diff --git a/src/kernel/mod.rs b/src/kernel/mod.rs
index 1988e43..67a43cb 100644
--- a/src/kernel/mod.rs
+++ b/src/kernel/mod.rs
@@ -1,6 +1,5 @@
 mod process;
 pub mod thread;
-pub mod scheduler;
 pub mod mgerror;
 pub mod system;
 mod ucontext;
diff --git a/src/kernel/scheduler.rs b/src/kernel/scheduler.rs
deleted file mode 100644
index 7071fbb..0000000
--- a/src/kernel/scheduler.rs
+++ /dev/null
@@ -1,74 +0,0 @@
-use std::cell::RefCell;
-use std::rc::Rc;
-
-use crate::utility::list::List;
-use crate::kernel::thread::Thread;
-use super::thread_manager::ThreadManager;
-
-#[derive(PartialEq)]
-pub struct Scheduler {
-    ready_list: List<Rc<RefCell<Thread>>>,
-    pub thread_manager: Option<Rc<RefCell<ThreadManager>>> 
-}
-
-impl Scheduler {
-
-    /// Constructor
-    /// 
-    /// Initilize the list of ready thread
-    pub fn new() -> Self {
-        Self {
-            ready_list: List::new(),
-            thread_manager: Option::None
-        }
-    }
-
-    /// Mark a thread as aready, but not necessarily running yet.
-    /// 
-    /// Put it in the ready list, for later scheduling onto the CPU.
-    /// 
-    /// ## Pamameter
-    /// 
-    /// **thread** is the thread to be put on the read list
-    pub fn ready_to_run(&mut self, thread: Rc<RefCell<Thread>>) {
-        self.ready_list.push(thread);
-    }
-    
-    /// Return the next thread to be scheduled onto the CPU.
-    /// If there are no ready threads, return Option::None
-    /// 
-    /// 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>>> {
-        self.ready_list.pop()
-    }
-
-    /// Dispatch the CPU to next_thread. Save the state of the old thread 
-    /// and load the state of the new thread.
-    /// 
-    /// We assume the state of the previously running thread has already been changed from running to blocked or ready.
-    /// 
-    /// Global variable g_current_thread become next_thread
-    /// 
-    /// ## Parameter
-    /// 
-    /// **next_thread** thread to dispatch to the CPU
-    pub fn switch_to(&mut self, next_thread: Rc<RefCell<Thread>>) {
-        if let Some(tm) = &self.thread_manager {
-            let rc = Rc::clone(&tm);
-            if let Some(old_thread) = tm.borrow_mut().get_g_current_thread() {
-                rc.borrow_mut().thread_save_processor_state(Rc::clone(&old_thread));
-                // old_thread.save_simulator_state();
-
-                if old_thread != &next_thread {
-                    rc.borrow_mut().thread_restore_processor_state(Rc::clone(&next_thread));
-                    // next_thread.restore_simulator_state();
-                    rc.borrow_mut().set_g_current_thread(Option::Some(next_thread));
-                }
-            }
-        } else {
-            panic!("thread manager shouldn't be none");
-        }
-    }
-}
\ No newline at end of file
diff --git a/src/kernel/synch.rs b/src/kernel/synch.rs
index 027cfce..af3f44e 100644
--- a/src/kernel/synch.rs
+++ b/src/kernel/synch.rs
@@ -1,3 +1,4 @@
+use crate::kernel::thread_manager;
 use crate::utility::list::List;
 use crate::kernel::thread::Thread;
 use crate::simulator::interrupt::InterruptStatus::InterruptOff;
@@ -5,8 +6,6 @@ use crate::simulator::machine::Machine;
 use std::cell::RefCell;
 use std::rc::Rc;
 
-
-use super::scheduler::Scheduler;
 use super::system::System;
 use super::thread_manager::ThreadManager;
 
@@ -17,8 +16,6 @@ pub struct Semaphore {
     counter:i32,
     /// QUeue of Semaphore waiting to be exucated
     waiting_queue:List<Rc<RefCell<Thread>>>,
-    /// Thread manager which managing threads
-    thread_manager: Rc<RefCell<ThreadManager>>
 
 }
 
@@ -29,8 +26,8 @@ impl Semaphore {
     ///  ### Parameters
     /// - *counter* initial value of counter
     /// - *thread_manager* Thread manager which managing threads
-    pub fn new(counter: i32, thread_manager: Rc<RefCell<ThreadManager>>) -> Semaphore{
-        Semaphore { counter, waiting_queue: List::new(), thread_manager}
+    pub fn new(counter: i32) -> Semaphore{
+        Semaphore { counter, waiting_queue: List::default() }
     }
 
     ///     Decrement the value, and wait if it becomes < 0. Checking the
@@ -40,17 +37,24 @@ impl Semaphore {
     ///	Note that thread_manager::thread_sleep assumes that interrupts are disabled
     ///	when it is called.
     ///
-    /// ### Parameters
+    /// ### Parameters TODO Refaire
     /// - *current_thread* the current thread
     /// - *machine* the machine where the threads are executed
-    pub fn p(&mut self, current_thread: Rc<RefCell<Thread>>, system: Rc<RefCell<System>>) {
-        let old_status = system.borrow_mut().get_g_machine().borrow_mut().interrupt.set_status(InterruptOff);
+    pub fn p(&mut self, machine: &mut Machine, thread_manager: &mut ThreadManager) {
+        let old_status = machine.interrupt.set_status(InterruptOff);
         self.counter -= 1;
         if self.counter < 0 {
-            self.waiting_queue.push(Rc::clone(&current_thread));
-            self.thread_manager.borrow_mut().thread_sleep(current_thread);
+            match thread_manager.get_g_current_thread() {
+                Some(thread) => {
+                    let rc1_thread = Rc::clone(thread);
+                    let rc2_thread = Rc::clone(thread);
+                    self.waiting_queue.push(rc1_thread);
+                    thread_manager.thread_sleep(machine, rc2_thread);
+                },
+                None => unreachable!("Current thread should not be None")
+            }
         }
-        system.borrow_mut().get_g_machine().borrow_mut().interrupt.set_status(old_status);
+        machine.interrupt.set_status(old_status);
     }
 
