writereadlock.cpp

关于联通的一个统一定制程序

// WriteReadLock.cpp: implementation of the CWriteReadLock class.
//
//////////////////////////////////////////////////////////////////////

#include "stdafx.h"
#include "WriteReadLock.h"

#ifdef _DEBUG
#undef THIS_FILE
static char THIS_FILE[]=__FILE__;
#define new DEBUG_NEW
#endif

//////////////////////////////////////////////////////////////////////
// Construction/Destruction
//////////////////////////////////////////////////////////////////////

CWriteReadLock::CWriteReadLock():m_uReaderNumber(20)
{
	hSemNumReaders = CreateSemaphore(NULL, m_uReaderNumber, 0X7FFFFFFF, NULL);
}

CWriteReadLock::CWriteReadLock(UINT uNumber):m_uReaderNumber(uNumber)
{
	hSemNumReaders = CreateSemaphore(NULL, m_uReaderNumber, 0X7FFFFFFF, NULL);
}

CWriteReadLock::~CWriteReadLock()
{
	CloseHandle(hSemNumReaders);
}

void CWriteReadLock::ReadLock()
{
	m_cs.Lock();
	WaitForSingleObject(hSemNumReaders,INFINITE);
	m_cs.Unlock();
}

void CWriteReadLock::ReadUnlock()
{
//	m_cs.Lock();
	ReleaseSemaphore(hSemNumReaders,1,NULL);
//	m_cs.Unlock();
}

void CWriteReadLock::WriteLock()
{
//	long lPrevious;

	m_cs.Lock();
	for(int i=0;i<(int)m_uReaderNumber;i++)
		WaitForSingleObject(hSemNumReaders,INFINITE);
//	ReleaseSemaphore(hSemNumReaders,1,&lPrevious);
//  lPrevious++;
}

void CWriteReadLock::WriteUnlock()
{
	ReleaseSemaphore(hSemNumReaders,m_uReaderNumber,NULL);
	m_cs.Unlock();
}