/***
    Copyright (C) 2021-2024 J Reece Wilson (a/k/a "Reece"). All rights reserved.

    File: AuConditionMutex.Generic.cpp
    Date: 2021-6-14
    Author: Reece
***/
#include <Source/RuntimeInternal.hpp>
#include "AuConditionMutex.Generic.hpp"
#include "../AuWakeInternal.hpp"
#include "SMTYield.hpp"

#if defined(_AURUNTIME_GENERICCM)

namespace Aurora::Threading::Primitives
{
    GenericConditionMutex::GenericConditionMutex()
    {
    }

    GenericConditionMutex::~GenericConditionMutex()
    {
    }

    bool GenericConditionMutex::TryLock()
    { 
        if (ThrdCfg::gPreferLinuxCondMutexSpinTryLock)
        {
            return this->TryLockHeavy();
        }
        else
        {
            return this->TryLockNoSpin();
        }
    }

    void GenericConditionMutex::Lock()
    {
        if (ThrdCfg::gPreferUnixPrimitivesNoSpin)
        {
            if (this->TryLockNoSpin())
            {
                return;
            }
        }
        else
        {
            if (this->TryLockHeavy())
            {
                return;
            }
        }

        AuAtomicAdd(&this->uSleeping_, 1u);

        while (!this->TryLockNoSpin())
        {
            static const AuUInt32 kRef { 1 };
            (void)InternalLTSWaitOnAddressHighRes(&this->uState_, &kRef, 4, 0);
        }

        AuAtomicSub(&this->uSleeping_, 1u);
    }

    void GenericConditionMutex::Unlock()
    {
        AuAtomicClearU8Lock(&this->uState_);

        if (AuAtomicLoad(&this->uSleeping_))
        {
            InternalLTSWakeOne(&this->uState_);
        }
    }

    bool GenericConditionMutex::TryLockNoSpin()
    {
        return AuAtomicTestAndSet(&this->uState_, 0) == 0;
    }

    bool GenericConditionMutex::TryLockHeavy()
    {
        return DoTryIfAlderLake([=]()
        {
            return this->TryLockNoSpin();
        }, &this->uState_);
    }

    bool GenericConditionMutex::LockAbsNS(AuUInt64 uEndTime)
    {
        bool bStatus { true };

        if (this->TryLock())
        {
            return true;
        }

        AuAtomicAdd(&this->uSleeping_, 1u);

        while (!this->TryLockNoSpin())
        {
            static const AuUInt32 kRef { 1 };

            if (uEndTime != 0)
            {
                if (!InternalLTSWaitOnAddressHighRes(&this->uState_, &kRef, 4, uEndTime))
                {
                    bStatus = false;
                    break;
                }
            }
            else
            {
                (void)InternalLTSWaitOnAddressHighRes(&this->uState_, &kRef, 4, uEndTime);
            }
        }

        AuAtomicSub(&this->uSleeping_, 1u);
        return bStatus;
    }

    bool GenericConditionMutex::LockNS(AuUInt64 uTimeout)
    {
        AuUInt64 uEndTime {};
        bool bStatus { true };

        if (this->TryLock())
        {
            return true;
        }

        if (uTimeout != 0)
        {
            uEndTime = AuTime::SteadyClockNS() + uTimeout;
        }

        if (!ThrdCfg::gPreferUnixPrimitivesNoSpin)
        {
            if (this->TryLockHeavy())
            {
                return true;
            }
        }

        AuAtomicAdd(&this->uSleeping_, 1u);

        while (!this->TryLockNoSpin())
        {
            static const AuUInt32 kRef { 1 };

            if (uTimeout != 0)
            {
                if (!InternalLTSWaitOnAddressHighRes(&this->uState_, &kRef, 4, uEndTime))
                {
                    bStatus = false;
                    break;
                }
            }
            else
            {
                (void)InternalLTSWaitOnAddressHighRes(&this->uState_, &kRef, 4, uEndTime);
            }
        }

        AuAtomicSub(&this->uSleeping_, 1u);
        return bStatus;
    }

    bool GenericConditionMutex::LockAbsMS(AuUInt64 timeout)
    {
        return this->LockAbsNS(AuMSToNS<AuUInt64>(timeout));
    }

    bool GenericConditionMutex::LockMS(AuUInt64 timeout)
    {
        return this->LockNS(AuMSToNS<AuUInt64>(timeout));
    }

    AuUInt GenericConditionMutex::GetOSHandle()
    {
        return 0;
    }

    AUKN_SYM IConditionMutex *ConditionMutexNew()
    {
        return _new ConditionMutexGenericImpl();
    }

    AUKN_SYM void ConditionMutexRelease(IConditionMutex *pMutex)
    {
        AuSafeDelete<ConditionMutexGenericImpl *>(pMutex);
    }

    AUROXTL_INTERFACE_SOO_SRC_EX(AURORA_SYMBOL_EXPORT, ConditionMutex, ConditionMutexGenericImpl)
}

#endif