myvtm/Common/AutoLock.h

#ifndef _AUTOLOCK_H
#define _AUTOLOCK_H
#include <winpr/synch.h>
#include <winpr/thread.h>
#include <winpr/sysinfo.h>


class CLockObject
{
private:
	CRITICAL_SECTION m_Section;
	bool m_bInit;
public:
	inline CLockObject():m_bInit(false){Init();}
	inline ~CLockObject(){if(m_bInit)::DeleteCriticalSection(&m_Section);}
	inline void Init(){if(!m_bInit)::InitializeCriticalSection(&m_Section);m_bInit=true;}
	inline void Clear(){if(m_bInit)::DeleteCriticalSection(&m_Section);m_bInit=false;}
	inline void Lock(){::EnterCriticalSection(&m_Section);}
	inline void Unlock(){::LeaveCriticalSection(&m_Section);}
	inline bool Trylock(){return ::TryEnterCriticalSection(&m_Section)==TRUE;}
};

class CAutoLock
{
private:
	CLockObject *m_pObject;
public:
	inline CAutoLock(CLockObject *pObject,DWORD nTimeOut=0):m_pObject(pObject)
	{
		if(m_pObject==NULL)
			return;
		if(nTimeOut==0)
			m_pObject->Lock();
		else
		{
			DWORD nBegin(::GetTickCount());
			while(!m_pObject->Trylock())
			{
				if(!SwitchToThread())
					Sleep(100);
				if(GetTimeDistance(nBegin)>=nTimeOut)
				{
					m_pObject=NULL;
					//assert(false);
					break;
				}
			}
		}
	}
	inline ~CAutoLock()
	{
		if(m_pObject)
			m_pObject->Unlock();
	}
	inline DWORD GetTimeDistance(DWORD nBegin)
	{
		DWORD nEnd(::GetTickCount());
		if(nEnd>=nBegin)
			return nEnd-nBegin;
		else
			return nEnd+!nBegin+1;
	}
};
#endif//_AUTOLOCK_H