From 05aff1311879fc07b1067c773dc66486d17b937c Mon Sep 17 00:00:00 2001
From: Braiden Vasco <braiden-vasco@users.noreply.github.com>
Date: Mon, 6 Nov 2017 12:06:28 +0000
Subject: [PATCH] Add function "hwint_unregister_handler"

---
 arch/hwint.c | 11 ++++++++++-
 arch/hwint.h |  1 +
 arch/main.c  | 16 +++++++++++-----
 arch/timer.c |  5 +++++
 arch/timer.h |  1 +
 5 files changed, 28 insertions(+), 6 deletions(-)

diff --git a/arch/hwint.c b/arch/hwint.c
index 4dbb5f3..d0edca6 100644
--- a/arch/hwint.c
+++ b/arch/hwint.c
@@ -52,6 +52,15 @@ void hwint_register_handler(unsigned int int_no, hwint_handler_t handler)
     }
 
     handlers[int_no] = handler;
-
     pic_enable(int_no);
 }
+
+void hwint_unregister_handler(unsigned int int_no)
+{
+    if (int_no >= INT_HWINT_COUNT) {
+        return;
+    }
+
+    pic_disable(int_no);
+    handlers[int_no] = 0;
+}
diff --git a/arch/hwint.h b/arch/hwint.h
index ee02f65..0443c18 100644
--- a/arch/hwint.h
+++ b/arch/hwint.h
@@ -4,5 +4,6 @@
 typedef void(*hwint_handler_t)();
 
 void hwint_register_handler(unsigned int int_no, hwint_handler_t handler);
+void hwint_unregister_handler(unsigned int int_no);
 
 #endif
diff --git a/arch/main.c b/arch/main.c
index 9968f2a..b0654f5 100644
--- a/arch/main.c
+++ b/arch/main.c
@@ -14,7 +14,8 @@ static struct KernelMQ_Info kinfo;
 
 #define TIMER_FREQ 50
 
-static unsigned long ticks = 0;
+static unsigned char timer_enabled = 1;
+static unsigned long timer_ticks = 0;
 
 static void on_timer();
 
@@ -79,7 +80,7 @@ void main(const struct KernelMQ_Info *const kinfo_ptr)
     timer_initialize(TIMER_FREQ);
     timer_register_handler(on_timer);
 
-    while (ticks < TIMER_FREQ * 3) {}
+    while (timer_enabled) {}
 
     for (unsigned int i = 0; i < kinfo.modules_count; ++i) {
         tasks_switch_to_user(kinfo.modules[i].base);
@@ -91,9 +92,14 @@ void main(const struct KernelMQ_Info *const kinfo_ptr)
 
 void on_timer()
 {
-    if (ticks % TIMER_FREQ == 0) {
-        logger_info_from("main", "Timer tick %u.", ticks);
+    if (timer_ticks % TIMER_FREQ == 0) {
+        logger_info_from("main", "Timer tick %u.", timer_ticks);
+
+        if (timer_ticks >= TIMER_FREQ * 3) {
+            timer_unregister_handler();
+            timer_enabled = 0;
+        }
     }
 
-    ++ticks;
+    ++timer_ticks;
 }
diff --git a/arch/timer.c b/arch/timer.c
index 19ee05f..d538abb 100644
--- a/arch/timer.c
+++ b/arch/timer.c
@@ -21,3 +21,8 @@ void timer_register_handler(timer_handler_t handler)
 {
     hwint_register_handler(0, handler);
 }
+
+void timer_unregister_handler()
+{
+    hwint_unregister_handler(0);
+}
diff --git a/arch/timer.h b/arch/timer.h
index b1b200f..d7d0992 100644
--- a/arch/timer.h
+++ b/arch/timer.h
@@ -8,5 +8,6 @@ typedef hwint_handler_t timer_handler_t;
 void timer_initialize(unsigned int frequency);
 
 void timer_register_handler(timer_handler_t handler);
+void timer_unregister_handler();
 
 #endif