80 lines
2.8 KiB
C++
80 lines
2.8 KiB
C++
/*****************************************************************************
|
|
* *
|
|
* S C H E D U L E R *
|
|
* *
|
|
*---------------------------------------------------------------------------*
|
|
* Beschreibung: Implementierung eines einfachen Zeitscheiben-Schedulers. *
|
|
* Rechenbereite Threads werden in 'readQueue' verwaltet. *
|
|
* *
|
|
* Autor: Michael, Schoettner, HHU, 22.8.2016 *
|
|
*****************************************************************************/
|
|
|
|
#ifndef __Scheduler_include__
|
|
#define __Scheduler_include__
|
|
|
|
#include "devices/CGA_Stream.h"
|
|
#include "kernel/threads/Dispatch.h"
|
|
#include "kernel/threads/Thread.h"
|
|
#include "lib/Queue.h"
|
|
#include "lib/SpinLock.h"
|
|
#include "user/lib/ArrayList.h"
|
|
#include "user/lib/Logger.h"
|
|
|
|
class Scheduler : public Dispatcher {
|
|
private:
|
|
Scheduler(const Scheduler& copy) = delete; // Verhindere Kopieren
|
|
|
|
// Queue readyQueue; // auf die CPU wartende Threads
|
|
|
|
// Scheduler wird evt. von einer Unterbrechung vom Zeitgeber gerufen,
|
|
// bevor er initialisiert wurde
|
|
bool has_idle_thread;
|
|
|
|
Logger log;
|
|
|
|
// NOTE: I would have to release the lock when switching threads but I don't know exactly how to do this
|
|
// in the assembly function
|
|
// SpinLock lock; // Use spinlock instead of cpu.disable_int() because it still allows preemption
|
|
// // for threads that don't use the scheduler
|
|
|
|
// NOTE: Using this instead of the Queue is a side effect, I added the ArrayList for different reasons
|
|
// but my Queue was shit so I replaced it (and didn't fix the Queue)
|
|
ArrayList<Thread*> ready_queue;
|
|
ArrayList<Thread*> block_queue;
|
|
|
|
public:
|
|
Scheduler() : has_idle_thread(false), log("SCHED") {}
|
|
|
|
// Scheduler initialisiert?
|
|
// Zeitgeber-Unterbrechung kommt evt. bevor der Scheduler fertig
|
|
// intiialisiert wurde!
|
|
bool preemption_enabled() const { return has_idle_thread; }
|
|
|
|
// ruft nur der Idle-Thread (erster Thread der vom Scheduler gestartet wird)
|
|
void enable_preemption() { has_idle_thread = true; }
|
|
|
|
// Scheduler starten
|
|
void schedule();
|
|
|
|
// Thread in readyQueue eintragen
|
|
void ready(Thread* that);
|
|
|
|
// Thread terminiert sich selbst
|
|
void exit();
|
|
|
|
// Thread mit 'Gewalt' terminieren
|
|
void kill(Thread* that);
|
|
void kill(unsigned int id);
|
|
|
|
// CPU freiwillig abgeben und Auswahl des naechsten Threads
|
|
void yield();
|
|
|
|
// Thread umschalten; wird aus der ISR des PITs gerufen
|
|
void preempt();
|
|
|
|
void block();
|
|
void deblock(Thread* that);
|
|
};
|
|
|
|
#endif
|