SDL_systimer.c
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/*
SDL - Simple DirectMedia Layer
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Copyright (C) 1997-2006 Sam Lantinga
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This library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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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
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Lesser General Public License for more details.
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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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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Sam Lantinga
slouken@libsdl.org
*/
/*
* TOS/MiNT timer driver
* based on vbl vector
*
* Patrice Mandin
*/
#include <stdio.h>
#include <sys/time.h>
#include <signal.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
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#include <mint/cookie.h>
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#include <mint/sysvars.h>
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#include <mint/osbind.h>
#include <mint/mintbind.h>
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#include "SDL_error.h"
#include "SDL_timer.h"
#include "SDL_timer_c.h"
#include "SDL_thread.h"
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#include "mint/SDL_vbltimer_s.h"
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/* The first ticks value of the application */
static Uint32 start;
static SDL_bool supervisor;
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static int mint_present; /* can we use Syield() ? */
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void SDL_StartTicks(void)
{
void *oldpile;
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unsigned long dummy;
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/* Set first ticks value */
oldpile=(void *)Super(0);
start=*((volatile long *)_hz_200);
Super(oldpile);
start *= 5; /* One _hz_200 tic is 5ms */
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mint_present = (Getcookie(C_MiNT, &dummy) == C_FOUND);
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}
Uint32 SDL_GetTicks (void)
{
Uint32 now;
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void *oldpile=NULL;
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/* 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);
}
return((now*5)-start);
}
void SDL_Delay (Uint32 ms)
{
Uint32 now;
now = SDL_GetTicks();
while ((SDL_GetTicks()-now)<ms){
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if (mint_present) {
Syield();
}
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}
}
/* 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;
/* Install RunTimer in vbl vector */
oldpile=(void *)Super(0);
timer_installed = !SDL_AtariVblInstall(RunTimer);
Super(oldpile);
if (!timer_installed) {
return(-1);
}
return(SDL_SetTimerThreaded(0));
}
void SDL_SYS_TimerQuit(void)
{
void *oldpile;
if (timer_installed) {
/* Uninstall RunTimer vbl vector */
oldpile=(void *)Super(0);
SDL_AtariVblUninstall(RunTimer);
Super(oldpile);
timer_installed = SDL_FALSE;
}
}
int SDL_SYS_StartTimer(void)
{
SDL_SetError("Internal logic error: MiNT uses vbl timer");
return(-1);
}
void SDL_SYS_StopTimer(void)
{
return;
}