AuroraRuntime/Include/Aurora/Threading/Threads/TLSVariable.hpp

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

    File: TLSVariable.hpp
    Date: 2021-6-11
    Author: Reece
***/
#pragma once

namespace Aurora::Threading::Threads
{
    AUKN_SYM bool DeadTest();

    template<typename T, bool isStatic = false>
    class TLSVariable
    {
    private:
        int _;
    
    public:
        TLSVariable() {}
        ~TLSVariable()
        {
            if constexpr (!isStatic)
            {
                if (DeadTest())
                {
                    return;
                }
                GetThread()->GetTlsView()->Remove(GetHandle());
            }
        }
        
        T& operator ->()
        {
            return Get();
        }
        
        operator T&()
        {
            return Get();
        }
        
        T operator *()
        {
            return Get();
        }

        TLSVariable& operator =(const T & val)
        {
            Get() = val;
            return *this;
        }

    private:

        AuUInt64 GetHandle()
        {
            if constexpr (isStatic)
            {
                return (AuUInt64(reinterpret_cast<AuUInt>(&_)) & (~kTlsKeyMask)) | kTlsKeyFollowsConvention | kTlsKeyStaticPointerHandle;
            }
            else
            {
                return (AuUInt64(reinterpret_cast<AuUInt>(&_)) & (~kTlsKeyMask)) | kTlsKeyFollowsConvention | kTlsKeyResettablePointerHandle;
            }
        }

        T &Get()
        {
            auto view = GetThread()->GetTlsView();
            auto ptr  = view->GetOrSetup(GetHandle(), 
                sizeof(T),
                [](void *buffer) -> void
                {
                    if constexpr (AuIsClass_v<T>)
                    {
                        new (buffer) T();
                    }
                    else
                    {
                        //std::memset(buffer, 0, sizeof(T));
                    }
                }, 
                [](void *buffer) -> void
                {
                    if constexpr (AuIsClass_v<T>)
                    {
                        reinterpret_cast<T *>(buffer)->~T();
                    }
                });
            return *reinterpret_cast<T *>(ptr);
        }
        
    };
}