From: michael DOT mauch AT gmx DOT de (Michael Mauch)
Newsgroups: comp.os.msdos.djgpp
Subject: Re: Intermittent Run-Time of DJGPP App under Win95
Date: Wed, 26 Nov 1997 12:13:31 +0100
Organization: Gerhard-Mercator-Universitaet -GH- Duisburg
Lines: 119
Message-ID: <348488fe.61835728@news.uni-duisburg.de>
References: <m0xaFyg-000S23C AT inti DOT gov DOT ar>
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To: djgpp AT delorie DOT com
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On Tue, 25 Nov 1997 11:07:41 GMT, "Salvador Eduardo Tropea (SET)"
<salvador AT inti DOT edu DOT ar> wrote:

> George Foot <mert0407 AT sable DOT ox DOT ac DOT uk> wrote:
> > 
> > Win95's Virtual Timer Device VxD provides three functions; in
> > particular, one of them (0x0101) returns the time in milliseconds that
> > Windows has been active, and another (0x0102) returns the time in
> > milliseconds that the current session has been actively executed (I
> > forget the exact wording -- it means, how many milliseconds of the
> > processor's time have been spent on this DOS box).  I believe you can
> > use a combination of the two to find out what percentage of CPU time
> > Windows is giving your application.  Is this the information you were
> > seeking?
> Don't know. I think it can help to make the program to meassure the problem.

I think it should be possible.

Regards...
	Michael

******* wintimer.c: ********

#include <string.h>
#include <dpmi.h>
#include <libc/bss.h>


#include "wintimer.h"


static int wintimer_bss = -1;


static unsigned long VTDcall(int func_num)
{
  static struct
  {
    unsigned short lo,hi;
  } VTD;   /* address of the Virtual Timer Device API entry point */

  __dpmi_regs regs; 

  if (wintimer_bss != __bss_count)
  {
    memset(&regs,0,sizeof(regs));
    regs.x.ax = 0x1684;
    regs.x.bx = 0x0005;
    regs.x.di = 0;
    regs.x.es = 0;
    if(__dpmi_simulate_real_mode_interrupt(0x2F,&regs))
      return 0; /* error: VTD API not available */

    VTD.lo = regs.x.di;
    VTD.hi = regs.x.es;
    if(!(VTD.lo | VTD.hi))
      return 0; /* error: VTD API not available */

    wintimer_bss = __bss_count;
  }
  memset(&regs,0,sizeof(regs));
  regs.x.ax = func_num;
  regs.x.cs = VTD.hi;
  regs.x.ip = VTD.lo;
  if(__dpmi_simulate_real_mode_procedure_retf(&regs))
    return 0; /* error: VTD API call failed */

  return regs.d.eax;
}


unsigned long WinTimerWindowsRunning(void)
{
  return VTDcall(0x101);
}

unsigned long WinTimerVirtualMachineRunning(void)
{
  return VTDcall(0x102);
}

#ifdef TEST

#include <stdio.h>

int main()
{
  unsigned long t1 = WinTimerWindowsRunning(),
                t2 = WinTimerVirtualMachineRunning();

  printf("Windows has been running for %lu milliseconds.\n", t1);
  printf("This virtual machine has been running for %lu
milliseconds.\n", t2);
  return 0;
}

#endif


******* wintimer.h: ********

#ifndef WINTIMER_H
#define WINTIMER_H

#ifdef __cplusplus
extern "C"
{
#endif

unsigned long WinTimerRunning(void);
unsigned long WinTimerVirtualMachineRunning(void);


#ifdef __cplusplus
}
#endif

#endif