//============================================================
//
// wintime.c - Win32 OSD core timing functions
//
//============================================================
//
// Copyright Aaron Giles
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or
// without modification, are permitted provided that the
// following conditions are met:
//
// * Redistributions of source code must retain the above
// copyright notice, this list of conditions and the
// following disclaimer.
// * Redistributions in binary form must reproduce the
// above copyright notice, this list of conditions and
// the following disclaimer in the documentation and/or
// other materials provided with the distribution.
// * Neither the name 'MAME' nor the names of its
// contributors may be used to endorse or promote
// products derived from this software without specific
// prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY AARON GILES ''AS IS'' AND
// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
// FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
// EVENT SHALL AARON GILES BE LIABLE FOR ANY DIRECT,
// INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
// DAMAGE (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
// PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
// ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
// LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
// IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//
//============================================================
// standard windows headers
#define WIN32_LEAN_AND_MEAN
#include <windows.h>
#include <mmsystem.h>
// MAME headers
#include "osdcore.h"
//============================================================
// GLOBAL VARIABLES
//============================================================
static osd_ticks_t ticks_per_second = 0;
static osd_ticks_t suspend_ticks = 0;
static BOOL using_qpc = TRUE;
//============================================================
// osd_ticks
//============================================================
osd_ticks_t osd_ticks(void)
{
LARGE_INTEGER performance_count;
// if we're suspended, just return that
if (suspend_ticks != 0)
return suspend_ticks;
// if we have a per second count, just go for it
if (ticks_per_second != 0)
{
// QueryPerformanceCounter if we can
if (using_qpc)
{
QueryPerformanceCounter(&performance_count);
return (osd_ticks_t)performance_count.QuadPart - suspend_ticks;
}
// otherwise, fall back to timeGetTime
else
return (osd_ticks_t)timeGetTime() - suspend_ticks;
}
// if not, we have to determine it
using_qpc = QueryPerformanceFrequency(&performance_count) && (performance_count.QuadPart != 0);
if (using_qpc)
ticks_per_second = (osd_ticks_t)performance_count.QuadPart;
else
ticks_per_second = 1000;
// call ourselves to get the first value
return osd_ticks();
}
//============================================================
// osd_ticks_per_second
//============================================================
osd_ticks_t osd_ticks_per_second(void)
{
return ticks_per_second;
}
//============================================================
// osd_sleep
//============================================================
void osd_sleep(osd_ticks_t duration)
{
DWORD msec;
// make sure we've computed ticks_per_second
if (ticks_per_second == 0)
(void)osd_ticks();
// convert to milliseconds, rounding down
msec = (DWORD)(duration * 1000 / ticks_per_second);
// only sleep if at least 2 full milliseconds
if (msec >= 2)
{
HANDLE current_thread = GetCurrentThread();
int old_priority = GetThreadPriority(current_thread);
// take a couple of msecs off the top for good measure
msec -= 2;
// bump our thread priority super high so that we get
// priority when we need it
SetThreadPriority(current_thread, THREAD_PRIORITY_TIME_CRITICAL);
Sleep(msec);
SetThreadPriority(current_thread, old_priority);
}
}