/***
    Copyright (C) 2023 J Reece Wilson (a/k/a "Reece"). All rights reserved.

    File: SMTYield.cpp
    Date: 2023-3-12
    Author: Reece
***/
#include <Source/RuntimeInternal.hpp>
#include "SMTYield.hpp"

namespace Aurora::Threading
{
    AUKN_SYM void SetSpinCountTimeout(AuUInt8 uTimeout)
    {
        gRuntimeConfig.threadingConfig.uSpinLoopPowerA = uTimeout;
    }

    AUKN_SYM AuUInt8 GetSpinCountTimeout()
    {
        return gRuntimeConfig.threadingConfig.uSpinLoopPowerA;
    }

    AUKN_SYM void SetThreadLocalAdditionalSpinCountTimeout(AuUInt8 uTimeout)
    {
        gHasThreadLocalTimeout = 1;
        tlsSpinCountLocal = uTimeout;
    }

    AUKN_SYM AuUInt32 GetTotalSpinCountTimeout()
    {
        AuUInt32 uCount {};
        
        if (!gRuntimeConfig.threadingConfig.bPlatformIsSMPProcessorOptimized)
        {
            return 16;
        }

        uCount = AuUInt32(gRuntimeConfig.threadingConfig.uSpinLoopPowerA);
        if (gHasThreadLocalTimeout)
        {
            uCount += 1u << AuUInt32(tlsSpinCountLocal);
        }

        return uCount;
    }

    AUKN_SYM const ThreadingConfig *GetThreadingConfig()
    {
        return &gRuntimeConfig.threadingConfig;
    }

    AUKN_SYM void SetThreadingConfig(const ThreadingConfig *pUpdateConfig)
    {
        if (!pUpdateConfig)
        {
            return;
        }

        gRuntimeConfig.threadingConfig = decltype(gRuntimeConfig.threadingConfig)(ThreadingConfig(*pUpdateConfig));

        Primitives::InitAdaptiveThreshold();
    }

    AUKN_SYM bool IsWaitOnRecommended();
}

namespace Aurora::Threading::Primitives
{
    void InitAdaptiveThreshold()
    {
        auto uCores = AuHwInfo::GetCPUInfo().uThreads;

        gUseFutexRWLock = gRuntimeConfig.threadingConfig.bPreferFutexRWLock &&
            IsWaitOnRecommended();

        if (uCores == 1)
        {
            gSpinAdaptiveThreshold = 0;
            gRuntimeConfig.threadingConfig.bPlatformIsSMPProcessorOptimized = false;
            return;
        }

        if (!gRuntimeConfig.threadingConfig.bForceEnableAdaptiveSpin)
        {
            gSpinAdaptiveThreshold = 0;
            return;
        }

        if (uCores >= 16)
        {
            gSpinAdaptiveThreshold = uCores / gRuntimeConfig.threadingConfig.uAdaptiveSpinCUCnt16;
        }
        else if (uCores >= 8 && gRuntimeConfig.threadingConfig.uAdaptiveSpinCUCnt8)
        {
            gSpinAdaptiveThreshold = uCores / gRuntimeConfig.threadingConfig.uAdaptiveSpinCUCnt8;
        }
        else if (uCores >= 4 && gRuntimeConfig.threadingConfig.uAdaptiveSpinCUCnt4)
        {
            gSpinAdaptiveThreshold = uCores / gRuntimeConfig.threadingConfig.uAdaptiveSpinCUCnt4;
        }
        else if (uCores >= 0 && gRuntimeConfig.threadingConfig.uAdaptiveSpinCUCnt0)
        {
            gSpinAdaptiveThreshold = uCores / gRuntimeConfig.threadingConfig.uAdaptiveSpinCUCnt0;
        }
        else
        {
            gSpinAdaptiveThreshold = 0;
        }
    }

    void InitAdaptiveThresholdFirstTime()
    {
        if (!gRuntimeConfig.threadingConfig.bForceEnableAdaptiveSpin &&
            gRuntimeConfig.threadingConfig.bPreferEnableAdaptiveSpin)
        {
        #if defined(AURORA_IS_LINUX_DERIVED)
            if (gRuntimeConfig.threadingConfig.bPreferLinuxAdaptiveSpin)
            {
                gRuntimeConfig.threadingConfig.bForceEnableAdaptiveSpin = true;
            }
        #else
            if (AuSwInfo::IsWindows10OrGreater())
            {
                gRuntimeConfig.threadingConfig.bForceEnableAdaptiveSpin = gRuntimeConfig.threadingConfig.bPreferNewWin32AdaptiveSpin;
            }
            else
            {
                gRuntimeConfig.threadingConfig.bForceEnableAdaptiveSpin = gRuntimeConfig.threadingConfig.bPreferOldWin32AdaptiveSpin;
            }
        #endif
        }

        InitAdaptiveThreshold();
    }
}