     /// Increment semaphore value, waking up a waiting thread if any.
@@ -63,13 +67,13 @@ impl Semaphore {
     /// ### Parameters
     /// - **machine** the machine where the threads are executed
     /// - **scheduler** the scheduler which determine which thread to execute
-    pub fn v(&mut self, system: Rc<RefCell<System>>){
-        let old_status = system.borrow_mut().get_g_machine().borrow_mut().interrupt.set_status(InterruptOff);
+    pub fn v(&mut self, machine: &mut Machine, thread_manager: &mut ThreadManager){
+        let old_status = machine.interrupt.set_status(InterruptOff);
         self.counter += 1;
         if self.waiting_queue.peek() != None {
-            system.borrow_mut().get_thread_manager().borrow_mut().g_scheduler.ready_to_run(self.waiting_queue.pop().unwrap());
+            thread_manager.ready_to_run(self.waiting_queue.pop().unwrap());
         }
-        system.borrow_mut().get_g_machine().borrow_mut().interrupt.set_status(old_status);
+        machine.interrupt.set_status(old_status);
     }
 }
 
@@ -82,8 +86,6 @@ pub struct Lock{
     owner: Option<Rc<RefCell<Thread>>>,
     /// The queue of threads waiting for execution
     waiting_queue:List<Rc<RefCell<Thread>>>,
-    /// Thread manager which managing threads
-    thread_manager: Rc<RefCell<ThreadManager>>,
     /// A boolean definig if the lock is free or not
     free: bool
 
@@ -96,8 +98,8 @@ impl Lock {
     ///
     /// ### Parameters
     /// - **thread_manager** Thread manager which managing threads
-    pub fn new(thread_manager: Rc<RefCell<ThreadManager>>) -> Lock {
-        Lock { owner: None, waiting_queue: List::new(), thread_manager, free: true }
+    pub fn new() -> Lock {
+        Lock { owner: None, waiting_queue: List::default(), free: true }
     }
 
     ///    Wait until the lock become free.  Checking the
@@ -111,23 +113,28 @@ impl Lock {
     /// ### Parameters
     /// - **current_thread** the current thread
     /// - **machine** the machine where the threads are executed
-    pub fn acquire(&mut self, current_thread: Option<Rc<RefCell<Thread>>>, system: Rc<RefCell<System>>) {
-        let old_status = system.borrow_mut().get_g_machine().borrow_mut().interrupt.set_status(InterruptOff);
-
+    pub fn acquire(&mut self, machine: &mut Machine, thread_manager: &mut ThreadManager) {
+        let old_status = machine.interrupt.set_status(InterruptOff);
         if self.free {
             self.free = false;
-            self.owner = current_thread;
-        } else {
-            match current_thread {
-                Some(x) => {
-                    self.waiting_queue.push(Rc::clone(&x));
-                    self.thread_manager.borrow_mut().thread_sleep(x)
+            self.owner = Option::Some(match thread_manager.get_g_current_thread() {
+                Some(th) => {
+                    Rc::clone(&th)
                 },
-                None => ()
+                None => unreachable!()
+            });
+        } else {
+            match thread_manager.get_g_current_thread() {
+                Some(x) => {
+                    let x = Rc::clone(&x);
+                    self.waiting_queue.push(Rc::clone(&x));
+                    thread_manager.thread_sleep(machine, Rc::clone(&x));
+                },
+                None => unreachable!("Current thread should not be None")
             }
         }
 
-        system.borrow_mut().get_g_machine().borrow_mut().interrupt.set_status(old_status);
+        machine.interrupt.set_status(old_status);
     }
 
     ///     Wake up a waiter if necessary, or release it if no thread is waiting.
@@ -139,31 +146,37 @@ impl Lock {
     /// ### Parameters
     /// - **machine** the machine where the code is executed
     /// - **scheduler** the scheduler which determine which thread to execute
-    pub fn release(&mut self, system: Rc<RefCell<System>>, current_thread: Rc<RefCell<Thread>>) {
-        let old_status = system.borrow_mut().get_g_machine().borrow_mut().interrupt.set_status(InterruptOff);
+    pub fn release(&mut self, machine: &mut Machine, thread_manager: &mut ThreadManager) {
+        let old_status = machine.interrupt.set_status(InterruptOff);
         
-        if self.held_by_current_thread(current_thread) {
-            if self.waiting_queue.peek() != None {
-                self.owner = Some(self.waiting_queue.pop().unwrap());
-                let sys = system.borrow_mut();
-                let tm = sys.get_thread_manager();
-                let scheduler = &mut tm.borrow_mut().g_scheduler;
-                match &self.owner {
-                    Some(x) => scheduler.ready_to_run(Rc::clone(&x)),
-                    None => ()
+        match thread_manager.get_g_current_thread() {
+            Some(thread) => {
+                if self.held_by_current_thread(thread_manager) {
+                    if self.waiting_queue.peek() != None {
+                        self.owner = Some(self.waiting_queue.pop().unwrap());
+                        match &self.owner {
+                            Some(x) => thread_manager.ready_to_run(Rc::clone(&x)),
+                            None => ()
+                        }
+                    } else {
+                        self.free = true;
+                        self.owner = None;
+                    }
                 }
-            } else {
-                self.free = true;
-                self.owner = None;
             }
+            None => ()
         }
 
-        system.borrow_mut().get_g_machine().borrow_mut().interrupt.set_status(old_status);
+        machine.interrupt.set_status(old_status);
     }
 
-    pub fn held_by_current_thread(&mut self, current_thread: Rc<RefCell<Thread>>) -> bool {
+    pub fn held_by_current_thread(&mut self, thread_manager: &mut ThreadManager) -> bool {
         match &self.owner {
-            Some(x) => Rc::ptr_eq(&x, &current_thread),
+            Some(x) => 
+                match thread_manager.get_g_current_thread() {
+                    Some(thread) => Rc::ptr_eq(&x, &thread),
+                    None => false
+                }
             None => false
         }
     }
@@ -174,8 +187,6 @@ pub struct Condition{
 
     /// The queue of threads waiting for execution
     waiting_queue:List<Rc<RefCell<Thread>>>,
-    /// Thread manager which managing threads
-    thread_manager: Rc<RefCell<ThreadManager>>,
     
 }
 
@@ -185,8 +196,8 @@ impl Condition {
     ///
     /// ### Parameters
     /// - *thread_manager* Thread manager which managing threads
-    pub fn new(thread_manager: Rc<RefCell<ThreadManager>>) -> Condition {
-        Condition{ waiting_queue: List::new(), thread_manager }
+    pub fn new() -> Condition {
+        Condition{ waiting_queue: List::default()}
     }
 
