From 1f01a561a36caee80202a8d10031a9046083cd46 Mon Sep 17 00:00:00 2001
From: ChUrl <christoph.urlacher@protonmail.com>
Date: Mon, 4 Jul 2022 14:54:25 +0200
Subject: [PATCH] fix scheduling bug when only 1 thread is available

---
 c_os/kernel/threads/Scheduler.cc | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/c_os/kernel/threads/Scheduler.cc b/c_os/kernel/threads/Scheduler.cc
index 35af795..dead80a 100644
--- a/c_os/kernel/threads/Scheduler.cc
+++ b/c_os/kernel/threads/Scheduler.cc
@@ -96,10 +96,12 @@ void Scheduler::yield() {
 
     /* hier muss Code eingefuegt werden */
 
-    // if (this->readyQueue.isEmpty()) {
-    //     // Idle thread running
-    //     return;
-    // }
+    // When only one thread exists (IdleThread) it can't yield as the readyqueue becomes empty
+    // and this is not handled anywhere else
+    if (this->readyQueue.isEmpty()) {
+        // Idle thread running
+        return;
+    }
 
     Thread& next = *(Thread*)this->readyQueue.dequeue();
     this->readyQueue.enqueue(this->get_active());