samples: philosophers: Migrate to new task declaration

Move away from the `kobj_define` task declaration to use the new
`#[zephyr::thread]` to define these.  This allows for a more natural
declaration where the thread just looks like an attribute added to a
regular function declaration.

This also eliminates the static Mutex, as the Mutex now has a
constructor that avoids allocation (it is still put in an Arc, though).

Signed-off-by: David Brown <[email protected]>

Author: d3zd3z

samples/philosophers/src/lib.rs

@@ -14,7 +14,7 @@ use alloc::boxed::Box;
 use alloc::vec::Vec;
 use zephyr::time::{sleep, Duration, Tick};
 use zephyr::{
-    kobj_define, printkln,
+    printkln,
     sync::{Arc, Mutex},
     sys::uptime_get,
 };
@@ -68,23 +68,15 @@ extern "C" fn rust_main() {
     printkln!("Hello world from Rust on {}", zephyr::kconfig::CONFIG_BOARD);
     printkln!("Time tick: {}", zephyr::time::SYS_FREQUENCY);
 
-    let stats = Arc::new(Mutex::new_from(
-        Stats::default(),
-        STAT_MUTEX.init_once(()).unwrap(),
-    ));
+    let stats = Arc::new(Mutex::new(Stats::default()));
 
     let syncers = get_syncer();
 
     printkln!("Pre fork");
 
     for (i, syncer) in (0..NUM_PHIL).zip(syncers.into_iter()) {
         let child_stat = stats.clone();
-        let thread = PHIL_THREADS[i]
-            .init_once(PHIL_STACKS[i].init_once(()).unwrap())
-            .unwrap();
-        thread.spawn(move || {
-            phil_thread(i, syncer, child_stat);
-        });
+        phil_thread(i, syncer, child_stat).start();
     }
 
     let delay = Duration::secs_at_least(10);
@@ -133,6 +125,7 @@ fn get_syncer() -> Vec<Arc<dyn ForkSync>> {
     get_channel_syncer()
 }
 
+#[zephyr::thread(stack_size = PHIL_STACK_SIZE, pool_size = NUM_PHIL)]
 fn phil_thread(n: usize, syncer: Arc<dyn ForkSync>, stats: Arc<Mutex<Stats>>) {
     printkln!("Child {} started: {:?}", n, syncer);
 
@@ -210,10 +203,3 @@ impl Stats {
         );
     }
 }
-
-kobj_define! {
-    static PHIL_THREADS: [StaticThread; NUM_PHIL];
-    static PHIL_STACKS: [ThreadStack<PHIL_STACK_SIZE>; NUM_PHIL];
-
-    static STAT_MUTEX: StaticMutex;
-}