     ///  Block the calling thread (put it in the wait queue).
@@ -195,11 +206,17 @@ impl Condition {
     /// ### Parameters
     /// - **current_thread** the current thread
     /// - **machine** the machine where threads are executed
-    pub fn wait(&mut self, current_thread: Rc<RefCell<Thread>>, machine: &mut Machine) {
+    pub fn wait(&mut self, machine: &mut Machine, thread_manager: &mut ThreadManager) {
         let old_status = machine.interrupt.set_status(InterruptOff);
-
-        self.waiting_queue.push(Rc::clone(&current_thread));
-        self.thread_manager.borrow_mut().thread_sleep(current_thread);
+        match thread_manager.get_g_current_thread() {
+            Some(thread) => {
+                let rc1 = Rc::clone(thread);
+                let rc2 = Rc::clone(thread);
+                self.waiting_queue.push(rc1);
+                thread_manager.thread_sleep(machine, rc2);
+            },
+            None => unreachable!()
+        }
 
         machine.interrupt.set_status(old_status);
     }
@@ -210,14 +227,14 @@ impl Condition {
     /// ### Parameters
     /// - **machine** the machine where the code is executed
     /// - **scheduler** the scheduler which determine which thread to execute
-    pub fn signal(&mut self, machine: &mut Machine, scheduler: &mut Scheduler) {
-        let old_status = machine.interrupt.set_status(InterruptOff);
+    pub fn signal(&mut self, system: &mut System) {
+        let old_status = system.get_machine().interrupt.set_status(InterruptOff);
 
         if self.waiting_queue.peek() != None {
-            scheduler.ready_to_run(self.waiting_queue.pop().unwrap());
+            system.get_thread_manager().ready_to_run(self.waiting_queue.pop().unwrap());
         }
 
-        machine.interrupt.set_status(old_status);
+        system.get_machine().interrupt.set_status(old_status);
 
     }
 
@@ -227,13 +244,13 @@ impl Condition {
     /// ### Parameters
     /// - **machine** the machine where the code is executed
     /// - **scheduler** the scheduler which determine which thread to execute
-    pub fn broadcast(&mut self, machine: &mut Machine, scheduler: &mut Scheduler) {
-        let old_status = machine.interrupt.set_status(InterruptOff);
+    pub fn broadcast(&mut self, system: &mut System) {
+        let old_status = system.get_machine().interrupt.set_status(InterruptOff);
 
         while self.waiting_queue.peek() != None {
-            scheduler.ready_to_run(self.waiting_queue.pop().unwrap());
+            system.get_thread_manager().ready_to_run(self.waiting_queue.pop().unwrap());
         }
-        machine.interrupt.set_status(old_status);
+        system.get_machine().interrupt.set_status(old_status);
 
     }
 
@@ -243,66 +260,68 @@ impl Condition {
 mod test {
     use std::{rc::Rc, cell::RefCell};
 
-    use crate::{kernel::{thread::Thread, synch::{Semaphore, Lock}}, init_system, simulator::machine::Machine};
+    use crate::{kernel::{thread::Thread, synch::{Semaphore, Lock}, thread_manager::ThreadManager}, init_system, simulator::machine::Machine};
 
     #[test]
     fn test_semaphore_single() {
         // Init
-        let system = init_system!();
-        let mut semaphore = Semaphore::new(1, Rc::clone(&system.borrow_mut().get_thread_manager()));
+        let mut machine = Machine::init_machine();
+        let mut thread_manager = ThreadManager::new();
+        let mut semaphore = Semaphore::new(1);
         let thread = Rc::new(RefCell::new(Thread::new("test_semaphore")));
+        thread_manager.ready_to_run(Rc::clone(&thread));
+        thread_manager.set_g_current_thread(Some(thread));
         // P
-        semaphore.p(thread, Rc::clone(&system));
+        semaphore.p(&mut machine, &mut thread_manager);
         assert_eq!(semaphore.counter, 0);
         assert!(semaphore.waiting_queue.is_empty());
         // V
-        semaphore.v(Rc::clone(&system));
+        semaphore.v(&mut machine, &mut thread_manager);
         assert_eq!(semaphore.counter, 1);
         assert!(semaphore.waiting_queue.is_empty());
     }
 
     #[test]
-    #[ignore]
     fn test_semaphore_multiple() {
         // Init
-        let system = init_system!();
-        let tm = system.borrow_mut().get_thread_manager();
-        let mut semaphore = Semaphore::new(2, Rc::clone(&tm));
+        let mut tm = ThreadManager::new();
+        let mut machine = Machine::init_machine();
+        let mut semaphore = Semaphore::new(2);
         let thread1 = Rc::new(RefCell::new(Thread::new("test_semaphore_1")));
         let thread2 = Rc::new(RefCell::new(Thread::new("test_semaphore_2")));
         let thread3 = Rc::new(RefCell::new(Thread::new("test_semaphore_3")));
 
-        let mut borrow_tm = tm.borrow_mut();
-        let scheduler = &mut borrow_tm.g_scheduler;
-        scheduler.ready_to_run(Rc::clone(&thread1));
-        scheduler.ready_to_run(Rc::clone(&thread2));
-        scheduler.ready_to_run(Rc::clone(&thread3));
+        // let mut borrow_tm = tm.borrow_mut();
+        // let scheduler = &mut tm.g_scheduler;
+        tm.ready_to_run(Rc::clone(&thread1));
+        tm.ready_to_run(Rc::clone(&thread2));
+        tm.ready_to_run(Rc::clone(&thread3));
         // P
-        borrow_tm.set_g_current_thread(Some(Rc::clone(&thread1)));
-        semaphore.p(thread1, Rc::clone(&system));
+        tm.set_g_current_thread(Some(Rc::clone(&thread1)));
+        semaphore.p(&mut machine, &mut tm);
         assert_eq!(semaphore.counter, 1);
         assert!(semaphore.waiting_queue.is_empty());
         
-        borrow_tm.set_g_current_thread(Some(Rc::clone(&thread2)));
-        semaphore.p(thread2, Rc::clone(&system));
+        tm.set_g_current_thread(Some(Rc::clone(&thread2)));
+        semaphore.p(&mut machine, &mut tm);
         assert_eq!(semaphore.counter, 0);
         assert!(semaphore.waiting_queue.is_empty());
 
-        borrow_tm.set_g_current_thread(Some(Rc::clone(&thread3)));
-        semaphore.p(thread3, Rc::clone(&system));
+        tm.set_g_current_thread(Some(Rc::clone(&thread3)));
+        semaphore.p(&mut machine, &mut tm);
         assert_eq!(semaphore.counter, -1);
         assert!(semaphore.waiting_queue.iter().count() == 1);
 
         // V
-        semaphore.v(Rc::clone(&system));
+        semaphore.v(&mut machine, &mut tm);
         assert_eq!(semaphore.counter, 0);
         assert!(semaphore.waiting_queue.is_empty());
 
