//-----------------------------------------------------------------------------
//
//	MutexImpl.cpp
//
//	WinRT implementation of the cross-platform mutex
//
//	Copyright (c) 2015 Microsoft Corporation
//	All rights reserved.
//
//	SOFTWARE NOTICE AND LICENSE
//
//	This file is part of OpenZWave.
//
//	OpenZWave is free software: you can redistribute it and/or modify
//	it under the terms of the GNU Lesser General Public License as published
//	by the Free Software Foundation, either version 3 of the License,
//	or (at your option) any later version.
//
//	OpenZWave is distributed in the hope that it will be useful,
//	but WITHOUT ANY WARRANTY; without even the implied warranty of
//	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//	GNU Lesser General Public License for more details.
//
//	You should have received a copy of the GNU Lesser General Public License
//	along with OpenZWave.  If not, see <http://www.gnu.org/licenses/>.
//
//-----------------------------------------------------------------------------
#include "Defs.h"
#include "MutexImpl.h"

namespace OpenZWave
{
	namespace Internal
	{
		namespace Platform
		{

//-----------------------------------------------------------------------------
//	<MutexImpl::MutexImpl>
//	Constructor
//-----------------------------------------------------------------------------
			MutexImpl::MutexImpl() :
					m_lockCount(0)
			{
				InitializeCriticalSectionEx(&m_criticalSection, 0, 0);
			}

//-----------------------------------------------------------------------------
//	<MutexImpl::~MutexImpl>
//	Destructor
//-----------------------------------------------------------------------------
			MutexImpl::~MutexImpl()
			{
				DeleteCriticalSection(&m_criticalSection);
			}

//-----------------------------------------------------------------------------
//	<MutexImpl::Lock>
//	Lock the mutex
//-----------------------------------------------------------------------------
			bool MutexImpl::Lock(bool const _bWait // = true;
					)
			{
				if (_bWait)
				{
					// We will wait for the lock
					EnterCriticalSection(&m_criticalSection);
					++m_lockCount;
					return true;
				}

				// Returns immediately, even if the lock was not available.
				if (TryEnterCriticalSection(&m_criticalSection))
				{
					++m_lockCount;
					return true;
				}

				return false;
			}

//-----------------------------------------------------------------------------
//	<MutexImpl::Unlock>
//	Release our lock on the mutex
//-----------------------------------------------------------------------------
			void MutexImpl::Unlock()
			{
				if (!m_lockCount)
				{
					// No locks - we have a mismatched lock/release pair
					assert(0);
				}
				else
				{
					--m_lockCount;
					LeaveCriticalSection(&m_criticalSection);
				}
			}

//-----------------------------------------------------------------------------
//	<MutexImpl::IsSignalled>
//	Test whether the mutex is free
//-----------------------------------------------------------------------------
			bool MutexImpl::IsSignalled()
			{
				return (0 == m_lockCount);
			}
		} // namespace Platform
	} // namespace Internal
} // namespace OpenZWave
