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New timer code, now avarages time index requests.

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Imported-from: https://svn.code.sf.net/p/dosbox/code-0/dosbox/trunk@262
This commit is contained in:
Sjoerd van der Berg 2002-09-06 20:03:37 +00:00
parent e51de71306
commit 0809de690d
1 changed files with 42 additions and 17 deletions
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59
src/hardware/timer.cpp
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@ -42,11 +42,22 @@ struct PIT_Block {
Bit32u last_ticks;
};
bool TimerAgain;
Bit32u LastTicks;
static PIT_Block pit[3];
static Bit32u pit_ticks; /* The amount of pit ticks one host tick is bit shifted */
static Bit32u timer_ticks; /* The amount of pit ticks bitshifted one timer cycle needs */
static Bit32u timer_buildup; /* The amount of pit ticks waiting */
static Bit32u timer_buildup; /* The amount of pit ticks waiting */
#define TIMER_AVERAGE 5
static struct TimerBlock {
float req[TIMER_AVERAGE];
Bitu req_index;
Bitu req_count;
float req_average;
Bitu ticks;
} timer;
#define PIT_TICK_RATE 1193182
#define PIT_SHIFT 9
#define MAX_PASSED ((PIT_TICK_RATE/4) << PIT_SHIFT) /* Alow 1/4 second of timer build up */
@ -55,8 +66,9 @@ static Bit32u timer_buildup; /* The amount of pit ticks waiting */
static void counter_latch(Bitu counter) {
/* Fill the read_latch of the selected counter with current count */
PIT_Block * p=&pit[counter];
//TODO Perhaps make it a bit64u for accuracy :)
Bit32u ticks=(((LastTicks - p->last_ticks) * pit_ticks) >> PIT_SHIFT) % p->cntr ;
timer.req_count++;
float pos=timer.req_average*timer.req_count;
Bit16u ticks=pos*p->cntr;
switch (p->mode) {
case 2:
case 3:
@ -233,29 +245,30 @@ void TIMER_SetNewMicro(TIMER_Block * block,Bitu micro) {
}
void TIMER_AddTicks(Bit32u ticks) {
/* This will run through registered handlers and handle the PIT ticks */
/* Add pit ticks to the counter */
timer_buildup+=ticks*pit_ticks;
if (timer_buildup>MAX_PASSED) timer_buildup=MAX_PASSED;
Bitu add_micro=ticks*1000;
/* Check if there are timer handlers that need to be called */
Bitu add_micro=timer.ticks*1000;
std::list<Timer *>::iterator i;
for(i=Timers.begin(); i != Timers.end(); ++i) {
Timer * timer=(*i);
switch (timer->type) {
Timer * timers=(*i);
switch (timers->type) {
case T_TICK:
timer->tick.handler(ticks);
if (timer.ticks) timers->tick.handler(timer.ticks);
break;
case T_MICRO:
timer->micro.count+=add_micro;
if (timer->micro.count>=timer->micro.total) {
timer->micro.count-=timer->micro.total;
timer->micro.handler();
timers->micro.count+=add_micro;
if (timers->micro.count>=timers->micro.total) {
timers->micro.count-=timers->micro.total;
timers->micro.handler();
}
break;
case T_DELAY:
/* Also unregister the timer handler from the list */
if (LastTicks>timer->delay.end) {
if (LastTicks>timers->delay.end) {
std::list<Timer *>::iterator remove;
timer->delay.handler();
timers->delay.handler();
remove=i++;
Timers.erase(remove);
}
@ -265,19 +278,30 @@ void TIMER_AddTicks(Bit32u ticks) {
};
};
timer.ticks=ticks;
}
void TIMER_CheckPIT(void) {
if (timer_buildup>timer_ticks) {
timer_buildup-=timer_ticks;
if (timer_buildup>timer_ticks) TimerAgain=true;
else TimerAgain=false;
/* Calculate amount of times the time index was requested */
timer.req[timer.req_index]=timer.req_count;
timer.req_index++;if (timer.req_index>=TIMER_AVERAGE) timer.req_index=0;
timer.req_count=0;
Bitu l;float total=0;
for (l=0;l<TIMER_AVERAGE;l++) total+=timer.req[l];
timer.req_average=1/(total/TIMER_AVERAGE);
PIC_ActivateIRQ(0);
return;
}
} else TimerAgain=false;
}
void TIMER_Init(void) {
Bitu i;
IO_RegisterWriteHandler(0x40,write_latch,"PIT Timer 0");
IO_RegisterWriteHandler(0x42,write_latch,"PIT Timer 2");
IO_RegisterWriteHandler(0x43,write_p43,"PIT Mode Control");
@ -293,7 +317,8 @@ void TIMER_Init(void) {
pit[0].mode=3;
timer_ticks=pit[0].cntr << PIT_SHIFT;
timer_buildup=0;
// first_timer=0;
timer.req_index=0;
for (i=0;i<TIMER_AVERAGE;i++) timer.req[i]=0;
pit_ticks=(PIT_TICK_RATE << PIT_SHIFT)/1000;
PIC_RegisterIRQ(0,&TIMER_CheckPIT,"PIT 0 Timer");
}