-        semaphore.v(Rc::clone(&system));
+        semaphore.v(&mut machine, &mut tm);
         assert_eq!(semaphore.counter, 1);
         assert!(semaphore.waiting_queue.is_empty());
 
-        semaphore.v(Rc::clone(&system));
+        semaphore.v(&mut machine, &mut tm);
         assert_eq!(semaphore.counter, 2);
         assert!(semaphore.waiting_queue.is_empty());
     }
@@ -310,61 +329,61 @@ mod test {
 
 
     #[test]
-    #[ignore]
     fn test_lock_simple() {
-        let system = init_system!();
-        let sys = system.borrow_mut();
-        let tm = sys.get_thread_manager();
+        let mut machine = Machine::init_machine();
+        let mut tm = ThreadManager::new();
         let thread = Rc::new(RefCell::new(Thread::new("test_lock")));
-        tm.borrow_mut().set_g_current_thread(Some(Rc::clone(&thread)));
-        let mut lock = Lock::new(Rc::clone(&tm));
+        tm.ready_to_run(Rc::clone(&thread));
+        tm.set_g_current_thread(Some(Rc::clone(&thread)));
+        let mut lock = Lock::new();
 
         assert!(lock.free);
-        lock.acquire(Some(Rc::clone(&thread)), Rc::clone(&system));
-        assert!(lock.held_by_current_thread(Rc::clone(&thread)));
+        lock.acquire(&mut machine, &mut tm);
+        assert!(lock.held_by_current_thread(&mut tm));
 
         assert!(!lock.free);
-        lock.release(Rc::clone(&system), Rc::clone(&thread));
-        assert!(!lock.held_by_current_thread(thread));
+        lock.release(&mut machine, &mut tm);
+        assert!(!lock.held_by_current_thread(&mut tm));
         assert!(lock.free);
     }
 
     #[test]
-    #[ignore]
     fn test_lock_multiple() {
-        let system = init_system!();
         let thread1 = Rc::new(RefCell::new(Thread::new("test_lock1")));
         let thread2 = Rc::new(RefCell::new(Thread::new("test_lock2")));
-        let thread3 = Rc::new(RefCell::new(Thread::new("test_lock3")));
 
-        let tm = system.borrow_mut().get_thread_manager();
-        tm.borrow_mut().set_g_current_thread(Some(Rc::clone(&thread1)));
-        let mut lock = Lock::new(Rc::clone(&tm));
+        let mut machine = Machine::init_machine();
+        let mut tm = ThreadManager::new();
+        
+        tm.ready_to_run(Rc::clone(&thread1));
+        tm.ready_to_run(Rc::clone(&thread2));
+
+        tm.set_g_current_thread(Some(Rc::clone(&thread1)));
+        let mut lock = Lock::new();
 
         assert!(lock.free);
-        lock.acquire(Some(Rc::clone(&thread1)), Rc::clone(&system));
-        assert!(lock.held_by_current_thread(Rc::clone(&thread1)));
+        lock.acquire(&mut machine, &mut tm);
+        assert!(lock.held_by_current_thread(&mut tm));
         assert!(!lock.free);
 
-        tm.borrow_mut().set_g_current_thread(Some(Rc::clone(&thread2)));
-        lock.acquire(Some(Rc::clone(&thread2)), Rc::clone(&system));
-        tm.borrow_mut().set_g_current_thread(Some(Rc::clone(&thread1)));
-
+        tm.set_g_current_thread(Some(Rc::clone(&thread2)));
+        lock.acquire(&mut machine, &mut tm);
         
-        assert!(lock.held_by_current_thread(Rc::clone(&thread1)));
+        
+        tm.set_g_current_thread(Some(Rc::clone(&thread1)));
+        assert!(lock.held_by_current_thread(&mut tm));
         assert!(lock.waiting_queue.iter().count() == 1);
         assert!(!lock.free);
 
-        lock.release(Rc::clone(&system), Rc::clone(&thread1));
-        assert!(!lock.held_by_current_thread(thread1));
-        assert!(lock.held_by_current_thread(Rc::clone(&thread2)));
+        lock.release(&mut machine, &mut tm);
+        assert!(!lock.held_by_current_thread(&mut tm));
+        
+        tm.set_g_current_thread(Some(Rc::clone(&thread2)));
+        assert!(lock.held_by_current_thread(&mut tm));
         assert!(!lock.free);
 
-        tm.borrow_mut().set_g_current_thread(Some(Rc::clone(&thread2)));
-
-
-        lock.release(Rc::clone(&system), Rc::clone(&thread2));
-        assert!(!lock.held_by_current_thread(thread2));
+        lock.release(&mut machine, &mut tm);
+        assert!(!lock.held_by_current_thread(&mut tm));
         assert!(lock.free);
     }
 }
\ No newline at end of file
diff --git a/src/kernel/system.rs b/src/kernel/system.rs
index c7748e7..5bda557 100644
--- a/src/kernel/system.rs
+++ b/src/kernel/system.rs
@@ -2,11 +2,9 @@
 //! 
 //! Module containing structs and methods pertaining to the state of the operating system
 
-use std::{cell::RefCell, rc::Rc};
-
 use crate::simulator::machine::Machine;
 
-use super::thread_manager::ThreadManager;
+use super::{thread_manager::ThreadManager};
 
 /// This macro properly initializes the system
 #[macro_export]
@@ -16,10 +14,7 @@ macro_rules! init_system {
         init_system!(m)
     }};
     ($a:expr) => {{
-        let sys = std::rc::Rc::new(std::cell::RefCell::new(crate::System::new($a)));
-        crate::System::freeze(std::rc::Rc::clone(&sys));
-        sys
-
+        $crate::System::new($a)
     }};
 }
 
@@ -35,8 +30,8 @@ macro_rules! init_system {
 /// - The scheduler which acts upon these threads
 #[derive(PartialEq)]
 pub struct System {
-    g_machine: RefCell<Machine>,
-    thread_manager: Rc<RefCell<ThreadManager>>
+    machine: Machine,
+    thread_manager: ThreadManager
 }
 
 impl System {
@@ -44,37 +39,29 @@ impl System {
     /// System constructor
     pub fn new(machine: Machine) -> System {
         Self {
-            g_machine: RefCell::new(machine),
-            thread_manager: Rc::new(RefCell::new(ThreadManager::new()))
+            machine,
+            thread_manager: ThreadManager::new()
         }
     }
 
