Initial revision

--HG--
extra : convert_revision : svn%3Ac70aab31-4412-0410-b14c-859654838e24/trunk%401

src/timer/linux/SDL_systimer.c

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+/*
+    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 */