AuroraRuntime/Source/Threading/Primitives/AuConditionMutex.NT.hpp

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

    File: AuConditionMutex.NT.hpp
    Date: 2021-6-12
    Author: Reece
***/
#pragma once

#include "AuIConditionMutexEx.hpp"

#if !defined(_AURUNTIME_GENERICCM)
namespace Aurora::Threading::Primitives
{
// Note: these magic numbers are powers of two such that you can use them as add/sub operations 
//       in place of masking. 
// ie: add = or
//     sub = and 
// assuming the bits are unset/set respectively

    static auto const kFutexBitWake	= 256u; // 2^8
    static auto const kFutexBitWait	= 512u; // 2^9, next byte over
        

    inline HANDLE gKeyedEventHandle { INVALID_HANDLE_VALUE };

    // Actually NT5.x
    struct NT4Mutex
    {
        volatile AuUInt32 uWaitCount {}; // yields while bits are high, dec to release one from the semaphore yield
    };

    struct Win32ConditionMutex final : IConditionMutexEx
    {
        Win32ConditionMutex();
        ~Win32ConditionMutex();

        auline bool TryLock() override;
        auline void Lock() override;
        auline void Unlock() override;
        AuUInt GetOSHandle() override;

        auline bool TryLockNoSpin();

    #if !defined(AURORA_FORCE_SRW_LOCKS)
        NT4Mutex lock_;
    #else
        SRWLOCK lock_;
    #endif
    };
    
    using ConditionMutexImpl = Win32ConditionMutex;
}
#endif