gspinlock.h

一个由Mike Gashler完成的机器学习方面的includes neural net, naive bayesian classifier, decision tree, KNN, a genet

/*
	Copyright (C) 2006, Mike Gashler

	This library 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 2.1 of the License, or (at your option) any later version.

	see http://www.gnu.org/copyleft/lesser.html
*/

#ifndef __GSPINLOCK_H__
#define __GSPINLOCK_H__

#ifndef WIN32
#include <pthread.h>
#endif


// A spin-lock for synchronization purposes
class GSpinLock
{
protected:
#ifdef _DEBUG
	const char* m_szUniqueStaticStringToIdentifyWhoLockedIt;
#endif
	unsigned int m_dwLocked;		// maintaned on all platform as posix mutexes don't have a way to get current state.
									// when not Win32 be aware that this value is shadowing the real mutex, and cannot be
									// depended on especially in a MP enviroment.
#ifndef WIN32
	pthread_mutex_t m_mutex;
#endif

public:
	GSpinLock();
	virtual ~GSpinLock();

#ifndef NO_TEST_CODE
	static void Test();
#endif // !NO_TEST_CODE

	void Lock(const char* szUniqueStaticStringToIdentifyWhoLockedIt);
	void Unlock();
	bool IsLocked() { return m_dwLocked != 0; }	// see note above about m_dwLocked.
};


class GSpinLockHolder
{
protected:
	GSpinLock* m_pLock;

public:
	GSpinLockHolder(GSpinLock* pLock, const char* szWhoHoldsTheLock)
	{
		m_pLock = pLock;
		pLock->Lock(szWhoHoldsTheLock);
	}

	~GSpinLockHolder()
	{
		m_pLock->Unlock();
	}
};

#endif // __GSPINLOCK_H__