diff --git a/src/kernel/thread_manager.rs b/src/kernel/thread_manager.rs
index 514d495..cb73fcc 100644
--- a/src/kernel/thread_manager.rs
+++ b/src/kernel/thread_manager.rs
@@ -90,21 +90,27 @@ use crate::{
             MachineOk,
             MachineError
         }
+    },
+    kernel::{
+        thread::Thread,
+        process::Process
     }
 };
 
-use super::{thread::Thread, process::Process};
+/// Using this type alias to simplify struct and method definitions
+type ThreadRef = Rc<RefCell<Thread>>;
+
 /// # Thread manager
 /// 
 /// An instance of this struct is responsible for managing threads on behalf of the system
 #[derive(PartialEq)]
 pub struct ThreadManager {
     /// Current running thread
-    pub g_current_thread: Option<Rc<RefCell<Thread>>>,
+    pub g_current_thread: Option<ThreadRef>,
     /// The list of alive threads
-    pub g_alive: List<Rc<RefCell<Thread>>>,
+    pub g_alive: List<ThreadRef>,
     /// Thread in ready state waiting to become active
-    ready_list: List<Rc<RefCell<Thread>>>,
+    ready_list: List<ThreadRef>,
     /// List of objects created by the thread manager (such as Locks and Semaphores)
     obj_addrs: ObjAddr,
     /// If true, enables debug mode
@@ -131,7 +137,7 @@ impl ThreadManager {
     /// ## Pamameter
     /// 
     /// **thread** is the thread to be put on the read list
-    pub fn ready_to_run(&mut self, thread: Rc<RefCell<Thread>>) {
+    pub fn ready_to_run(&mut self, thread: ThreadRef) {
         self.ready_list.push(thread);
     }
 
@@ -141,7 +147,7 @@ impl ThreadManager {
     /// Thread is removed from the ready list.
     /// 
     /// **return** Thread thread to be scheduled
-    pub fn find_next_to_run(&mut self) -> Option<Rc<RefCell<Thread>>> {
+    pub fn find_next_to_run(&mut self) -> Option<ThreadRef> {
         self.ready_list.pop()
     }
 
@@ -155,7 +161,7 @@ impl ThreadManager {
     /// ## Parameter
     /// 
     /// **next_thread** thread to dispatch to the CPU
-    pub fn switch_to(&mut self, machine: &mut Machine, next_thread: Rc<RefCell<Thread>>) {
+    pub fn switch_to(&mut self, machine: &mut Machine, next_thread: ThreadRef) {
         if let Some(old_thread) = self.get_g_current_thread() {
             let old_thread = old_thread.clone();
             self.thread_save_processor_state(machine, old_thread.clone());
@@ -175,7 +181,7 @@ impl ThreadManager {
     }
 
     /// Start a thread, attaching it to a process
-    pub fn start_thread(&mut self, thread: Rc<RefCell<Thread>>, owner: Rc<RefCell<Process>>, func_pc: u64, sp_loc: u64, argument: i64) {
+    pub fn start_thread(&mut self, thread: ThreadRef, owner: Rc<RefCell<Process>>, func_pc: u64, sp_loc: u64, argument: i64) {
         let mut thread_m = thread.borrow_mut();
         assert_eq!(thread_m.process, Option::None);
         thread_m.process = Option::Some(Rc::clone(&owner));
@@ -187,7 +193,7 @@ impl ThreadManager {
     }
 
     /// Wait for another thread to finish its execution
-    pub fn thread_join(&mut self, machine: &mut Machine, waiter: Rc<RefCell<Thread>>, waiting_for: Rc<RefCell<Thread>>) {
+    pub fn thread_join(&mut self, machine: &mut Machine, waiter: ThreadRef, waiting_for: ThreadRef) {
         let waiting_for = Rc::clone(&waiting_for);
         while self.get_g_alive().contains(&waiting_for) {
             self.debug(format!("Joining \"{}\" to \"{}\"", waiter.borrow().get_name(), waiting_for.borrow().get_name()));
@@ -198,7 +204,7 @@ impl ThreadManager {
     /// Relinquish the CPU if any other thread is runnable.
     /// 
     /// Cannot use yield as a function name -> reserved name in rust
-    pub fn thread_yield(&mut self, machine: &mut Machine, thread: Rc<RefCell<Thread>>) {
+    pub fn thread_yield(&mut self, machine: &mut Machine, thread: ThreadRef) {
         let old_status = machine.interrupt.set_status(crate::simulator::interrupt::InterruptStatus::InterruptOff);
         
         self.debug(format!("Yeilding thread: {}", thread.borrow().get_name()));
@@ -212,7 +218,7 @@ impl ThreadManager {
     }
 
     /// Put the thread to sleep and relinquish the processor
-    pub fn thread_sleep(&mut self, machine: &mut Machine, thread: Rc<RefCell<Thread>>) {
+    pub fn thread_sleep(&mut self, machine: &mut Machine, thread: ThreadRef) {
         debug_assert_eq!(Option::Some(Rc::clone(&thread)), self.g_current_thread);
         debug_assert_eq!(machine.interrupt.get_status(), InterruptStatus::InterruptOff);
 
@@ -227,7 +233,7 @@ impl ThreadManager {
     }
 
     /// Finish the execution of the thread and prepare its deallocation
-    pub fn thread_finish(&mut self, machine: &mut Machine, thread: Rc<RefCell<Thread>>) {
+    pub fn thread_finish(&mut self, machine: &mut Machine, thread: ThreadRef) {
         let old_status = machine.interrupt.set_status(InterruptStatus::InterruptOff);
         assert!(self.g_alive.remove(Rc::clone(&thread)));
         self.debug(format!("Sleeping thread {}", thread.borrow().get_name()));
@@ -237,7 +243,7 @@ impl ThreadManager {
     }
 
 	/// Save the CPU state of a user program on a context switch.
-    pub fn thread_save_processor_state(&mut self, machine: &mut Machine, thread: Rc<RefCell<Thread>>) {
+    pub fn thread_save_processor_state(&mut self, machine: &mut Machine, thread: ThreadRef) {
         let mut t = thread.borrow_mut();
         for i in 0..NUM_INT_REGS {
             t.thread_context.int_registers[i] = machine.read_int_register(i);
@@ -249,7 +255,7 @@ impl ThreadManager {
     }
 
     /// Restore the CPU state of a user program on a context switch.
-    pub fn thread_restore_processor_state(&self, machine: &mut Machine, thread: Rc<RefCell<Thread>>) {
+    pub fn thread_restore_processor_state(&self, machine: &mut Machine, thread: ThreadRef) {
         let t: Ref<_> = thread.borrow();
         for i in 0..NUM_INT_REGS {
             machine.write_int_register(i, t.thread_context.int_registers[i]);
@@ -372,17 +378,17 @@ impl ThreadManager {
     }
 
     /// Currently running thread
-    pub fn get_g_current_thread(&mut self) -> &Option<Rc<RefCell<Thread>>> {
+    pub fn get_g_current_thread(&mut self) -> &Option<ThreadRef> {
         &self.g_current_thread
     }
 
     /// List of alive threads
-    pub fn get_g_alive(&mut self) -> &mut List<Rc<RefCell<Thread>>> {
+    pub fn get_g_alive(&mut self) -> &mut List<ThreadRef> {
         &mut self.g_alive
     }
 
     /// Set currently running thread
-    pub fn set_g_current_thread(&mut self, thread: Option<Rc<RefCell<Thread>>>) {
+    pub fn set_g_current_thread(&mut self, thread: Option<ThreadRef>) {
         self.g_current_thread = thread
     }