task: move Scheduler into a trait, define static-sized scheduler implementation, expose as a system task runner in platform

src/main.rs

@@ -10,7 +10,7 @@ mod mappings;
 mod buffers;
 
 use crate::platform::{DefaultBoard, Board};
-use crate::task::{Task, Scheduler};
+use crate::task::{FixedSizeScheduler, Scheduler};
 use crate::render::{Surfaces, Renderer};
 use crate::geometry::Rectangle;
 
@@ -26,20 +26,17 @@ fn main() {
     log::info!("Surface implementation: {}", core::any::type_name_of_val(&output));
 
     log::info!("Creating animations");
-    let mut tasks: Vec<Box<dyn Task + 'static>> = vec![
+    let mut animations = FixedSizeScheduler::new([
         Box::new(animations::IdleTask::new(&mut surfaces)),
         Box::new(animations::TestPattern::new(surfaces.new_surface(&Rectangle::everything()).unwrap())),
     ];
 
-    tasks.append(&mut board.system_tasks());
-    tasks.push(Box::new(Renderer::new(output, surfaces)));
-
-    let mut runner = Scheduler::new(tasks);
-
-    log::info!("Runner ready: {:?}", runner);
+    let mut renderer = FixedSizeScheduler::new([Box::new(Renderer::new(output, surfaces))]);
 
     log::info!("Ready to rock and roll");
     loop {
-        runner.tick();
+        animations.tick();
+        system.tick();
+        renderer.tick();
     }
 }