use super::{channel, Receiver, Sender};
use alloc::sync::Arc;
use core::{
pin::Pin,
task::{Context, Poll},
};
use futures_util::{stream::Stream, task::AtomicWaker};
pub fn async_channel<T: 'static>() -> (AsyncSender<T>, AsyncReceiver<T>) {
let (tx, rx) = channel();
let waker = Arc::new(AtomicWaker::new());
(
AsyncSender {
tx,
waker: waker.clone(),
},
AsyncReceiver { rx, waker },
)
}
#[repr(C)]
pub struct AsyncSender<T: 'static> {
tx: Sender<T>,
waker: Arc<AtomicWaker>,
}
impl<T: 'static> AsyncSender<T> {
pub fn send(&self, data: T) {
self.tx.send(data);
self.waker.wake();
}
}
impl<T: 'static> Clone for AsyncSender<T> {
fn clone(&self) -> AsyncSender<T> {
AsyncSender {
tx: self.tx.clone(),
waker: self.waker.clone(),
}
}
}
#[repr(C)]
pub struct AsyncReceiver<T: 'static> {
rx: Receiver<T>,
waker: Arc<AtomicWaker>,
}
impl<T: 'static> Clone for AsyncReceiver<T> {
fn clone(&self) -> AsyncReceiver<T> {
AsyncReceiver {
rx: self.rx.clone(),
waker: self.waker.clone(),
}
}
}
impl<T: 'static> Stream for AsyncReceiver<T> {
type Item = T;
fn poll_next(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
if let Ok(v) = self.rx.recv() {
Poll::Ready(Some(v))
} else {
self.waker.register(cx.waker());
Poll::Pending
}
}
}