sched.h

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// See the end of this file for license information.

#ifndef TORSION_SCHED_H
#define TORSION_SCHED_H

#include "irq.h"
#include "task.h"
#include "list.h"
#include "timer.h"

class Scheduler;
extern Scheduler scheduler;

// TODO: To make the scheduler persistent, the active_tasks list, curr_task
// and the timer callbacks list must all be persistent. What's more, none of
// these lists can contain nodes created from non-persistent memory, because
// otherwise some linked list prev/next pointers within a node will will not
// be persistent. But it doesn't make sense to make all of these nodes
// persistent. For example, the context_switch timer callback can easily be
// recreated on boot, and the floppy driver is not itself persistent, so it
// makes no sense for the motor kill callback to be allocated from persistent
// virtual memory. One solution would be to manually copy individual
// persistent nodes of the pertinent lists into persistent virtual memory
// upon each checkpoint, and then load in these nodes upon boot, adding them
// to the statically created active_tasks/callbacks lists.



class Scheduler {
public:
  List<Task> active_tasks;    
  Task* curr_task;      
  Task kernel_task;     
  Task idle_task;     

  Timer_callback context_switch_callback;
  static const unsigned TIMESLICE_SIZE = 10;

  void
  init();

  void
  create_task(Task_func start_function);

  void
  print();
};

void
context_switch();

void
sleep(unsigned milliseconds);

bool
wakeup(void* task);

void
die();

void
idle_function();

#endif

/* Torsion Operating System, Copyright (C) 2000-2004 Dan Helfman
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation; either version 2 of the License, or (at your
 * option) any later version.
 * 
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details (in the COPYING file).
 * 
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

---

Torsion Operating System, Copyright (C) 2000-2004 Dan Helfman