/*
	 * If calibration cycle occurred after we get curCounter
	 */

	if (curCounter.QuadPart <= perfCounterLastCall) {
	    /*
	     * Calibrated file-time is saved from posix in 100-ns ticks
	     * Calibrated file-time is saved from Posix in 100-ns ticks
	     */

	    return fileTimeLastCall / 10;
	}

	/*
	 * If it appears to be more than 1.1 seconds since the last trip
	 * through the calibration loop, the performance counter may have
	 * jumped forward. (See MSDN Knowledge Base article Q274323 for a
	 * description of the hardware problem that makes this test
	 * necessary.) If the counter jumps, we don't want to use it directly.
	 * Instead, we must return system time. Eventually, the calibration
	 * loop should recover.
	 */

	if (curCounter.QuadPart - perfCounterLastCall <
		11 * curCounterFreq * timeInfo.calibrationInterv / 10
	) {
	    /* Calibrated file-time is saved from posix in 100-ns ticks */
	    /* Calibrated file-time is saved from Posix in 100-ns ticks */
	    return NativeCalc100NsTicks(fileTimeLastCall,
		perfCounterLastCall, curCounterFreq, curCounter.QuadPart) / 10;
	}
    }

    /*
     * High resolution timer is not available.

	/*
	 * If we are in the valid range, let the C run-time library handle it.
	 * Otherwise we need to fake it. Note that this algorithm ignores
	 * daylight savings time before the epoch.
	 */

	/*
	 * Hm, Borland's localtime manages to return NULL under certain
	 * Hmm, Borland's localtime manages to return NULL under certain
	 * circumstances (e.g. wintime.test, test 1.2). Nobody tests for this,
	 * since 'localtime' isn't supposed to do this, possibly leading to
	 * crashes.
	 *
	 * Patch: We only call this function if we are at least one day into
	 * the epoch, else we handle it ourselves (like we do for times < 0).
	 * H. Giese, June 2003

     */

    GetSystemTimeAsFileTime(&curFileTime);
    QueryPerformanceCounter(&timeInfo.perfCounterLastCall);
    QueryPerformanceFrequency(&timeInfo.curCounterFreq);
    timeInfo.fileTimeLastCall.LowPart = curFileTime.dwLowDateTime;
    timeInfo.fileTimeLastCall.HighPart = curFileTime.dwHighDateTime;
    /* Calibrated file-time will be saved from posix in 100-ns ticks */
    /* Calibrated file-time will be saved from Posix in 100-ns ticks */
    timeInfo.fileTimeLastCall.QuadPart -= timeInfo.posixEpoch.QuadPart;

    ResetCounterSamples(timeInfo.fileTimeLastCall.QuadPart,
	    timeInfo.perfCounterLastCall.QuadPart,
	    timeInfo.curCounterFreq.QuadPart);

    /*

    Tcl_WideInt vt1;		/* Tcl time one second from now. */
    Tcl_WideInt tdiff;		/* Difference between system clock and Tcl
				 * time. */
    Tcl_WideInt driftFreq;	/* Frequency needed to drift virtual time into
				 * step over 1 second. */

    /*
     * Sample performance counter and system time (from posix epoch).
     * Sample performance counter and system time (from Posix epoch).
     */

    GetSystemTimeAsFileTime(&curSysTime);
    curFileTime.LowPart = curSysTime.dwLowDateTime;
    curFileTime.HighPart = curSysTime.dwHighDateTime;
    curFileTime.QuadPart -= timeInfo.posixEpoch.QuadPart;
    /* If calibration still not needed (check for possible time switch) */
    if ( curFileTime.QuadPart > lastFileTime.QuadPart
      && curFileTime.QuadPart < lastFileTime.QuadPart +
      				    (timeInfo.calibrationInterv * 10000000)
    ) {
    	/* again in next one second */
	return;
    }
    QueryPerformanceCounter(&curPerfCounter);

    lastFileTime.QuadPart = curFileTime.QuadPart;

    /*
     * We devide by timeInfo.curCounterFreq.QuadPart in several places. That
     * We divide by timeInfo.curCounterFreq.QuadPart in several places. That
     * value should always be positive on a correctly functioning system. But
     * it is good to be defensive about such matters. So if something goes
     * wrong and the value does goes to zero, we clear the
     * timeInfo.perfCounterAvailable in order to cause the calibration thread
     * to shut itself down, then return without additional processing.
     */