use crate::async_engine::AsyncEngine;
use crate::async_engine::SpawnedFuture;
use crate::utils::queue::AsyncQueue;
use std::cell::Cell;
use std::rc::Rc;
pub struct RunToplevelFuture {
_future: SpawnedFuture<()>,
}
pub struct RunToplevel {
cleared: Cell<bool>,
queue: AsyncQueue<Box<dyn FnOnce()>>,
}
impl RunToplevel {
pub fn install(eng: &Rc<AsyncEngine>) -> (RunToplevelFuture, Rc<RunToplevel>) {
let slf = Rc::new(RunToplevel {
cleared: Default::default(),
queue: Default::default(),
});
let future = eng.spawn("run toplevel", {
let slf = slf.clone();
async move {
loop {
let f = slf.queue.pop().await;
f();
}
}
});
let future = RunToplevelFuture { _future: future };
(future, slf)
}
pub fn schedule<F: FnOnce() + 'static>(&self, f: F) {
self.schedule_dyn(Box::new(f));
}
pub fn clear(&self) {
self.cleared.set(true);
self.queue.clear();
}
fn schedule_dyn(&self, f: Box<dyn FnOnce()>) {
if self.cleared.get() {
return;
}
self.queue.push(f);
}
}