Fix global var

src/utility/system.rs

@@ -1,9 +1,17 @@
+use std::sync::{Mutex, RwLock};
+
+use lazy_static::lazy_static;
+
 use crate::kernel::thread::Thread;
+extern crate lazy_static;
+
+lazy_static! {
+    pub static ref g_current_thread: RwLock<Option<Thread>> = RwLock::new(Option::None);
+    pub static ref g_thread_to_be_destroyed: RwLock<Option<Thread>> = RwLock::new(Option::None);
+}
 
 
-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);
-
+#[derive(PartialEq)]
 pub enum ObjectType {
     SEMAPHORE_TYPE,
     LOCK_TYPE,