SDL_systimer.c
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/*
SDL - Simple DirectMedia Layer
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Copyright (C) 1997-2012 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
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slouken@libsdl.org
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*/
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#include "SDL_config.h"
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#ifdef SDL_TIMER_UNIX
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#include <stdio.h>
#include <sys/time.h>
#include <signal.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
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#include "SDL_timer.h"
#include "../SDL_timer_c.h"
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/* The clock_gettime provides monotonous time, so we should use it if
it's available. The clock_gettime function is behind ifdef
for __USE_POSIX199309
Tommi Kyntola (tommi.kyntola@ray.fi) 27/09/2005
*/
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#if HAVE_NANOSLEEP || HAVE_CLOCK_GETTIME
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#include <time.h>
#endif
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#if SDL_THREAD_PTH
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#include <pth.h>
#endif
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#if SDL_THREADS_DISABLED
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#define USE_ITIMER
#endif
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/* The first ticks value of the application */
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#ifdef HAVE_CLOCK_GETTIME
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static struct timespec start;
#else
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static struct timeval start;
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#endif /* HAVE_CLOCK_GETTIME */
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void SDL_StartTicks(void)
{
/* Set first ticks value */
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#if HAVE_CLOCK_GETTIME
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clock_gettime(CLOCK_MONOTONIC,&start);
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gettimeofday(&start, NULL);
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}
Uint32 SDL_GetTicks (void)
{
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#if HAVE_CLOCK_GETTIME
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Uint32 ticks;
struct timespec now;
clock_gettime(CLOCK_MONOTONIC,&now);
ticks=(now.tv_sec-start.tv_sec)*1000+(now.tv_nsec-start.tv_nsec)/1000000;
return(ticks);
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Uint32 ticks;
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struct timeval now;
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gettimeofday(&now, NULL);
ticks=(now.tv_sec-start.tv_sec)*1000+(now.tv_usec-start.tv_usec)/1000;
return(ticks);
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}
void SDL_Delay (Uint32 ms)
{
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#if SDL_THREAD_PTH
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pth_time_t tv;
tv.tv_sec = ms/1000;
tv.tv_usec = (ms%1000)*1000;
pth_nap(tv);
#else
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int was_error;
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#if HAVE_NANOSLEEP
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struct timespec elapsed, tv;
#else
struct timeval tv;
Uint32 then, now, elapsed;
#endif
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/* Set the timeout interval */
#if HAVE_NANOSLEEP
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elapsed.tv_sec = ms/1000;
elapsed.tv_nsec = (ms%1000)*1000000;
#else
then = SDL_GetTicks();
#endif
do {
errno = 0;
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#if HAVE_NANOSLEEP
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tv.tv_sec = elapsed.tv_sec;
tv.tv_nsec = elapsed.tv_nsec;
was_error = nanosleep(&tv, &elapsed);
#else
/* 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;
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was_error = select(0, NULL, NULL, NULL, &tv);
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#endif /* HAVE_NANOSLEEP */
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} while ( was_error && (errno == EINTR) );
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#endif /* SDL_THREAD_PTH */
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}
#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) */
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SDL_memset(&action, 0, sizeof(action));
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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;
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SDL_memset(&timer, 0, (sizeof timer));
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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 */
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#endif /* SDL_TIMER_UNIX */