/*---------------------------------------------------------------------------*
  Project:  Horizon
  File:     os_CriticalSection.cpp

  Copyright (C)2009 Nintendo Co., Ltd.  All rights reserved.

  These coded instructions, statements, and computer programs contain
  proprietary information of Nintendo of America Inc. and/or Nintendo
  Company Ltd., and are protected by Federal copyright law.  They may
  not be disclosed to third parties or copied or duplicated in any form,
  in whole or in part, without the prior written consent of Nintendo.

  $Rev: 16750 $
 *---------------------------------------------------------------------------*/

#include <nn/assert.h>
#include <nn/config.h>
#include <nn/os/os_CriticalSection.h>
#include <nn/fnd/fnd_Interlocked.h>
#include <nn/os/os_Timer.h>

//---------------------------------------------------------------------------

using namespace nn;
using namespace nn::fnd;
using namespace nn::svc;
using namespace nn::os;
using namespace nn::util;

namespace nn{ namespace os{

void CriticalSection::EnterImpl()
{
    for(;;)
    {
        // この時点でカウンタをチェックすることで TryEnterImpl を呼び出すよりも
        // 高速に他のスレッドがクリティカルセクションに侵入しているかを判定します。
        if( *m_Counter > 0 )
        {
            if( TryEnterImpl() )
            {
                break;
            }
        }

        // 他のスレッドがクリティカルセクションに侵入していたら
        // カウンタをデクリメントして待機します。
        m_Counter.DecrementAndWaitIfLessThan(0);
    }
}

}} // namespace nn::os

#include <new>

using namespace nn::os;

extern "C" {

void nnosCriticalSectionInitialize(nnosCriticalSection* p)
{
    new (p) CriticalSection(nn::WithInitialize());
}

bool nnosCriticalSectionTryInitialize(nnosCriticalSection* p)
{
    new (p) CriticalSection(nn::WithInitialize());
    CriticalSection* pCriticalSection = reinterpret_cast<CriticalSection*>(p);
    Result result = pCriticalSection->TryInitialize();
    return result.IsSuccess();
}

void nnosCriticalSectionEnter(nnosCriticalSection* p)
{
    CriticalSection* pCriticalSection = reinterpret_cast<CriticalSection*>(p);
    pCriticalSection->Enter();
}

bool nnosCriticalSectionTryEnter(nnosCriticalSection* p)
{
    CriticalSection* pCriticalSection = reinterpret_cast<CriticalSection*>(p);
    return pCriticalSection->TryEnter();
}

void nnosCriticalSectionLeave(nnosCriticalSection* p)
{
    CriticalSection* pCriticalSection = reinterpret_cast<CriticalSection*>(p);
    pCriticalSection->Leave();
}

void nnosCriticalSectionFinalize(nnosCriticalSection* p)
{
    CriticalSection* pCriticalSection = reinterpret_cast<CriticalSection*>(p);
    pCriticalSection->~CriticalSection();
}

}