diff --git a/src/kernel/exception.rs b/src/kernel/exception.rs
index 4a58876..cff65ca 100644
--- a/src/kernel/exception.rs
+++ b/src/kernel/exception.rs
@@ -2,7 +2,7 @@ use std::{cell::RefCell, rc::Rc};
 
 use crate::{simulator::{machine::{ExceptionType, Machine}, error::{MachineOk, MachineError}}};
 
-use super::{system::System, thread::Thread, synch::Semaphore};
+use super::{system::System, thread::Thread};
 
 type Error = String;
 
@@ -200,21 +200,12 @@ fn syscall(machine: &mut Machine, system: &mut System) -> Result<MachineOk, Mach
 
 fn sc_p(machine: &mut Machine, system: &mut System) -> Result<MachineOk, MachineError> {
     let id_sema = machine.int_reg.get_reg(10);
-    match system.get_obj_addrs().search_semaphore(id_sema as i32) {
-        Some(sema) => { sema.p(machine, system.get_thread_manager()); Ok(MachineOk::Ok) }
-        None => Err(format!("Coudn't find semaphore {}", id_sema))?
-    }
+    system.get_thread_manager().sem_p(id_sema as i32, machine)
 }
 
 fn sc_v(machine: &mut Machine, system: &mut System) -> Result<MachineOk, MachineError> {
     let id_sema = machine.int_reg.get_reg(10);
-    match system.get_obj_addrs().search_semaphore(id_sema as i32) {
-        Some(sema) => { 
-            sema.v(machine, system.get_thread_manager()); 
-            Ok(MachineOk::Ok) 
-        },
-        None => Err(format!("Couldn't find semaphore {}", id_sema))?
-    }
+    system.get_thread_manager().sem_v(id_sema as i32, machine)
 }
 
 fn sc_sem_create(machine: &mut Machine) -> Result<MachineOk, MachineError> {
diff --git a/src/kernel/synch.rs b/src/kernel/synch.rs
index f3682f3..e4600ac 100644
--- a/src/kernel/synch.rs
+++ b/src/kernel/synch.rs
@@ -7,12 +7,13 @@ use std::rc::Rc;
 use super::thread_manager::ThreadManager;
 
 ///     Structure of a Semaphore used for synchronisation
+#[derive(PartialEq)]
 pub struct Semaphore {
 
     /// Counter of simultanous Semaphore
-    counter:i32,
+    pub counter:i32,
     /// QUeue of Semaphore waiting to be exucated
-    waiting_queue:List<Rc<RefCell<Thread>>>,
+    pub waiting_queue:List<Rc<RefCell<Thread>>>,
 
 }
 
@@ -78,7 +79,8 @@ impl Semaphore {
 /// Lock used for synchronisation, can be interpreted has a Semaphore with a
 /// counter of 1
 /// It's used for critical parts
-pub struct Lock{
+#[derive(PartialEq)]
+pub struct Lock {
 
     /// Thread owning the lock
     owner: Option<Rc<RefCell<Thread>>>,
diff --git a/src/kernel/system.rs b/src/kernel/system.rs
index 6e30fa2..9305444 100644
--- a/src/kernel/system.rs
+++ b/src/kernel/system.rs
@@ -3,7 +3,6 @@
 //! Module containing structs and methods pertaining to the state of the operating system
 
 use super::{thread_manager::ThreadManager};
-use crate::utility::objaddr::ObjAddr;
 
 /// # System
 /// 
@@ -16,8 +15,7 @@ use crate::utility::objaddr::ObjAddr;
 /// - The thread to be destroyed next
 /// - The scheduler which acts upon these threads
 pub struct System {
-    thread_manager: ThreadManager,
-    obj_addrs: ObjAddr
+    thread_manager: ThreadManager
 }
 
 impl System {
@@ -28,14 +26,12 @@ impl System {
         &mut self.thread_manager
     }
 
-    pub fn get_obj_addrs(&mut self) -> &mut ObjAddr { &mut self.obj_addrs }
-
 }
 
 impl Default for System {
     /// System constructor
     fn default() -> Self {
-        Self { thread_manager: ThreadManager::new(), obj_addrs: ObjAddr::init() }
+        Self { thread_manager: ThreadManager::new() }
     }
 }
 
diff --git a/src/kernel/thread_manager.rs b/src/kernel/thread_manager.rs
index ee0bd86..b388163 100644
--- a/src/kernel/thread_manager.rs
+++ b/src/kernel/thread_manager.rs
@@ -1,8 +1,8 @@
 use std::{rc::Rc, cell::{RefCell, Ref}};
 
