AuroraRuntime/Source/IO/Loop/WaitSingle.NT.cpp

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

    File: WaitSingle.NT.cpp
    Date: 2021-10-1
    Author: Reece
***/
#include <Source/RuntimeInternal.hpp>
#include "WaitSingle.hpp"

namespace Aurora::IO::Loop
{
    bool WaitSingleGeneric::WaitForAtleastOne(AuUInt32 timeout, const AuList<AuUInt> &handles, AuUInt &one)
    {
        if (handles.empty())
        {
            return {};
        }

        if (handles.size() == 1)
        {
            one = 0;

            DWORD ret { WAIT_IO_COMPLETION };
            AuUInt64 uEndTimeSteady = timeout ?
                AuTime::SteadyClockNS() + AuMSToNS<AuUInt64>(timeout) :
                0;

            do
            {
                AuUInt32 uRemMS { INFINITE };

                ret = WaitForSingleObjectEx(reinterpret_cast<HANDLE>(handles.at(0)), uRemMS, true);

                if (timeout &&
                    ret != WAIT_IO_COMPLETION &&
                    ret != WAIT_OBJECT_0)
                {
                    auto uNow = AuTime::SteadyClockNS();
                    if (uNow >= uEndTimeSteady)
                    {
                        break;
                    }

                    uRemMS = AuNSToMS<AuUInt64>(uEndTimeSteady);
                    if (!uRemMS)
                    {
                        break;
                    }
                }
            }
            while (ret == WAIT_IO_COMPLETION);

            return ret == WAIT_OBJECT_0;
        }
        else
        {
            AuList<HANDLE> ntHandles;
            ntHandles.reserve(handles.size());
            
            for (const auto &handle : handles)
            {
                if (!AuTryInsert(ntHandles, reinterpret_cast<HANDLE>(handle)))
                {
                    return false;
                }
            }

            DWORD ret { WAIT_IO_COMPLETION };
            AuUInt64 uEndTimeSteady = timeout ? 
                AuTime::SteadyClockNS() + AuMSToNS<AuUInt64>(timeout) : 0;

            do
            {
                AuUInt32 uRemMS { INFINITE };

                ret = WaitForMultipleObjectsEx(ntHandles.size(), ntHandles.data(), false, uRemMS, true);
                if (ret < WAIT_OBJECT_0)
                {
                    continue;
                }

                if (ret < ntHandles.size())
                {
                    one = handles[ret];
                    return true;
                }

                if (timeout)
                {
                    auto uNow = AuTime::SteadyClockNS();
                    if (uNow >= uEndTimeSteady)
                    {
                        break;
                    }

                    uRemMS = AuNSToMS<AuUInt64>(uEndTimeSteady);
                    if (!uRemMS)
                    {
                        break;
                    }
                }
            }
            while (ret == WAIT_IO_COMPLETION);

            return false;
        }
    }

    bool WaitSingleGeneric::WaitForOne(AuUInt32 timeout, AuUInt handle)
    {
        DWORD ret;

        do
        {
            ret = WaitForSingleObjectEx(reinterpret_cast<HANDLE>(handle), timeout, true);
        }
        while (ret == WAIT_IO_COMPLETION);

        return ret == WAIT_OBJECT_0;
    }

    void WaitSingleGeneric::OnPresleep()
    {

    }

    void WaitSingleGeneric::OnFinishSleep()
    {

    }
    
    ELoopSource WaitSingleGeneric::GetType()
    {
        return ELoopSource::eSourceInternalReserved1;
    }
}