feat: SMP stage 1 (4 harts, per-hart guarded stacks, home-core affinity, IPIs, TLB shootdown, one temporary kernel lock), 4-core storm

crates/domain/src/scheduler/multi_core.rs

@@ -47,6 +47,23 @@ impl MultiCoreScheduler {
         self.placements.get(thread.raw() as usize)?.as_ref()
     }
 
+    pub fn num_cores(&self) -> u8 {
+        self.num_cores
+    }
+
+    /// The highest priority waiting in `core`'s run queue.
+    pub fn highest_waiting(&self, core: CoreId) -> Option<Priority> {
+        self.core(core)?.highest_waiting_priority()
+    }
+
+    /// The core whose run queue holds `thread`, if any.
+    pub fn queued_on(&self, thread: ThreadId) -> Option<CoreId> {
+        self.active()
+            .iter()
+            .find(|c| c.is_queued(thread))
+            .map(|c| c.core())
+    }
+
     /// Whether `thread` waits in some core's run queue.
     pub fn is_queued(&self, thread: ThreadId) -> bool {
         self.active().iter().any(|c| c.is_queued(thread))