/*

SDL - Simple DirectMedia Layer

Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002 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@libsdl.org

*/

#ifdef SAVE_RCSID

static char rcsid =

"@(#) $Id$";

#endif

#define INCL_DOSMISC

#define INCL_DOSERRORS

#define INCL_DOSSEMAPHORES

#define INCL_DOSDATETIME

#define INCL_DOSPROCESS

#define INCL_DOSPROFILE

#define INCL_DOSEXCEPTIONS

#include <os2.h>

#include "SDL_thread.h"

#include "SDL_timer.h"

#include "SDL_timer_c.h"

#include "SDL_error.h"

#define TIME_WRAP_VALUE (~(DWORD)0)

/* The first high-resolution ticks value of the application */

static long long hires_start_ticks;

/* The number of ticks per second of the high-resolution performance counter */

static ULONG hires_ticks_per_second;

void SDL_StartTicks(void)

{

DosTmrQueryFreq(&hires_ticks_per_second);

DosTmrQueryTime((PQWORD)&hires_start_ticks);

}

DECLSPEC Uint32 SDLCALL SDL_GetTicks(void)

{

long long hires_now;

ULONG ticks = ticks;

DosTmrQueryTime((PQWORD)&hires_now);

/*

hires_now -= hires_start_ticks;

hires_now *= 1000;

hires_now /= hires_ticks_per_second;

*/

/* inline asm to avoid runtime inclusion */

_asm {

push edx

push eax

mov eax, dword ptr hires_now

mov edx, dword ptr hires_now+4

sub eax, dword ptr hires_start_ticks

sbb edx, dword ptr hires_start_ticks+4

mov ebx,1000

mov ecx,edx

mul ebx

push eax

push edx

mov eax,ecx

mul ebx

pop eax

add edx,eax

pop eax

mov ebx, dword ptr hires_ticks_per_second

div ebx

mov dword ptr ticks, eax

pop edx

pop eax

}

return ticks;

}

/* High resolution sleep, originally made by Ilya Zakharevich */

DECLSPEC void SDLCALL SDL_Delay(Uint32 ms)

{

/* This is similar to DosSleep(), but has 8ms granularity in time-critical

threads even on Warp3. */

HEV hevEvent1 = 0; /* Event semaphore handle */

HTIMER htimerEvent1 = 0; /* Timer handle */

APIRET rc = NO_ERROR; /* Return code */

int ret = 1;

ULONG priority = 0, nesting; /* Shut down the warnings */

PPIB pib;

PTIB tib;

char *e = NULL;

APIRET badrc;

int switch_priority = 50;

DosCreateEventSem(NULL, /* Unnamed */

&hevEvent1, /* Handle of semaphore returned */

DC_SEM_SHARED, /* Shared needed for DosAsyncTimer */

FALSE); /* Semaphore is in RESET state */

if (ms >= switch_priority)

switch_priority = 0;

if (switch_priority)

{

if (DosGetInfoBlocks(&tib, &pib)!=NO_ERROR)

switch_priority = 0;

else

{

/* In Warp3, to switch scheduling to 8ms step, one needs to do

DosAsyncTimer() in time-critical thread. On laters versions,

more and more cases of wait-for-something are covered.

It turns out that on Warp3fp42 it is the priority at the time

of DosAsyncTimer() which matters. Let's hope that this works

with later versions too... XXXX

*/

priority = (tib->tib_ptib2->tib2_ulpri);

if ((priority & 0xFF00) == 0x0300) /* already time-critical */

switch_priority = 0;

/* Make us time-critical. Just modifying TIB is not enough... */

/* tib->tib_ptib2->tib2_ulpri = 0x0300;*/

/* We do not want to run at high priority if a signal causes us

to longjmp() out of this section... */

if (DosEnterMustComplete(&nesting))

switch_priority = 0;

else

DosSetPriority(PRTYS_THREAD, PRTYC_TIMECRITICAL, 0, 0);

}

}

if ((badrc = DosAsyncTimer(ms,

(HSEM) hevEvent1, /* Semaphore to post */

&htimerEvent1))) /* Timer handler (returned) */

e = "DosAsyncTimer";

if (switch_priority && tib->tib_ptib2->tib2_ulpri == 0x0300)

{

/* Nobody switched priority while we slept... Ignore errors... */

/* tib->tib_ptib2->tib2_ulpri = priority; */ /* Get back... */

if (!(rc = DosSetPriority(PRTYS_THREAD, (priority>>8) & 0xFF, 0, 0)))

rc = DosSetPriority(PRTYS_THREAD, 0, priority & 0xFF, 0);

}

if (switch_priority)

rc = DosExitMustComplete(&nesting); /* Ignore errors */

/* The actual blocking call is made with "normal" priority. This way we

should not bother with DosSleep(0) etc. to compensate for us interrupting

higher-priority threads. The goal is to prohibit the system spending too

much time halt()ing, not to run us "no matter what". */

if (!e) /* Wait for AsyncTimer event */

badrc = DosWaitEventSem(hevEvent1, SEM_INDEFINITE_WAIT);

if (e) ; /* Do nothing */

else if (badrc == ERROR_INTERRUPT)

ret = 0;

else if (badrc)

e = "DosWaitEventSem";

if ((rc = DosCloseEventSem(hevEvent1)) && !e) { /* Get rid of semaphore */

e = "DosCloseEventSem";

badrc = rc;

}

if (e)

{

SDL_SetError("[SDL_Delay] : Had error in %s(), rc is 0x%x\n", e, badrc);

}

}

/* Data to handle a single periodic alarm */

static int timer_alive = 0;

static SDL_Thread *timer = NULL;

static int RunTimer(void *unused)

{

DosSetPriority(PRTYS_THREAD, PRTYC_TIMECRITICAL, 0, 0);

while ( timer_alive ) {

if ( SDL_timer_running ) {

SDL_ThreadedTimerCheck();

}

SDL_Delay(10);

}

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: OS/2 uses threaded timer");

return(-1);

}

void SDL_SYS_StopTimer(void)

{

return;

}