samples: work-philosophers: Adjust for new futures version

Adjust for the new futures version, where there is a builder that then
has a `start` that returns a `Work` that only holds on to the
allocation, and waits for an answer.

Signed-off-by: David Brown <david.brown@linaro.org>

Author: d3zd3z

samples/work-philosophers/src/lib.rs

@@ -10,7 +10,7 @@
 
 extern crate alloc;
 
-use zephyr::{printkln, sync::Arc, task::Wake, time::{Duration, NoWait}, work::futures::FutureWorkPoll};
+use zephyr::{printkln, time::Duration, work::futures::{sleep, WorkBuilder}};
 
 /// How many philosophers.  There will be the same number of forks.
 const _NUM_PHIL: usize = 6;
@@ -47,11 +47,7 @@ extern "C" fn rust_main() {
     // TODO: How to do as much on the stack as we can, for now, don't worry too much.
     // let mut th = pin!(th);
 
-    let mut th = FutureWorkPoll::new(th);
-    let result = th.as_mut().submit(NoWait).unwrap();
-    if !result.enqueued() {
-        panic!("Problem submitting initial work: {:?}", result);
-    }
+    let th = WorkBuilder::new().start(th);
 
     let result = th.sync_join();
     printkln!("th result: {:?}", result);
@@ -96,25 +92,21 @@ extern "C" fn rust_main() {
     */
 }
 
-/// Our local workqueue worker.
-struct PWaker;
-
-impl Wake for PWaker {
-    fn wake(this: Arc<Self>) {
-        // Note that being able to call this 'self' would require the unstable
-        // `abritrary_self_types` feature.
-        let _ = this;
-        todo!()
-    }
-}
-
 async fn phil_thread(n: usize) -> usize {
     printkln!("Child {} started", n);
-    zephyr::work::futures::sleep(Duration::millis_at_least(1000)).await;
+    show_it().await;
+    sleep(Duration::millis_at_least(1000)).await;
     printkln!("Child {} done sleeping", n);
     42
 }
 
+async fn show_it() {
+    for i in 0..10 {
+        sleep(Duration::millis_at_least(1)).await;
+        printkln!("Tick: {i}");
+    }
+}
+
 /*
 fn phil_thread(n: usize, syncer: Arc<dyn ForkSync>, stats: Arc<Mutex<Stats>>) {
     printkln!("Child {} started: {:?}", n, syncer);