wayland: implement fifo-v1

src/tasks/const_clock.rs

@@ -0,0 +1,49 @@
+use {
+    crate::{
+        io_uring::IoUring,
+        utils::{
+            asyncevent::AsyncEvent, errorfmt::ErrorFmt, event_listener::EventSource, timer::TimerFd,
+        },
+    },
+    std::{rc::Rc, time::Duration},
+    uapi::c,
+};
+
+pub async fn run_const_clock<T, F>(
+    duration: Duration,
+    ring: &Rc<IoUring>,
+    source: &EventSource<T>,
+    mut f: F,
+) where
+    T: ?Sized,
+    F: FnMut(Rc<T>),
+{
+    let timer = match TimerFd::new(c::CLOCK_MONOTONIC) {
+        Ok(fd) => fd,
+        Err(e) => {
+            log::error!("Could not create timerfd: {}", ErrorFmt(e));
+            return;
+        }
+    };
+    if let Err(e) = timer.program(Some(duration), Some(duration)) {
+        log::error!("Could not program timerfd: {}", ErrorFmt(e));
+        return;
+    }
+    let ae = Rc::new(AsyncEvent::default());
+    loop {
+        if let Err(e) = timer.expired(&ring).await {
+            log::error!("Could not wait for timerfd to expire: {}", ErrorFmt(e));
+            return;
+        }
+        let mut dispatched_any = false;
+        for el in source.iter() {
+            dispatched_any = true;
+            f(el);
+        }
+        if !dispatched_any {
+            let ae2 = ae.clone();
+            source.on_attach(Box::new(move || ae2.trigger()));
+            ae.triggered().await;
+        }
+    }
+}