Sweden-Number/dlls/winedos/timer.c

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/*
* 8253/8254 Programmable Interval Timer (PIT) emulation
*
* Copyright 2003 Jukka Heinonen
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 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
* Lesser General Public License for more details.
*
* 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include "config.h"
#include "dosexe.h"
#include "wine/debug.h"
#include "wingdi.h"
#include "winuser.h"
WINE_DEFAULT_DEBUG_CHANNEL(int);
/*
* FIXME: Use QueryPerformanceCounter for
* more precise GetTimer implementation.
* FIXME: Use QueryPerformanceCounter (or GetTimer implementation)
* in timer tick routine to compensate for lost ticks.
* This should also make it possible to
* emulate really fast timers.
* FIXME: Support special timer modes in addition to periodic mode.
* FIXME: Make sure that there are only limited number
* of pending timer IRQ events queued. This makes sure that
* timer handling does not eat all available memory even
* if IRQ handling stops for some reason (suspended process?).
* This is easy to do by using DOSRELAY parameter.
* FIXME: Use timeSetEvent, NtSetEvent or timer thread for more precise
* timing.
* FIXME: Move Win16 timer emulation code here.
*/
/* The PC clocks ticks at 1193180 Hz. */
#define TIMER_FREQ 1193180
/* Unique system timer identifier. */
static UINT_PTR TIMER_id = 0;
/* Time when timer IRQ was last queued. */
static DWORD TIMER_stamp = 0;
/* Timer ticks between timer IRQs. */
static UINT TIMER_ticks = 0;
/***********************************************************************
* TIMER_TimerProc
*/
static void CALLBACK TIMER_TimerProc( HWND hwnd,
UINT uMsg,
UINT_PTR idEvent,
DWORD dwTime )
{
TIMER_stamp = dwTime;
DOSVM_QueueEvent( 0, DOS_PRIORITY_REALTIME, NULL, NULL );
}
/***********************************************************************
* TIMER_DoSetTimer
*/
static void WINAPI TIMER_DoSetTimer( ULONG_PTR arg )
{
INT millis = MulDiv( arg, 1000, TIMER_FREQ );
/* sanity check - too fast timer */
if (millis < 1)
millis = 1;
TRACE_(int)( "setting timer tick delay to %d ms\n", millis );
if (TIMER_id)
KillTimer( NULL, TIMER_id );
TIMER_id = SetTimer( NULL, 0, millis, TIMER_TimerProc );
TIMER_stamp = GetTickCount();
TIMER_ticks = arg;
}
/***********************************************************************
* DOSVM_GetTimer
*/
UINT WINAPI DOSVM_GetTimer( void )
{
if (!DOSVM_IsWin16())
{
DWORD millis = GetTickCount() - TIMER_stamp;
INT ticks = MulDiv( millis, TIMER_FREQ, 1000 );
/* sanity check - tick wrap or suspended process or update race */
if (ticks < 0 || ticks >= TIMER_ticks)
ticks = 0;
return ticks;
}
return 0;
}
/***********************************************************************
* DOSVM_SetTimer
*/
void WINAPI DOSVM_SetTimer( UINT ticks )
{
if (!DOSVM_IsWin16())
MZ_RunInThread( TIMER_DoSetTimer, ticks );
}
/***********************************************************************
* DOSVM_Int08Handler
*
* DOS interrupt 08h handler (IRQ0 - TIMER).
*/
void WINAPI DOSVM_Int08Handler( CONTEXT86 *context )
{
BIOSDATA *bios_data = DOSVM_BiosData();
CONTEXT86 nested_context = *context;
FARPROC16 int1c_proc = DOSVM_GetRMHandler( 0x1c );
nested_context.SegCs = SELECTOROF(int1c_proc);
nested_context.Eip = OFFSETOF(int1c_proc);
/*
* Update BIOS ticks since midnight.
*
* FIXME: What to do when number of ticks exceeds ticks per day?
*/
bios_data->Ticks++;
/*
* If IRQ is called from protected mode, convert
* context into VM86 context. Stack is invalidated so
* that DPMI_CallRMProc allocates a new stack.
*/
if (!ISV86(&nested_context))
{
nested_context.EFlags |= V86_FLAG;
nested_context.SegSs = 0;
}
/*
* Call interrupt 0x1c.
*/
DPMI_CallRMProc( &nested_context, NULL, 0, TRUE );
DOSVM_AcknowledgeIRQ( context );
}