/*

Copyright (C) 2016 Apple Inc. All Rights Reserved.

See LICENSE.txt for this sample’s licensing information

Abstract:

Part of Core Audio Public Utility Classes

*/

//=============================================================================

//  Includes

//=============================================================================

#include "CAHostTimeBase.h"

Float64         CAHostTimeBase::sFrequency = 0;

Float64         CAHostTimeBase::sInverseFrequency = 0;

UInt32          CAHostTimeBase::sMinDelta = 0;

UInt32          CAHostTimeBase::sToNanosNumerator = 0;

UInt32          CAHostTimeBase::sToNanosDenominator = 0;

pthread_once_t  CAHostTimeBase::sIsInited = PTHREAD_ONCE_INIT;

#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;

        //  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);

        sFrequency = static_cast<Float64>(*((UInt64*)&theFrequency));

    #endif

    sInverseFrequency = 1.0 / sFrequency;

    #if Log_Host_Time_Base_Parameters

        DebugPrintf("Host Time Base Parameters");

        DebugPrintf(" Minimum Delta:          %lu", (unsigned long)sMinDelta);

        DebugPrintf(" Frequency:              %f", sFrequency);

        DebugPrintf(" To Nanos Numerator:     %lu", (unsigned long)sToNanosNumerator);

        DebugPrintf(" To Nanos Denominator:   %lu", (unsigned long)sToNanosDenominator);

    #endif

}