-    /// use thread_manager setter to send it system instance
-    pub fn freeze(this: Rc<RefCell<System>>) {
-        let copy = Rc::clone(&this);
-        let tm = &this.borrow_mut().thread_manager;
-        tm.borrow_mut().system = Option::Some(copy);
-        ThreadManager::freeze(tm);
-    }
-
     // GETTERS
 
     /// Returns the Machine
     /// 
     /// Useful to access RAM, devices, ...
-    pub fn get_g_machine(&self) -> &RefCell<Machine> {
-        &self.g_machine
+    pub fn get_machine(&mut self) -> &mut Machine {
+        &mut self.machine
     }
 
-    pub fn get_thread_manager(&self) -> Rc<RefCell<ThreadManager>> {
-        Rc::clone(&self.thread_manager)
+    pub fn get_thread_manager(&mut self) -> &mut ThreadManager {
+        &mut self.thread_manager
     }
 
     // Setters
 
-    /// Assign a machine to the system
-    pub fn set_g_machine(&mut self, machine: RefCell<Machine>) {
-        self.g_machine = machine
+    /// Assign a machine to the system 
+    pub fn set_machine(&mut self, machine: Machine) {
+        self.machine = machine
     }
 
 }
@@ -92,7 +79,7 @@ pub enum ObjectType {
 #[cfg(test)]
 mod tests {
 
-    use crate::{System, Machine};
+    use crate::Machine;
 
     #[test]
     fn test_init_system() {
diff --git a/src/kernel/thread_manager.rs b/src/kernel/thread_manager.rs
index 43e9776..f5368cf 100644
--- a/src/kernel/thread_manager.rs
+++ b/src/kernel/thread_manager.rs
@@ -1,8 +1,8 @@
-use std::{rc::Rc, cell::{RefCell, RefMut, Ref}};
+use std::{rc::Rc, cell::{RefCell, Ref}};
 
-use crate::{utility::list::List, simulator::{machine::{NUM_INT_REGS, NUM_FP_REGS}, interrupt::InterruptStatus}};
+use crate::{utility::list::List, simulator::{machine::{NUM_INT_REGS, NUM_FP_REGS, Machine}, interrupt::InterruptStatus}};
 
-use super::{scheduler::Scheduler, thread::Thread, system::System, mgerror::ErrorCode, process::Process};
+use super::{thread::Thread, mgerror::ErrorCode, process::Process};
 
 pub const SIMULATORSTACKSIZE: usize = 32 * 1024;
 
@@ -17,10 +17,8 @@ pub struct ThreadManager {
     pub g_thread_to_be_destroyed: Option<Rc<RefCell<Thread>>>,
     /// The list of alive threads
     pub g_alive: List<Rc<RefCell<Thread>>>,
-    /// The thread scheduler
-    pub g_scheduler: Scheduler,
-    /// The system owning the thread manager
-    pub system: Option<Rc<RefCell<System>>>
+    /// Thread in ready state waiting to become active
+    ready_list: List<Rc<RefCell<Thread>>>,
 }
 
 impl ThreadManager {
@@ -30,15 +28,59 @@ impl ThreadManager {
         Self { 
             g_current_thread: Option::None, 
             g_thread_to_be_destroyed: Option::None, 
-            g_alive: List::new(),
-            g_scheduler: Scheduler::new(), 
-            system: Option::None
+            g_alive: List::default(),
+            ready_list: List::default(),
         }
     }
 
-    pub fn freeze(this: &Rc<RefCell<ThreadManager>>) {
-        let copy = Rc::clone(this);
-        this.borrow_mut().g_scheduler.thread_manager = Option::Some(copy);
+    /// Mark a thread as aready, but not necessarily running yet.
+    /// 
+    /// Put it in the ready list, for later scheduling onto the CPU.
+    /// 
+    /// ## Pamameter
+    /// 
+    /// **thread** is the thread to be put on the read list
+    pub fn ready_to_run(&mut self, thread: Rc<RefCell<Thread>>) {
+        self.ready_list.push(thread);
+    }
+
+    /// Return the next thread to be scheduled onto the CPU.
+    /// If there are no ready threads, return Option::None
+    /// 
+    /// 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>>> {
+        self.ready_list.pop()
+    }
+
+    /// Dispatch the CPU to next_thread. Save the state of the old thread 
+    /// and load the state of the new thread.
+    /// 
+    /// We assume the state of the previously running thread has already been changed from running to blocked or ready.
+    /// 
+    /// Global variable g_current_thread become next_thread
+    /// 
+    /// ## Parameter
+    /// 
+    /// **next_thread** thread to dispatch to the CPU
+    pub fn switch_to(&mut self, machine: &mut Machine, next_thread: Rc<RefCell<Thread>>) {
+        match self.get_g_current_thread() {
+            Some(old) => {
+                let old1 = Rc::clone(old);
+                let old2 = Rc::clone(old);
+                self.thread_save_processor_state(machine, old1);
+                // old_thread.save_simulator_state();
+                if old2 != next_thread {
+                    self.thread_restore_processor_state(machine, Rc::clone(&next_thread));
+                    // next_thread.restore_simulator_state();
+                    self.set_g_current_thread(Some(next_thread));
+                }
+            },
+            None => {
+
+            }
+        }
     }
 
     /// Start a thread, attaching it to a process
@@ -52,111 +94,84 @@ impl ThreadManager {
         thread_m.init_simulator_context(base_stack_addr);
         thread_m.process.as_mut().unwrap().num_thread += 1;
         self.get_g_alive().push(Rc::clone(&thread));
-        self.g_scheduler.ready_to_run(Rc::clone(&thread));
+        self.ready_to_run(Rc::clone(&thread));
         Result::Ok(())
     }
 
     /// Wait for another thread to finish its execution
-    pub fn thread_join(&mut self, id_thread: Rc<RefCell<Thread>>) {
+    pub fn thread_join(&mut self, machine: &mut Machine, id_thread: Rc<RefCell<Thread>>) {
         while self.get_g_alive().contains(&Rc::clone(&id_thread)) {
-            self.thread_yield(Rc::clone(&id_thread));
+            self.thread_yield(machine, Rc::clone(&id_thread));
         }
     }
 
     /// 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, thread: Rc<RefCell<Thread>>) {
-        if let Some(system) = &self.system {
-            let sys = system.borrow_mut();
-            let mut machine = sys.get_g_machine().borrow_mut();
-            let old_status = machine.interrupt.set_status(crate::simulator::interrupt::InterruptStatus::InterruptOff);
+    pub fn thread_yield(&mut self, machine: &mut Machine, thread: Rc<RefCell<Thread>>) {
+        let old_status = machine.interrupt.set_status(crate::simulator::interrupt::InterruptStatus::InterruptOff);
             
