scheduler done

src/utility/system.rs

@@ -1,3 +1,8 @@
+use crate::kernel::thread::Thread;
+
+
+pub static g_current_thread: Box<Option<Thread>> = Box::new(Option::None);
+pub static g_thread_to_be_destroyed: Box<Option<Thread>> = Box::new(Option::None);
 
 pub enum ObjectType {
     SEMAPHORE_TYPE,