www.pudn.com > HTMLLog.zip > synchronizations.h

/************************************************************************************* 
 ************************************************************************************* 
 **																					** 
 ** File name:		synchronizations.h.												** 
 **																					** 
 ** Description:	Header file of synchronization classes.							** 
 **																					** 
 ** Last update:	February 2002.													** 
 **																					** 
 ** Updated by:		Desyatnikov Stas.													** 
 **																					** 
 ** Copyright (C) 2002. All rights reserved.										** 
 **																					** 
 ************************************************************************************* 
 *************************************************************************************/ 
 
#ifndef __SYNCHRONIZATIONS_H__ 
#define __SYNCHRONIZATIONS_H__ 
 
#ifdef WIN32 
	#include  
	#include  
#elif OS_VXWORKS 
	#include  
	#include   
#endif 
 
class CLock 
{ 
public: 
	virtual int Remove() { return 1; } 
	virtual int Acquire() { return 1; } 
	virtual int Release() { return 1; } 
	virtual int TryAcquire() { return 1; } 
	//Overridables for RW locks 
	virtual int AcquireRead() { return 1; } 
	virtual int AcquireWrite() { return 1; } 
	virtual int TryAcquireRead() { return 1; } 
	virtual int TryAcquireWrite() { return 1; } 
}; 
 
class CNULLLock : public CLock 
{ 
}; 
 
class CSectionLock : public CLock 
{ 
#ifdef WIN32 
	CRITICAL_SECTION	m_cs; 
#elif OS_VXWORKS 
	SEM_ID				m_cs; 
#endif 
 
 
public: 
	CSectionLock() 
	{ 
#ifdef WIN32 
		InitializeCriticalSection( &m_cs ); 
#elif OS_VXWORKS 
		//Recursive semaphore, init to full - available state 
		m_cs = semMCreate( SEM_Q_PRIORITY );  
#endif 
	} 
	 
	~CSectionLock() 
	{ 
		Remove(); 
	} 
 
	virtual int Remove()  
	{ 
		Release(); 
#ifdef WIN32 
		DeleteCriticalSection( &m_cs ); 
#elif OS_VXWORKS 
		return semDelete( m_cs ) != ERROR; 
#endif 
		return 1; 
	} 
	 
	virtual int Acquire()  
	{ 
#ifdef WIN32 
		EnterCriticalSection( &m_cs ); 
#elif OS_VXWORKS 
		return semTake( m_cs, WAIT_FOREVER ) != ERROR; 
#endif 
		//printf("Locked by thread:%d\n", GetCurrentThreadId()); 
		return 1; 
	} 
 
	virtual int Release()  
	{ 
#ifdef WIN32 
		LeaveCriticalSection( &m_cs ); 
#elif OS_VXWORKS 
		return semGive( m_cs ) != ERROR; 
#endif 
		return 1; 
	} 
 
	virtual int TryAcquire()  
	{ 
#ifdef WIN32 
		//Somehow doesnt work on NT4 
		//return TryEnterCriticalSection( &m_cs ); 
		EnterCriticalSection( &m_cs ); 
		return 1; 
#elif OS_VXWORKS 
		return semTake( m_cs, 1 ) != ERROR; 
#endif 
	} 
}; 
 
 
//Guard must be a stack object, so the LockRef does not need protection 
class CGuard 
{ 
	CLock*	m_pLock; 
	uint	m_uiLockRef; 
public: 
	CGuard( CLock* pLock ) 
	{ 
		m_pLock = pLock; 
		m_uiLockRef = 0; 
	} 
	 
	int Lock() 
	{ 
		int iRet = m_pLock->Acquire(); 
		m_uiLockRef += ( iRet != 0 ); 
 
		return m_uiLockRef; 
	} 
 
	int Unlock() 
	{ 
		if ( m_pLock && m_uiLockRef ) 
			m_uiLockRef -= ( m_pLock->Release() != 0 ); 
		 
		return m_uiLockRef; 
	} 
	~CGuard() 
	{ 
		Unlock(); 
	} 
}; 
 
#endif //__SYNCHRONIZATIONS_H__