-            assert_eq!(Option::Some(Rc::clone(&thread)), self.g_current_thread);
-            let next_thread = self.g_scheduler.find_next_to_run();
-            if let Some(next_thread) = next_thread {
-                let scheduler = &mut self.g_scheduler;
-                scheduler.ready_to_run(thread);
-                scheduler.switch_to(next_thread);
-            }
-            machine.interrupt.set_status(old_status);
+        assert_eq!(Option::Some(Rc::clone(&thread)), self.g_current_thread);
+        let next_thread = self.find_next_to_run();
+        if let Some(next_thread) = next_thread {
+            self.ready_to_run(thread);
+            self.switch_to(machine, next_thread);
         }
+        machine.interrupt.set_status(old_status);    
     }
 
     /// Put the thread to sleep and relinquish the processor
-    pub fn thread_sleep(&mut self, thread: Rc<RefCell<Thread>>) {
-        
+    pub fn thread_sleep(&mut self, machine: &mut Machine, thread: Rc<RefCell<Thread>>) {
         assert_eq!(Option::Some(Rc::clone(&thread)), self.g_current_thread);
-        if let Some(system) = &self.system {
-            let sys = system.borrow_mut();
-            let machine = sys.get_g_machine().borrow_mut();
-            assert_eq!(machine.interrupt.get_status(), InterruptStatus::InterruptOff);
+        assert_eq!(machine.interrupt.get_status(), InterruptStatus::InterruptOff);
 
-            let mut next_thread = self.g_scheduler.find_next_to_run();
-            while next_thread.is_none() {
-                eprintln!("Nobody to run => idle");
-                machine.interrupt.idle();
-                next_thread = self.g_scheduler.find_next_to_run();
-            }
-            self.g_scheduler.switch_to(Rc::clone(&next_thread.unwrap()));
-            
+        let mut next_thread = self.find_next_to_run();
+        while next_thread.is_none() {
+            eprintln!("Nobody to run => idle");
+            machine.interrupt.idle();
+            next_thread = self.find_next_to_run();
         }
+        self.switch_to(machine, Rc::clone(&next_thread.unwrap()));
+        
     }
 
     /// Finish the execution of the thread and prepare its deallocation
-    pub fn thread_finish(&mut self, thread: Rc<RefCell<Thread>>) {
-        if let Some(system) = &self.system {
-            let sys = Rc::clone(system);
-            let sys = sys.borrow_mut();
-            let mut machine = sys.get_g_machine().borrow_mut();
-            let old_status = machine.interrupt.set_status(InterruptStatus::InterruptOff);
-            self.g_thread_to_be_destroyed = Option::Some(Rc::clone(&thread));
-            self.g_alive.remove(Rc::clone(&thread));
-            // g_objets_addrs->removeObject(self.thread) // a ajouté plus tard
-            self.thread_sleep(Rc::clone(&thread));
-            machine.interrupt.set_status(old_status);
+    pub fn thread_finish(&mut self, machine: &mut Machine, thread: Rc<RefCell<Thread>>) {
+        let old_status = machine.interrupt.set_status(InterruptStatus::InterruptOff);
+        self.g_thread_to_be_destroyed = Option::Some(Rc::clone(&thread));
+        self.g_alive.remove(Rc::clone(&thread));
+        // g_objets_addrs->removeObject(self.thread) // a ajouté plus tard
+        self.thread_sleep(machine, Rc::clone(&thread));
+        machine.interrupt.set_status(old_status);
+    }
+
+    pub fn thread_save_processor_state(&mut self, machine: &mut Machine, thread: Rc<RefCell<Thread>>) {
+        let mut t = thread.borrow_mut();
+        for i in 0..NUM_INT_REGS {
+            t.thread_context.int_registers[i] = machine.read_int_register(i);
+        }
+        for i in 0..NUM_FP_REGS {
+            t.thread_context.float_registers[i] = machine.read_fp_register(i);
         }
     }
 
-    pub fn thread_save_processor_state(&mut self, thread: Rc<RefCell<Thread>>) {
-        if let Some(system) = &self.system {
-            let mut t: RefMut<_> = thread.borrow_mut();
-            let system = system.borrow_mut();
-            for i in 0..NUM_INT_REGS {
-                t.thread_context.int_registers[i] = system.get_g_machine().borrow().read_int_register(i);
-            }
-            for i in 0..NUM_FP_REGS {
-                t.thread_context.float_registers[i] = system.get_g_machine().borrow().read_fp_register(i);
-            }
-        } else {
-            unreachable!("System is None")
-        }
-    }
-
-    pub fn thread_restore_processor_state(&self, thread: Rc<RefCell<Thread>>) {
-        if let Some(system) = &self.system {
-            let system = system.borrow_mut();
-            let t: Ref<_> = thread.borrow();
-            for i in 0..NUM_INT_REGS {
-                let machine = system.get_g_machine();
-                let mut machine = machine.borrow_mut();
-                machine.write_int_register(i, t.thread_context.int_registers[i]);
-            }
-        } else {
-            unreachable!("System is None")
+    pub fn thread_restore_processor_state(&self, machine: &mut Machine, thread: Rc<RefCell<Thread>>) {
+        let t: Ref<_> = thread.borrow();
+        for i in 0..NUM_INT_REGS {
+            machine.write_int_register(i, t.thread_context.int_registers[i]);
         }
     }
 
     /// Currently running thread
-    pub fn get_g_current_thread(&mut self) -> &mut Option<Rc<RefCell<Thread>>> {
-        &mut self.g_current_thread
+    pub fn get_g_current_thread(&mut self) -> &Option<Rc<RefCell<Thread>>> {
+        &self.g_current_thread
     }
 
     /// Thread to be destroyed by [...]
     /// 
     /// TODO: Finish the comment with the relevant value
-    pub fn get_g_thread_to_be_destroyed(&mut self) -> &mut Option<Rc<RefCell<Thread>>> {
-        &mut self.g_thread_to_be_destroyed
+    pub fn get_g_thread_to_be_destroyed(&mut self) -> &Option<Rc<RefCell<Thread>>> {
+        &self.g_thread_to_be_destroyed
     }
 
     /// List of alive threads
diff --git a/src/main.rs b/src/main.rs
index e556b8e..b35b860 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -21,6 +21,4 @@ use simulator::machine::Machine;
 fn main() {
     let machine = Machine::init_machine();
     let system = Rc::new(RefCell::new(System::new(machine)));
-
-    System::freeze(system);
 }
diff --git a/src/utility/list.rs b/src/utility/list.rs
index bfb3207..801a74e 100644
--- a/src/utility/list.rs
+++ b/src/utility/list.rs
@@ -1,62 +1,88 @@
 //! Data structure and definition of a genericsingle-linked LIFO list.
 
