services/kernel_state.h

   1 /* Quarn OS
   2  *
   3  * Kernel state controller
   4  *
   5  * Copyright (C) 2008-2009 Pawel Dziepak
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License along
  18  * with this program; if not, write to the Free Software Foundation, Inc.,
  19  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  */
  22
  23 /* Interface for kernel state controller. Manes has to inform instance of this
  24  * class when any change of the kernel state happens. Functions that want to
  25  * monitor changes has to be hardcoded into set_state() procedure.
  26  */
  27
  28 #ifndef _KERNEL_STATE_H_
  29 #define _KERNEL_STATE_H_
  30
  31 #include "manes/cds/component.h"
  32
  33 #include "libs/list.h"
  34 #include "libs/delegate.h"
  35
  36 namespace manes {
  37 class error;
  38 }
  39
  40 namespace services {
  41
  42         /**
  43          * All information about current kernel state
  44          * This class stores all information about current kernel state that
  45          * might be useful for other parts of the kernel. This information
  46          * should be transported by Manes. This class does not support
  47          * multiprocessors machines.
  48          */
  49         class kernel_state : public manes::cds::component {
  50         public:
  51                 /** Types of execution environment */
  52                 typedef enum {
  53                         starting, /**< kernel is launching */
  54                         kernel, /**< cpu operates in kernel mode */
  55                         user, /**< cpu operates in user mode */
  56                         iowait, /**< cpu waits for hardware */
  57                         frozen, /**< cpu waits for any action */
  58                         halting /**< system is being halted */
  59                 } state;
  60
  61         private:
  62                 /**
  63                  * Current execution environment
  64                  * This variable stores information about current state of the
  65                  * kernel and cpu.
  66                  */
  67                 state _state;
  68
  69                 /**
  70                  * Time count
  71                  * Number of pit ticks since starting Quarn OS.
  72                  */
  73                 int time;
  74
  75                 /**
  76                  * Timers methods
  77                  * Delegates that have to be called on each pit tick.
  78                  */
  79                 list<delegate<void> > time_tick_call;
  80
  81         public:
  82                 kernel_state();
  83
  84                 virtual void add_time_tick_call(delegate<void>);
  85                 virtual void del_time_tick_call(delegate<void>);
  86                 virtual void increase_time();
  87                 virtual int get_time() const;
  88
  89                 virtual bool set_state(state new_state);
  90                 virtual state get_state() const;
  91
  92                 virtual unsigned int get_memory_size() const;
  93
  94                 virtual manes::error *new_error(const char *x);
  95
  96                 static void register_type();
  97         };
  98 }
  99
 100 #endif