-use crate::{utility::list::List, simulator::{machine::{NUM_INT_REGS, NUM_FP_REGS, Machine}, interrupt::InterruptStatus}};
+use crate::{utility::{list::List, objaddr::ObjAddr}, simulator::{machine::{NUM_INT_REGS, NUM_FP_REGS, Machine}, interrupt::InterruptStatus, error::{MachineOk, MachineError}}};
 
-use super::{thread::Thread, process::Process};
+use super::{thread::Thread, process::Process, synch::Semaphore};
 
 pub const SIMULATORSTACKSIZE: usize = 32 * 1024;
 
@@ -19,6 +19,7 @@ pub struct ThreadManager {
     pub g_alive: List<Rc<RefCell<Thread>>>,
     /// Thread in ready state waiting to become active
     ready_list: List<Rc<RefCell<Thread>>>,
+    obj_addrs: ObjAddr
 }
 
 impl ThreadManager {
@@ -30,6 +31,7 @@ impl ThreadManager {
             g_thread_to_be_destroyed: Option::None, 
             g_alive: List::default(),
             ready_list: List::default(),
+            obj_addrs: ObjAddr::init(),
         }
     }
 
@@ -171,6 +173,49 @@ impl ThreadManager {
         machine.pc = t.thread_context.pc;
     }
 
+    pub fn sem_p(&mut self, id_sema: i32, machine: &mut Machine) -> Result<MachineOk, MachineError> {
+        match self.get_g_current_thread() {
+            Some(thread) => {
+                let rc1_thread = Rc::clone(thread);
+                let rc2_thread = Rc::clone(thread);
+                let sema = self.get_obj_addrs().search_semaphore(id_sema as i32);
+                if let Some(sema) = sema {
+                    let old_status = machine.interrupt.set_status(InterruptStatus::InterruptOff);
+                    sema.counter -= 1;
+                    if sema.counter < 0 {
+                        sema.waiting_queue.push(rc1_thread);
+                        self.thread_sleep(machine, rc2_thread);
+                    }
+                    machine.interrupt.set_status(old_status);
+                    Ok(MachineOk::Ok)
+                } else {
+                    Err("Cannot find semaphore")?
+                }
+            },
+            None => unreachable!("Current thread should not be None")
+        }   
+    }
+
+    pub fn sem_v(&mut self, id_sema: i32, machine: &mut Machine) -> Result<MachineOk, MachineError> {
+        let sema = self.get_obj_addrs().search_semaphore(id_sema as i32);
+        match sema {
+            Some(sema) => {
+                let old_status = machine.interrupt.set_status(InterruptStatus::InterruptOff);
+                sema.counter += 1;
+                match sema.waiting_queue.pop() {
+                    Some(thread) => self.ready_to_run(thread),
+                    None => ()
+                }
+                machine.interrupt.set_status(old_status);
+                Ok(MachineOk::Ok)
+            },
+            None => {
+                Err("Cannot find semaphore")?
+            }
+        }
+        
+    }
+
     /// Currently running thread
     pub fn get_g_current_thread(&mut self) -> &Option<Rc<RefCell<Thread>>> {
         &self.g_current_thread
@@ -198,6 +243,10 @@ impl ThreadManager {
         self.g_thread_to_be_destroyed = thread
     }
 
+    pub fn get_obj_addrs(&mut self) -> &mut ObjAddr {
+        &mut self.obj_addrs 
+    }
+
 }
 
 #[cfg(test)]
diff --git a/src/utility/objaddr.rs b/src/utility/objaddr.rs
index c898f63..92769aa 100644
--- a/src/utility/objaddr.rs
+++ b/src/utility/objaddr.rs
@@ -15,6 +15,7 @@ use crate::kernel::synch::{ Semaphore, Lock };
 /// A method allows to detect of an object corresponding to a given
 /// identifier exists; this is used to check the parameters of system
 /// calls.
+#[derive(PartialEq)]
 pub struct ObjAddr {
     last_id: i32,
     semaphores: HashMap<i32, Semaphore>,
@@ -47,12 +48,12 @@ impl ObjAddr {
     }
 
     /// Searches for a semaphore of id **id** in self
-    pub fn search_semaphore(&self, id: i32) -> Option<&mut Semaphore> {
+    pub fn search_semaphore(&mut self, id: i32) -> Option<&mut Semaphore> {
         self.semaphores.get_mut(&id)
     }
 
     /// Searches for a lock of id **id** in self
-    pub fn search_lock(&self, id:i32) -> Option<&mut Lock> {
+    pub fn search_lock(&mut self, id:i32) -> Option<&mut Lock> {
         self.locks.get_mut(&id)
     }