add possibility to ask thread to suicide itself

c_os/kernel/threads/Scheduler.cc

@@ -194,6 +194,34 @@ void Scheduler::kill(unsigned int tid, bse::unique_ptr<Thread>* ptr) {
     cpu.enable_int();
 }
 
+// TODO: Can't retrive the thread right now because it's not clear when it's finished,
+//       maybe introduce a exited_queue and get it from there
+void Scheduler::nice_kill(unsigned int tid, bse::unique_ptr<Thread>* ptr) {
+    cpu.disable_int();
+
+    for (bse::unique_ptr<Thread>& thread : block_queue) {
+        if (thread->tid == tid) {
+            thread->suicide();
+            log << INFO << "Nice killed thread in block_queue with id: " << tid << endl;
+            deblock(tid);
+            cpu.enable_int();
+            return;
+        }
+    }
+
+    for (bse::unique_ptr<Thread>& thread : ready_queue) {
+        if (thread->tid == tid) {
+            thread->suicide();
+            log << INFO << "Nice killed thread in ready_queue with id: " << tid << endl;
+            cpu.enable_int();
+            return;
+        }
+    }
+
+    log << ERROR << "Can't nice kill thread (not found) with id: " << tid << endl;
+    cpu.enable_int();
+}
+
 /*****************************************************************************
  * Methode:         Scheduler::yield                                         *
  *---------------------------------------------------------------------------*

c_os/kernel/threads/Scheduler.h

@@ -90,6 +90,13 @@ public:
     void kill(unsigned int tid, bse::unique_ptr<Thread>* ptr);
     void kill(unsigned int tid) { kill(tid, nullptr); }
 
+    // Ask thread to exit
+    // NOTE: I had many problems with killing threads that were stuck in some semaphore
+    //       or were involved in any locking mechanisms, so with this a thread can make sure
+    //       to "set things right" before exiting itself (but could also be ignored)
+    void nice_kill(unsigned int tid, bse::unique_ptr<Thread>* ptr);
+    void nice_kill(unsigned int tid) { nice_kill(tid, nullptr); }
+
     // CPU freiwillig abgeben und Auswahl des naechsten Threads
     void yield();