// 
// Copyright @ 2016 Hangzhou Topzen Ltd.
// Author: Wu Jiubao (wujb@hztopzen.com) @ 2016-09
//

#ifndef __THREADPOOL_H
#define __THREADPOOL_H

#include <list>
#include "Thread.h"
#include "Semaphore.h"
#include "BaseTypes.h"
#include "Locks.h"

namespace tzc {

class CWorkerThread;
class CJob;

// thread pool, manage all threads
class DECLDLL CThreadPool : public tzc::OSThread {
	friend class CWorkerThread;
#ifdef THREADPOOL_SINGLETON
private:
	CThreadPool();
	virtual ~CThreadPool();
#else
public:
	CThreadPool();
	CThreadPool(TZ_Uint32 num);
	virtual ~CThreadPool();
#endif

public:
#ifdef THREADPOOL_SINGLETON
	static CThreadPool * GetInstance(void);
	static void DeleteInstance(void);
#endif
	TZ_INT Initialize();

	void SetMaxThreadNum(TZ_Uint32 maxNum);
	TZ_Uint32 GetMaxThreadNum(void);

	void SetLowIdleThreadNum(TZ_Uint32 minNum);
	TZ_Uint32 GetLowIdleThreadNum(void);

	void SetHighIdleThreadNum(TZ_Uint32 highNum);
	TZ_Uint32 GetHighIdleThreadNum(void);

	TZ_Uint32 GetIdleThreadNum(void);
	TZ_Uint32 GetAllThreadNum(void);
	TZ_Uint32 GetBusyThreadNum(void);

	void SetInitThreadNum(TZ_Uint32 initNum);
	TZ_Uint32 GetInitThreadNum(void);

	void TerminateAll(void);
	void PushJob(CJob * job);

protected:
	virtual void Entry();

	TZ_INT setJob2WorkerThread(CJob * job);

	CWorkerThread * getIdleThread(void);

	void appendToIdleList(CWorkerThread * jobthread);

	void moveToBusyList(CWorkerThread * idlethread);
	void moveToIdleList(CWorkerThread * busythread);

	void deleteIdleThread(TZ_Uint32 num);
	void createIdleThread(TZ_Uint32 num);

private:
#ifdef THREADPOOL_SINGLETON
	static CThreadPool * _instance;
	static tzc::Mutex _insMutex;
#endif

	tzc::Mutex m_busyMutex;	// used for operating m_busyList
	tzc::Mutex m_idleMutex;	// used for operating m_idleList
	tzc::Mutex m_jobMutex;	// used for getting idle thread to do job

	std::list<CWorkerThread *> m_threadList; // all threads in thread pool
	std::list<CWorkerThread *> m_busyList;	 // busy threads in thread pool
	std::list<CWorkerThread *> m_idleList;	 // idle threads in thread pool
	std::list<CJob *> m_jobList;

	TZ_Uint32 m_maxNum;		// max number of thread
	TZ_Uint32 m_availLow;	// the lowest available threads in thread pool
	TZ_Uint32 m_availHigh;	// the highest available threads in thread pool
	TZ_Uint32 m_availNum;	// current available threads in thread pool
	TZ_Uint32 m_initNum;	// init number of thread
	TZ_Uint32 m_jobNum;		// job number in the m_jobList
};

inline void CThreadPool::SetMaxThreadNum(TZ_Uint32 maxNum)
{
	m_maxNum = maxNum;
}

inline TZ_Uint32 CThreadPool::GetMaxThreadNum(void)
{
	return m_maxNum;
}

inline void CThreadPool::SetLowIdleThreadNum(TZ_Uint32 minNum)
{
	m_availLow = minNum;
}

inline TZ_Uint32 CThreadPool::GetLowIdleThreadNum(void)
{
	return m_availLow;
}

inline void CThreadPool::SetHighIdleThreadNum(TZ_Uint32 highNum)
{
	m_availHigh = highNum;
}

inline TZ_Uint32 CThreadPool::GetHighIdleThreadNum(void)
{
	return m_availHigh;
}

inline TZ_Uint32 CThreadPool::GetIdleThreadNum(void)
{
	return m_availNum;
}

inline TZ_Uint32 CThreadPool::GetAllThreadNum(void)
{
	ScopedLock lock(m_idleMutex);

	return m_threadList.size();
}

inline TZ_Uint32 CThreadPool::GetBusyThreadNum(void)
{
	ScopedLock lock(m_busyMutex);

	return m_busyList.size();
}

inline void CThreadPool::SetInitThreadNum(TZ_Uint32 initNum)
{
	m_initNum = initNum;
}

inline TZ_Uint32 CThreadPool::GetInitThreadNum(void)
{
	return m_initNum;
}


// work thread, all threads start to wait for job when be constructed
class DECLDLL CWorkerThread : public tzc::OSThread
{
	friend class CThreadPool;

private:
	CWorkerThread(CThreadPool * thrPool);
	virtual ~CWorkerThread();

	virtual void Entry();

	void StartWork(CJob * job);
	void StopWork(void);

private:
	CThreadPool * m_threadPool;
	CJob * m_job;

	TZ_BOOL m_bExit;

	tzc::Semaphore m_jobCond;
};


// base class of Job, all concrete jobs should inherit it and implement the Run()
class DECLDLL CJob {
public:
	CJob(const std::string & jobName, void * jobData);
	virtual ~CJob();

	TZ_Uint32 GetJobNo(void);

	TZ_BOOL ToDeleted(void);

	virtual void Run() = 0;	

protected:
	static TZ_Uint32 _jobNo;
	static tzc::Mutex _jobNoMutex;

	TZ_Uint32 m_jobNo;

	TZ_BOOL m_toDeleted;

	std::string m_jobName;

	void * m_jobData;
};

} // namespace tzc

#endif /*-----#ifndef _THREADPOOL_H-----*/