Bochs/bochs/iodev/virt_timer.h
2006-05-27 15:54:49 +00:00

159 lines
5.1 KiB
C++

////////////////////////////////////////////////////////////////////////
// $Id: virt_timer.h,v 1.11 2006-05-27 15:54:49 sshwarts Exp $
/////////////////////////////////////////////////////////////////////////
//
// Copyright (C) 2002 MandrakeSoft S.A.
//
// MandrakeSoft S.A.
// 43, rue d'Aboukir
// 75002 Paris - France
// http://www.linux-mandrake.com/
// http://www.mandrakesoft.com/
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2 of the License, or (at your option) any later version.
//
// This library 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
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
/////////////////////////////////////////////////////////////////////////
#ifndef _BX_VIRT_TIMER_H
#define _BX_VIRT_TIMER_H
// should be adjusted if want to support more SMP processors
#define BX_MAX_VIRTUAL_TIMERS (32)
#define BX_NULL_VIRTUAL_TIMER_HANDLE 10000
#define BX_MAX_VIRTUAL_TIME (0x7fffffff)
class bx_virt_timer_c : public logfunctions
{
private:
struct {
bx_bool inUse; // Timer slot is in-use (currently registered).
Bit64u period; // Timer periodocity in virtual useconds.
Bit64u timeToFire; // Time to fire next (in virtual useconds).
bx_bool active; // 0=inactive, 1=active.
bx_bool continuous; // 0=one-shot timer, 1=continuous periodicity.
bx_timer_handler_t funct; // A callback function for when the
// timer fires.
// This function MUST return.
void *this_ptr; // The this-> pointer for C++ callbacks
// has to be stored as well.
char id[BxMaxTimerIDLen]; // String ID of timer.
} timer[BX_MAX_VIRTUAL_TIMERS];
unsigned numTimers; // Number of currently allocated timers.
//Variables for the timer subsystem:
Bit64u current_timers_time;
Bit64u timers_next_event_time;
Bit64u last_sequential_time;
bx_bool in_timer_handler;
//Variables for the time sync subsystem:
Bit64u virtual_next_event_time;
Bit64u current_virtual_time;
//Real time variables:
Bit64u last_real_time;
Bit64u total_real_usec;
Bit64u last_realtime_delta;
//System time variables:
Bit64u last_usec;
Bit64u usec_per_second;
Bit64u stored_delta;
Bit64u last_system_usec;
Bit64u em_last_realtime;
//Virtual timer variables:
Bit64u total_ticks;
Bit64u last_realtime_ticks;
Bit64u ticks_per_second;
bx_bool init_done;
int system_timer_id;
//Whether or not to use virtual timers.
bx_bool use_virtual_timers;
bx_bool virtual_timers_realtime;
// A special null timer is always inserted in the timer[0] slot. This
// make sure that at least one timer is always active, and that the
// duration is always less than a maximum 32-bit integer, so a 32-bit
// counter can be used for the current countdown.
static const Bit64u NullTimerInterval;
static void nullTimer(void* this_ptr);
//Step the given number of cycles, optionally calling any timer handlers.
void periodic(Bit64u time_passed);
//Called when next_event_time changes.
void next_event_time_update(void);
//Called to advance the virtual time.
// calls periodic as needed.
void advance_virtual_time(Bit64u time_passed);
public:
bx_virt_timer_c();
virtual ~bx_virt_timer_c() {}
//Get the current virtual time.
// This may return the same value on subsequent calls.
Bit64u time_usec(void);
//Get the current virtual time.
// This will return a monotonically increasing value.
// MUST NOT be called from within a timer handler.
Bit64u time_usec_sequential(void);
//Register a timer handler to go off after a given interval.
//Register a timer handler to go off with a periodic interval.
int register_timer( void *this_ptr, bx_timer_handler_t handler,
Bit32u useconds,
bx_bool continuous, bx_bool active, const char *id);
//unregister a previously registered timer.
bx_bool unregisterTimer(unsigned timerID);
void start_timers(void);
//activate a deactivated but registered timer.
void activate_timer( unsigned timer_index, Bit32u useconds,
bx_bool continuous );
//deactivate (but don't unregister) a currently registered timer.
void deactivate_timer( unsigned timer_index );
//Timer handler passed to pc_system
static void pc_system_timer_handler(void* this_ptr);
//The real timer handler.
void timer_handler();
//Initialization
void init(void);
#if BX_SUPPORT_SAVE_RESTORE
void register_state(void);
#endif
};
extern bx_virt_timer_c bx_virt_timer;
#endif // _BX_VIRT_TIMER_H