From 4a5de13d1e68bc241ab507aaedec26330a3f84be Mon Sep 17 00:00:00 2001
From: EDiasAlberto <proxamon1@gmail.com>
Date: Wed, 16 Oct 2024 18:45:28 +0100
Subject: [PATCH] implement recent_cpu calculations on every second

---
 src/devices/timer.c  |  4 ++++
 src/threads/thread.c | 10 +++++++---
 2 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/src/devices/timer.c b/src/devices/timer.c
index 63e15f6..3e481cc 100644
--- a/src/devices/timer.c
+++ b/src/devices/timer.c
@@ -199,6 +199,10 @@ static void
 timer_interrupt (struct intr_frame *args UNUSED)
 {
   ticks++;
+  if (ticks % TIMER_FREQ == 0)
+  {
+    calculate_recent_cpu ();
+  }
   for (struct list_elem *e = list_begin (&sleeping_threads);
        e != list_end (&sleeping_threads); e = list_next (e))
     {
diff --git a/src/threads/thread.c b/src/threads/thread.c
index 47cd5c4..62a8c57 100644
--- a/src/threads/thread.c
+++ b/src/threads/thread.c
@@ -375,11 +375,15 @@ calculate_priority (void)
 	return 0;
 }
 
-fp32_t
+void
 calculate_recent_cpu (void)
 {
-  /* Not yet implemented */
-  return { 0 };
+  struct thread *t = thread_current ();
+  fp32_t curr_recent_cpu = t->recent_cpu;
+  fp32_t curr_load_avg = fp_mul_int(thread_get_load_avg (), 2);
+  fp32_t recent_cpu_coeff = fp_div(curr_load_avg, fp_add_int(curr_load_avg, 1));
+  fp32_t new_recent_cpu = fp_add_int(fp_mul(recent_cpu_coeff, curr_recent_cpu), thread_get_nice ());
+  t->recent_cpu = new_recent_cpu;
 }
 
 void