HeadCountAlgo/links/common/include/ObjectPool.h

// 
// Copyright @ 2014 Hangzhou Topzen Ltd.
// Author: Yab Bin (yanb@es.zju.edu.cn) @ 2014-12
//

#ifndef  __OBJECTPOOL_H
#define  __OBJECTPOOL_H

#include "BaseTypes.h"
#include "BaseHeaders.h"
#include "Locks.h"

namespace tzc {

template <typename T>
class ObjectPool {

public:
	enum __OBJPOOL_ERROR {

		OPSucess = 0,
		OPNoFreeObj,
		OPNoTaskObj,
		OPEmptyPool
	};

public:
	ObjectPool();
	~ObjectPool();

	// return 0 if successful, -1 while error occurs
	TZ_INT	PopObj(T & Obj);

	TZ_INT	PopFreeObj(T & Obj);
	TZ_INT	PopTaskObj(T & Obj);

	void PushFreeObj(T & Obj);
	void PushTaskObj(T & Obj);

	TZ_INT	GetFreeCnt();
	TZ_INT	GetTaskCnt();

	TZ_INT	GetOPError() const;

private:
	void SetOPError(const TZ_INT errcode);

private:
	Mutex		 m_mtxFreePool;
	std::list<T> m_vFreePool;

	Mutex 		 m_mtxTaskPool;
	std::list<T> m_vTaskPool;

	TZ_INT m_OPErrno;
};

template <typename T>
ObjectPool<T>::ObjectPool():
	m_OPErrno(OPSucess)
{
}

template <typename T>
ObjectPool<T>::~ObjectPool()
{
	m_vFreePool.clear();
	m_vTaskPool.clear();
}

template <typename T>
TZ_INT ObjectPool<T>::GetOPError() const
{
	return m_OPErrno;
}

template <typename T>
void ObjectPool<T>::SetOPError(const TZ_INT errcode)
{
	m_OPErrno = errcode;
}

template<typename T>
TZ_INT ObjectPool<T>::PopObj(T & Obj)
{
	if (this->GetTaskCnt())
	{
		return this->PopTaskObj(Obj);
	}

	if (this->GetFreeCnt())
	{
		return this->PopFreeObj(Obj);
	}

	this->SetOPError(OPEmptyPool);

	return -1;
}

template<typename T>
TZ_INT ObjectPool<T>::PopFreeObj(T & Obj)
{
	m_mtxFreePool.Lock();

	if(m_vFreePool.empty())
	{
		m_mtxFreePool.Unlock();

		this->SetOPError(OPNoFreeObj);
		return -1;
	}

	Obj = m_vFreePool.front();
	m_vFreePool.pop_front();

	m_mtxFreePool.Unlock();

	this->SetOPError(OPSucess);

	return 0;
}

template <typename T>
TZ_INT ObjectPool<T>::PopTaskObj(T & Obj)
{
	m_mtxTaskPool.Lock();

	if(m_vTaskPool.empty())
	{
		m_mtxTaskPool.Unlock();

		this->SetOPError(OPNoTaskObj);
	
		return -1;
	}

	Obj = m_vTaskPool.front();
	m_vTaskPool.pop_front();

	m_mtxTaskPool.Unlock();

	this->SetOPError(OPSucess);

	return 0;
}

template <typename T>
void ObjectPool<T>::PushFreeObj(T & Obj)
{
	m_mtxFreePool.Lock();
	m_vFreePool.push_back(Obj);
	m_mtxFreePool.Unlock();
}

template <typename T>
void ObjectPool<T>::PushTaskObj(T & Obj)
{
	m_mtxTaskPool.Lock();
	m_vTaskPool.push_back(Obj);
	m_mtxTaskPool.Unlock();
}

template <typename T>
TZ_INT ObjectPool<T>::GetFreeCnt()
{
	m_mtxFreePool.Lock();
	TZ_INT iTmpCount(m_vFreePool.size());
	m_mtxFreePool.Unlock();

	return iTmpCount;
}

template <typename T>
TZ_INT ObjectPool<T>::GetTaskCnt()
{
	m_mtxTaskPool.Lock();
	TZ_INT iTmpCount(m_vTaskPool.size());
	m_mtxTaskPool.Unlock();

	return iTmpCount;
}

}	// namespace tzc

#endif   /* ----- #ifndef __OBJECTPOOL_H  ----- */