Handle timer interrupts using async task too

src/driver/timer.rs

@@ -0,0 +1,48 @@
+use crate::{interrupts, print};
+use core::future::Future;
+use core::{
+    pin::Pin,
+    sync::atomic::Ordering,
+    task::{Context, Poll},
+};
+
+fn next_tick(current_tick: u64) -> impl Future<Output = u64> {
+    NextTick {
+        ticks: current_tick,
+    }
+}
+
+struct NextTick {
+    ticks: u64,
+}
+
+impl Future for NextTick {
+    type Output = u64;
+
+    fn poll(mut self: Pin<&mut Self>, cx: &mut Context) -> Poll<u64> {
+        let current_ticks = interrupts::TIMER_TICKS.load(Ordering::Acquire);
+
+        if self.ticks < current_ticks {
+            self.ticks += 1;
+            return Poll::Ready(self.ticks);
+        }
+
+        interrupts::TIMER_INTERRUPT_WAKER.register(&cx.waker());
+        let current_ticks = interrupts::TIMER_TICKS.load(Ordering::Acquire);
+        if self.ticks < current_ticks {
+            self.ticks += 1;
+            Poll::Ready(self.ticks)
+        } else {
+            Poll::Pending
+        }
+    }
+}
+
+pub async fn print_ticks() {
+    let mut current_ticks = interrupts::TIMER_TICKS.load(Ordering::Acquire);
+
+    loop {
+        current_ticks = next_tick(current_ticks).await;
+        print!(".");
+    }
+}