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Avoid switch to supervisor mode in SDL_GetTicks, by updating system counter from vbl interrupt

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--HG--
branch : SDL-1.2
extra : convert_revision : svn%3Ac70aab31-4412-0410-b14c-859654838e24/branches/SDL-1.2%402337
This commit is contained in:
Patrice Mandin 2007-06-09 19:52:05 +00:00
parent ebf84b70dd
commit 32a4452933
3 changed files with 32 additions and 38 deletions
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61
src/timer/mint/SDL_systimer.c
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@ -53,18 +53,18 @@ void SDL_MintAudio_CheckFpu(void);
/* The first ticks value of the application */
static Uint32 start;
static volatile SDL_bool supervisor;
static SDL_bool read_hz200_from_vbl = SDL_FALSE;
static int mint_present; /* can we use Syield() ? */
void SDL_StartTicks(void)
{
void *oldpile;
void *old_stack;
unsigned long dummy;
/* Set first ticks value */
oldpile=(void *)Super(0);
start=*((volatile long *)_hz_200);
Super(oldpile);
old_stack = (void *)Super(0);
start = *((volatile long *)_hz_200);
Super(old_stack);
start *= 5; /* One _hz_200 tic is 5ms */
@ -73,21 +73,14 @@ void SDL_StartTicks(void)
Uint32 SDL_GetTicks (void)
{
Uint32 now;
void *oldpile=NULL;
Uint32 now = start;
/* Check if we are in supervisor mode
(this is the case when called from SDL_ThreadedTimerCheck,
which is called from RunTimer, running in the vbl vector)
*/
if (!supervisor) {
oldpile=(void *)Super(0);
}
now=*((volatile long *)_hz_200);
if (!supervisor) {
Super(oldpile);
if (read_hz200_from_vbl) {
now = SDL_Atari_hz200;
} else {
void *old_stack = (void *)Super(0);
now = *((volatile long *)_hz_200);
Super(old_stack);
}
return((now*5)-start);
@ -108,44 +101,36 @@ void SDL_Delay (Uint32 ms)
/* Data to handle a single periodic alarm */
static SDL_bool timer_installed=SDL_FALSE;
static void RunTimer(void)
{
supervisor=SDL_TRUE;
SDL_ThreadedTimerCheck();
supervisor=SDL_FALSE;
}
/* This is only called if the event thread is not running */
int SDL_SYS_TimerInit(void)
{
void *oldpile;
supervisor=SDL_FALSE;
void *old_stack;
SDL_MintAudio_CheckFpu();
/* Install RunTimer in vbl vector */
oldpile=(void *)Super(0);
timer_installed = !SDL_AtariVblInstall(RunTimer);
Super(oldpile);
old_stack = (void *)Super(0);
timer_installed = !SDL_AtariVblInstall(SDL_ThreadedTimerCheck);
Super(old_stack);
if (!timer_installed) {
return(-1);
}
read_hz200_from_vbl = SDL_TRUE;
return(SDL_SetTimerThreaded(0));
}
void SDL_SYS_TimerQuit(void)
{
void *oldpile;
/* Uninstall RunTimer vbl vector */
if (timer_installed) {
/* Uninstall RunTimer vbl vector */
oldpile=(void *)Super(0);
SDL_AtariVblUninstall(RunTimer);
Super(oldpile);
void *old_stack = (void *)Super(0);
SDL_AtariVblUninstall(SDL_ThreadedTimerCheck);
Super(old_stack);
timer_installed = SDL_FALSE;
}
read_hz200_from_vbl = SDL_FALSE;
}
int SDL_SYS_StartTimer(void)