CreateMutex(NULL,TRUE,_T("PreventSecondInstance"))//有什么具体含义吗?

C/C++ code

bool bFound = false;m_hMutexOneInstantance=CreateMutex(NULL,TRUE,_T("PreventSecondInstance"));if(GetLastError()==ERROR_ALREADY_EXISTS)    bFound=TRUE;if(m_hMutexOneInstantance)    ReleaseMutex(m_hMutexOneInstantance);if (bFound==TRUE){     ::AfxMessageBox("已经有一个程序在运行");    return false;}