/*

SDL - Simple DirectMedia Layer

Copyright (C) 1997, 1998, 1999, 2000, 2001 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 <sys/time.h>

#include <signal.h>

#include <unistd.h>

#include <string.h>

#include <errno.h>

#include "SDL_error.h"

#include "SDL_timer.h"

#include "SDL_timer_c.h"

#if defined(DISABLE_THREADS) || defined(FORK_HACK)

#define USE_ITIMER

#endif

/* The following defines should really be determined at configure time */

#ifdef linux

/* Linux select() changes its timeout parameter upon return to contain

the remaining time. Most other unixen leave it unchanged or undefined. */

#define SELECT_SETS_REMAINING

#elif defined(__bsdi__) || defined(__FreeBSD__) || defined(__sun__)

#define USE_NANOSLEEP

#endif

/* The first ticks value of the application */

static struct timeval start;

void SDL_StartTicks(void)

{

/* Set first ticks value */

gettimeofday(&start, NULL);

}

Uint32 SDL_GetTicks (void)

{

struct timeval now;

Uint32 ticks;

gettimeofday(&now, NULL);

ticks=(now.tv_sec-start.tv_sec)*1000+(now.tv_usec-start.tv_usec)/1000;

return(ticks);

}

void SDL_Delay (Uint32 ms)

{

int was_error;

#ifdef USE_NANOSLEEP

struct timespec elapsed, tv;

#else

struct timeval tv;

#ifndef SELECT_SETS_REMAINING

Uint32 then, now, elapsed;

#endif

#endif

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

#ifdef SELECT_SETS_REMAINING

tv.tv_sec = ms/1000;

tv.tv_usec = (ms%1000)*1000;

#elif defined(USE_NANOSLEEP)

elapsed.tv_sec = ms/1000;

elapsed.tv_nsec = (ms%1000)*1000000;

#else

then = SDL_GetTicks();

#endif

do {

errno = 0;

#ifdef USE_NANOSLEEP

tv.tv_sec = elapsed.tv_sec;

tv.tv_nsec = elapsed.tv_nsec;

was_error = nanosleep(&tv, &elapsed);

#else

#ifndef SELECT_SETS_REMAINING

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

now = SDL_GetTicks();

elapsed = (now-then);

then = now;

if ( elapsed >= ms ) {

break;

}

ms -= elapsed;

tv.tv_sec = ms/1000;

tv.tv_usec = (ms%1000)*1000;

#endif

was_error = select(0, NULL, NULL, NULL, &tv);

#endif /* USE_NANOSLEEP */

} while ( was_error && (errno == EINTR) );

}

#ifdef USE_ITIMER

static void HandleAlarm(int sig)

{

Uint32 ms;

if ( SDL_alarm_callback ) {

ms = (*SDL_alarm_callback)(SDL_alarm_interval);

if ( ms != SDL_alarm_interval ) {

SDL_SetTimer(ms, SDL_alarm_callback);

}

}

}

int SDL_SYS_TimerInit(void)

{

struct sigaction action;

/* Set the alarm handler (Linux specific) */

memset(&action, 0, sizeof(action));

action.sa_handler = HandleAlarm;

action.sa_flags = SA_RESTART;

sigemptyset(&action.sa_mask);

sigaction(SIGALRM, &action, NULL);

return(0);

}

void SDL_SYS_TimerQuit(void)

{

SDL_SetTimer(0, NULL);

}

int SDL_SYS_StartTimer(void)

{

struct itimerval timer;

timer.it_value.tv_sec = (SDL_alarm_interval/1000);

timer.it_value.tv_usec = (SDL_alarm_interval%1000)*1000;

timer.it_interval.tv_sec = (SDL_alarm_interval/1000);

timer.it_interval.tv_usec = (SDL_alarm_interval%1000)*1000;

setitimer(ITIMER_REAL, &timer, NULL);

return(0);

}

void SDL_SYS_StopTimer(void)

{

struct itimerval timer;

memset(&timer, 0, (sizeof timer));

setitimer(ITIMER_REAL, &timer, NULL);

}

#else /* USE_ITIMER */

#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: Linux uses threaded timer");

return(-1);

}

void SDL_SYS_StopTimer(void)

{

return;

}

#endif /* USE_ITIMER */