dlls/winedos/timer.c

   1 /*
   2  * 8253/8254 Programmable Interval Timer (PIT) emulation
   3  *
   4  * Copyright 2003 Jukka Heinonen
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19  */
  20
  21 #include "config.h"
  22
  23 #include "dosexe.h"
  24 #include "wine/debug.h"
  25 #include "wingdi.h"
  26 #include "winuser.h"
  27
  28 WINE_DEFAULT_DEBUG_CHANNEL(int);
  29
  30 /*
  31  * FIXME: Move timer ioport handling here and remove
  32  *        Dosvm.GetTimer/Dosvm.SetTimer.
  33  * FIXME: Use QueryPerformanceCounter for
  34  *        more precise GetTimer implementation.
  35  * FIXME: Use QueryPerformanceCounter (or GetTimer implementation)
  36  *        in timer tick routine to compensate for lost ticks.
  37  *        This should also make it possible to
  38  *        emulate really fast timers.
  39  * FIXME: Support special timer modes in addition to periodic mode.
  40  * FIXME: Make sure that there are only limited number
  41  *        of pending timer IRQ events queued. This makes sure that
  42  *        timer handling does not eat all available memory even
  43  *        if IRQ handling stops for some reason (suspended process?).
  44  *        This is easy to do by using DOSRELAY parameter.
  45  * FIXME: Use timeSetEvent, NtSetEvent or timer thread for more precise
  46  *        timing.
  47  * FIXME: Move Win16 timer emulation code here.
  48  */
  49
  50 /* The PC clocks ticks at 1193180 Hz. */
  51 #define TIMER_FREQ 1193180
  52
  53 /* Unique system timer identifier. */
  54 static UINT_PTR TIMER_id = 0;
  55
  56 /* Time when timer IRQ was last queued. */
  57 static DWORD TIMER_stamp = 0;
  58
  59 /* Timer ticks between timer IRQs. */
  60 static UINT TIMER_ticks = 0;
  61
  62
  63 /***********************************************************************
  64  *              TIMER_TimerProc
  65  */
  66 static void CALLBACK TIMER_TimerProc( HWND     hwnd,
  67                                       UINT     uMsg,
  68                                       UINT_PTR idEvent,
  69                                       DWORD    dwTime )
  70 {
  71     TIMER_stamp = dwTime;
  72     DOSVM_QueueEvent( 0, DOS_PRIORITY_REALTIME, NULL, NULL );
  73 }
  74
  75
  76 /***********************************************************************
  77  *              TIMER_DoSetTimer
  78  */
  79 static void WINAPI TIMER_DoSetTimer( ULONG_PTR arg )
  80 {
  81     INT millis = MulDiv( arg, 1000, TIMER_FREQ );
  82
  83     /* sanity check - too fast timer */
  84     if (millis < 1)
  85         millis = 1;
  86
  87     TRACE_(int)( "setting timer tick delay to %d ms\n", millis );
  88
  89     if (TIMER_id)
  90         KillTimer( NULL, TIMER_id );
  91
  92     TIMER_id = SetTimer( NULL, 0, millis, TIMER_TimerProc );
  93     TIMER_stamp = GetTickCount();
  94     TIMER_ticks = arg;
  95 }
  96
  97
  98 /***********************************************************************
  99  *              GetTimer (WINEDOS.@)
 100  */
 101 UINT WINAPI DOSVM_GetTimer( void )
 102 {
 103     if (!DOSVM_IsWin16())
 104     {
 105         DWORD millis = GetTickCount() - TIMER_stamp;
 106         INT   ticks = MulDiv( millis, TIMER_FREQ, 1000 );
 107
 108         /* sanity check - tick wrap or suspended process or update race */
 109         if (ticks < 0 || ticks >= TIMER_ticks)
 110             ticks = 0;
 111
 112         return ticks;
 113     }
 114
 115     return 0;
 116 }
 117
 118
 119 /***********************************************************************
 120  *              SetTimer (WINEDOS.@)
 121  */
 122 void WINAPI DOSVM_SetTimer( UINT ticks )
 123 {
 124     if (!DOSVM_IsWin16())
 125         MZ_RunInThread( TIMER_DoSetTimer, ticks );
 126 }
 127
 128
 129 /***********************************************************************
 130  *              DOSVM_Int08Handler
 131  *
 132  * DOS interrupt 08h handler (IRQ0 - TIMER).
 133  */
 134 void WINAPI DOSVM_Int08Handler( CONTEXT86 *context )
 135 {
 136     BIOSDATA *bios_data      = BIOS_DATA;
 137     CONTEXT86 nested_context = *context;
 138     FARPROC16 int1c_proc     = DOSVM_GetRMHandler( 0x1c );
 139
 140     nested_context.SegCs = SELECTOROF(int1c_proc);
 141     nested_context.Eip   = OFFSETOF(int1c_proc);
 142
 143     /*
 144      * Update BIOS ticks since midnight.
 145      *
 146      * FIXME: What to do when number of ticks exceeds ticks per day?
 147      */
 148     bios_data->Ticks++;
 149
 150     /*
 151      * If IRQ is called from protected mode, convert
 152      * context into VM86 context. Stack is invalidated so
 153      * that DPMI_CallRMProc allocates a new stack.
 154      */
 155     if (!ISV86(&nested_context))
 156     {
 157         nested_context.EFlags |= V86_FLAG;
 158         nested_context.SegSs = 0;
 159     }
 160
 161     /*
 162      * Call interrupt 0x1c.
 163      */
 164     DPMI_CallRMProc( &nested_context, NULL, 0, TRUE );
 165
 166     DOSVM_AcknowledgeIRQ( context );
 167 }