root/trunk/PublicUtility/CAHostTimeBase.cpp

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/*=============================================================================
        CAHostTimeBase.cp

=============================================================================*/

//=============================================================================
//      Includes
//=============================================================================

#include "CAHostTimeBase.h"

Float64 CAHostTimeBase::sFrequency = 0;
UInt32  CAHostTimeBase::sMinDelta = 0;
UInt32  CAHostTimeBase::sToNanosNumerator = 0;
UInt32  CAHostTimeBase::sToNanosDenominator = 0;
UInt32  CAHostTimeBase::sFromNanosNumerator = 0;
UInt32  CAHostTimeBase::sFromNanosDenominator = 0;
bool    CAHostTimeBase::sUseMicroseconds = false;
bool    CAHostTimeBase::sIsInited = false;
#if Track_Host_TimeBase
UInt64  CAHostTimeBase::sLastTime = 0;
#endif

//=============================================================================
//      CAHostTimeBase
//
//      This class provides platform independent access to the host's time base.
//=============================================================================

void    CAHostTimeBase::Initialize()
{
        //      get the info about Absolute time
        #if TARGET_OS_MAC
                struct mach_timebase_info       theTimeBaseInfo;
                mach_timebase_info(&theTimeBaseInfo);
                sMinDelta = 1;
                sToNanosNumerator = theTimeBaseInfo.numer;
                sToNanosDenominator = theTimeBaseInfo.denom;
                sFromNanosNumerator = sToNanosDenominator;
                sFromNanosDenominator = sToNanosNumerator;

                //      the frequency of that clock is: (sToNanosDenominator / sToNanosNumerator) * 10^9
                sFrequency = static_cast<Float64>(sToNanosDenominator) / static_cast<Float64>(sToNanosNumerator);
                sFrequency *= 1000000000.0;
        #elif TARGET_OS_WIN32
                LARGE_INTEGER theFrequency;
                QueryPerformanceFrequency(&theFrequency);
                sMinDelta = 1;
                sToNanosNumerator = 1000000000ULL;
                sToNanosDenominator = *((UInt64*)&theFrequency);
                sFromNanosNumerator = sToNanosDenominator;
                sFromNanosDenominator = sToNanosNumerator;
                sFrequency = static_cast<Float64>(*((UInt64*)&theFrequency));
        #endif

        
        #if     Log_Host_Time_Base_Parameters
                DebugMessage(  "Host Time Base Parameters");
                DebugMessageN1(" Minimum Delta:          %lu", sMinDelta);
                DebugMessageN1(" Frequency:              %f", sFrequency);
                DebugMessageN1(" To Nanos Numerator:     %lu", sToNanosNumerator);
                DebugMessageN1(" To Nanos Denominator:   %lu", sToNanosDenominator);
                DebugMessageN1(" From Nanos Numerator:   %lu", sFromNanosNumerator);
                DebugMessageN1(" From Nanos Denominator: %lu", sFromNanosDenominator);
        #endif

        sIsInited = true;
}