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use std::task::{Context, Poll};
use std::time::Duration;
use std::{future::Future, io};
use once_cell::sync::Lazy;
use super::syscore::*;
use super::waker::*;
use crate::spawn_blocking;
pub use super::handle::*;
pub struct Proactor(SysProactor);
impl Proactor {
pub fn get() -> &'static Proactor {
static PROACTOR: Lazy<Proactor> =
Lazy::new(|| Proactor(SysProactor::new().expect("cannot initialize poll backend")));
&PROACTOR
}
pub fn wake(&self) {
self.0.wake().expect("failed to wake thread");
}
pub fn wait(&self, max_event_size: usize, duration: Option<Duration>) -> io::Result<usize> {
self.0.wait(max_event_size, duration)
}
pub(crate) fn inner(&self) -> &SysProactor {
&self.0
}
}
pub fn drive<T>(future: impl Future<Output = T>) -> T {
let p = Proactor::get();
let waker = waker_fn(move || {
p.wake();
});
let cx = &mut Context::from_waker(&waker);
futures_util::pin_mut!(future);
let driver = spawn_blocking(move || loop {
let _ = p.wait(1, None);
});
futures_util::pin_mut!(driver);
loop {
if let Poll::Ready(val) = future.as_mut().poll(cx) {
return val;
}
cx.waker().wake_by_ref();
let _ = driver.as_mut().poll(cx);
}
}