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

    File: AuSpinLock.cpp
    Date: 2021-6-12
    Author: Reece
***/
#include <Source/RuntimeInternal.hpp>
#include "AuSpinLock.hpp"
#include "SMTYield.hpp"

namespace Aurora::Threading::Primitives
{
    SpinLock::SpinLock()
    {
        this->state_ = 0;
    }

    bool SpinLock::HasOSHandle(AuMach &mach)
    {
        return false;
    }

    bool SpinLock::TryLock()
    {
        return DoTryIfAlderLake([=]()
            {
                return AuAtomicTestAndSet(&this->state_, 0) == 0;
            }, &this->state_);
    }

    bool SpinLock::HasLockImplementation()
    {
        return true;
    }

    void SpinLock::SlowLock()
    {
        auto status = LockNS(0);
        SysAssert(status, "Couldn't lock Mutex object");
    }

    bool SpinLock::LockAbsNS(AuUInt64 timeout)
    {
        if (timeout == 0)
        {
            while (true)
            {
                if (DoTryIfAlderLake([=]()
                {
                    return AuAtomicTestAndSet(&this->state_, 0) == 0;
                }, &this->state_))
                {
                    return true;
                }
            }
        }
        else
        {
            while (AuAtomicTestAndSet(&this->state_, 0))
            {
                if (DoTryIfAlderLake([=]()
                {
                    return AuAtomicTestAndSet(&this->state_, 0) == 0;
                }, &this->state_))
                {
                    return true;
                }

                if (timeout <= AuTime::SteadyClockNS())
                {
                    return false;
                }
            }

            return true;
        }

        return true;
    }

    bool SpinLock::LockNS(AuUInt64 timeout)
    {
        if (timeout == 0)
        {
            while (true)
            {
                if (DoTryIfAlderLake([=]()
                {
                    return AuAtomicTestAndSet(&this->state_, 0) == 0;
                }, &this->state_))
                {
                    return true;
                }
            }
        }
        else
        {
            timeout += AuTime::SteadyClockNS();

            while (AuAtomicTestAndSet(&this->state_, 0))
            {
                if (DoTryIfAlderLake([=]()
                {
                    return AuAtomicTestAndSet(&this->state_, 0) == 0;
                }, &this->state_))
                {
                    return true;
                }

                if (timeout <= AuTime::SteadyClockNS())
                {
                    return false;
                }
            }

            return true;
        }

        return true;
    }

    bool SpinLock::LockMS(AuUInt64 timeout)
    {
        return LockNS(AuMSToNS<AuUInt64>(timeout));
    }

    void SpinLock::Unlock()
    {
        this->state_ = 0;
    }
}