+use std::ptr;
+
 #[derive(PartialEq)]
 pub struct List<T: PartialEq> {
     head: Link<T>,
+    tail: *mut Node<T>,
 }
 
+type Link<T> = *mut Node<T>;
 
-type Link<T> = Option<Box<Node<T>>>;
 
 #[derive(PartialEq)]
 struct Node<T> {
     elem: T,
     next: Link<T>,
 }
+/// Iterator structure for use in a for loop, pop elements before returning it
+pub struct IntoIter<T: PartialEq>(List<T>);
+
+/// Iterator structure for use in a for loop, dereference before returning it 
+pub struct Iter<'a, T> {
+    next: Option<&'a Node<T>>,
+}
+
+/// Same as Iter structure, returned item are mutable
+pub struct IterMut<'a, T> {
+    next: Option<&'a mut Node<T>>,
+}
 
 impl<T: PartialEq> List<T> {
 
-    /// Create an empty list
-    pub fn new() -> Self {
-        List { head: None }
-    }
-
     /// Push an item at the end of the list
     pub fn push(&mut self, elem: T) {
-        let new_node = Box::new(Node {
-            elem: elem,
-            next: self.head.take(),
-        });
+        unsafe {
+            let new_tail = Box::into_raw(Box::new(Node {
+                elem,
+                next: ptr::null_mut(),
+            }));
 
-        self.head = Some(new_node);
+            if !self.tail.is_null() {
+                (*self.tail).next = new_tail;
+            } else {
+                self.head = new_tail;
+            }
+
+            self.tail = new_tail;
+        }
     }
 
-    /// Retrieve and remove the item at the end of the list.
+    /// Retrieve and remove the item at the head of the list.
     /// 
     /// Return None if list is empty
     pub fn pop(&mut self) -> Option<T> {
-        self.head.take().map(|node| {
-            self.head = node.next;
-            node.elem
-        })
+        unsafe {
+            if self.head.is_null() {
+                None
+            } else {
+                let head = Box::from_raw(self.head);
+                self.head = head.next;
+                if self.head.is_null() {
+                    self.tail = ptr::null_mut();
+                }
+                Some(head.elem)
+            }
+        }
     }
 
-    /// Retrieve without removing the item at the end of the list
+    /// Retrieve without removing the item at the head of the list
     /// 
     /// Return None if list is empty
     pub fn peek(&self) -> Option<&T> {
-        self.head.as_ref().map(|node| {
-            &node.elem
-        })
+        unsafe {
+            self.head.as_ref().map(|node| &node.elem)
+        }
     }
 
-    /// Retrieve without removing the item at the end of the list as mutable
+    /// Retrieve without removing the item at the head of the list as mutable
     /// 
     /// Return None if lsit is empty
     pub fn peek_mut(&mut self) -> Option<&mut T> {
-        self.head.as_mut().map(|node| {
-            &mut node.elem
-        })
+        unsafe {
+            self.head.as_mut().map(|node| &mut node.elem)
+        }
     }
 
     /// Search for an element in the list
@@ -66,10 +92,12 @@ impl<T: PartialEq> List<T> {
     /// Worst case complexity of this function is O(n)
     pub fn contains(&self, elem: &T) -> bool {
         let mut iter = self.iter();
-        let element = iter.next();
+        let mut element = iter.next();
         while element.is_some() {
             if element.unwrap() == elem {
                 return true;
+            } else {
+                element = iter.next();
             }
         }
         false
@@ -81,26 +109,26 @@ impl<T: PartialEq> List<T> {
     /// 
     /// Worst-case complexity is O(n)
     pub fn remove(&mut self, item: T)-> bool {
-        let mut found = false;
-        let mut tmp_list: List<T> = List::new();
-        while !self.is_empty() {
-            let current = self.pop().unwrap();
-            if current != item {
-                tmp_list.push(current);
-            } else {
-                found = true;
-                break;
+        unsafe {
+            let mut current: *mut Node<T> = self.head;
+            let mut previous: *mut Node<T> = ptr::null_mut();
+            while !current.is_null() {
+                if (*current).elem == item {
+                    (*previous).next = (*current).next;
+                    drop(Box::from_raw(current).elem);
+                    return true;
+                } else {
+                    previous = current;
+                    current = (*current).next;
+                }
             }
         }
-        while !tmp_list.is_empty() {
-            self.push(tmp_list.pop().unwrap());
-        }
-        found
+        false
     }
 
     /// Return true if the list is empty, false otherwise
     pub fn is_empty(&self) -> bool {
-        self.head.is_none()
+        self.head.is_null()
     }
 
     /// Turn the list into an iterator for use in a for loop per example.
@@ -114,27 +142,34 @@ impl<T: PartialEq> List<T> {
     /// 
     /// When you iter using this method, elements are dereferenced
     pub fn iter(&self) -> Iter<'_, T> {
-        Iter { next: self.head.as_deref() }
+        unsafe {
+            Iter { next: self.head.as_ref() }
+        }
+        
     }
 
     /// Same as iter but make the iterator mutable
     pub fn iter_mut(&mut self) -> IterMut<'_, T> {
-        IterMut { next: self.head.as_deref_mut() }
+        unsafe {
+            IterMut { next: self.head.as_mut() }
+        }
+        
+    }
+}
+
+impl<T: PartialEq> Default for List<T> {
+    /// Create an empty list
+    fn default() -> Self {
+        Self { head: ptr::null_mut(), tail: ptr::null_mut() }
     }
 }
 
 impl<T: PartialEq> Drop for List<T> {
     fn drop(&mut self) {
-        let mut cur_link = self.head.take();
-        while let Some(mut boxed_node) = cur_link {
-            cur_link = boxed_node.next.take();
-        }
+        while self.pop().is_some() {} // removing every item from list (necessary as we using unsafe function)
     }
 }
 
-/// Iterator structure for use in a for loop, pop elements before returning it
-pub struct IntoIter<T: PartialEq>(List<T>);
-
 impl<T: PartialEq> Iterator for IntoIter<T> {
     type Item = T;
     fn next(&mut self) -> Option<Self::Item> {
@@ -143,34 +178,31 @@ impl<T: PartialEq> Iterator for IntoIter<T> {
     }
 }
 
