src/timer/dc/SDL_systimer.c
author Sam Lantinga
Mon, 06 Feb 2006 08:28:51 +0000
changeset 1330 450721ad5436
parent 1312 c9b51268668f
child 1358 c71e05b4dc2e
permissions -rw-r--r--
It's now possible to build SDL without any C runtime at all on Windows,
using Visual C++ 2005
     1 /*
     2     SDL - Simple DirectMedia Layer
     3     Copyright (C) 1997-2006 Sam Lantinga
     4 
     5     This library is free software; you can redistribute it and/or
     6     modify it under the terms of the GNU Lesser General Public
     7     License as published by the Free Software Foundation; either
     8     version 2.1 of the License, or (at your option) any later version.
     9 
    10     This library is distributed in the hope that it will be useful,
    11     but WITHOUT ANY WARRANTY; without even the implied warranty of
    12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    13     Lesser General Public License for more details.
    14 
    15     You should have received a copy of the GNU Lesser General Public
    16     License along with this library; if not, write to the Free Software
    17     Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
    18 
    19     Sam Lantinga
    20     slouken@libsdl.org
    21 */
    22 
    23 #include <kos.h>
    24 
    25 #include "SDL_thread.h"
    26 #include "SDL_timer.h"
    27 #include "SDL_error.h"
    28 #include "SDL_timer_c.h"
    29 
    30 static unsigned start;
    31 
    32 /* 
    33 	jif =  ms * HZ /1000
    34 	ms  = jif * 1000/HZ
    35 */
    36 
    37 void SDL_StartTicks(void)
    38 {
    39 	/* Set first ticks value */
    40 	start = jiffies;
    41 }
    42 
    43 Uint32 SDL_GetTicks(void)
    44 {
    45 	return((jiffies-start)*1000/HZ);
    46 }
    47 
    48 void SDL_Delay(Uint32 ms)
    49 {
    50 	thd_sleep(ms);
    51 }
    52 
    53 /* Data to handle a single periodic alarm */
    54 static int timer_alive = 0;
    55 static SDL_Thread *timer = NULL;
    56 
    57 static int RunTimer(void *unused)
    58 {
    59 	while ( timer_alive ) {
    60 		if ( SDL_timer_running ) {
    61 			SDL_ThreadedTimerCheck();
    62 		}
    63 		SDL_Delay(10);
    64 	}
    65 	return(0);
    66 }
    67 
    68 /* This is only called if the event thread is not running */
    69 int SDL_SYS_TimerInit(void)
    70 {
    71 	timer_alive = 1;
    72 	timer = SDL_CreateThread(RunTimer, NULL);
    73 	if ( timer == NULL )
    74 		return(-1);
    75 	return(SDL_SetTimerThreaded(1));
    76 }
    77 
    78 void SDL_SYS_TimerQuit(void)
    79 {
    80 	timer_alive = 0;
    81 	if ( timer ) {
    82 		SDL_WaitThread(timer, NULL);
    83 		timer = NULL;
    84 	}
    85 }
    86 
    87 int SDL_SYS_StartTimer(void)
    88 {
    89 	SDL_SetError("Internal logic error: DC uses threaded timer");
    90 	return(-1);
    91 }
    92 
    93 void SDL_SYS_StopTimer(void)
    94 {
    95 	return;
    96 }