Function register_current_thread_task_host 

pub fn register_current_thread_task_host(
    env: &Env,
    registration_high: u32,
    registration_low: u32,
    dispatch: Option<Unknown<'_>>,
) -> Result<()>

Install a native-owned host turn used to poll CurrentThread runnables without re-entering arbitrary future waker locks. Called once per importing environment. JavaScript callbacks are rejected synchronously.