Mercurial > sdl-ios-xcode
changeset 3955:40b6b5744e05 SDL-1.2
Avoid switch to supervisor mode in SDL_GetTicks, by updating system counter from vbl interrupt
| author | Patrice Mandin <patmandin@gmail.com> |
|---|---|
| date | Sat, 09 Jun 2007 19:52:05 +0000 |
| parents | 649fba69eccd |
| children | 3868bebb9f5b |
| files | src/timer/mint/SDL_systimer.c src/timer/mint/SDL_vbltimer.S src/timer/mint/SDL_vbltimer_s.h |
| diffstat | 3 files changed, 32 insertions(+), 38 deletions(-) [+] |
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--- a/src/timer/mint/SDL_systimer.c Fri Jun 08 21:44:40 2007 +0000 +++ b/src/timer/mint/SDL_systimer.c Sat Jun 09 19:52:05 2007 +0000 @@ -53,18 +53,18 @@ /* 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 @@ 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 @@ /* 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)
--- a/src/timer/mint/SDL_vbltimer.S Fri Jun 08 21:44:40 2007 +0000 +++ b/src/timer/mint/SDL_vbltimer.S Sat Jun 09 19:52:05 2007 +0000 @@ -27,6 +27,7 @@ */ #define _vbl_queue 0x456 +#define _hz_200 0x4ba .text @@ -42,6 +43,7 @@ lea _my_vbl,a0 clrw vbl_mutex + movel _hz_200.w, _SDL_Atari_hz200 /* Stop interrupts */ @@ -108,6 +110,9 @@ /*--- Our vbl ---*/ _my_vbl: + /* Update _hz_200 */ + movel _hz_200.w, _SDL_Atari_hz200 + /* Verify if this is not already running */ tstw vbl_mutex @@ -147,6 +152,8 @@ .data .even + .comm _SDL_Atari_hz200,4*1 + .even .comm vbl_mutex,2*1 .even .comm my_vector,4*1
--- a/src/timer/mint/SDL_vbltimer_s.h Fri Jun 08 21:44:40 2007 +0000 +++ b/src/timer/mint/SDL_vbltimer_s.h Sat Jun 09 19:52:05 2007 +0000 @@ -28,6 +28,8 @@ * Patrice Mandin */ +extern volatile long SDL_Atari_hz200; + /* Functions prototypes */ extern int SDL_AtariVblInstall(void *newvector); extern void SDL_AtariVblUninstall(void *newvector);