/*

SDL - Simple DirectMedia Layer

Copyright (C) 1997-2004 Sam Lantinga

This library is free software; you can redistribute it and/or

modify it under the terms of the GNU Library 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

Library General Public License for more details.

You should have received a copy of the GNU Library General Public

License along with this library; if not, write to the Free

Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA

Sam Lantinga

slouken@devolution.com

*/

#ifdef SAVE_RCSID

static char rcsid =

"@(#) $Id$";

#endif

#include <stdio.h>

#include <time.h>

#include <sys/time.h>

#include <unistd.h>

#include <string.h>

#include <errno.h>

#include "SDL_error.h"

#include "SDL_timer.h"

#include "SDL_timer_c.h"

#ifdef DISABLE_THREADS

/* Timer start/reset time */

static Uint32 timerStart;

/* Timer running function */

void RISCOS_CheckTimer();

#else

#include <pthread.h>

extern Uint32 riscos_main_thread;

extern int riscos_using_threads;

extern Uint32 SDL_ThreadID();

extern Uint32 SDL_EventThreadID(void);

#endif

extern void RISCOS_BackgroundTasks(void);

/* The first ticks value of the application */

clock_t start;

void SDL_StartTicks(void)

{

/* Set first ticks value */

start = clock();

}

Uint32 SDL_GetTicks (void)

{

clock_t ticks;

ticks=clock()-start;

#if CLOCKS_PER_SEC == 1000

return(ticks);

#elif CLOCKS_PER_SEC == 100

return (ticks * 10);

#else

return ticks*(1000/CLOCKS_PER_SEC);

#endif

}

void SDL_Delay (Uint32 ms)

{

Uint32 now,then,elapsed;

#ifndef DISABLE_THREADS

int is_event_thread;

if (riscos_using_threads)

{

is_event_thread = 0;

if (SDL_EventThreadID())

{

if (SDL_EventThreadID() == SDL_ThreadID()) is_event_thread = 1;

} else if (SDL_ThreadID() == riscos_main_thread) is_event_thread = 1;

} else is_event_thread = 1;

#endif

/*TODO: Next version of unixlib may allow us to use usleep here */

/* for non event threads */

/* Set the timeout interval - Linux only needs to do this once */

then = SDL_GetTicks();

do {

/* Do background tasks required while sleeping as we are not multithreaded */

#ifdef DISABLE_THREADS

RISCOS_BackgroundTasks();

#else

/* For threaded build only run background tasks in event thread */

if (is_event_thread) RISCOS_BackgroundTasks();

#endif

/* Calculate the time interval left (in case of interrupt) */

now = SDL_GetTicks();

elapsed = (now-then);

then = now;

if ( elapsed >= ms ) {

break;

}

ms -= elapsed;

#ifndef DISABLE_THREADS

/* Need to yield to let other threads have a go */

if (riscos_using_threads) pthread_yield();

#endif

} while ( 1 );

}

#ifdef DISABLE_THREADS

/* Non-threaded version of timer */

int SDL_SYS_TimerInit(void)

{

return(0);

}

void SDL_SYS_TimerQuit(void)

{

SDL_SetTimer(0, NULL);

}

int SDL_SYS_StartTimer(void)

{

timerStart = SDL_GetTicks();

return(0);

}

void SDL_SYS_StopTimer(void)

{

/* Don't need to do anything as we use SDL_timer_running

to detect if we need to check the timer */

}

void RISCOS_CheckTimer()

{

if (SDL_timer_running && SDL_GetTicks() - timerStart >= SDL_alarm_interval)

{

Uint32 ms;

ms = SDL_alarm_callback(SDL_alarm_interval);

if ( ms != SDL_alarm_interval )

{

if ( ms )

{

SDL_alarm_interval = ROUND_RESOLUTION(ms);

} else

{

SDL_alarm_interval = 0;

SDL_timer_running = 0;

}

}

if (SDL_alarm_interval) timerStart = SDL_GetTicks();

}

}

#else

/* Threaded version of timer - based on code for linux */

#include "SDL_thread.h"

/* Data to handle a single periodic alarm */

static int timer_alive = 0;

static SDL_Thread *timer = NULL;

static int RunTimer(void *unused)

{

while ( timer_alive ) {

if ( SDL_timer_running ) {

SDL_ThreadedTimerCheck();

}

SDL_Delay(1);

}

return(0);

}

/* This is only called if the event thread is not running */

int SDL_SYS_TimerInit(void)

{

timer_alive = 1;

timer = SDL_CreateThread(RunTimer, NULL);

if ( timer == NULL )

return(-1);

return(SDL_SetTimerThreaded(1));

}

void SDL_SYS_TimerQuit(void)

{

timer_alive = 0;

if ( timer ) {

SDL_WaitThread(timer, NULL);

timer = NULL;

}

}

int SDL_SYS_StartTimer(void)

{

SDL_SetError("Internal logic error: RISCOS uses threaded timer");

return(-1);

}

void SDL_SYS_StopTimer(void)

{

return;

}

#endif /* DISABLE_THREADS */