning in a blocking task to avoid undefined reference to JS objects. But in my situation, wasm program running in the WebWorker is not in a blocking task, and all JS objects it uses just stay in the Worker. spawn shouldn't panic under this situation.

The possible fix may be setting a flag to indicate whether the program is in a blocking_task, and decides to panic only when the progra was in a blocking_task.

[temeddix]

Hi, thanks for the report :)

Totally agreed, if your main event loop is inside a web worker, calling spawn should definitely be supported.

We might need a small design change for this. How should we determine the "main event loop"? In other words, the "main worker"?