/* * 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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, 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: 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 /* How many timer IRQs can be pending at any time. */ #define TIMER_MAX_PENDING 20 /* 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; /* Number of pending timer IRQs. */ static LONG TIMER_pending = 0; /* Number of milliseconds between IRQs. */ static DWORD TIMER_millis = 0; /*********************************************************************** * TIMER_Relay * * Decrement the number of pending IRQs after IRQ handler has been * called. This function will be called even if application has its * own IRQ handler that does not jump to builtin IRQ handler. */ static void TIMER_Relay( CONTEXT *context, void *data ) { InterlockedDecrement( &TIMER_pending ); } /*********************************************************************** * TIMER_TimerProc */ static void CALLBACK TIMER_TimerProc( HWND hwnd, UINT uMsg, UINT_PTR idEvent, DWORD dwTime ) { LONG pending = InterlockedIncrement( &TIMER_pending ); DWORD delta = (dwTime >= TIMER_stamp) ? (dwTime - TIMER_stamp) : (0xffffffff - (TIMER_stamp - dwTime)); if (pending >= TIMER_MAX_PENDING) { if (delta >= 60000) { ERR( "DOS timer has been stuck for 60 seconds...\n" ); TIMER_stamp = dwTime; } InterlockedDecrement( &TIMER_pending ); } else { DWORD i; /* Calculate the number of valid timer interrupts we can generate */ DWORD count = delta / TIMER_millis; /* Forward the timestamp with the time used */ TIMER_stamp += (count * TIMER_millis); /* Generate interrupts */ for(i=0;i<count;i++) { DOSVM_QueueEvent( 0, DOS_PRIORITY_REALTIME, TIMER_Relay, 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; /* Remember number of milliseconds to wait */ TIMER_millis = millis; } /*********************************************************************** * DOSVM_SetTimer */ void DOSVM_SetTimer( UINT ticks ) { /* PIT interprets zero as a maximum length delay. */ if (ticks == 0) ticks = 0x10000; if (!DOSVM_IsWin16()) MZ_RunInThread( TIMER_DoSetTimer, ticks ); } /*********************************************************************** * DOSVM_Int08Handler * * DOS interrupt 08h handler (IRQ0 - TIMER). */ void WINAPI DOSVM_Int08Handler( CONTEXT *context ) { BIOSDATA *bios_data = DOSVM_BiosData(); CONTEXT 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 ); }