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

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

namespace Aurora::Threading::Threads
{
    void  TLSViewImpl::Remove(AuUInt64 key)
    {
        LockGuard<Primitives::SpinLock> re(&lock_);

        auto a = tls_.find(key);
        if (a == tls_.end())
        {
            return;
        }

        const auto &handler = a->second.second;
        if (handler)
        {
            handler(a->second.first);
        }

        tls_.erase(a);
    }

    TLSViewImpl::~TLSViewImpl()
    {
        for (const auto &itr : tls_)
        {
            const auto &handler = itr.second.second;
            if (handler)
            {
                handler(itr.second.first);
            }
        }

        tls_.clear();
    }

    void *TLSViewImpl::GetTLS(AuUInt64 key, AuMach length, bool noAutoCreate)
    {
        LockGuard<Primitives::SpinLock> re(&lock_);
        std::pair<void*, TlsCb>*value;

        if (!length)
        {
            return nullptr;
        }

        if (!TryFind(tls_, key, value))
        {
            if (noAutoCreate)
            {
                return nullptr;
            }
        
            auto buf = Memory::ZAlloc<void *>(length);
            if (!buf)
            {
                return nullptr;
            }

            auto ok = TryInsertNoEnd(tls_, std::make_pair(key, std::make_pair(buf, TlsCb {})));
            if (!ok)
            {
                Memory::Free(buf);
                return nullptr;
            }

            ConsiderRehash();

            return buf;
        }
        
        return value->first;
    }

    void *TLSViewImpl::InitTLS(AuUInt64 key, AuMach length, const TlsCb &init, const TlsCb &deinit)
    {
        LockGuard<Primitives::SpinLock> re(&lock_);
        std::pair<void*, TlsCb>*value;

        if (!length)
        {
            return nullptr;
        }

        if (TryFind(tls_, key, value))
        {
            return value->first;
        }

        auto buf = Memory::ZAlloc<void *>(length);
        if (!buf)
        {
            return nullptr;
        }

        TlsCb deinitcb = deinit;
        auto ok = TryInsertNoEnd(tls_, std::make_pair(key, std::make_pair(buf, deinitcb)));
        if (!ok)
        {
            Memory::Free(buf);
            return nullptr;
        }

        ConsiderRehash();
    
        if (init)
        {
            init(buf);
        }
 
        return buf;
    }

    void TLSViewImpl::ConsiderRehash()
    {
        try
        {
            // prevent Add, Remove, Add, Remove stalls 
            fence_++; 
            if ((fence_ % 10) == 0)
            {
                tls_.rehash(tls_.size());
            }
        }
        catch (...)
        {

        }
    }
}