feat(kernel): add Send and Receive IPC syscalls with rendezvous

crates/kernel/src/lib.rs

@@ -194,6 +194,32 @@ impl<P: Platform> Kernel<P> {
         self.scheduler.remove(tid);
     }
 
+    #[cfg(test)]
+    pub fn switch_to_thread_for_test(&mut self, tid: ThreadId) {
+        use domain::scheduler::Scheduler;
+        let core = self.platform.core_id();
+
+        if let Some(current) = self.scheduler.current(core) {
+            if current == tid {
+                return;
+            }
+            if let Ok(t) = self.threads.get_mut(current) {
+                if matches!(t.state(), ThreadState::Running(_)) {
+                    let priority = t.priority();
+                    let _ = t.preempt();
+                    self.scheduler.add(current, priority, core);
+                }
+            }
+        }
+
+        if let Ok(t) = self.threads.get(tid) {
+            if matches!(t.state(), ThreadState::Ready) {
+                self.scheduler.next(core);
+                let _ = self.threads.get_mut(tid).map(|t| t.set_running(core));
+            }
+        }
+    }
+
     #[cfg(test)]
     pub fn create_endpoint_for_test(&mut self) -> types::id::EndpointId {
         self.endpoints.create().expect("create endpoint")