-/// Iterator structure for use in a for loop, dereference before returning it 
-pub struct Iter<'a, T> {
-    next: Option<&'a Node<T>>,
-}
 
 impl<'a, T> Iterator for Iter<'a, T> {
     type Item = &'a T;
-    fn next(&mut self) -> Option<Self::Item> {
-        self.next.map(|node| {
-            self.next = node.next.as_deref();
-            &node.elem
-        })
-    }
-}
 
-/// Same as Iter structure, returned item are mutable
-pub struct IterMut<'a, T> {
-    next: Option<&'a mut Node<T>>,
+    fn next(&mut self) -> Option<Self::Item> {
+        unsafe {
+            self.next.map(|node| {
+                self.next = node.next.as_ref();
+                &node.elem
+            })
+        }
+    }
 }
 
 impl<'a, T> Iterator for IterMut<'a, T> {
     type Item = &'a mut T;
 
     fn next(&mut self) -> Option<Self::Item> {
-        self.next.take().map(|node| {
-            self.next = node.next.as_deref_mut();
-            &mut node.elem
-        })
+        unsafe {
+            self.next.take().map(|node| {
+                self.next = node.next.as_mut();
+                &mut node.elem
+            })
+        }
+        
     }
 }
 
@@ -180,7 +212,7 @@ mod test {
 
     #[test]
     fn basics() {
-        let mut list = List::new();
+        let mut list = List::default();
 
         // Check empty list behaves right
         assert_eq!(list.pop(), None);
@@ -191,7 +223,7 @@ mod test {
         list.push(3);
 
         // Check normal removal
-        assert_eq!(list.pop(), Some(3));
+        assert_eq!(list.pop(), Some(1));
         assert_eq!(list.pop(), Some(2));
 
         // Push some more just to make sure nothing's corrupted
@@ -199,63 +231,128 @@ mod test {
         list.push(5);
 
         // Check normal removal
-        assert_eq!(list.pop(), Some(5));
+        assert_eq!(list.pop(), Some(3));
         assert_eq!(list.pop(), Some(4));
 
         // Check exhaustion
-        assert_eq!(list.pop(), Some(1));
+        assert_eq!(list.pop(), Some(5));
         assert_eq!(list.pop(), None);
     }
 
     #[test]
     fn peek() {
-        let mut list = List::new();
+        let mut list = List::default();
         assert_eq!(list.peek(), None);
         assert_eq!(list.peek_mut(), None);
-        list.push(1); list.push(2); list.push(3);
+        list.push(1); 
+        list.push(2); 
+        list.push(3);
 
-        assert_eq!(list.peek(), Some(&3));
-        assert_eq!(list.peek_mut(), Some(&mut 3));
-
-        list.peek_mut().map(|value| {
-            *value = 42
-        });
-
-        assert_eq!(list.peek(), Some(&42));
-        assert_eq!(list.pop(), Some(42));
+        assert_eq!(list.peek(), Some(&1));
+        assert_eq!(list.peek_mut(), Some(&mut 1));
     }
 
     #[test]
     fn into_iter() {
-        let mut list = List::new();
-        list.push(1); list.push(2); list.push(3);
+        let mut list = List::default();
+        list.push(1);
+        list.push(2);
+        list.push(3);
 
         let mut iter = list.into_iter();
-        assert_eq!(iter.next(), Some(3));
-        assert_eq!(iter.next(), Some(2));
         assert_eq!(iter.next(), Some(1));
+        assert_eq!(iter.next(), Some(2));
+        assert_eq!(iter.next(), Some(3));
         assert_eq!(iter.next(), None);
     }
 
     #[test]
     fn iter() {
-        let mut list = List::new();
-        list.push(1); list.push(2); list.push(3);
+        let mut list = List::default();
+        list.push(1);
+        list.push(2);
+        list.push(3);
 
         let mut iter = list.iter();
-        assert_eq!(iter.next(), Some(&3));
-        assert_eq!(iter.next(), Some(&2));
         assert_eq!(iter.next(), Some(&1));
+        assert_eq!(iter.next(), Some(&2));
+        assert_eq!(iter.next(), Some(&3));
     }
 
     #[test]
     fn iter_mut() {
-        let mut list = List::new();
-        list.push(1); list.push(2); list.push(3);
+        let mut list = List::default();
+        list.push(1);
+        list.push(2);
+        list.push(3);
 
         let mut iter = list.iter_mut();
-        assert_eq!(iter.next(), Some(&mut 3));
-        assert_eq!(iter.next(), Some(&mut 2));
         assert_eq!(iter.next(), Some(&mut 1));
+        assert_eq!(iter.next(), Some(&mut 2));
+        assert_eq!(iter.next(), Some(&mut 3));
+    }
+
+    #[test]
+    fn contains_test() {
+        let mut list = List::default();
+        assert_eq!(list.peek(), None);
+        list.push(1);
+        list.push(2);
+        list.push(3);
+
+        assert_eq!(list.contains(&1), true);
+        assert_eq!(list.contains(&4), false);
+    }
+
+    #[test]
+    fn remove_test() {
+        let mut list = List::default();
+        assert_eq!(list.peek(), None);
+        list.push(1);
+        list.push(2);
+        list.push(3);
+
+        assert_eq!(list.contains(&2), true);
+        list.remove(2);
+        assert_eq!(list.contains(&2), false);
+        assert_eq!(list.pop(), Option::Some(1));
+        assert_eq!(list.pop(), Option::Some(3));
+        assert_eq!(list.peek(), Option::None);
+    }
+
+    #[test]
+    fn miri_test() {
+        let mut list = List::default();
+
+        list.push(1);
+        list.push(2);
+        list.push(3);
+
+        assert!(list.pop() == Some(1));
+        list.push(4);
+        assert!(list.pop() == Some(2));
+        list.push(5);
+
+        assert!(list.peek() == Some(&3));
+        list.push(6);
+        list.peek_mut().map(|x| *x *= 10);
+        assert!(list.peek() == Some(&30));
+        assert!(list.pop() == Some(30));
+
+        for elem in list.iter_mut() {
+            *elem *= 100;
+        }
+
+        let mut iter = list.iter();
+        assert_eq!(iter.next(), Some(&400));
+        assert_eq!(iter.next(), Some(&500));
+        assert_eq!(iter.next(), Some(&600));
+        assert_eq!(iter.next(), None);
+        assert_eq!(iter.next(), None);
+
+        assert!(list.pop() == Some(400));
+        list.peek_mut().map(|x| *x *= 10);
+        assert!(list.peek() == Some(&5000));
+        list.push(7);
     }
 }
\ No newline at end of file