From 250db2c90f2bb18cf7105f8dbab80894a8595c67 Mon Sep 17 00:00:00 2001
From: apio <blobs.trading@gmail.com>
Date: Mon, 17 Oct 2022 17:14:22 +0200
Subject: [PATCH] Scheduler: add an append_task() function

---
 kernel/include/thread/Scheduler.h |  2 ++
 kernel/src/thread/Scheduler.cpp   | 38 +++++++++++++++++++------------
 2 files changed, 25 insertions(+), 15 deletions(-)

diff --git a/kernel/include/thread/Scheduler.h b/kernel/include/thread/Scheduler.h
index 832dec01..dd5ee1bd 100644
--- a/kernel/include/thread/Scheduler.h
+++ b/kernel/include/thread/Scheduler.h
@@ -27,4 +27,6 @@ namespace Scheduler
     void reap_tasks();
 
     void reset_task(Task* task, ELFImage* new_image);
+
+    void append_task(Task* task);
 }
\ No newline at end of file
diff --git a/kernel/src/thread/Scheduler.cpp b/kernel/src/thread/Scheduler.cpp
index c9d66fdb..b9cc852a 100644
--- a/kernel/src/thread/Scheduler.cpp
+++ b/kernel/src/thread/Scheduler.cpp
@@ -33,6 +33,26 @@ extern "C" void idle_task_function();
 
 static uint64_t frequency;
 
+void Scheduler::append_task(Task* task)
+{
+    if (!base_task)
+    {
+        ASSERT(!end_task);
+        base_task = task;
+        end_task = base_task;
+        task->next_task = task;
+        task->prev_task = task;
+    }
+    else
+    {
+        end_task->next_task = task;
+        task->prev_task = end_task;
+        base_task->prev_task = task;
+        task->next_task = base_task;
+        end_task = task;
+    }
+}
+
 void Scheduler::init()
 {
     memset(&idle_task, 0, sizeof(Task));
@@ -78,11 +98,7 @@ void Scheduler::add_kernel_task(void (*task)(void))
     new_task->task_sleep = 0;
     new_task->task_time = 0;
     new_task->cpu_time = 0;
-    end_task->next_task = new_task;
-    new_task->prev_task = end_task;
-    base_task->prev_task = new_task;
-    new_task->next_task = base_task;
-    end_task = new_task;
+    append_task(new_task);
     new_task->state = new_task->Running;
     task_num++;
     kinfoln("Adding kernel task: starts at %lx, tid %ld, stack at %lx, total tasks: %ld", new_task->regs.rip,
@@ -102,11 +118,7 @@ Task* Scheduler::create_user_task()
     new_task->task_sleep = 0;
     new_task->task_time = 0;
     new_task->cpu_time = 0;
-    end_task->next_task = new_task;
-    new_task->prev_task = end_task;
-    base_task->prev_task = new_task;
-    new_task->next_task = base_task;
-    end_task = new_task;
+    append_task(new_task);
     task_num++;
     return new_task;
 }
@@ -152,11 +164,7 @@ long Scheduler::load_user_task(const char* filename)
     new_task->task_sleep = 0;
     new_task->task_time = 0;
     new_task->cpu_time = 0;
-    end_task->next_task = new_task;
-    new_task->prev_task = end_task;
-    base_task->prev_task = new_task;
-    new_task->next_task = base_task;
-    end_task = new_task;
+    append_task(new_task);
     new_task->state = new_task->Running;
     task_num++;
     kinfoln("Adding user task: loaded at %lx, tid %ld, stack at %lx, total tasks: %ld", new_task->regs.rip,