jonaskruckenberg.de
Next Generation WASM Microkernel Operating System
1// Copyright 2025 Jonas Kruckenberg
2//
3// Licensed under the Apache License, Version 2.0, <LICENSE-APACHE or
4// http://apache.org/licenses/LICENSE-2.0> or the MIT license <LICENSE-MIT or
5// http://opensource.org/licenses/MIT>, at your option. This file may not be
6// copied, modified, or distributed except according to those terms.
7
8use core::future::Future;
9use core::pin::Pin;
10use core::task::{Context, Poll};
11
12/// Yields execution to back to the runtime.
13pub async fn yield_now() {
14 /// Yield implementation
15 struct YieldNow {
16 yielded: bool,
17 }
18
19 impl Future for YieldNow {
20 type Output = ();
21
22 fn poll(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<()> {
23 // ready!(crate::trace::trace_leaf(cx));
24
25 if self.yielded {
26 return Poll::Ready(());
27 }
28
29 self.yielded = true;
30
31 // Yielding works by immediately calling `wake_by_ref` which will reinsert this
32 // task into the queue (essentially a reschedule) and then returning `Poll::Pending`
33 // to signal that this task is not done yet
34 cx.waker().wake_by_ref();
35 Poll::Pending
36 }
37 }
38
39 YieldNow { yielded: false }.await;
40}