//------------------------------------------------------------------------------
// <copyright file="LqrSMACReaderWriter.h" company="LiquidRobotics">
//
// Copyright (c) 2014 Liquid Robotics, Inc.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
//
// This software is associated with a release.  Liquid Robotics makes no
// representation that the design, interfaces or component distribution will
// remain unchanged in future releases.
//
// </copyright>
//
// <summary>
// </summary>
//
// <owner></owner>
//------------------------------------------------------------------------------

#ifndef __LQRSMACREADERWRITER_H__
#define __LQRSMACREADERWRITER_H__

#include "LqrSMACLockableConcept.h"
#include "LqrSMACSemaphore.h"
#include "LqrSMACSharedLib.h"

namespace LiquidRobotics {
namespace SMACFramework {

namespace ReaderWriterDetail {

	const unsigned Infinite = ~0;

}

class SHARED_LIB_PUBLIC ReaderWriterCommon
{
public:

	enum LockStates
	{
		LOCK_FOR_READ,
		LOCK_FOR_WRITE,
		NOT_LOCKED
	};
};

class SHARED_LIB_PUBLIC ReaderWriterData : public LockableConceptMutex, public ReaderWriterCommon
{
public:

	typedef boost::shared_ptr<ReaderWriterData> Ptr;

	ReaderWriterData();
	virtual ~ReaderWriterData();

	Semaphore readSem;
	Semaphore writeSem;
	unsigned numReaders;
};

class ReaderWriterLock;

class SHARED_LIB_PUBLIC ReaderWriter
{
public:

	typedef boost::shared_ptr<ReaderWriter> Ptr;
	typedef ReaderWriterLock Lock;

	ReaderWriter();
	virtual ~ReaderWriter();

private:

	friend class ReaderWriterLock;

	ReaderWriterData::Ptr rwData;
};

class SHARED_LIB_PUBLIC ReaderWriterLock : public ReaderWriterCommon
{
public:

	typedef boost::shared_ptr<ReaderWriterLock> Ptr;

	ReaderWriterLock(ReaderWriter& readerWriter, LockStates action = LOCK_FOR_READ, unsigned timeout = ReaderWriterDetail::Infinite, bool throwOnError = true);
	virtual ~ReaderWriterLock();

	LockStates GetState() const;
	bool Lock(LockStates action = LOCK_FOR_READ, unsigned timeout = ReaderWriterDetail::Infinite, bool throwOnError = true);
	bool LockForRead(unsigned timeout = ReaderWriterDetail::Infinite, bool throwOnError = true);
	bool LockForWrite(unsigned timeout = ReaderWriterDetail::Infinite, bool throwOnError = true);
	bool ReadLockToWriteLock(unsigned timeout = ReaderWriterDetail::Infinite, bool throwOnError = true);
	bool Unlock();
	bool WriteLockToReadLock(bool throwOnError = true);

	virtual void lock();
	virtual bool try_lock();
	virtual void unlock();

private:

	LockableConceptMutex lockable;
	LockStates state;
	ReaderWriterData::Ptr rwData;
};

class LockableConceptReaderWriter : public LockableConcept<ReaderWriterLock>
{
public:

	typedef ReaderWriterLock Lock;
	typedef ReaderWriterLock::Ptr LockPtr;

	LockableConceptReaderWriter()
	: LockableConcept<ReaderWriterLock>(rwLockObj)
	, rwLockObj(rwObj, ReaderWriterCommon::NOT_LOCKED)
	{
	}

protected:

	ReaderWriter rwObj;
	ReaderWriterLock rwLockObj;
};

}
}


#endif
